Induced M2 Macrophage Polarization Research Articles

Histone deacetylase 8 inhibition prevents the progression of peritoneal fibrosis by counteracting the epithelial-mesenchymal transition and blockade of M2 macrophage polarization.

Peritoneal dialysis (PD) is an effective replacement therapy for end-stage renal disease patients. However, long-term exposure to peritoneal dialysate will lead to the development of peritoneal fibrosis. Epigenetics has been shown to play an important role in peritoneal fibrosis, but the role of histone deacetylases 8 (HDAC8) in peritoneal fibrosis have not been elucidated. In this research, we focused on the role and mechanisms of HDAC8 in peritoneal fibrosis and discussed the mechanisms involved. We examined the expression of HDAC8 in the peritoneum and dialysis effluent of continuous PD patients. Then we assessed the role and mechanism of HDAC8 in peritoneal fibrosis progression in mouse model of peritoneal fibrosis induced by high glucose peritoneal dialysis fluid by using PCI-34051. In vitro, TGF-β1 or IL-4 were used to stimulate human peritoneal mesothelial cells (HPMCs) or RAW264.7 cells to establish two cell injury models to further explore the role and mechanism of HDAC8 in epithelial-mesenchymal transition (EMT) and macrophage polarization. We found that HDAC8 expressed highly in the peritoneum from patients with PD-related peritonitis. We further revealed that the level of HDAC8 in the dialysate increased over time, and HDAC8 was positively correlated with TGF-β1 and vascular endothelial growth factor (VEGF), and negatively correlated with cancer antigen 125. In mouse model of peritoneal fibrosis induced by high glucose dialysate, administration of PCI-34051 (a selective HDAC8 inhibitor) significantly prevented the progression of peritoneal fibrosis. Treatment with PCI-34051 blocked the phosphorylation of epidermal growth factor receptor (EGFR) and the activation of its downstream signaling pathways ERK1/2 and STAT3/HIF-1α. Inhibition of HDAC8 also reduced apoptosis. In vitro, HDAC8 silencing with PCI-34051 or siRNA inhibited TGF-β1-induced EMT and apoptosis in HPMCs. In addition, continuous high glucose dialysate or IL-4 stimulation induced M2 macrophage polarization. Blockade of HDAC8 reduced M2 macrophage polarization by inhibiting the activation of STAT6 and PI3K/Akt signaling pathways. We demonstrated that HDAC8 promoted the EMT of HPMCs via EGFR/ERK1/2/STAT3/HIF-1α, induced M2 macrophage polarization via STAT6 and PI3K/Akt signaling pathways, and ultimately accelerated the process of peritoneal fibrosis.

Bioinspired Piezoelectric Periosteum to Augment Bone Regeneration via Synergistic Immunomodulation and Osteogenesis.

Ideal periosteum materials are required to participate in a sequence of bone repair-related physiological events, including the initial immune response, endogenous stem cell recruitment, angiogenesis, and osteogenesis. However, conventional tissue-engineered periosteal materials have difficulty achieving these functions by simply mimicking the periosteum via structural design or by loading exogenous stem cells, cytokines, or growth factors. Herein, we present a novel biomimetic periosteum preparation strategy to comprehensively enhance the bone regeneration effect using functionalized piezoelectric materials. The resulting biomimetic periosteum possessing an excellent piezoelectric effect and improved physicochemical properties was prepared using a biocompatible and biodegradable poly(3-hydroxybutyric acid-co-3-hydrovaleric acid) (PHBV) polymer matrix, antioxidized polydopamine-modified hydroxyapatite (PHA), and barium titanate (PBT), which were further incorporated into the polymer matrix to fabricate a multifunctional piezoelectric periosteum by a simple one-step spin-coating method. The addition of PHA and PBT dramatically enhanced the physicochemical properties and biological functions of the piezoelectric periosteum, resulting in improved surface hydrophilicity and roughness, enhanced mechanical performance, tunable degradation behavior, and stable and desired endogenous electrical stimulations, which is conducive to accelerating bone regeneration. Benefiting from endogenous piezoelectric stimulation and bioactive components, the as-fabricated biomimetic periosteum demonstrated favorable biocompatibility, osteogenic activity, and immunomodulatory functions in vitro, which not only promoted adhesion, proliferation, and spreading as well as osteogenesis of mesenchymal stem cells (MSCs) but also effectively induced M2 macrophage polarization, thereby suppressing reactive oxygen species (ROS)-induced inflammatory reactions. Through in vivo experiments, the biomimetic periosteum with endogenous piezoelectric stimulation synergistically accelerated the formation of new bone in a rat critical-sized cranial defect model. The whole defect was almost completely covered by new bone at 8 weeks post treatment, with a thickness close to that of the host bone. Collectively, with its favorable immunomodulatory and osteogenic properties, the biomimetic periosteum developed here represents a novel method to rapidly regenerate bone tissue using piezoelectric stimulation.

MiR-155 regulates M2 polarization of hepatitis B virus-infected tumour-associated macrophages which in turn regulates the malignant progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) initiated by hepatitis B virus (HBV) infection is a complicated process. MiR-155 can alter the immune microenvironment to affect the host's anti-infective ability. This study investigated the mechanism by which miR-155 affects tumour-associated macrophage (TAM) polarization at a molecular level, thus affecting the malignant progression of HBV+ HCC. MiR-155 and TAM-related cytokine expression were analysed by qRT-PCR. The distribution of TAMs was detected by immunohistochemistry. The effect of the aberrant miR-155 expression on macrophage polarization was examined by flow cytometry. The targeted relationship was verified by dual-luciferase assay, and the protein level of src homology 2 domain-containing inositol polyphosphate 5-phosphatase 1 (SHIP1) was detected by western blot. The proliferation of HCC cells was examined by CCK-8 and colony formation assays. Invasion and migration of HCC cells were detected by transwell assay. In HBV+ HCC tissues, miR-155 was significantly highly expressed and the number of CD206-positive TAM (CD206+ TAM) and CD68-positive TAM (CD68+ TAM) were higher than those in HBV- HCC tissues. In addition, miR-155 overexpression significantly promoted M2-type macrophage polarization, whilst miR-155 silencing expression significantly promoted M1-type macrophage polarization. Besides, the miR-155/SHIP1 axis accelerated HCC cell invasion, proliferation and migration by inducing M2-type macrophage polarization. MiR-155 accelerates HCC cell proliferation, migration and invasion by targeting SHIP1 expression and inducing macrophage M2 polarization. This finding provides new insights into the development of novel therapeutic strategies for combatting HBV+ HCC and a new reference for exploring anti-tumour immunotherapy.

Combined saline and vildagliptin induced M2 macrophage polarization in hepatic injury induced by acute kidney injury.

Acute kidney injury (AKI) is a prevalent medical condition accompanied by mutual affection of other organs, including the liver resulting in complicated multiorgan malfunction. Macrophages play a vital role during tissue injury and healing; they are categorized into "classically activated macrophages" (M1) and "alternatively activated macrophages" (M2). The present study investigated and compared the conventional fluid therapy vs Dipeptidyl peptidase 4 inhibitor (DPP-4i) vildagliptin on the liver injury induced by AKI and evaluated the possible molecular mechanisms. Thirty rats comprised five groups (n = 6 rats/group): control, AKI, AKI+saline (received 1.5 mL of normal saline subcutaneous injection), AKI+vildagliptin (treated with oral vildagliptin 10 mg/kg), AKI+saline+vildagliptin. AKI was induced by intramuscular (i.m) injection of 50% glycerol (5 ml/kg). At the end of the work, we collected serum and liver samples for measurements of serum creatinine, blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrotic factor-α (TNF-α), and interleukin-10 (IL-10). Liver samples were processed for assessment of inducible nitric oxide synthase (iNOS) as a marker for M1, arginase 1 (Arg-1) as an M2 marker, c-fos, c-Jun, mitogen-activated protein kinase (MAPK), activator protein 1 (AP-1), and high-mobility-group-box1 (HMGB1) protein. The difference was insignificant regarding the relative expression of AP-1, c-Jun, c-fos, MAPK, and HMGB between the AKI+saline group and the AKI+Vildagliptin group. The difference between the same two groups concerning the hepatic content of the M1 marker (iNOS) and the M2 marker Arg-1 was insignificant. However, combined therapy produced more pronounced changes in these markers, as the difference in their relative expression between the AKI+saline+Vildagliptin group and both the AKI+saline group and the AKI+Vildagliptin group was significant. Accordingly, we suggest that the combined saline and vildagliptin hepatoprotective effect involves the downregulation of the MAPK/AP-1 signaling pathway.

Analysis of miR-203a-3p/SOCS3-mediated induction of M2 macrophage polarization to promote diabetic wound healing based on epidermal stem cell-derived exosomes

BackgroundThe development of therapeutic strategies to improve wound healing in individual diabetic patients remains challenging. Stem cell-derived exosomes represent a promising nanomaterial, and microRNAs (miRNAs) can be isolated from them. It is important to identify the potential therapeutic role of specific miRNAs, given that miRNAs can play a therapeutic role. MethodsqPCR, flow cytometry, and western blotting were used to verify the effect of epidermal stem cell-derived exosomes (EpiSC-EXOs) on M2 macrophage polarization and SOCS3 expression. By screening key miRNAs targeting SOCS3 in EpiSC-EXOs by high-throughput sequencing, we verified the mechanism in vitro. Finally, an animal model was used to verify the effect of promoting healing. ResultsThe use of EpiSC-EXOs reduced SOCS3 expression and promoted M2 macrophage polarization. The abundant miR-203a-3p present in the EpiSC-EXOs specifically bound to SOCS3 and activated the JAK2/STAT3 signaling pathway to induce M2 macrophage polarization. Treatment of the db/db mouse wound model with miR-203a-3p agomir exerted a pro-healing effect. ConclusionsOur results demonstrated that the abundant miR-203a-3p present in EpiSC-EXOs can promote M2 macrophage polarization by downregulating SOCS3 and suggested that diabetic wounds can obtain better healing effects through this mechanism.

Gut microbiota-derived ursodeoxycholic acid alleviates low birth weight-induced colonic inflammation by enhancing M2 macrophage polarization

BackgroundLow birth weight (LBW) is associated with intestinal inflammation and dysbiosis after birth. However, the underlying mechanism remains largely unknown.ObjectiveIn the present study, we aimed to investigate the metabolism, therapeutic potential, and mechanisms of action of bile acids (BAs) in LBW-induced intestinal inflammation in a piglet model.MethodsThe fecal microbiome and BA profile between LBW and normal birth weight (NBW) neonatal piglets were compared. Fecal microbiota transplantation (FMT) was employed to further confirm the linkage between microbial BA metabolism and intestinal inflammation. The therapeutic potential of ursodeoxycholic acid (UDCA), a highly differentially abundant BA between LBW and NBW piglets, in alleviating colonic inflammation was evaluated in both LBW piglets, an LBW-FMT mice model, and a DSS-induced colitis mouse model. The underlying cellular and molecular mechanisms by which UDCA suppresses intestinal inflammation were also investigated in both DSS-treated mice and a macrophage cell line. Microbiomes were analyzed by using 16S ribosomal RNA sequencing. Fecal and intestinal BA profiles were measured by using targeted BA metabolomics. Levels of farnesoid X receptor (FXR) were knocked down in J774A.1 cells with small interfering RNAs.ResultsWe show a significant difference in both the fecal microbiome and BA profiles between LBW and normal birth weight animals in a piglet model. Transplantation of the microbiota of LBW piglets to antibiotic-treated mice leads to intestinal inflammation. Importantly, oral administration of UDCA, a major BA diminished in the intestinal tract of LBW piglets, markedly alleviates intestinal inflammation in LBW piglets, an LBW-FMT mice model, and a mouse model of colitis by inducing M2 macrophage polarization. Mechanistically, UDCA reduces inflammatory cytokine production by engaging BA receptor FXR while suppressing NF-κB activation in macrophages.ConclusionsThese findings establish a causal relationship between LBW-associated intestinal abnormalities and dysbiosis, suggesting that restoring intestinal health and postnatal maldevelopment of LBW infants may be achieved by targeting intestinal microbiota and BA metabolism.Csb1K8fsfkBeFAHhY-1wroVideo

LINC00963 promotes the malignancy and metastasis of lung adenocarcinoma by stabilizing Zeb1 and exosomes-induced M2 macrophage polarization

BackgroundLong intergenic non-coding RNA 00963 (LINC00963) is an oncogenic lncRNA in human cancers. However, little is known on how it impacts the pathogenesis of lung adenocarcinoma (LUAD).MethodsBiological effects on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) were examined by CCK-8, colony formation, EdU incorporation, transwell, and immunofluorescence assays, respectively. Macrophage polarization was evaluated by flow cytometry. Ubiquitination of Zeb1 was examined by co-immunoprecipitation. The location of LINC00963 in LUAD tissues and cell lines was tested by FISH assay. The LINC00963/HNRNPA2B1/Siah1 mRNA complex interaction was verified using RNA pull-down and immunoprecipitation assays. The exact roles of LINC00963 were further validated in metastasis and xenograft models.ResultsHigher LINC00963 expression in LUAD patients positively correlated with shorter overall survival, higher stages, and metastasis. LINC00963 mainly localized in the cytoplasm and aggravated malignant phenotypes of LUAD cells in vitro and metastasis in vivo. Mechanistically, LINC00963 directly interacted HNRNPA2B1 protein to trigger the degradation of Siah1 mRNA, which inhibited the ubiquitination and degradation of Zeb1. Moreover, exosomal LINC00963 derived from LUAD cells induced M2 macrophage polarization and promoted LUAD growth and metastasis.ConclusionBy stabilizing Zeb1 in cancer cells and delivering exosomes to induce M2 macrophage polarization, LINC00963 promoted the malignancy and metastasis of LUAD. Targeting LINC00963 may become a valuable therapeutic target for LUAD.

Knockdown of PTEN promotes colon cancer progression and induces M2 macrophage polarization in the colon cancer cell environment.

This article aims to study the effect of phosphate and tension homolog deleted on chromosome ten (PTEN) knockdown on colon cancer progression and macrophage polarization in the cancer environment. The expression of PTEN in colon cancer tissues and colon cancer cells was significantly lower than in precancerous tissues or CCD-18Co cells, and the decrease was most evident in SW620 cells. The expressions of phosphate (p)-p38, c-Jun N-terminal kinase (JNK), activator protein 1 (AP-1), B-cell lymphoma-2 (Bcl-2) protein in colon cancer tissues and cells were significantly higher than in precancerous tissues or CCD-18Co cells (P-values < 0.05). Bcl-2-associated X (Bax) and Caspase-3 expressions in colon cancer tissues and cells were significantly lower than in precancerous tissues or CCD-18Co cells (P-values < 0.05). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was applied to measure cell viability. Transwell evaluated the cell migration and invasion ability. Si-PTEN improved the proliferation, migration, and invasion of SW620 cells (P-values < 0.05). The expression levels of arginase-1 (Arg-1), CD163, CD206 in colon cancer tissues were significantly higher than in precancerous tissues (P-values < 0.05). The cell cycle, the number of M1 and M2 double-positive cells were assessed by flow cytometry. Si-PTEN reduced the expression of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and inducible nitric oxide synthase (iNOS), which upregulated the expression of Arg-1, CD206, CD163, p-p38, JNK, and AP-1 (P-values < 0.05). Si-PTEN promoted colon cancer progression and induced the polarization of M2 tumor-associated macrophages in the colon cancer cell environment.

Periodontitis Promotes the Progression of Oral Squamous Cell Carcinoma by Inducing Macrophage M2 Polarization

To investigate the role of periodontitis in the development of oral squamous cell carcinoma (OSCC) and to determine whether periodontitis microorganisms induce M2 macrophage (M2) polarization and promote tumor progression. The tumor tissues of OSCC patients with periodontitis and those without periodontitis were collected and immunohistochemistry tests were done to validate the trend of changes in M2 macrophages. A mouse model of OSCC accompanied by periodontitis was established by treating mice with drinking water containing four antibiotics for three consecutive days, applying in the mouths of the mice a coat of bacteria collected from the saliva of patients with periodontitis once every other day for five times, and injecting in their buccal mucosa OSCC cells (SCC7). We observed the effect of periodontitis on the development of OSCC, analyzed the M2 macrophage content in the tumor tissues, and analyzed salivary microbiota structure, and examined the pathological changes in the spleen and colon tissues of the mice. Finally, we collected saliva from patients with periodontitis, co-cultured it with mice peripheral blood mononuclear cells (PBMC) and SCC7 cells, and examined M2 macrophage percentage by flow cytometry. Immunohistochemical findings from the clinical samples showed that M2-polarized macrophages in OSCC patients with periodontitis were more enriched (27.01%±2.12%) compared with those of OSCC patients without periodontitis (17.00%±3.66%). The OSCC mice with periodontitis (PO group) had tumors of larger size and lower survival rate than OSCC mice (O group) did. Furthermore, the expression rate of Ki67-positive cells (35.49%±5.00%) was significantly higher than that of O group (23.89%±4.13%) ( P<0.05). According to the results of flow cytometry, M2 macrophage expression (24.97%±4.41%) in PO group was higher than that of O group (5.75%±0.52%) ( P<0.05). In addition, qPCR results showed that gene expression of M2 macrophage-related factors, Arg1, IL-10, and CD206, showed an overall upward trend. Immunohistochemistry results showed that the positive expression of M2 macrophages was significantly increased in the PO group (21.82%±4.16%) compared to that of the O group (9.64%±0.60%) ( P<0.05). Mice in the PO group showed changes in their oral flora structure, exhibiting increased bands and diversity. The white pulp in their spleen tissue decreased and the boundary of the red pulp became indistinct with severe bleeding. The morphology of the colon glands was abnormal and the U-shaped crypt was damaged rather seriously. According to the results of cell experiment, when co-culturing PBMC with SCC7 cells, the presence of periodontitis microorganisms increased the polarization of M2 macrophages (71.00%±0.66%). Periodontitis promotes the development of OSCC by inducing M2 polarization in tumor-associated macrophages. Hence, periodontitis treatment holds important values for OSCC patients.

BST2 induced macrophage M2 polarization to promote the progression of colorectal cancer.

Background: Tumor-associated macrophages (TAMs) are one of the most prominent tumor-infiltrating immune cells in the tumor microenvironment (TME) of CRC and play a vital role in the progression of CRC. BST2 was predicted to be associated with the infiltration of TAMs. However, its potential function by which CRC cells and TAMs interact with each other still needs further investigation. Methods: The target genes in CRC were selected by bioinformatics screening. The level of bone marrow stromal cell antigen 2 (BST2) in CRC cells and tissues was determined by qRT‒PCR, Western blotting, and immunohistochemistry staining. In vitro and in vivo assays were applied to clarify the function of BST2. Results: In this study, according to bioinformatics analysis, a nomogram based on the risk score (constructed by BST2 and CAV1 (caveolin-1)) and clinical features was built and displayed satisfactory prognostic value. Upregulated BST2 was significantly related to Braf mutation, dMMR/MSI-H, CMS1 subtype, and immune response and was a potential biomarker for predicting immune checkpoint blockade therapy. Silencing BST2 in CRC obviously restrained CRC progression and M2 TAM polarization. The infiltration of TAMs was positively correlated with the high expression of BST2, and depletion of TAMs alleviated the protumoural effect of BST2 in CRC in vivo. In vitro experiments revealed that a reduction in BST2 in CRC inhibited CRC proliferation and migration and also M2 polarization. Conclusion: These findings indicated that BST2 played a vital role in CRC progression and might be a predictable marker for immunotherapy.

Disc regeneration by injectable fucoidan-methacrylated dextran hydrogels through mechanical transduction and macrophage immunomodulation

Modulating a favorable inflammatory microenvironment that facilitates the recovery of degenerated discs is a key strategy in the treatment of intervertebral disc (IVD) degeneration (IDD). More interestingly, well-mechanized tissue-engineered scaffolds have been proven in recent years to be capable of sensing mechanical transduction to enhance the proliferation and activation of nucleus pulposus cells (NPC) and have demonstrated an increased potential in the treatment and recovery of degenerative discs. Additionally, existing surgical procedures may not be suitable for IDD treatment, warranting the requirement of new regenerative therapies for the restoration of disc structure and function. In this study, a light-sensitive injectable polysaccharide composite hydrogel with excellent mechanical properties was prepared using dextrose methacrylate (DexMA) and fucoidan with inflammation-modulating properties. Through numerous in vivo experiments, it was shown that the co-culture of this composite hydrogel with interleukin-1β-stimulated NPCs was able to promote cell proliferation whilst preventing inflammation. Additionally, activation of the caveolin1-yes-associated protein (CAV1-YAP) mechanotransduction axis promoted extracellular matrix (ECM) metabolism and thus jointly promoted IVD regeneration. After injection into an IDD rat model, the composite hydrogel inhibited the local inflammatory response by inducing macrophage M2 polarization and gradually reducing the ECM degradation. In this study, we propose a fucoidan-DexMA composite hydrogel, which provides an attractive approach for IVD regeneration.

CCL3 aggravates intestinal damage in NEC by promoting macrophage chemotaxis and M1 macrophage polarization.

NEC is a life-threatening gastrointestinal disease in neonates, the pathogenesis of which remains poorly understood. CCL3 levels in intestinal tissue of mice were measured and analyzed. HE staining was used to assess pathological changes in intestinal tissue. FCM was used to detect the proportion and phenotype of macrophages. RNA-seq and RT-PCR were used to evaluate the effect of CCL3 on macrophages. CCL3 was highly expressed in the intestinal tissues of mice with NEC and induced macrophage infiltration. Transcriptome data showed that CCL3 strongly induced a transition in the phenotype of macrophages into a proinflammatory one. Mechanistically, in vivo experiments confirmed that CCL3 induced M1 macrophage polarization in NEC intestinal tissue, thereby aggravating inflammatory injury of intestinal tissue, which was alleviated by anti-CCL3 treatment. In addition, in vitro experiments showed that CCL3 significantly enhances the expression of M1-related genes in both PMφ and BMDM while inhibiting the expression of M2-related genes, which was also alleviated by anti-CCl3 treatment. Our data elucidated the involvement of CCL3 in the pathogenesis of NEC, in which upregulated CCL3 expression exacerbated inflammatory intestinal damage by regulating macrophage chemotaxis and M1 phenotype polarization, suggesting that blocking CCL3 may be a potential strategy for effective intervention in NEC. Our study represents an important conceptual advancement that CCL3 may be one of the key culprits of intestinal tissue damage in patients with NEC. CCL3 aggravates inflammatory intestinal injury and intestinal mucosal barrier imbalance by regulating the chemotaxis, polarization, and function of macrophages. Blocking CCL3 significantly reduced NEC-mediated intestinal injury, suggesting a new potential therapeutic strategy.

Vascular endothelial growth factor attenuates neointimal hyperplasia of decellularized small-diameter vascular grafts by modulating the local inflammatory response.

Small-diameter vascular grafts (diameter <6mm) are in high demand in clinical practice. Neointimal hyperplasia, a common complication after implantation of small-diameter vascular grafts, is one of the common causes of graft failure. Modulation of local inflammatory responses is a promising strategy to attenuates neointimal hyperplasia. Vascular endothelial growth factor (VEGF) is an angiogenesis stimulator that also induces macrophage polarization and modulates inflammatory responses. In the present study, we evaluated the effect of VEGF on the neointima hyperplasia and local inflammatory responses of decellularized vascular grafts. In the presence of rhVEGF-165 in RAW264.6 macrophage culture, rhVEGF-165 induces RAW264.6 macrophage polarization to M2 phenotype. Decellularized bovine internal mammary arteries were implanted into the subcutaneous and infrarenal abdominal aorta of New Zealand rabbits, with rhVEGF-165 applied locally to the adventitial of the grafts. The vascular grafts were removed en-bloc and submitted to histological and immunofluorescence analyses on days 7 and 28 following implantation. The thickness of the fibrous capsule and neointima was thinner in the VEGF group than that in the control group. In the immunofluorescence analysis, the number of M2 macrophages and the ratio of M2/M1 macrophages in vascular grafts in the VEGF group were higher than those in the control group, and the proinflammatory factor IL-1 was expressed less than in the control group, but the anti-inflammatory factor IL-10 was expressed more. In conclusion, local VEGF administration attenuates neointimal hyperplasia in decellularized small-diameter vascular grafts by inducing macrophage M2 polarization and modulating the inflammatory response.

Extracellular Vesicle-Packaged circATP2B4 Mediates M2 Macrophage Polarization via miR-532-3p/SREBF1 Axis to Promote Epithelial Ovarian Cancer Metastasis.

Ovarian cancer is one of the most common gynecologic malignancies with a highly immunosuppressive tumor microenvironment (TME) and poor prognosis. Circular RNA (circRNA) is a type of noncoding RNA with high stability, which has been shown to play an important role in biological processes and TME reprogramming in a variety of tumors. The biological function of a novel circRNA, circATP2B4, in epithelial ovarian cancer (EOC) was detected and evaluated. Transmission electron microscopy, differential ultracentrifugation and qRT-PCR were used to verify the existence of extracellular vesicles (EV)-packaged circATP2B4. Macrophage uptake of circATP2B4 was determined by EVs tracing. Dual luciferase reporter, FISH, Western blotting, and flow cytometry assays were used to investigate the interactions between circATP2B4 and miR-532-3p as well as sterol regulatory element-binding factor 1 (SREBF1) expression in macrophages. CircATP2B4 was upregulated in EOC tissues and positively correlated with ovarian cancer progression. Functionally, circATP2B4 promoted carcinogenic progression and metastasis of EOC both in vitro and in vivo. Mechanistically, EV-packaged circATP2B4 in EOC could be transmitted to infiltrated macrophages and acted as competing endogenous RNA of miR-532-3p to relieve the repressive effect of miR-532-3p on its target SREBF1. Furthermore, circATP2B4 induced macrophage M2 polarization by regulating the miR-532-3p/SREBF1/PI3Kα/AKT axis, thereby leading to immunosuppression and ovarian cancer metastasis. Collectively, these data indicate that circATP2B4-containing EVs generated by EOC cells promoted M2 macrophages polarization and malignant behaviors of EOC cells. Thus, targeting EVs-packaged circATP2B4 may provide a potential diagnosis and treatment strategy for ovarian cancer.

Precise delivery of doxorubicin and imiquimod through pH-responsive tumor microenvironment-active targeting micelles for chemo- and immunotherapy.

Recently, combining immunotherapy and chemotherapy has become a promising strategy to treat cancer. However, this therapeutic strategy still has its limitations because of the adverse effects caused by the simultaneous administration of multiple therapeutic agents. Using nanoparticles is an effective approach to successfully combine these therapies because they can reduce side effects, increase circulation time, and ensure the delivery of cytotoxic agents to tumor tissues. In this study, dual pH-sensitive and tumor microenvironment (TME)-active targeting micelles comprising poly(propyl methacrylate-co-glucosamine/histidine/doxorubicin) (P(PAA-co-GLU/HIS/DOX) and methoxy-poly(ethylene glycol)-block-poly(l-lysine) were prepared to encapsulate an immunomodulator, imiquimod (IMQ). Because these micelles can expose glucose targeting ligands at the TME and pH-dependently release IMQ and DOX, micelles effectively inhibit the growth of 4T1 cells selectively and highly accumulate in 4T1 cells as the pH decreased to 6.5. Moreover, in RAW 264.7​cells, these micelles prevent cell death and induce M1 macrophage polarization. In 4T1 orthotopic tumor-bearing mice, micelles not only exhibited high tumor accumulation, effective tumor inhibition, and fewer adverse effects, but also dramatically increased the number of mature dendritic cells, activate cytotoxic T cells, and polarize M1-like macrophages in tumor tissues. Overall, these micelles exhibit precise pH responsiveness and ideal drug delivery capabilities for combined chemo- and immunotherapy; these results significantly contribute to the future development of nanomedicines in cancer therapy.

GBP5 exacerbates rosacea-like skin inflammation by skewing macrophage polarization towards M1 phenotype through the NF-κB signalling pathway.

Rosacea is a chronic inflammatory skin disease with increased macrophage infiltration. However, the molecular mechanism remains unclear. To determine the significance of macrophage infiltration, and the correlation between Guanylate-binding protein 5 (GBP5) and polarization of macrophages in rosacea-like inflammation. Here we tested the hypothesis that Guanylate-binding protein 5 (GBP5) aggravates rosacea-like skin inflammation by promoting the polarization of the M1 macrophages through the NF-κB signalling pathway. We depleted macrophage by injecting clodronate-containing liposomes. We next explored the association between GBP5 and macrophage in rosacea tissue through transcriptome analysis and immunofluorescence analysis. We evaluated the severity of rosacea-like skin inflammation when BALB/c mice were injected with GBP5 siRNA intradermally daily for three consecutive days. At last, to study the causality of knocking down GBP5-blunted M1 macrophage polarization, THP-1 cell was treated with GBP5 siRNA. Macrophage depletion ameliorated rosacea-like skin inflammation in mice, implying the important role of macrophages in rosacea. Based on the transcriptome analysis, Guanylate-binding protein 5 (GBP5) was identified as hub gene that was associated with macrophage infiltration in rosacea. Next, we found that GBP5 expression was significantly upregulated in rosacea tissues and positively correlated with macrophage infiltration, the immunofluorescence analysis revealed the co-localization between GBP5 and macrophages. In vivo, silencing of GBP5 attenuated rosacea-like skin inflammation in the LL-37-induced mouse model and suppressed the expression of M1 signature genes such as IL-6, iNOS and TNF-a. In vitro, knocking down GBP5 significantly blunted the polarization of the M1 macrophages partly by repressing the activation of the NF-κB signalling pathways. Together, our study revealed the important role of macrophages in rosacea and identified GBP5 as a key regulator of rosacea by inducing M1 macrophage polarization via NF-κB signalling pathways.

Small extracellular vesicles from Ptpn1-deficient macrophages alleviate intestinal inflammation by reprogramming macrophage polarization via lactadherin enrichment

Tyrosine-protein phosphatase non-receptor type 1 (Ptpn1) is known to be involved in macrophage polarization. However, whether and how Ptpn1 regulates macrophage phenotype to affect intestinal epithelial barrier function remains largely unexplored. Herein, we investigated the impact of Ptpn1 and macrophage-derived small extracellular vesicles (sEVs) on macrophage-intestinal epithelial cell (IEC) interactions in the context of intestinal inflammation. We found that Ptpn1 knockdown shifts macrophages toward the anti-inflammatory M2 phenotype, thereby promoting intestinal barrier integrity and suppressing inflammatory response in the macrophage-IEC co-culture model. We further revealed that conditioned medium or sEVs isolated from Ptp1b knockdown macrophages are the primary factor driving the beneficial outcomes. Consistently, administration of the sEVs from Ptpn1-knockdown macrophages reduced disease severity and ameliorated intestinal inflammation in LPS-challenged mice. Furthermore, depletion of macrophages in mice abrogated the protective effect of Ptpn1-knockdown macrophage sEVs against Salmonella Typhimurium infection. Importantly, we found lactadherin to be highly enriched in the sEVs of Ptpn1-knockdown macrophages. Administration of recombinant lactadherin alleviated intestinal inflammation and barrier dysfunction by inducing macrophage M2 polarization. Interestingly, sEVs lactadherin was also internalized by macrophages and IECs, leading to macrophage M2 polarization and enhanced intestinal barrier integrity. Mechanistically, the anti-inflammatory and barrier-enhancing effect of lactadherin was achieved by reducing TNF-α and NF-κB activation. Thus, we demonstrated that sEVs from Ptpn1-knockdown macrophages mediate the communication between IECs and macrophages through enrichment of lactadherin. The outcome could potentially lead to the development of novel therapies for intestinal inflammatory disorders.

MIR4435-2HG in exosomes promotes gastric carcinogenesis by inducing M2 polarization in macrophages.

Gastric cancer (GC) is a cancer with a high mortality rate. lncRNAs play a role in regulating GC tumorigenesis. In this paper, we analyzed differentially expressed lncRNAs between GC and adjacent normal tissues using multiple bioinformatics tools to identify new potential targets in GC. Cell viability and migration ability were detected using the Cell Counting Kit-8 (CCK-8) and transwell assays, MIR4435-2HG was negatively correlated with the survival rate of GC patients, and by inhibiting the activity of MIR4435-2HG, the viability and migration ability of GC cells could be reduced. In addition, RT- qPCR and western blot to detect gene and protein level expression, transmission electron microscopy and nanoparticle tracking analysis (NTA) to study the efficiency of exosome isolation, and flow cytometry to observe cell differentiation were employed, delivery of MIR4435-2HG shRNA via MKN45 cell-derived exosomes significantly reversed the MKN45 exosome-induced M2 polarization in macrophages. Furthermore, the low expression of MIR4435-2HG in MKN45 cell-derived exosomes inhibited the Jagged1/Notch and JAK1/STAT3 pathways in macrophages; MIR4435-2HG downregulated exosomes were found to significantly inhibit GC tumor growth in vivo by establishing a mouse model. In short, MKN45 cell-derived exosomes deliver lncRNA MIR4435-2HG, which promotes gastric carcinogenesis by inducing macrophage M2 polarization.

Dioscin induces M1 macrophage polarization through Connexin-43 Channels in Tumor-associated-macrophages-mediated melanoma metastasis

BackgroundTumor-associated macrophages (TAMs) are important constituent parts of tumor microenvironment that connected with tumor metastasis in melanoma. Connexin 43 (Cx43) was expressed in all the immune cells which modulated different aspects of immune response. However, the concrete molecular mechanism maintains unclear. PurposeThe study aimed to find a natural drug monomer effectively reversed the polarity of tumor-associated macrophages inhibiting melanoma metastasis and improving survival time. MethodsFlow cytometry was used to determine the effects of dioscin on the macrophage phenotype. Western bolt and ELISA were performed to explore the underlying mechanism of dioscin and a co-culture experiment in vitro was applied to assess the role of dioscin on TAMs-mediated melanoma proliferation, invasion and migration. Moreover, in vivo melanoma metastasis models were established for examining effects of dioscin on TAMs-mediated melanoma metastasis. ResultsDioscin repolarized macrophages from M2 towards M1-like phenotype. Dioscin suppressed M2-like phenotype macrophages through enhanced the expression and transport function of Cx43. Furthermore, the stimulation IFN-γ/STAT1 pathway and suppression IL-4/JAK2/STAT3 pathway were major mechanism of dioscin. Importantly, dioscin suppressed Cx43G21R mutation TAMs induced proliferation, invasion, migration and metastasis of melanoma cells. It worthily noting that dioscin ameliorated tumor-associated-macrophages-mediated melanoma metastasis in vitro and vivo. ConclusionDioscin re-polarized macrophages from M2 to M1 phenotype through activation of Cx43-gap-junction-intercellular-communications (Cx43-GJs)/IFN-γ/STAT1 pathway and inhibition of Cx43-GJs/IL-4/JAK2/STAT3 suppressing migration, invasion and metastasis of melanoma, which provided a theoretical and experimental basis for treating melanoma metastasis.

TMIC-57. USING SINGLE-CELL SEQUENCING AND SPATIAL TRANSCRIPTOMICS TO IDENTIFY CANCER-ASSOCIATED FIBROBLASTS IN GLIOBLASTOMA AND DEFINING THEIR PRO-TUMORAL EFFECTS

Abstract Cancer-associated fibroblasts (CAFs) constitute a key component of the tumor microenvironment. Pro-tumoral cancer-associated fibroblasts were presumed absent in glioblastoma given the lack of brain fibroblasts. Using single-cell RNA sequencing we identified CAFs in patient GBMs. CAFs were identified using a negative selection strategy to filter endothelial, epithelial, immune cells and pericytes and for the positive expression of previously defined CAF markers. Copy number variation (CNV) analysis was performed to distinguish CAFs from malignant cells. Single-cell spatial transcriptomics from 16 GBM patients confirmed the proximity of CAFs to mesenchymal GBM stem cells (GSCs), endothelial cells, and M2-macrophages. Serial trypsinization of glioblastoma specimens yielded cells with CAF morphology and transcriptomic profile. CAFs were chemotactically attracted to GSCs and CAFs induced GSC proliferation. To identify CAF and GSC interaction mediators, we created a resource of inferred crosstalk by mapping expression of receptors to their cognate ligands, identifying PDGF and TGFB as mediators of GSC effects on CAFs, and osteopontin and HGF as mediators of CAF-induced GSC enrichment. Furthermore, CAFs were found to induce M2-macrophage polarization by producing the EDA fibronectin variant which binds macrophage toll-like receptor 4 (TLR4) in a targetable manner. Glioblastoma CAFs were enriched in the subventricular zone which houses the neural stem cells that houses GSCs. Including CAFs in GSC-derived xenografts induced in vivo tumor growth and reduced survival in two different xenograft models. These findings are among the first to identify glioblastoma CAFs and their GSC interactions, making them an intriguing target for Glioblastomas.