Proportion Of M2 Macrophages Research Articles

Anti-Inflammatory Effect of Curcumin on the Mouse Model of Myocardial Infarction through Regulating Macrophage Polarization.

Inflammation causes tissue damage and promotes ventricular remodeling after myocardial infarction (MI), and the infiltration and polarization of macrophages play an important role in regulating inflammation post-MI. Here, we investigated the anti-inflammatory function of curcumin after MI and studied its relationship with macrophage polarization. In vivo, curcumin not only attenuated ventricular remodeling 3 months after MI but also suppressed inflammation during the first 7 days post-MI. Importantly, the results of qPCR and immunochemistry showed that curcumin decreased M1 (iNOS, CCL2, and CD86) but increased M2 macrophage (Arg1, CD163, and CD206) marker expression in the myocardium of MI mice during the first 7 days post-MI. And flow cytometry analysis indicated that curcumin suppressed M1 (CD45+Gr-1-CD11b+iNOS+ cells) but enhanced M2 macrophage (CD45+Gr-1-CD11b+Arg+ cells) expansion in the myocardium of MI mice during the first 7 days post-MI. In vitro, curcumin decreased LPS/IFNγ-elevated M1 macrophage marker (iNOS and CD86) expression and the proportion of M1 macrophages (iNOS+F4/80+ cells) but increased LPS/IFNγ-suppressed M2 macrophage marker (Arg1 and CD206) expression and the proportion of M2 macrophages (Arg1+F4/80+ cells). In addition, curcumin modulates M1/M2 macrophage polarization partly via AMPK. In conclusion, curcumin suppressed the MI-induced inflammation by modulating macrophage polarization partly via the AMPK pathway.

Exosome membrane-modified M2 macrophages targeted nanomedicine: Treatment for allergic asthma

BackgroundsExosomes are naturally secreted nanovesicles that have emerged as a promising therapeutic nanodelivery platform due to their specific composition, biological properties, and stability. Modifying synthetic nanoparticles with the intrinsic hallmarks of exosome membrane to create exosome mimetics could lead to safe and efficient smart silencer delivery. ObjectivesThe study focuses on exploring the combination of polylactic-co-glycolic acid (PLGA)-based nanoparticles with naturally occurring exosome membrane from M2 macrophages to deliver a Dnmt3aos smart silencer to treat allergic asthma (AA) in mice. Materials and methodsExosome membrane of M2 macrophages and PLGA nanoparticles (PLGA NPs) wrapped with the smart silencer of Dnmt3aos (Dnmt3aossmart silencer) were first synthesized. The resulting exosome membrane coated PLGA@Dnmt3aossmart silencer (EM-PLGA@Dnmt3aossmart silencer) was administered intravenously into Der f1-induced asthma mice, which was followed by the investigation of therapeutic outcomes and the mechanism in vivo. ResultsSeven infusions of EM-PLGA@Dnmt3aossmart silencer ameliorated AA with a marked reduction of lung inflammation. After intravenous injection, the EM-PLGA@Dnmt3aossmart silencer was distributed in various organs, including the lungs, with retention over 48 h, and it targeted M2 macrophages. Moreover, the injections of EM-PLGA@Dnmt3aossmart silencer markedly decreased the proportion of M2 macrophages and inflammatory cytokines in the airway. More importantly, the EM-PLGA@Dnmt3aossmart silencer treatment did not obviously suppress the overall immune function of host. ConclusionTo our knowledge, this study provides the first experimental evidence of the ability of EM-PLGA@Dnmt3aossmart silencer to target M2 macrophages in the treatment of AA by combining exosome membrane and biomaterials, thus presenting a novel immunotherapy for the allergic disease.

Caveolin-1 Deficiency Protects Mice Against Carbon Tetrachloride-Induced Acute Liver Injury Through Regulating Polarization of Hepatic Macrophages.

Polarization of hepatic macrophages plays a crucial role in the injury and repair processes of acute and chronic liver diseases. However, the underlying molecular mechanisms remain elusive. Caveolin-1 (Cav1) is the structural protein of caveolae, the invaginations of the plasma membrane. It has distinct functions in regulating hepatitis, cirrhosis, and hepatocarcinogenesis. Given the increasing number of cases of liver cancer, nonalcoholic steatohepatitis, and non-alcoholic fatty liver disease worldwide, investigations on the role of Cav1 in liver diseases are warranted. In this study, we aimed to investigate the role of Cav1 in the pathogenesis of acute liver injury. Wild-type (WT) and Cav1 knockout (KO) mice (Cav1tm1Mls) were injected with carbon tetrachloride (CCl4). Cav1 KO mice showed significantly reduced degeneration, necrosis, and apoptosis of hepatocytes and decreased level of alanine transaminase (ALT) compared to WT mice. Moreover, Cav1 was required for the recruitment of hepatic macrophages. The analysis of the mRNA levels of CD86, tumor necrosis factor (TNF), and interleukin (IL)-6, as well as the protein expression of inducible nitric oxide synthase (iNOS), indicated that Cav1 deficiency inhibited the polarization of hepatic macrophages towards the M1 phenotype in the injured liver. Consistent with in vivo results, the expressions of CD86, TNF, IL-6, and iNOS were significantly downregulated in Cav1 KO macrophages. Also, fluorescence-activated cell sorting (FACS) analysis showed that the proportion of M1 macrophages was significantly decreased in the liver tissues obtained from Cav1 KO mice following CCl4 treatment. In summary, our results showed that Cav1 deficiency protected mice against CCl4-induced acute liver injury by regulating polarization of hepatic macrophages. We provided direct genetic evidence that Cav1 expressed in hepatic macrophages contributed to the pathogenesis of acute liver injury by regulating the polarization of hepatic macrophages towards the M1 phenotype. These findings suggest that Cav1 expressed in macrophages may represent a potential therapeutic target for acute liver injury.

Malnutrition delayed wound healing after tooth extraction by HMGB1-related prolonged inflammation

Malnutrition causes prolonged inflammation, resulting in delayed wound healing. High mobility group box-1 (HMGB1) is a damage-associated molecular pattern that is present in the nuclei of macrophages and is secreted into the extracellular milieu in response to stimuli. It stimulates the production of interleukin-1β (IL-1β) through the receptors for advanced glycation end products (RAGE), inducing an inflammatory response, which is an essential response to initiate wound healing. We hypothesized that malnutrition may interfere with this cascade, causing abnormal inflammation and ultimately delaying wound healing. We used tooth-extracted mice with malnutrition fed with low-casein diet for two weeks. On days 3 and 7 after tooth extraction, the wound tissue was histologically observed and analyzed for several factors in the inflammation-regeneration lineage, including IL-1β, mesenchymal stem cells, myeloperoxidase activity, HMGB1, macrophage polarization, and adenosine 5-triphosphate (ATP). On day 7, delayed wound healing was observed with the following findings under malnutrition conditions: decreased mRNA expression of genes for regeneration and mesenchymal stem cell (MSC) accumulation, an obvious increase in myeloperoxidase and IL-1β mRNA expression, an increase in HMGB1 levels, and an increase in ATP concentration in tissues with elevated proportion of M2 macrophages. These results suggest that the significantly increased secretion of HMGB1 associated with the upregulated production of ATP and IL-1β secretion via the RAGE pathway may interfere with the resolution of inflammation and wound healing under the state of malnutrition.

Evaluation of homologous recombination deficiency (HRD) score and immuno-tumor microenvironment (iTME) as biomarkers of soft tissue sarcoma (STS) survival and response to immune checkpoint inhibitor therapy.

11568 Background: Soft tissue sarcoma (STS) are highly heterogenous in both histology and underlying genetic alterations, resulting in heterogenous outcomes of standard therapy. With recent stride of immunotherapies in oncology it is crucial to find the optimal match of the new therapies to disease subtypes. HRDScore and iTME parameters are two top candidate biomarkers to predict clinical outcomes in complex diseases such as STS. Methods: We prospectively profiled 102 Chinese STS patients who had received more than 1 line of prior treatment, mainly chemo-drugs. We then classified the patients according to their HRDScore (calculated from WES data using the Richardson method, ref. Telli M.L. et al. Clin. Cancer Res. 2016) and iTME parameters (calculated from RNAseq data using CIBERSORT method). Lastly, we tested the correlation of HRDScore or iTME with patient survival and clinic outcomes of anti-PD-1/L1 based combination therapy. Results: The histological subtypes of the patients included 32 LMS, 44 LPS, and 26 others (such as UPS, clear cell, myxofibrosarcoma, uterus LMS etc.). The top mutation genes (frequency > 5%) included TP53 29%, KMT2C 16%, NOTCH2 9%, ATRX 8%, NF1 8%, RB1 8% and PTEN 6%. The patients could be classified to HRD-high or HRD-low (HRDScore > or < = 42). Alternatively, unsupervised clustering of iTME revealed three patient subgroups (named iTME-I, -II, and -III). While all the three groups are characterized by a generally suppressed immune environment, iTME-I have high proportion of M0 macrophages and median M2 macrophages; iTME-II have high proportion of M2 macrophages but low M0 cells; and iTME-type III are low in both M0 and M2 cells. No significant M1 cells present in all the three iTME groups. Patient survivals were correlated with the iTME types but not HRDScore in Kaplan-Meyer analysis. The trend of survival time was iTME-III > iTME-II > iTME-I, with an HR = 0.156 for iTME-III over iTME-I (p = 0.008, log-rank test). Treatment response of anti-PD-1/L1 based combination therapies also showed a positive correlation to iTME-III, but not HRDScore although the small sample size prevented a definitive conclusion. Clinical evaluation of the 22 patients who received anti-PD-1/L1 therapy showed 1 PD (20%) and 4 SD/PR (80%) in iTME-III, 4 PD (40%) and 6 SD/PR (60%) in iTME-II, and 1 PD (33%) and 2 SD (67%) in iTME-I. Conclusions: iTME is a better biomarker than HRDScore in STS for survival and treatment outcomes. Differential Infiltration of M0 and M2 macrophages can distinguish patients with different survival and response to anti-PD-1/L1 combination therapy. The iTME subtypes may be used for treatment screen of combination immunotherapy but larger and randomized clinical studies are required to validate the discovery.

Nobiletin Alleviates Non-alcoholic Steatohepatitis in MCD-Induced Mice by Regulating Macrophage Polarization.

Non-alcoholic steatohepatitis (NASH) is an inflammatory disorder that is characterized by chronic activation of the hepatic inflammatory response and subsequent liver damage. The regulation of macrophage polarization in liver is closely related to the progression of NASH. The orphan nuclear receptor retinoic-acid-related orphan receptor α (RORα) and Krüppel-like factor 4 (KLF4) are key regulators which promote hepatic macrophages toward M2 phenotype and protect against NASH in mice. Nobiletin (NOB), a natural polymethoxylated flavone, is previously reported as a RORα regulator in diet-induced obese mice. However, it is still unclear whether NOB has the protective effect on NASH. In this study, we investigated the role of NOB in NASH using a methionine and choline deficient (MCD)-induced NASH mouse model. Our results showed that NOB ameliorated hepatic damage and fibrosis in MCD fed mice. NOB treatment reduced the infiltration of macrophages and neutrophils in the liver in MCD-fed mice. Of importance, NOB significantly increased the proportion of M2 macrophages and the expression of anti-inflammatory factors in vivo and in vitro. Meanwhile, NOB also decreased the population of M1 macrophages and the expression of proinflammatory cytokines. Mechanistically, NOB elevated KLF4 expression in macrophages. Inhibition of KLF4 abolished NOB regulated macrophage polarization. Furthermore, the regulation of NOB in KLF4 expression was dependent on RORα.

Study on the Immune Escape Mechanism of Acute Myeloid Leukemia With DNMT3A Mutation.

DNA (cytosine-5)-methyltransferase 3A (DNMT3A)-mutated acute myeloid leukemia (AML) has a poor prognosis, but the exact mechanism is still unclear. Here, we aimed to explore the mechanism of immune escape in AML with DNMT3A mutation. We constructed a DNMT3A knockout clone and DNMT3A-R882H-mutated clones. RNA-seq results showed that transcription factors and macrophage inflammatory proteins were significantly downregulated in the DNMT3A mutant clones. KEGG enrichment and gene set enrichment analysis (GSEA) showed that a large number of genes were enriched in inflammatory immune-related pathways, such as the toll-like receptor signaling pathway. Therefore, we co-cultured AML cells with macrophages. The DNMT3A-mutated AML cells attenuated M1 macrophage polarization and resisted its killing effect in vitro and in vivo. In xenografts, the tumor volumes in the experimental group were significantly larger than those in the control group, and the proportion of M2 macrophages was significantly higher. After the co-culture, the increase in pro-inflammatory cytokine expression in the mutant cells was significantly lower than that in the control group, while that in immunosuppressive factors was not significantly different. In co-cultivated supernatants, the concentration of inflammatory factors in the experimental group was significantly lower than that in the control group, while that of immunosuppressive factors was significantly higher. Resistin significantly promoted the expression of inflammatory proteins in AML cells. It relieved the inhibitory effect of DNMT3A mutation, promoted the phenotypic recovery of the co-cultured macrophages, eliminated resistance, and regulated the immune microenvironment. Thus, resistin may serve as an ancillary drug for patients with DNMT3A-mutated AML.

Identification and analysis of immune microenvironment characterization and key signal pathways in liver metastasis.

e15004 Background: The liver represents a common site for metastatic disease, patients with advanced malignancies were usually associated with worse prognostic outcomes once liver metastasis has occurred. The aim of this study was to explore the immune microenvironment characterization and key signal pathways of liver metastasis in colorectal cancer (CRC) and breast cancer (BRCA), and to provide potential targets and decision-making basis for the diagnosis and treatment of patients with liver metastasis. Methods: Two datasets (GSE49355 and GSE58708) were downloaded from the Gene Expression Omnibus (GEO) database, and patients with primary tumors and paired liver metastases were enrolled. Data were processed by the limma and Deseq2 package and the differentially expressed genes (DEGs) were identified. Gene Ontology (GO), Kyoto Enrichment of Genes and Genomes (KEGG) and Reactome pathway analysis was performed using clusterProfiler package. Prognosis markers were identified via survival analysis of The Cancer Genome Atlas (TCGA) databases. CIBERSORT algorithm was used to calculate the proportions of 22 types of infiltrated immune cells. We used Spearman’s correlation analysis to describe the correlation between gene expression and microsatellite instability (MSI) or tumor mutational burden (TMB) score. Results: We investigated 16 patients with paired specimens (3 patients with BRCA and 13 patients with CRC). A total of 424 and 49 DEGs were identified in the BRCA and CRC samples. Only 26 DEGs were shared by the two kinds of cancers. The functional enrichment analysis suggested that the functions of DEGs were mainly related to cholesterol metabolism, complement and coagulation cascades, platelet activation etc. The survival analysis indicated that high expression levels of SERPINA3 was associated with a better prognosis in TCGA-BRCA (P = 0.01), while high ITIH2 and COLEC11 expression correlated with poor prognosis in TCGA-COAD (P = 0.045 and P = 0.013, respectively). CIBERSORT analysis revealed a significantly increased proportion of M2-macrophages and decreased proportion of activated mast cells in liver metastases. The Spearman correlation analysis showed that the SERPINA3 expression had a significantly negative relationship with the TMB (r = -0.26, P＜0.001) in TCGA-BRCA, but not significantly associated with the MSI (r = -0.02, P = 0.520), while the COLEC11 expression was significantly correlate negatively with the MSI and TMB (r = -0.15, P < 0.001 and r = -0.23, P < 0.001, respectively) in TCGA-COAD. Conclusions: The immune microenvironment of liver metastases exhibits a significant increase in the proportion of M2-macrophages and a significant decrease in the proportion of activated mast cells, and the key signal pathways implicate cholesterol metabolism and platelet activation. The specific mechanism needs to be further elucidated. Support: 81972853, 81572279, LC2019ZD009.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Regulate Macrophage Polarization to Attenuate Systemic Lupus Erythematosus-Associated Diffuse Alveolar Hemorrhage in Mice.

Background and ObjectivesTo investigate the effect and the underlying mechanism of exosomes secreted by human umbilical cord mesenchymal stem cells (hUCMSCs) on diffuse alveolar hemorrhage (DAH) in murine lupus.Methods and ResultsExosomes were extracted from cultured hUCMSCs by ultracentrifugation. The expressions of exosome markers (Alix, CD63 and TSG101) were measured for identification of hUCMSC-derived exosomes (hUCMSC-exosomes). The alveolar hemorrhage of DAH mice was revealed by H&E staining. The primary alveolar macrophages were isolated from bronchoalveolar lavage fluid (BALF) of DAH mice. The expressions of M1 macrophage markers (iNOS, IL-6, TNF-α and IL-1β) and M2 macrophage markers (Arg1, IL-10, TGF-β and chi3l3) were detected. Flow cytometry measured the ratio of M1/M2 macrophages. ELISA measured the secretion of pro-inflammatory cytokines (IL-6 and TNF-α) and anti-inflammatory cytokines (IL-10 and TGF-β). DAH mice had hemorrhage and small-vessel vasculitis in the lung, with neutrophil and monocyte infiltration observed around the capillary and small artery. Furthermore, increases of IL-6 and TNF-α, and decreases of IL-10 and TGF-β were detected in the BALF of DAH mice. M1 makers were overexpressed in alveolar macrophages of DAH mice while M2 makers were lowly expressed. DAH mice had a higher proportion of M1 macrophages than M2 macrophages. After hUCMSC-exosome or methylprednisolone treatment in DAH mice, the alveolar injuries and inflammatory responses were attenuated, and the proportion of M2 macrophages was increased.ConclusionshUCMSC-exosomes attenuate DAH-induced inflammatory responses and alveolar hemorrhage by regulating macrophage polarization.

Azithromycin alleviates systemic lupus erythematosus via the promotion of M2 polarisation in lupus mice

Our previous study demonstrated that azithromycin could promote alternatively activated (M2) macrophages under lupus conditions in vitro, which might be beneficial for lupus treatment. Thus, the aim of this study was to further confirm whether azithromycin can drive M2 polarisation in lupus and ultimately alleviate systemic lupus erythematosus (SLE) in vivo. Lymphocyte-derived DNA (ALD-DNA)-induced mice (induced lupus model) and MRL-Faslpr mice (spontaneous lupus model) were both used in the experiment. First, we observed symptoms of lupus by assessing the levels of serum anti-dsDNA antibodies and serum creatinine and renal pathology. We found that both murine models showed increased levels of serum anti-dsDNA antibodies and creatinine, enhanced glomerular fibrosis and cell infiltration, basement membrane thickening and elevated IgG deposition. After azithromycin treatment, all these medical indexes were alleviated, and kidney damage was effectively reversed. Next, macrophage polarisation was assessed in the spleen and kidneys. Macrophage infiltration in the spleen was notably decreased after azithromycin treatment in both murine models, with a remarkably elevated proportion of M2 macrophages. In addition, the expression of interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), CD86, toll-like receptor (TLR)2 and TLR4 was extremely downregulated, while the expression of transforming growth factor (TGF)-β, arginase-1 (Arg-1), chitinase-like 3 (Ym-1), found in inflammatory zone (Fizz-1) and mannose receptor (CD206) was significantly upregulated in the kidneys after azithromycin treatment. Taken together, our results indicated for the first time that azithromycin could alleviate lupus by promoting M2 polarisation in vivo. These findings exploited the newly discovered potential of azithromycin, a conventional drug with verified safety, affordability and global availability, which could be a novel treat-to-target strategy for SLE via macrophage modulation.

Neoadjuvant chemoradiation alters biomarkers of anticancer immunotherapy responses in locally advanced rectal cancer

BackgroundNeoadjuvant chemoradiation therapy (CRT) is a widely used preoperative treatment strategy for locally advanced rectal cancer (LARC). However, a few studies have evaluated the molecular changes caused by neoadjuvant CRT...

15-Deoxy-△12,14-Prostaglandin J2 Promotes Resolution of Experimentally Induced Colitis.

Uncontrolled macrophage functions cause failure to resolve gut inflammation and has been implicated in the pathogenesis of inflammatory bowel disease (IBD). 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), one of endogenous lipid mediators formed from arachidonic acid during the inflammatory process, has been reported to terminate inflammation. However, the pro-resolving effect of 15d-PGJ2 on intestinal inflammation and underlying molecular mechanisms remain largely unknown. In the present study, we examined the effects of 15d-PGJ2 on the resolution of dextran sulfate sodium (DSS)-induced murine colitis that mimics human IBD. Pharmacologic inhibition of prostaglandin D synthase (PGDS) responsible for the synthesis of 15d-PGJ2 hampered resolution of inflammation in the colonic mucosa of mice treated with DSS. Notably, intraperitoneal injection of 15d-PGJ2 accelerated the resolution of experimentally induced colitis. 15d-PGJ2 treatment reduced the number of neutrophils and M1 macrophages, while it increased the proportion of M2 macrophages. Moreover, 15d-PGJ2 treated mice exhibited the significantly reduced proportion of macrophages expressing the pro-inflammatory cytokine, IL-6 with concomitant suppression of STAT3 phosphorylation in the colonic mucosa of mice administered 2.5% DSS in drinking water. Taken together, these findings clearly indicate that 15d-PGJ2, endogenously generated from arachidonic acid by cyclooxygenase-2 and PGDS activities in inflamed tissue, promotes resolution of intestinal colitis.

Exosomal miR-487a derived from m2 macrophage promotes the progression of gastric cancer

ABSTRACT Tumor-associated macrophages contribute to cell growth, development, and metastasis in various cancers. However, the underlying mechanisms of M2 macrophage that modulate the progression of gastric cancer (GC) remain largely unknown. In this study, we detected the ratio of macrophages in GC tissues and found that the proportion of M2 macrophages was increased in GC tissues. We then co-cultured GC cells with M1 and M2 macrophages, respectively, and then assessed cell proliferation and tumorigenicity of GC cells by MTT and colony formation assay. The results indicated that M2 macrophages promoted the proliferation of GC cells, but M1 not. Besides, GW4869, an exosomes inhibitor, reduced the effects induced by M2 macrophage. Then, we isolated and identified exosomes derived from M1 and M2 macrophage, and confirmed that the exosomes could be taken up by GC cells. We demonstrated that M2 macrophage-exosomes could induce the proliferation and tumorigenesis in vitro and in vivo. Moreover, miR-487a was enriched in M2 macrophage-exosomes and further determined that miR-487a exert the functions by targeting TIA1. In conclusion, exosomal miR-487a derived from M2 macrophage promotes the proliferation and tumorigenesis in gastric cancer, and the novel findings might be helpful to the development of novel diagnostic and therapeutic methods in GC.

Luteolin Regulates the Differentiation of Regulatory T Cells and Activates IL-10-Dependent Macrophage Polarization against Acute Lung Injury.

Objectives Inflammatory disease characterized by clinical destructive respiratory disorder is called acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Studies have shown that luteolin exerts anti-inflammatory effects by increasing regulatory T cells (Tregs). In this study, we aimed to determine the effects of luteolin on ALI/ARDS and Treg differentiation. Methods In this paper, we used cecal ligation puncture (CLP) to generate an ALI mouse model to determine the effects of luteolin on ALI/ARDS. Lung tissues were stained for interleukin- (IL-) 17A and myeloperoxidase (MPO) by immunohistochemical analysis. The levels of Treg-related cytokines in serum and bronchoalveolar lavage fluid (BALF) of mice were detected. The protein levels of NF-κB p65 in lung tissues were measured. Macrophage phenotypes in lung tissues were measured using immunofluorescence. The proportion of Tregs in splenic mononuclear cells and peripheral blood mononuclear cells (PBMCs) was quantified. Furthermore, in vitro, we evaluated the effects of luteolin on Treg differentiation, and the effects of IL-10 immune regulation on macrophage polarization were examined. Results Luteolin alleviated lung injury and suppressed uncontrolled inflammation and downregulated IL-17A, MPO, and NF-κB in the lungs of CLP-induced mouse models. At this time, luteolin upregulated the level of IL-10 in serum and BALF and the frequency of CD4+CD25+FOXP3+ Tregs in PBMCs and splenic mononuclear cells of CLP mice. Luteolin treatment decreased the proportion of M1 macrophages and increased the proportion of M2 macrophages in lungs of CLP-induced mouse models. In vitro, administration of luteolin significantly induced Treg differentiation, and IL-10 promoted the polarization of M2 macrophages but reduced the polarization of M1 macrophages. Conclusions Luteolin alleviated lung injury and suppressed uncontrolled inflammation by inducing the differentiation of CD4+CD25+FOXP3+ Tregs and upregulating the expression of IL-10. Furthermore, the anti-inflammatory cytokine IL-10 promoted polarization of M2 macrophages in vitro. Luteolin-induced Treg differentiation from naïve CD4+ T cells may be a potential mechanism for regulating IL-10 production.

Experimental study on preparation and anti-tumor efficiency of nanoparticles targeting M2 macrophages

This study aimed to develop an effective therapy against M2 macrophages and to investigate the effects of imidazole and mannose modified carboxymethyl chitosan-nanoparticles (MIC-NPs) on tumor growth and antitumor immune responses. MIC-NPs were constructed and analyzed through 1H NMR, nano-laser particle size analyzer, and transmission electron microscopy. The nanoparticles were mainly distributed in 75–85 nm, and zeta potential was 1.5 mV. Cytotoxicity studies in vitro and in vivo indicated that MIC-NPs were safe. The targeting effect of MIC-NPs on M2 macrophages was observed through fluorescence microscope and microplate system. The results demonstrated the uptake of a large amount of FITC-loaded MIC-NPs by M2. Cell growth inhibition experiments showed that MIC-NPs significantly inhibited M2 through cell apoptosis. The evaluation of anti-tumor activity in vivo showed that MIC-NPs could accumulate in the tumor site to exert an anti-tumor effect. Flow cytometry showed that the proportion of M2 macrophages at the tumor site in the experimental group was significantly lower than that in the control group, while the Treg cells and cytotoxic T cells (CTL) were found to be increased. PCR detection showed that the cDNA of FIZZ, MR, TGF-β, and arginase, closely related to M2 macrophages, in the experimental group, was significantly lower than that in the control group, but there was no significant difference in the cDNA of Treg cell characteristic Foxp3 between the two groups. These results suggest that MIC-NPs are expected to provide a new and effective treatment for tumor.

The Immune Cell Landscape in Renal Allografts

Immune cell infiltration plays an important role in the pathophysiology of kidney grafts, but the composition of immune cells is ill-defined. Here, we aimed at evaluating the levels and composition of infiltrating immune cells in kidney grafts. We used CIBERSORT, an established algorithm, to estimate the proportions of 22 immune cell types based on gene expression profiles. We found that non-rejecting kidney grafts were characteristic with high rates of M2 macrophages and resting mast cells. The proportion of M1 macrophages and activated NK cells were increased in antibody-mediated rejection (ABMR). In T cell-mediated rejection (TCMR), a significant increase in CD8 T cell and γδT cell infiltration was observed. CD8 positive T cells were dramatically increased in mixed-ABMR/TCMR. Then, the function of ABMR and TCMR prognostic molecular biomarkers were identified. Finally, we described the gene expression of molecular markers for ABMR diagnosis was elevated and related to the ratio of monocytes and M1 macrophages in ABMR biopsies, while the expression of TCMR diagnosis markers was increased too and positively correlated with γδT cells and activated CD4 memory T cells in TCMR biopsies. Our data suggest that CIBERSORT’s deconvolution analysis of gene expression data provides valuable information on the composition of immune cells in renal allografts.

MXD1 is a Potential Prognostic Biomarker and Correlated With Specific Molecular Change and Tumor Microenvironment Feature in Esophageal Squamous Cell Carcinoma.

Background: Identification of novel biomarkers is crucial for the diagnosis and treatment of esophageal squamous cell carcinoma (ESCC). This study aimed to reveal the clinical significance and molecular characteristics of MYC-associated factor X dimerization protein 1 (MXD1) in ESCC. Patients and methods: We collected 3 ESCC cohorts to investigate the effect of MXD1 on clinical outcomes. In addition, we compared and analyzed the possible transcription changes between MXD1-low and MXD1-high ESCC patients using bioinformatics. Moreover, immunohistochemical analysis was conducted to confirm the potential impact of MXD1 on the prognosis and tumor immune microenvironment (TIME). Results: MXD1 messenger RNA (mRNA) expression was significantly lower in tumors than in normal tissues. Low expression of MXD1 in ESCC was associated with a more aggressive tumor stage and worse prognosis at both the mRNA and protein levels. Moreover, MXD1-low ESCC showed upregulation of epithelial–mesenchymal transition and extracellular matrix-related gene sets, and significantly higher NFE2L2 and KIAA1324L mutation frequencies. In contrast, MXD1-high ESCC showed upregulation of tumor differentiation and immune-related gene sets. Furthermore, the CIBERSORT approach showed that high expression of MXD1 was associated with a higher proportion of neutrophils but a lower proportion of M2 macrophages. At the protein level, MXD1 expression was positively correlated with programmed cell death 1 ligand 1 (PDL1) and CD8 expression. In silico analysis predicted that MXD1-high ESCC was more likely to benefit from immunotherapy. Conclusion: This study suggests that MXD1 is a crucial prognostic factor in ESCC patients and is closely associated with specific transcriptional changes and TIME features.

Synergistic Therapy of Celecoxib-Loaded Magnetism-Responsive Hydrogel for Tendon Tissue Injuries

Tendon tissue injury is very common and always associated with pain, tissue swelling and even malformation if not treated on time. Traditional therapeutic strategies, such as cryotherapy, electrical therapy, ultrasound therapy and anti-inflammatory drug, are still unsatisfying. In this work, a synergistic therapy, based on the combination of celecoxib drug and pulsed electromagnetic field (PEMF) regimens, was developed for the treatment of tendon injury. This celecoxib-loaded magnetism-responsive hydrogel dressing (gelatin/Fe3O4/celecoxib) showed good biocompatibility and coordinated drug release behavior under the PEMF, which could effectively reduce the inflammatory reaction of macrophage cells with the incremental proportion of M2 macrophages at the injury site. CatWalk gait analysis further verified this synergistic effect of combination therapy for achieving the outstanding recovery of the injured tendon tissue. Thus, this magnetism-responsive hydrogel may represent a promising alternative strategy in clinics for promoting tendon healing.

Let-7d inhibits intratumoral macrophage M2 polarization and subsequent tumor angiogenesis by targeting IL-13 and IL-10.

The microRNA let-7d has been reported to be a tumor suppressor in renal cell carcinoma (RCC). Tumor-associated macrophages (TAM) are M2-polarized macrophages that can enhance tumor growth and angiogenesis in many human cancers. However, the role of let-7d in TAM-associated RCC progression remains elusive. First, we observed a strongly inverse correlation between let-7d expression and microvessel density in RCC tissues. Furthermore, the proliferation, migration, and tube formation of HUVECs were significantly inhibited by conditioned medium from a coculture system of the phorbol myristate acetate pretreated human THP-1 macrophages and let-7d-overexpressing RCC cells. Moreover, the proportion of M2 macrophages was significantly lower in the group that was cocultured with let-7d-overexpressing RCC cells. Subcutaneous xenografts formed by the injection of let-7d-overexpressing RCC cells together with THP-1 cells resulted in a significant decrease in the M2 macrophage ratio and microvessel density compared with those formed by the injection of control RCC cells with THP-1 cells. In silico and experimental analysis revealed interleukin-10 (IL-10) and IL-13 as let-7d target genes. Importantly, the addition of IL-10 and IL-13 counteracted the inhibitory effects of the conditioned medium from the coculture system with let-7d-overexpressing RCC cells in vitro. Additionally, overexpression of IL-10 and IL-13 reversed the effects of let-7d on macrophage M2 polarization and tumor angiogenesis in vivo. Finally, the expression of IL-10 and IL-13 were inversely correlated with the expression of let-7d in RCC clinical specimens. These results suggest that let-7d may inhibit intratumoral macrophage M2 polarization and subsequent tumor angiogenesis by targeting IL-10 and IL-13.

Integration of the Tumor Mutational Burden and Tumor Heterogeneity Identify an Immunological Subtype of Melanoma With Favorable Survival.

The tumor mutational burden (TMB) has been reported as a predictive marker of the response to immune checkpoint inhibition (ICI) therapy in previous melanoma clinical trials. However, the TMB alone is not sufficient to accurately predict immunotherapy benefit. Additional biomarkers are needed for better stratification of immunotherapy-sensitive patients. In the present study, mutation data and survival information of patients with melanoma were collected from several immunotherapy studies, and tumor heterogeneity was estimated using mutant-allele tumor heterogeneity (MATH). The benefit score was defined as the ratio between the TMB and tumor heterogeneity, and optimal critical values were selected to group patients and evaluate their response to ICI treatment. The benefit score significantly improved the performance of stratifying the overall survival of patients compared with the TMB alone as a predictor in two independent cohorts (p = 0.0068 vs. p = 0.1 and p = 0.045 vs. p = 0.13), in which patients were treated with Ipilimumab and Nivolumab, respectively. In another cohort of patients with melanoma receiving mixed ICI treatment, the benefit score was also positively associated with higher overall survival (p = 0.022) and outperformed the TMB alone, with a significance of p = 0.089. The benefit score showed a positive correlation with clonal TMB, a reported immunotherapy marker, and exceeded it in immunotherapy response prediction. Besides, a high benefit score was found to be associated with higher proportions of natural killer cells, lower proportions of M2 macrophages and elevated CD8 T cells, all of which favor ICI therapy. In summary, tumor heterogeneity combined with the TMB showed superior efficacy in predicting the response to ICI therapy. This might further help to delineate the mechanisms of immunotherapy in patients with melanoma.