Proportion Of M1 Research Articles

Kallikrein-related peptidase 10 predicts prognosis and mediates tumor immunomodulation in colorectal cancer

The incidence and mortality rates of colorectal cancer (CRC) have significantly increased in recent years. It has been shown that early diagnosis of CRC improves the five-year survival of patients compared to late diagnosis, as patients with stage I disease have a five-year survival rate as high as 90 %. Through bioinformatics analysis, we identified Kallikrein 10 (KLK10), a member of the Kallikrein family, as a reliable predictor of CRC progression, particularly in patients with early-stage CRC. Furthermore, single-cell analysis revealed that KLK10 was highly expressed in tumor and partial immune cells. Analysis of the biological functions of KLK10 using the Kyoto encyclopedia of genes and genomes and gene ontology indicated that KLK10 plays a role in the proliferation and differentiation of cancer cells, along with the maintenance of tumor function and immune regulation, explicitly by T cells and macrophages. EdU cell proliferation staining, plate clone formation assay, and cell scratch assay demonstrated that KLK10 inhibition by siRNA affected the proliferation and migration of CRC cells. Cell cycle detection by flow cytometry demonstrated that KLK10 inhibition led to cell cycle arrest in the G1 phase. In addition, the proportion of M1 and M2 macrophages in 45 tumor specimens was analyzed by immunohistochemistry, the proportion of CD4+ T cells and CD8+ T cells in plasma was identified by flow cytometry, and their correlation with KLK10 was analyzed. The effects of KLK10 on T cells and macrophages were verified in independent cell experiments. The results revealed that KLK10 also activates CD4+ T cells, mediating M2-type macrophage polarization.

Characterization and identification of primarily cultured astrocytes and microglia

The aim of this study was to investigate the growth characteristics of primarily cultured astrocytes and microglia of different generations and then optimize the method for obtaining primary astrocytes and microglia effectively. Primarily cultured microglia were isolated and purified from the cortices of neonatal mice. The proliferation curve of mixed glia cells was measured by Cell Counting Kit-8 (CCK-8) assay, the proportion of astrocytes and microglia was detected by flow cytometry, and the polarization of the two types of glia cells was identified by immunofluorescence staining. Cell growth results showed that the mixed glia cells of P0 and P1 generation had the best proliferative activity; 97.3% of the high purity microglia could be obtained by mechanical shaking at 170 r/min for 30 min, and there was no significant difference in the morphology of ionized calcium-binding adapter molecule 1 (Iba-1) positive microglia and the proportion of M1 and M2 phenotype among the P0, P1 and P2 generations of microglia isolated by the above methods. Moreover, 95.7 % of the high purity astrocytes could be obtained by astrocyte cell surface antigen-2 (ACSA-2) magnetic beads separation, and there was no significant difference in the morphology of glial fibrillary acidic protein (GFAP) positive astrocyte and the proportion of A1 and A2 phenotype among the P0, P1 and P2 generations of astrocyte isolated by the above methods. Taken together, this study observed the growth characteristics of primarily cultured microglia and astrocyte in vitro, and then proved the best generations for purifying microglia and astrocytes. Finally, we optimized the methods of obtaining microglia and astrocyte, and verified that continuous culture within 2 generations will not affect the functional phenotypes of glia cells. These results provide technical support for studying the molecular mechanism of inflammation-associated diseases in nervous system.

Single-cell transcriptomes reveal the heterogeneity and microenvironment of vestibular schwannoma.

Vestibular schwannoma (VS) is the most common benign tumor in the cerebellopontine angle and internal auditory canal. Illustrating the heterogeneous cellular components of VS could provide insights into its various growth patterns. Single-cell RNA sequencing was used to profile transcriptomes from 7 VS samples and 2 normal nerves. Multiplex immunofluorescence was employed to verify the data set results. Bulk RNA sequencing was conducted on 5 normal nerves and 44 VS samples to generate a prediction model for VS growth. A total of 83 611 cells were annotated as 14 distinct cell types. We uncovered the heterogeneity in distinct VS tumors. A subset of Schwann cells with the vascular endothelial growth factor biomarker was significantly associated with fast VS growth through mRNA catabolism and peptide biosynthesis. The macrophages in the normal nerves were largely of the M2 phenotype, while no significant differences in the proportions of M1 and M2 macrophages were found between slow-growing and fast-growing VS. The normal spatial distribution of fibroblasts and vascular cells was destroyed in VS. The communications between Schwann cells and vascular cells were strengthened in VS compared with those in the normal nerve. Three cell clusters were significantly associated with fast VS growth and could refine the growth classification in bulk RNA. Our findings offer novel insights into the VS microenvironment at the single-cell level. It may enhance our understanding of the different clinical phenotypes of VS and help predict growth characteristics. Molecular subtypes should be included in the treatment considerations.

Exploration of the mechanism of reinfusion of fresh autologous blood in type 2 diabetes mice to induce macrophage polarization and inhibit erythrocyte damage.

Type 2 diabetes triggers an inflammatory response that can damage red blood cells. M2 macrophages have inhibitory effects on inflammation, and play an important role in tissue damage repair and fibrosis. Autologous blood transfusion has the potential to inhibit red blood cell damage by mediating macrophage polarization. Swiss mice were used to establish a suitable type 2 diabetes model, and autologous blood transfusion was carried out. The mice were killed, the blood of the mice was collected and CD14+ monocytes were sorted. The expression levels of phenotypic molecules CD16, CD32 and CD206 in CD14+ monocytes were analyzed by flow cytometry. The proportion of M1 and M2 macrophages were analyzed by flow cytometry. The Q value, P50 , 2,3-diphosphoglycerate and Na+ -K+ -ATPase of red blood cells were detected. The red blood cell osmotic fragility test analyzed the red blood cell osmotic fragility. Western blot analysis was used to analyze the expression changes of erythrocyte surface membrane proteins or transporters erythrocyte membrane protein band 4.1, sphingosine-1-phosphate, glycolipid transfer protein and signal peptide peptidase-like 2A. Autologous blood transfusion induced a significant increase in the number of macrophages. The state and capacity of blood cells improved with autologous blood transfusion. Reinfusion of fresh autologous blood in type 2 diabetes mice made erythrocytes shrink. The expression of erythrocyte-related proteins proved that the erythrocyte injury in the reinfusion of fresh autologous blood + type 2 diabetes group was significantly reduced. The reinfusion of fresh autologous blood into the body of patients with type 2 diabetes can induce macrophage polarization to M2, thereby inhibiting red blood cell damage.

WITHDRAWN: Exploration of the mechanism of reinfusion of fresh autologous blood in type 2 diabetic body to induce macrophage polarization and inhibit erythrocyte damage

BackgroundType 2 diabetes (T2D) triggers an inflammatory response that can damage red blood cells. M2 macrophages have inhibitory effects on inflammation and play an important role in tissue damage repair and fibrosis. Autologous blood transfusion has the potential to inhibit red blood cell damage by mediating macrophage polarization. MethodsSwiss mice were used to establish a suitable type 2 diabetes model and autologous blood transfusion was performed. The mice were executed, the blood of the mice was collected, and CD14+ monocytes were sorted. The expression levels of phenotypic molecules CD16, CD32 and CD206 in CD14+ monocytes were analyzed by flow cytometry. The proportion of M1 and M2 macrophages were analyzed by flow cytometry. The Q value, P50, 2,3-DPG and Na+-K+-ATPase of red blood cells were detected. The red blood cell osmotic fragility test analyzed the RBC osmotic fragility. Western Blot analysis was used to analyze the expression changes of erythrocyte surface membrane proteins or transporters EPB41, S1P, GLTP and SPPL2A. ResultsAutologous blood transfusion induced a significant increase in the number of macrophages. The state and capacity of blood cells improved with autologous blood transfusion. Reinfusion of fresh autologous blood in T2D body made erythrocytes shrank. The expression of erythrocyte-related proteins proved that the erythrocyte injury in the Fresh+T2D group was significantly reduced. ConclusionThe reinfusion of fresh autologous blood into the body of patients with type 2 diabetes can induce macrophage polarization to M2, thereby inhibiting red blood cell damage.

Abstract P065: Effects of metformin on breast tissue inflammation in premenopausal women with components of metabolic syndrome

Abstract Background: Obesity, with increasing worldwide prevalence, is associated with increased breast cancer burden. The association is attributed to multiple metabolic disturbances including chronic inflammation due to dysfunctional adipose tissue. Features of local breast adipose tissue inflammation such as macrophage infiltration and an enriched pro-inflammatory gene signature were recently reported in mouse models of obesity and in women with high adiposity or metabolic disorders. Strategies that can reduce obesity-induced chronic inflammation may lead to reduction of breast cancer risk. Metformin, a widely used anti-diabetic drug, exerts favorable effects on multiple metabolic disturbances. This study aims to evaluate the clinical effects of metformin on breast tissue inflammation. Methods: Macrophage infiltration and polarization were determined in breast core needle biopsies collected at baseline and 6 months after agent intervention from a Phase II randomized, double-blind, placebo-controlled trial of metformin in premenopausal women with components of metabolic syndrome. Macrophage infiltration was assessed using a pan macrophage marker (CD68) by immunohistochemistry (IHC). M1 and M2 macrophages were assessed using CD40 and CD206 surface markers, respectively, by IHC. The primary endpoint is the change in macrophage density in breast adipose tissue. Secondary endpoints include the change in macrophage density in breast stroma and epithelium tissues, the proportion of M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages in breast adipose, stroma, and epithelium tissues. Results: Baseline biopsies from 76 participants (40 in the metformin arm and 36 in the placebo arm) were available for CD68 analysis. The baseline CD68 density was 22.48 ± 3.25, 67.26 ± 9.68, 418.81± 71.02 (mean±SE) per mm2 in breast adipose, stroma, and epithelium tissues, respectively. Biopsies from 71 participants (34 in the metformin arm and 37 in the placebo arm) were available for CD68 analysis at 6 months. Comparing to placebo, metformin intervention led to a significant reduction in CD68 density in breast adipose tissue (p = 0.01) but did not change the CD68 density in breast epithelium and stroma tissues. Conclusion: Metformin intervention resulted in favorable changes in macrophage infiltration in breast adipose tissue in premenopausal women with component of metabolic syndrome. Studies are ongoing to evaluate the effects of metformin on macrophage polarization. Citation Format: Liane E. Pinto, Sara Centuori, Jose Guillen-Rodriguez, Denise J. Roe, Edgar Tapia, Pavani Chalasani, H-H. Sherry Chow. Effects of metformin on breast tissue inflammation in premenopausal women with components of metabolic syndrome. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P065.

“M1/M2” Muscularis Macrophages Are Associated with Reduction of Interstitial Cells of Cajal and Glial Cells in Achalasia

Background and AimsSeveral studies showed muscularis macrophages (MMφ) are associated with GI motility disorders. The purpose of this study was to preliminary explore the association between MMφ and achalasia.MethodsTissue samples of the lower esophageal sphincter (LES) high‐pressure zone were obtained from 27 achalasia patients and 10 controls. Immunohistochemistry for MMφ, interstitial cells of Cajal (ICC), neuronal nitric oxide synthase (nNOS), and glial cells were conducted. Histological characteristics were compared between groups, and correlation analysis was performed.ResultsFewer ICC was found in achalasia compared with controls (P = 0.018), and the level of M1 macrophages was higher than that in controls no matter in terms of the number or the proportion of M1(P = 0.026 for M1 and 0.037 for M1/MMφ). Statistical differences were found between two groups in terms of proportion of M2 and ratio of M1 to M2 (P = 0.048 for M2/ MMφ and < 0.001 for M1/M2). For the correlation analysis, significant correlations were detected between levels of nNOS, ICC, and glial cells in patients with achalasia (P = 0.026 for nNOS and ICC, 0.001 for nNOS and glial cells, 0.019 for ICC and glial cells). There were significant correlations between M2/MMφ and levels of ICC (P = 0.019), glial cells (P = 0.004), and nNOS (P = 0.135).ConclusionPatients with achalasia had a higher level of M1/M2 ratio in LES and significant correlations were found between M2/MMφ and numbers of ICC and glial cells, which suggested that MMφ were probably associated with occurrence and development of achalasia.

Imbalanced M1 and M2 Macrophage Polarization in Bone Marrow Provokes Impairment of the Hematopoietic Microenvironment in a Mouse Model of Hemophagocytic Lymphohistiocytosis.

Lipopolysaccharide (LPS) treatment induced hemophagocytic lymphohistiocytosis in senescence-accelerated mice (SAMP1/TA-1), but not in senescence-resistant control mice (SAMR1). SAMP1/TA-1 treated with LPS exhibited functional impairment of the hematopoietic microenvironment, which disrupted the dynamics of hematopoiesis. Macrophages are a major component of the bone marrow (BM) hematopoietic microenvironment, which regulates hematopoiesis. Qualitative and quantitative changes in activated macrophages in LPS-treated SAMP1/TA-1 are thought to contribute to the functional deterioration of the hematopoietic microenvironment. Thus, we examined the polarization of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages, and the dynamics of macrophage production in the BM of SAMP1/TA-1 and SAMR1 after LPS treatment. After LPS treatment, the proportions of M1 and M2 macrophages and the numbers of macrophage progenitor (CFU-M) cells increased in both SAMP1/TA-1 and SAMR1. However, compared to the SAMR1, the increase in the M1 macrophage proportion was prolonged, and the increase in the M2 macrophage proportion was delayed. The increase in the number of CFU-M cells was prolonged in SAMP1/TA-1 after LPS treatment. In addition, the levels of transcripts encoding an M1 macrophage-inducing cytokine (interferon-γ) and macrophage colony-stimulating factor were markedly increased, and the increases in the levels of transcripts encoding M2 macrophage-inducing cytokines (interleukin (IL)-4, IL-10, and IL-13) were delayed in SAMP1/TA-1 when compared to SAMR1. Our results suggest that LPS treatment led to the severely imbalanced polarization of activated M1/M2 macrophages accompanied by a prolonged increase in macrophage production in the BM of SAMP1/TA-1, which led to the impairment of the hematopoietic microenvironment, and disrupted the dynamics of hematopoiesis.

Correlation Between Immune-Related Genes and Tumor-Infiltrating Immune Cells With the Efficacy of Neoadjuvant Chemotherapy for Breast Cancer.

Background: In the absence of targeted therapy or clear clinically relevant biomarkers, neoadjuvant chemotherapy (NAC) is still the standard neoadjuvant systemic therapy for breast cancer. Among the many biomarkers predicting the efficacy of NAC, immune-related biomarkers, such as immune-related genes and tumor-infiltrating lymphocytes (TILs), play a key role. Methods: We analyzed gene expression from several datasets in the Gene Expression Omnibus (GEO) database and evaluated the relative proportion of immune cells using the CIBERSORT method. In addition, mIHC/IF detection was performed on clinical surgical specimens of triple-negative breast cancer patients after NAC. Results: We obtained seven immune-related genes, namely, CXCL1, CXCL9, CXCL10, CXCL11, IDO1, IFNG, and ORM1 with higher expression in the pathological complete response (pCR) group than in the non-pCR group. In the pCR group, the levels of M1 and γδT macrophages were higher, while those of the M2 macrophages and mast cells were lower. After NAC, the proportions of M1, γδT cells, and resting CD4 memory T cells were increased, while the proportions of natural killer cells and dendritic cells were decreased with downregulated immune-related genes. The results of mIHC/IF detection and the prognostic information of corresponding clinical surgical specimens showed the correlation of proportions of natural killer cells, CD8-positive T cells, and macrophages with different disease-free survival outcomes. Conclusion: The immune-related genes and immune cells of different subtypes in the tumor microenvironment are correlated with the response to NAC in breast cancer, and the interaction between TILs and NAC highlights the significance of combining NAC with immunotherapy to achieve better clinical benefits.

Clinical significance of detection of mononuclear phagocyte subsets in blood and bronchoalveolar lavage fluid (BALF) in pulmonary sarcoidosis.

This study aimed to investigate the clinical significance of the detection of mononuclear phagocytes subsets in pulmonary sarcoidosis blood and bronchoalveolar lavage fluid (BALF). For this purpose, a total of 52 patients with pulmonary sarcoidosis were selected as the study group, 52 healthy people served as the "NC Group a" (peripheral blood mononuclear cell control group), 47 patients with chronic cough and no pulmonary sarcoidosis who underwent bronchoscopy were used as "control group b" (alveolar lavage fluid macrophage control group). Fasting peripheral blood and BALF were collected, and flow cytometry was used to detect monocytes and macrophage subpopulations. The monocytes and macrophage subpopulations of the study group were compared before and after treatment. The results showed that the proportion of CD14++CD16- subgroup of patients with pulmonary sarcoidosis was lower than that of healthy people (74.21±4.10% vs 84.32±4.76%); The proportion of CD14++CD16+ subgroups of patients with pulmonary sarcoidosis was higher than that of healthy people (7.42±4.08% vs 3.95±1.94%); The proportion of CD14+CD16++ subgroups of patients with pulmonary sarcoidosis was higher than that of healthy people in the control group, but the difference was not significant. After 2 months of treatment, the proportion of CD14++CD16- subgroups in peripheral blood mononuclear cells increased, and the proportion of CD14++CD16+ subgroups decreased. The proportion of M1 in patients with pulmonary sarcoidosis was lower than that in patients with non-pulmonary nodules (24.32±11.36% vs 47.03±13.86%); the proportion of M2 in patients with pulmonary sarcoidosis was higher than the proportion of M2 in patients with non-pulmonary nodules (75.40±10.23% vs 52.53±12.01%). After treatment, the proportion of M1 of BALF macrophages in patients with pulmonary sarcoidosis was increased (P<0.05), and the proportion of M2 was reduced (P<0.05). In general, detection of changes in peripheral blood mononuclear cell subpopulations and BALF macrophage subpopulations in patients with pulmonary sarcoidosis has certain clinical significance for the treatment.

Characterisation of Macrophage Polarisation in Mice Infected with Ninoa Strain of Trypanosoma cruzi.

Macrophages (MΦ) play a key role in the development of the protective immune response against Trypanosoma cruzi infection. To determine the role of MΦ subtypes M1 and M2 in the development of immunity against the Mexican strain of T. cruzi (Ninoa strain), we have analysed in a time course the infection and characterised the M1 and M2 subtypes in two mouse models, BALB/c and C57BL/6. After infection, BALB/c mice developed an increased blood parasite load and the parasites were cleared from the blood one week later than in C57BL/6 mice. However, similar cellular infiltrate and cardiac alterations were observed between BALB/c and C57BL/6 mice. At 36 days, the T. cruzi infection differentially modulated the expression of immune cells, and both the BALB/c and C57BL/6 mice significantly reduced TCD4+ cells. However, BALB/c mice produced significantly more TCD8+ than C57BL/6 mice in the spleen and lymph nodes. Furthermore, BALB/c mice produce significantly more MΦ in the spleen, while C57BL/6 produce similar levels to uninfected mice. The M1 MΦ ratio increased significantly at 3–5 days post-infection (dpi), but then decreased slightly. On the contrary, the M2 MΦ were low at the beginning of the infection, but the proportion of M1 and M2 MΦ at 36 dpi was similar. Importantly, the MΦ subtypes M2c and M2d significantly increased the induction of tissue repair by the end of the acute phase of the infection. These results indicate that the Ninoa strain has developed strategies to modulate the immune response, with fine differences depending on the genetic background of the host.

Transforming Growth Factor-β1 Promotes M1 Alveolar Macrophage Polarization in Acute Lung Injury by Up-Regulating DNMT1 to Mediate the microRNA-124/PELI1/IRF5 Axis.

ObjectiveMacrophages function as key orchestrators in the pathogenesis of acute lung injury (ALI). The current study sets out to investigate the molecular mechanism of transforming growth factor-β (TGFβ1) in the regulation of M1 alveolar macrophage polarization in ALI by modulating DNA methyltransferase 1 (DNMT1), along with the microRNA (miR)-124/Pellino 1 (PELI1)/interferon regulatory factor 5 (IRF5) axis.MethodsFirst, ALI mouse models were established, and the proportion of M1 and M2 macrophages in mouse lung tissues was detected using flow cytometry. The targeting relationship between miR-124 and PELI1 was verified with the help of a dual luciferase gene reporter assay. Following TGFβ1 knockdown, RT-qPCR and Western blot assay were performed to analyze the expression patterns of TGFβ1, DNMT1, miR-124, and PELI1 and M1/M2 polarization markers in the lung tissues of ALI mice. Immunofluorescence was further employed to detect nuclear translocation of IRF5 in macrophages.ResultsThe polarization of M1 macrophages was found to be positively correlated with the severity of lung injury. TGFβ1, DNMT1, PELI1 were highly expressed, while miR-124 was down-regulated in ALI mice, and IRF5 was primarily distributed in the nucleus. TGFβ1 promoted the polarization of M1 alveolar macrophages by up-regulating DNMT1. Furthermore, DNMT1 down-regulated the expression of miR-124, which led to enhancement of M1 alveolar macrophage polarization. Meanwhile, over-expression of miR-124 inhibited the nuclear translocation of IRF5 and suppressed M1 alveolar macrophage polarization. On the other hand, over-expression of PELI1 reversed the above trends.ConclusionCollectively, our findings indicated that TGFβ1 can promote the expression of DNMT1, which down-regulates miR-124 to activate PELI1 and nuclear translocation of IRF5, thereby aggravating ALI in mice.

MUC1 Mitigates Renal Injury and Inflammation in Endotoxin-Induced Acute Kidney Injury by Inhibiting the TLR4-MD2 Axis and Reducing Pro-inflammatory Macrophages Infiltration.

Sepsis is the leading cause of acute kidney injury (AKI) in critical care patients. A cornerstone of sepsis-associated AKI is dysregulated inflammation driven by excessive activation of Toll-like receptor 4 (TLR4) pathway. MUC1, a membrane-bound mucin expressed in both epithelial tubular cells and renal macrophages, has been shown to be involved in the regulation of TLRs. Therefore, we hypothesized that MUC1 could mitigate the renal inflammatory response to TLR4 activation. To test this hypothesis, we used a murine model of endotoxin-induced AKI by intraperitoneal injection of LPS. We showed that Muc1-/- mice have a more severe renal dysfunction, an increased activation of the tissular NF-kB pathway and secreted more pro inflammatory cytokines compare to Muc1+/+ mice. By flow cytometry, we observed that the proportion of M1 (pro-inflammatory) macrophages in the kidneys of Muc1-/- mice was significantly increased. In human and murine primary macrophages, we showed that MUC1 is only induced in M1 type macrophages and that macrophages derived from Muc1-/- mice secreted more pro-inflammatory cytokines. Eventually, in HEK293 cells, we showed that MUC1 cytosolic domain (CT) seems necessary for the negative regulation of TLR4 by proximity ligation assay, MUC1-CT is in close relationship with TLR4 and acts as a competitive inhibitor of the recruitment of MYD88. Overall our results support that in the context of endotoxin-induced AKI, MUC1 plays a significant role in controlling disease severity by regulating negatively the TLR4-MD2 axis.

Circular RNA hsa_circ_0005567 overexpression promotes M2 type macrophage polarization through miR-492/SOCS2 axis to inhibit osteoarthritis progression

ABSTRACT Synovial macrophage polarization is essential for osteoarthritis (OA) development. Our study aims to investigate the underlying function and the molecular mechanisms of hsa_circ_0005567 in macrophage polarization. Circular RNA (CircRNA), microRNA (miRNA), and mRNA expression levels were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR). RNA pull down, luciferase reporter were employed to test the interaction between miR-492 and hsa_circ_0005567/suppressors of cytokine signaling 2 (SOCS2). Ectopic overexpression was used to evaluate the function of hsa_circ_0005567. The supernatant of THP-1 cells was used to incubate chondrocytes. Cell Counting Kit-8 (CCK-8) and flow cytometry were conducted to determine cell viability, proportion of M1 or M2 macrophages and apoptotic rate. The results showed that the hsa_circ_0005567 expression level was downregulated in the synovial tissues of osteoarthritis patients. Overexpression of hsa_circ_0005567 inhibited M1 macrophage polarization, and promoted M2 macrophage polarization. Hsa_circ_0005567 was proved to be a molecular sponge for miR-492, and SOCS2 was verified as the target of miR-492. MiR-492 mimic could reverse the effect of hsa_circ_0005567 overexpression on macrophage polarization. Besides, the supernatant from LPS-treated THP-1 macrophage significantly decreased chondrocytes cell viability and increased cell apoptosis ratio, which was reversed by hsa_circ_0005567 overexpression. In conclusion, hsa_circ_0005567 overexpression promoted M2 macrophage polarization through miR-492/SOCS2 axis to reduced chondrocyte apoptosis, which could inhibit osteoarthritis progression.

Emerging role of targeting macrophages in rheumatoid arthritis: Focus on polarization, metabolism and apoptosis.

Macrophages maintain a dynamic balance in physiology. Various known or unknown microenvironmental signals influence the polarization, activation and death of macrophages, which creates an imbalance that leads to disease. Rheumatoid arthritis (RA) is characterized by the massive infiltration of a variety of chronic inflammatory cells in synovia. Abundant activated macrophages found in RA synovia are an early hallmark of RA, and the number of these macrophages can be decreased after effective treatment. In RA, the proportion of M1 (pro‐inflammatory macrophages) is higher than that of M2 (anti‐inflammatory macrophages). The increased pro‐inflammatory ability of macrophages is related to their excessive activation and proliferation as well as an enhanced anti‐apoptosis ability. At present, there are no clinical therapies specific to macrophages in RA. Understanding the mechanisms and functional consequences of the heterogeneity of macrophages will aid in confirming their potential role in inflammation development. This review will outline RA‐related macrophage properties (focus on polarization, metabolism and apoptosis) as well as the origin of macrophages. The molecular mechanisms that drive macrophage properties also be elucidated to identify novel therapeutic targets for RA and other autoimmune disease.

Nonlinear response to cancer nanotherapy due to macrophage interactions revealed by mathematical modeling and evaluated in a murine model via CRISPR-modulated macrophage polarization.

Tumor-associated macrophages (TAMs) have been shown to both aid and hinder tumor growth, with patient outcomes potentially hinging on the proportion of M1, pro-inflammatory/growth-inhibiting, to M2, growth-supporting, phenotypes. Strategies to stimulate tumor regression by promoting polarization to M1 are a novel approach that harnesses the immune system to enhance therapeutic outcomes, including chemotherapy. We recently found that nanotherapy with mesoporous particles loaded with albumin-bound paclitaxel (MSV-nab-PTX) promotes macrophage polarization towards M1 in breast cancer liver metastases (BCLM). However, it remains unclear to what extent tumor regression can be maximized based on modulation of the macrophage phenotype, especially for poorly perfused tumors such as BCLM. Here, for the first time, a CRISPR system is employed to permanently modulate macrophage polarization in a controlled in vitro setting. This enables the design of 3D co-culture experiments mimicking the BCLM hypovascularized environment with various ratios of polarized macrophages. We implement a mathematical framework to evaluate nanoparticle-mediated chemotherapy in conjunction with TAM polarization. The response is predicted to be not linearly dependent on the M1:M2 ratio. To investigate this phenomenon, the response is simulated via the model for a variety of M1:M2 ratios. The modeling indicates that polarization to an all-M1 population may be less effective than a combination of both M1 and M2. Experimental results with the CRISPR system confirm this model-driven hypothesis. Altogether, this study indicates that response to nanoparticle-mediated chemotherapy targeting poorly perfused tumors may benefit from a fine-tuned M1:M2 ratio that maintains both phenotypes in the tumor microenvironment during treatment.

Human cytomegalovirus IE2 protein regulates macrophage-mediated immune escape by upregulating GRB2 expression in UL122 genetically modified mice.

Although cytomegalovirus (HCMV) infection is asymptomatic in healthy individuals, the virus can remain latent for many years due to its ability to evade host immune surveillance. However, reactivation of HCMV can lead to life-threatening disease. Recent studies have shown that HCMV infection mediates immune escape by regulating macrophage activity, although the role of the HCMV-encoded IE2 protein is unclear. A ul122 transgenic mouse model was created to stably expresses the IE2 protein, and the proportion of M1 and M2 macrophage populations in their spleen and bone marrow was compared to that in wild-type controls. In addition, the phagocytic function of the macrophages was evaluated in terms of neutral red dye uptake. Spleen and bone marrow macrophages in IE2-expressing mice were mainly of the M2 phenotype and displayed enhanced phagocytic function compared to that in control mice. The relative levels of expression of macrophage-related GRB2 and of IL-4, IFN-γ, IL-13, and TNF-α were also analyzed in the spleen and bone marrow of the two groups. The IE2-expressing mice had increased expression of GRB2 and increased expression of the M2-related cytokines IL-4 and IL-13. Taken together, the current results suggest that HCMV IE2 polarizes the host macrophages to the M2 type via a GRB2/IL-4-related pathway, which enables long-term survival of the virus in the host.

Decellularized brain matrix enhances macrophage polarization and functional improvements in rat spinal cord injury

Spinal cord injury (SCI) is a devastating lesion lacking effective treatment options currently available in clinics. The inflammatory process exacerbates the extent of the lesion through a secondary injury mechanism, where proinflammatory classically activated macrophages (M1) are prevalent at the lesion site. However, the polarized alternatively activated anti-inflammatory macrophages (M2) are known to play an important role in wound healing and regeneration following SCI. Herein, we introduce porcine brain decellularized extracellular matrix (dECM) to modulate the macrophages in the injured spinal cord. The hydrogels with collagen and dECM at various dECM concentrations (1, 5, and 8 mg/ml) were used to cultivate primary macrophages and neurons. The dECM hydrogels were shown to promote the polarization of macrophages toward M2 phase and the neurite outgrowth of cortical and hippocampal neurons. When the dECM hydrogels were applied to rat SCI models, the proportion of M1 and M2 macrophages in the injured spinal cord was substantially altered. When received dECM concetration of 5 mg/ml, the expression of molecules associated with M2 (CD206, arginase1, and IL-10) was significantly increased. Consistently, the population of total macrophages and cavity area were substantially reduced in the dECM-treated groups. As a result, the locomotor functions of injured spinal cord, as assessed by BBB and ladder scoring, were significantly improved. Collectively, the porcine brain dECM with optimal concentration promotes functional recovery in SCI models through the activation of M2 macrophages, suggesting the promising use of the engineered hydrogels in the treatment of acute SCI. Statement of significanceSpinal cord injury (SCI) is a devastating lesion, lacking effective treatment options currently available in clinics. Here we delineated that the treatment of injured spinal cord with porcine brain decellularized matrix-based hydrogels for the first time, and could modulate the macrophage polarization and the ultimate functional recovery. When appropriate formulations were applied to a contused spinal cord model in rats, the decellularized matrix hydrogels shifted the macrophages to polarize to pro-regenerative M2 phenotype, decreased the size of lesion cavity, and finally promoted the locomotor functions until 8 weeks following the injury. We consider this work can significantly augment the matrix(biomaterial)-based therapeutic options, as an alternative to drug or cell-free approaches, for the treatment of acute injury of spinal cord.

Silencing of lncRNA SNHG20 delays the progression of nonalcoholic fatty liver disease to hepatocellular carcinoma via regulating liver Kupffer cells polarization.

This study aims to investigate the role of long noncoding RNA SNHG20 in the progression of nonalcoholic fatty liver disease (NALFD) to hepatocellular carcinoma (HCC), and to elucidate whether polarization of Kupffer cells (KCs, liver macrophages) was involved in this process. Mouse NALFD was induced by 16 weeks of high-fat diet (HFD) feeding. Mouse NALFD-HCC was induced by 36 weeks of HFD feeding (from 1 week to 36 weeks) and 20 weeks of diethyl nitrosamine (DEN) administration (from 17 weeks to 36 weeks). The LV-shRNA- and LV-sh-SNHG20-infected RAW264.7 cells were injected into the NALFD mice followed by DEN treatment to evaluate the role of SNHG20 in regulating the progression of NALFD to HCC in mice. The proportion of M1 and M2 macrophages was determined by flow cytometry. The levels of M1-related inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α and M2-related Arg-1 and interleukin (IL)-10 were also examined. SNHG20 expression was decreased in NALFD but increased in NALFD-HCC, both in human and experimental mouse livers. Furthermore, human and mouse NALFD-HCC KCs displayed decreased M1/M2 ratio compared with NALFD KCs. Moreover, SNHG20 overexpression induced M2 polarization through activating STAT6, whereas SNHG20 silencing suppressed M1 polarization in RAW264.7 macrophages and delayed the progression of NALFD to HCC in mice. SNHG20 may facilitate the progression of NALFD to HCC via inducing liver KCs M2 polarization via STAT6 activation.

Nanomedicine-driven neuropathic pain relief in a rat model is associated with macrophage polarity and mast cell activation

We explored the immune neuropathology underlying multi-day relief from neuropathic pain in a rat model initiated at the sciatic nerve, by using a nanoemulsion-based nanomedicine as a biological probe. The nanomedicine is theranostic: both therapeutic (containing celecoxib drug) and diagnostic (containing near-infrared fluorescent (NIRF) dye) and is small enough to be phagocytosed by circulating monocytes. We show that pain-like behavior reaches a plateau of maximum hypersensitivity 8 days post-surgery, and is the rationale for intravenous delivery at this time-point. Pain relief is evident within 24 h, lasting approximately 6 days. The ipsilateral sciatic nerve and associated L4 and L5 dorsal root ganglia (DRG) tissue of both nanomedicine and control (nanoemulsion without drug) treated animals was investigated by immunofluorescence and confocal microscopy at the peak of pain relief (day-12 post-surgery), and when pain-like hypersensitivity returns (day-18 post-surgery). At day-12, a significant reduction of infiltrating macrophages, mast cells and mast cell degranulation was observed at the sciatic nerve following treatment. In the DRG, there was no effect of treatment at both day-12 and day-18. Conversely, at the DRG, there is a significant increase in macrophage infiltration and mast cell degranulation at day-18. The treatment effect on immune pathology in the sciatic nerve was investigated further by assessing the expression of macrophage cyclooxygenase-2 (COX-2)—the drug target—and extracellular prostaglandin E2 (PGE2), as well as the proportion of M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages. At day-12, there is a significant reduction of COX-2 positive macrophages, extracellular PGE2, and a striking reversal of macrophage polarity. At day-18, these measures revert to levels observed in control-treated animals. Here we present a new paradigm of immune neuropathology research, by employing a nanomedicine to target a mechanism of neuropathic pain—resulting in long-lasting pain relief--whilst revealing novel immune pathology at the injured nerve and associated DRG.