Macrophage Expression Research Articles

High glucose promotes lipopolysaccharide-induced macrophage pyroptosis through GSDME O-GlcNAcylation.

The high glucose (HG) environment in diabetic periodontitis aggravates the damage of periodontal tissue. Pyroptosis has been shown to be positively correlated with the severity of periodontitis, including macrophage pyroptosis. O-GlcNAcylation is a posttranslational modification that is involved in the pathogenesis of periodontitis. However, whether HG regulates macrophage pyroptosis through O-GlcNAcylation remains uncertain. This study aimed to investigate the effect of HG on the O-GlcNAcylation level of a pyroptosis regulator GSDME in macrophages to further probe the mechanisms of diabetic periodontitis. Blood samples were collected from patients with diabetic periodontitis. THP-1 monocytes were induced to differentiate into macrophages by phorbol 12-myristate 13-acetate and then treated with HG to simulate periodontitis invitro. GSDME expression of blood samples and macrophages was measured by quantitative real-time PCR. Pyroptosis was assessed by propidium iodide staining, measurement of cell viability, cytotoxicity, protein levels of inflammation factors, and pyroptosis-related proteins. O-GlcNAcylation of GSDME was analyzed using co-immunoprecipitation (co-IP), IP, and western blot. The results showed that GSDME expression was elevated in patients with periodontitis and HG-treated macrophages. HG inhibited cell viability but increased LDH content, levels of IL-1β, IL-18, TNF-α, NLRP3, GSDMD, and Caspase-1, indicating that HG promoted pyroptosis of macrophages, which was reversed by GSDME knockdown. HG treatment increased O-GlcNAcylation in macrophages. Mechanically, GSDME interacted with OGT, and OGT knockdown suppressed O-GlcNAcylation of GSDME at Ser (S)339 site. Knockdown of OGT inhibited pyroptosis in HG-treated macrophages, while GSDME overexpression partially reversed this inhibition. HG treatment enhanced OGT-mediated GSDME O-GlcNAcylation, thereby augmenting pyroptosis in LPS-induced macrophages. These results may provide a novel sight for the treatment of periodontitis.

A novel cytoprotective organ perfusion platform for reconstructing homeostasis of DCD liver while alleviating IRI injury

AbstractPump is a vital component for expelling the perfusate in small animal isolated organ normothermic machine perfusion (NMP) systems whose flexible structure and rhythmic contraction play a crucial role in maintaining perfusion system homeostasis. However, the continuous extrusion forming with the rigid stationary shaft of the peristaltic pumps can damage cells, leading to metabolic disorders and eventual dysfunction of transplanted organs. Here, we developed a novel biomimetic blood‐gas system (BBGs) for preventing cell damage. This system mimics the cardiac cycle and features an adjustable inspiratory‐to‐expiratory (IE) ratio to mitigate acidosis caused by continuous oxygen inhalation. In our study, adipose stem cells (ADSCs) were cultured within the circulatory system for 10 min, 2, and 4 h. Compared to the peristaltic pump, the BBGs significantly reduced cell apoptosis and morphological injury while enhancing cell proliferation and adhesion. Additionally, when the supernatant from ADSCs was introduced to LPS‐induced macrophages for 24 h, the BBGs group demonstrated a more pronounced anti‐inflammatory effect, characterized by reduced M1 macrophage expression. Besides, with isolated rat livers from donation after circulatory death (DCD) perfusion with ADSCs for 6 h by the BBGs, we detected fewer apoptotic cells and a reduced inflammatory response, evidenced by down‐regulated TNF‐α expression. The development of BBGs demonstrates the feasibility of recreating physiological liquid–gas circulation in vitro, offering an alternative platform for isolated organ perfusion, especially for applications involving cell therapy.

Iron chelating, antioxidant, and anti-inflammatory properties of brazilin from Caesalpinia sappan Linn

BackgroundIron overload and inflammation are severe conditions that can lead to various chronic diseases. However, the current iron chelator drugs have their limitations. The phytochemical compounds from herbals, such as brazilin, the major active compound in Caesalpinia sappan Linn., have significant therapeutic potential in various chronic diseases. Our study was designed to examine the effect of brazilin on iron chelating properties, antioxidant activity in hepatocytes, and anti-inflammatory potential in macrophages. MethodsThis study focused on the isolation, purification, and evaluation of brazilin, the principal bioactive constituent found in C. sappan wood. Brazilin was extracted via methanol maceration followed by column chromatography purification. The purified compound was characterized using high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). The antioxidant potential of brazilin was assessed by in vitro assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazolin-6-sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). Furthermore, its cellular antioxidant activity was evaluated using hydrogen peroxide-induced oxidative stress in the hepatocellular carcinoma cell line (Huh-7). The iron-chelating capacity of brazilin was determined spectrophotometrically, and Job's plot method was used to elucidated the stoichiometry of the iron-brazilin complex formation. The anti-inflammatory properties of brazilin were investigated in lipopolysaccharide (LPS)-stimulated macrophages (RAW 264.7). Nitric oxide (NO) inhibition was quantified using the Griess reagent, while the expression levels of pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were evaluated by RT-qPCR. ResultsThe results demonstrated that brazilin exhibited potent antioxidant activity in vitro and hepatocytes in a concentration-dependent manner. It also showed anti-inflammatory activity, in which NO production was significantly reduced and IL-6 and TNF-α expression in LPS-induced macrophages were repressed. Furthermore, it can bind ferric and ferrous ions. Brazilin acts as a bidentate iron chelator that forms a complex with iron in a 2:1 ratio, and two water molecules are used as additional chelators in this complex. ConclusionsOur findings have significant implications. Brazilin can potentially alleviate the harmful effects of iron-induced oxidative stress and inflammatory disorders.

Comprehensive analysis of macrophage-associated inflammatory genes in AMI based on bulk combined with single-cell sequencing data.

Previous studies have highlighted the crucial role of macrophages in the post-acute myocardial infarction (AMI) inflammatory response. This study specifically focused on investigating macrophage-related targets involved in the inflammatory response after AMI. Bioinformatics methods were applied for identifying differentially expressed genes (DEGs) in datasets GSE163465, GSE236374, and GSE183272 obtained from the Gene Expression Omnibus (GEO) database. Communication analysis was conducted to analyze macrophages in AMI. Subsequent analyses encompassed functional enrichment analysis of Co-DEGs using Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG). Gene set variation analysis (GSVA) and immune infiltration analysis were carried out for screening key genes. Validation of the bioinformatics analysis results involved original and GSE114695 datasets, supported by quantitative real time polymerase chain reaction (qRT-PCR). Animal experiments confirmed the upregulation of Saa3, Acp5, and Fcgr4 genes in AMI mouse myocardial tissues. A total of 80 and 1,907 DEGs were respectively identified by analyzing scRNA-seq and bulk RNA-seq data. The overlapping Co-DEGs were found to be closely associated with inflammation-associated pathways, specifically the PI3K-Akt-mTOR pathway. Screening based on GSVA scores and macrophage-associated scores highlighted four key genes (Saa3, Ms4a4c, Acp5, and Fcgr4). Immunoinfiltration analysis revealed their close association with macrophages. Dataset validation corroborated these findings. Experimental validation focused on Saa3, Ms4a4c, Acp5, and Fcgr4, demonstrating the upregulation of their expression in cardiac macrophages in the AMI group, consistent with previous reports. This study provides new perspectives on AMI treatment. In addition, Saa3, Acp5, and Fcgr4 exhibit potential as biomarkers for improving cardiac repair and slowing down the development of heart failure after AMI.

The BRD4 Inhibitor I-BET-762 Reduces HO-1 Expression in Macrophages and the Pancreas of Mice.

In pancreatic cancer, the tumor microenvironment (TME) accounts for up to 90% of the tumor mass. Pancreatitis, characterized by the increased infiltration of macrophages into the pancreas, is a known risk factor for pancreatic cancer. The NRF2 (nuclear factor erythroid 2-related factor 2) transcription factor regulates responses to oxidative stress and can promote cancer and chemoresistance. NRF2 also attenuates inflammation through the regulation of macrophage-specific genes. Heme oxygenase 1 (HO-1) is expressed by anti-inflammatory macrophages to degrade heme, and its expression is dependent on NRF2 translocation to the nucleus. In macrophages stimulated with conditioned media from pancreatic cancer cells, HO-1 protein levels increased, which correlated with higher NRF2 expression in the nuclear fraction. Significant differences in macrophage infiltration and HO-1 expression were detected in LSL-KrasG12D/+; Pdx-1-Cre (KC) mice, Nrf2 whole-body knockout (KO) mice and wildtype mice with pancreatitis. Since epigenetic modulation is a mechanism used by tumors to regulate the TME, using small molecules as epigenetic modulators to activate immune recognition is therapeutically desirable. When the bromodomain inhibitor I-BET-762 was used to treat macrophages or mice with pancreatitis, high levels of HO-1 were reduced. This study shows that bromodomain inhibitors can be used to prevent physiological responses to inflammation that promote tumorigenesis.

APP-CD74 axis mediates endothelial cell-macrophage communication to promote kidney injury and fibrosis.

Kidney injuries often carry a grim prognosis, marked by fibrosis development, renal function loss, and macrophage involvement. Despite extensive research on macrophage polarization and its effects on other cells, like fibroblasts, limited attention has been paid to the influence of non-immune cells on macrophages. This study aims to address this gap by shedding light on the intricate dynamics and diversity of macrophages during renal injury and repair. During the initial research phase, the complexity of intercellular communication in the context of kidney injury was revealed using a publicly available single-cell RNA sequencing library of the unilateral ureteral obstruction (UUO) model. Subsequently, we confirmed our findings using an independent dataset from a renal ischemia-reperfusion injury (IRI) model. We treated two different types of endothelial cells with TGF-β and co-cultured their supernatants with macrophages, establishing an endothelial cell and macrophage co-culture system. We also established a UUO and an IRI mouse model. Western blot analysis, flow cytometry, immunohistochemistry and immunofluorescence staining were used to validate our results at multiple levels. Our analysis revealed significant changes in the heterogeneity of macrophage subsets during both injury processes. Amyloid β precursor protein (APP)-CD74 axis mediated endothelial-macrophage intercellular communication plays a dominant role. In the in vitro co-culture system, TGF-β triggers endothelial APP expression, which subsequently enhances CD74 expression in macrophages. Flow cytometry corroborated these findings. Additionally, APP and CD74 expression were significantly increased in the UUO and IRI mouse models. Immunofluorescence techniques demonstrated the co-localization of F4/80 and CD74 in vivo. Our study unravels a compelling molecular mechanism, elucidating how endothelium-mediated regulation shapes macrophage function during renal repair. The identified APP-CD74 signaling axis emerges as a promising target for optimizing renal recovery post-injury and preventing the progression of chronic kidney disease.

Thermosensitive and injectable chitosan-based hydrogel embedding umbilical cord mesenchymal stem cells for β-cell repairing in type 2 diabetes mellitus

A thermosensitive and injectable hydrogel composed of chitosan (CS), chitosan biguanide hydrochloride (CSG) and collagen (CO) could embed umbilical cord mesenchymal stem cells (UC-MSCs), then was applied for the type 2 diabetes mellitus (T2DM) treatment in vivo. UC-MSCs could adhere well on CS/CSG/CO hydrogel surface and cell division could be clearly observed. Especially, UC-MSCs maintained alive till they grew in CS/CSG/CO hydrogel for 8 days, while the amount of UC-MSCs was limited due to the steric hindrance in hydrogel. To T2DM mice contrastive treatment by intraperitoneal injection for thirteen weeks, UC-MSCs + Hydrogel group could improve the impaired glucose tolerance, maintain glucose homeostasis in vivo, and restore islet morphology for T2DM mice. The immunofluorescence staining and western blot experiments further displayed that both the nuclear antigen Ki67 for cell proliferation and pancreatic duodenal homeobox-1 (Pdx1) expression in UC-MSCs + Hydrogel group were significantly higher than the expressions in untreated T2DM group and treated UC-MSCs + PBS group, which indicated that UC-MSCs + Hydrogel elevated β cell transcriptional activity. Moreover, the positivity rates of iNOS and CD163 in UC-MSCs + Hydrogel group were generally decreased and increased, respectively, compared to those in untreated T2DM group and treated UC-MSCs + PBS group. It displayed that UC-MSCs + Hydrogel could reduce M1 macrophage expression and increase M2 macrophage polarization in T2DM mice.

Identification of potential therapeutic targets for nonischemic cardiomyopathy in European ancestry: an integrated multiomics analysis

BackgroundNonischemic cardiomyopathy (NISCM) is a clinical challenge with limited therapeutic targets. This study aims to identify promising drug targets for NISCM.MethodsWe utilized cis-pQTLs from the deCODE study, which includes data from 35,559 Icelanders, and SNPs from the FinnGen study, which includes data from 1,754 NISCM cases and 340,815 controls of Finnish ancestry. Mendelian randomization (MR) analysis was performed to estimate the causal relationship between circulating plasma protein levels and NISCM risk. Proteins with significant associations underwent false discovery rate (FDR) correction, followed by Bayesian colocalization analysis. The expression of top two proteins, LILRA5 and NELL1, was further analyzed using various NISCM datasets. Descriptions from the Human Protein Atlas (HPA) validated protein expression. The impact of environmental exposures on LILRA5 was assessed using the Comparative Toxicogenomics Database (CTD), and molecular docking identified the potential small molecule interactions.ResultsMR analysis identified 255 circulating plasma proteins associated with NISCM, with 16 remaining significant after FDR correction. Bayesian colocalization analysis identified LILRA5 and NELL1 as significant, with PP.H4 > 0.8. LILRA5 has a protective effect (OR = 0.758, 95% CI, 0.670–0.857) while NELL1 displays the risk effect (OR = 1.290, 95% CI, 1.199–1.387) in NISCM. Decreased LILRA5 expression was found in NISCM such as diabetic, hypertrophic, dilated, and inflammatory cardiomyopathy, while NELL1 expression increased in hypertrophic cardiomyopathy. HPA data indicated high LILRA5 expression in neutrophils, macrophages and endothelial cells within normal heart and limited NELL1 expression. Immune infiltration analysis revealed decreased neutrophil in diabetic cardiomyopathy. CTD analysis identified several small molecules that affect LILRA5 mRNA expression. Among these, Estradiol, Estradiol-3-benzoate, Gadodiamide, Topotecan, and Testosterone were found to stably bind to the LILRA5 protein at the conserved VAL-15 or THR-133 residues in the Ig-like C2 domain.ConclusionBased on European Ancestry Cohort, this study reveals that LILRA5 and NELL1 are potential therapeutic targets for NISCM, with LILRA5 showing particularly promising prospects in diabetic cardiomyopathy. Several small molecules interact with LILRA5, implying potential clinical implication.

Cinobufagin inhibits M2‑like tumor‑associated macrophage polarization to attenuate the invasion and migration of lung cancer cells.

Macrophages have crucial roles in immune responses and tumor progression, exhibiting diverse phenotypes based on environmental cues. In the present study, the impact of cinobufagin (CB) on macrophage polarization and the consequences on tumor‑associated behaviors were investigated. Morphological transformations of THP‑1 cells into M0, M1 and M2 macrophages were observed, including distinct changes in the size, shape and adherence properties of these cells. CB treatment inhibited the viability of A549 and LLC cells in a concentration‑dependent manner, with an IC50 of 28.8 and 30.12 ng/ml, respectively. CB at concentrations of <30 ng/ml had no impact on the viability of M0 macrophages and lung epithelial (BEAS‑2B) cells. CB influenced the expression of macrophage surface markers, reducing CD206 positivity in M2 macrophages without affecting CD86 expression in M1 macrophages. CB also altered certain expression profiles at the mRNA level, notably downregulating macrophage receptor with collagenous structure (MARCO) expression in M2 macrophages and upregulating tumor necrosis factor‑α and interleukin‑1β in both M0 and M1 macrophages. Furthermore, ELISA analyses revealed that CB increased the levels of pro‑inflammatory cytokines in M1 macrophages and reduced the levels of anti‑inflammatory factors in M2 macrophages. CB treatment also attenuated the migration and invasion capacities of A549 and LLC cells stimulated by M2 macrophage‑conditioned medium. Additionally, CB modulated peroxisome proliferator‑activated receptor γ (PPARγ) and MARCO expression in M2 macrophages and epithelial‑mesenchymal transition in A549 cells, which was partially reversed by rosiglitazone, a PPARγ agonist. Finally, CB and cisplatin treatments hindered tumor growth in vivo, with distinct impacts on animal body weight and macrophage marker expression in tumor tissues. In conclusion, the results of the present study demonstrated that CB exerted complex regulatory effects on macrophage polarization and tumor progression, suggesting its potential as a modulator of the tumor microenvironment and a therapeutic for cancer treatment.

IDH2 regulates macrophage polarization and tumorigenesis by modulating mitochondrial metabolism in macrophages

BackgroundTargeting the tumor microenvironment represents an emerging therapeutic strategy for cancer. Macrophages are an essential part of the tumor microenvironment. Macrophage polarization is modulated by mitochondrial metabolism, including oxidative phosphorylation (OXPHOS), the tricarboxylic acid (TCA) cycle, and reactive oxygen species content. Isocitrate dehydrogenase 2 (IDH2), an enzyme involved in the TCA cycle, reportedly promotes cancer progression. However, the mechanisms through which IDH2 influences macrophage polarization and modulates tumor growth remain unknown.MethodsIn this study, IDH2-deficient knockout (KO) mice and primary cultured bone marrow-derived macrophages (BMDMs) were used. Both in vivo subcutaneous tumor experiments and in vitro co-culture experiments were performed, and samples were collected for analysis. Western blotting, RNA quantitative analysis, immunohistochemistry, and flow cytometry were employed to confirm changes in mitochondrial function and the resulting polarization of macrophages exposed to the tumor microenvironment. To analyze the effect on tumor cells, subcutaneous tumor size was measured, and growth and metastasis markers were identified.ResultsIDH2-deficient macrophages co-cultured with cancer cells were found to possess increased mitochondrial dysfunction and fission than wild-type BMDM. Additionally, the levels of M2-associated markers decreased, whereas M1-associated factor levels increased in IDH2-deficient macrophages. IDH2-deficient macrophages were predominantly M1. Tumor sizes in the IDH2-deficient mouse group were significantly smaller than in the wild-type mouse group. IDH2 deficiency in macrophages was associated with inhibited tumor growth and epithelial–mesenchymal transition.ConclusionsOur findings suggest that IDH2 deficiency inhibits M2 macrophage polarization and suppresses tumorigenesis. This study underlines the potential contribution of IDH2 expression in macrophages and tumor microenvironment remodeling, which could be useful in clinical cancer research.

Metformin modulates microbiota and improves blood pressure and cardiac remodeling in a rat model of hypertension.

Metformin has been attributed to cardiovascular protection even in the absence of diabetes. Recent observations suggest that metformin influences the gut microbiome. We aimed to investigate the influence of metformin on the gut microbiota and hypertensive target organ damage in hypertensive rats. Male double transgenic rats overexpressing the human renin and angiotensinogen genes (dTGR), a model of angiotensin II-dependent hypertension, were treated with metformin (300 mg/kg/day) or vehicle from 4 to 7 weeks of age. We assessed gut microbiome composition and function using shotgun metagenomic sequencing and measured blood pressure via radiotelemetry. Cardiac and renal organ damage and inflammation were evaluated by echocardiography, histology, and flow cytometry. Metformin treatment increased the production of short-chain fatty acids (SCFA) acetate and propionate in feces without altering microbial composition and diversity. It significantly reduced systolic and diastolic blood pressure and improved cardiac function, as measured by end-diastolic volume, E/A, and stroke volume despite increased cardiac hypertrophy. Metformin reduced cardiac inflammation by lowering macrophage infiltration and shifting macrophage subpopulations towards a less inflammatory phenotype. The observed improvements in blood pressure, cardiac function, and inflammation correlated with fecal SCFA levels in dTGR. Invitro, acetate and propionate altered M1-like gene expression in macrophages, reinforcing anti-inflammatory effects. Metformin did not affect hypertensive renal damage or microvascular structure. Metformin modulated the gut microbiome, increased SCFA production, and ameliorated blood pressure and cardiac remodeling in dTGR. Our findings confirm the protective effects of metformin in the absence of diabetes, highlighting SCFA as a potential mediators.

The identification of key molecules and pathways in the crosstalk of calcium oxalate-treated TCMK-1 cells and macrophage via exosomes

The interplay between crystals and epithelial cells forms the cornerstone of kidney stone development, communication between epithelial cells and macrophages emerging as a pivotal role in this process. We conducted next-generation sequencing on the secreted exosomes of TCMK-1 cells treated with calcium oxalate monohydrate (OX_EXO) or controls (NC_EXO), and on the macrophage cell line RAW264.7 stimulated with OX_EXO or NC_EXO, followed by validation of differentially expressed target proteins and miRNAs through Western blot and PCR. UPSET plots were employed to identify genes co-targeted by exosomal miRNAs. Various bioinformatic analyses were employed to predict potential mechanisms of the dysregulated genes. We integrated sequencing data from the GEO database, and validated findings using clinical patient urine and kidney tissues. We identified 665 differentially expressed exosomal miRNAs between OX_EXO and NC_EXO. Among the top 10 down-regulated miRNAs, the most targeted genes were AAK1 and NUFIP2, whereas PLCB1 was significantly targeted among the top 10 up-regulated miRNAs. In clinical specimens, we confirmed the differential expressions of five homologous miRNAs, as well as CNOT3, CNCNA1C, APEX1, and TMEM199. In conclusion, treatment of TCMK-1 cells with calcium oxalate significantly alerted the expression profile of exosomal miRNAs, subsequently influencing gene expression in macrophages, thereby modulating the processes of kidney stone formation.

Glucose-Dependent Insulinotropic Polypeptide Inhibits AGE-Induced NADPH Oxidase-Derived Oxidative Stress Generation and Foam Cell Formation in Macrophages Partly via AMPK Activation.

Glucose-dependent insulinotropic polypeptide (GIP) of the incretin group has been shown to exert pleiotropic actions. There is growing evidence that advanced glycation end products (AGEs), senescent macromolecules formed at an accelerated rate under chronic hyperglycemic conditions, play a role in the pathogenesis of atherosclerotic cardiovascular disease in diabetes. However, whether and how GIP could inhibit the AGE-induced foam cell formation of macrophages, an initial step of atherosclerosis remains to be elucidated. In this study, we address these issues. We found that AGEs increased oxidized low-density-lipoprotein uptake into reactive oxygen species (ROS) generation and Cdk5 and CD36 gene expressions in human U937 macrophages, all of which were significantly blocked by [D-Ala2]GIP(1-42) or an inhibitor of NADPH oxidase activity. An inhibitor of AMP-activated protein kinase (AMPK) attenuated all of the beneficial effects of [D-Ala2]GIP(1-42) on AGE-exposed U937 macrophages, whereas an activator of AMPK mimicked the effects of [D-Ala2]GIP(1-42) on foam cell formation, ROS generation, and Cdk5 and CD36 gene expressions in macrophages. The present study suggests that [D-Ala2]GIP(1-42) could inhibit the AGE-RAGE-induced, NADPH oxidase-derived oxidative stress generation in U937 macrophages via AMPK activation and subsequently suppress macrophage foam cell formation by reducing the Cdk5-CD36 pathway.

Abstract B053: Tumor-associated macrophages diminishes IL1RAP-targeting CAR-T cell therapy efficacy in Ewing sarcoma

Abstract Ewing sarcoma (EwS) is a pediatric malignancy of soft tissue and bone with a poor prognosis, especially in its metastatic stages. We have previously identified IL1RAP as a promising target for immunotherapies like chimeric antigen receptor (CAR) T cell therapy against EwS. However, CAR-T cells, despite their success in hematological cancers, often show limited efficacy against solid tumors. In orthotopic xenograft models of Ewing sarcoma (EwS) we have observed that CD11b+ CD206+ macrophages, known as tumor-associated macrophages (TAMs), surround the primary tumor. Treatment with IL1RAP-targeting CAR-T cells specific to EwS results in T cells localizing with these macrophages and failing to infiltrate the primary tumor. This study aims to characterize the impact of TAMs on CAR-T cell efficacy in EwS. We hypothesized that TAMs, polarized by Ewing sarcoma cells, suppress IL1RAP CAR-T cell activity. To model these interactions, we co-cultured EwS cells, macrophages, and CAR-T cells, performing luciferin-based in vitro cytotoxicity assays. THP-1 monocytes were differentiated into macrophages and polarized into M1 or M2 states using cytokines (LPS + IFN-y, IL-4 + IL-13), or differentiated into TAMs by co-culture with EwS cell lines. In vitro cytotoxicity assays were conducted using luciferase-expressing EwS target cells, polarized THP-1 macrophages, and IL1RAP CAR-T effector cells, with luminescence indicating EwS cell survival. We found that M1 macrophages did not affect CAR-T cell targeting of EwS cells, whereas M2 macrophages and TAMs significantly decreased specific lysis (p &amp;lt; 0.001). Conditioned media from polarized macrophages had no effect on CAR-T cell performance against EwS, suggesting that physical proximity or direct contact with TAMs is necessary to suppress CAR-T cell function. Western blot analysis of polarized THP-1 macrophages revealed that M2-polarized macrophages upregulated IL1RAP expression compared to M1 macrophages. Ongoing experiments aim to determine whether elevated IL1RAP expression in M2 macrophages redirects IL1RAP CAR-T cells away from EwS cells or if M2 macrophages mediate general suppression of CAR-T cell activity. Additionally, we are investigating whether THP-1-derived TAMs and primary macrophages also upregulate IL1RAP expression when polarized and how this affects syngeneic CAR-T cell performance. Our findings indicate that TAMs can influence the efficacy of IL1RAP-targeting CAR-T cells against EwS. Further investigation into the specific mechanisms responsible for this suppressive effect could enhance CAR-T therapy for Ewing sarcoma and potentially other solid tumors. Citation Format: Yue Zhou (Joe) Huang, Melanie Rouleu, Poul Sorensen. Tumor-associated macrophages diminishes IL1RAP-targeting CAR-T cell therapy efficacy in Ewing sarcoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pediatric Cancer Research; 2024 Sep 5-8; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl):Abstract nr B053.

MAFB in Macrophages Regulates Prostaglandin E2-Mediated Lipid Mediator Class Switch through ALOX15 in Ischemic Acute Kidney Injury.

Monocytes and macrophages express the transcription factor MAFB (V-maf musculoaponeurotic fibrosarcoma oncogene homolog B) and protect against ischemic acute kidney injury (AKI). However, the mechanism through which MAFB alleviates AKI in macrophages remains unclear. In this study, we induced AKI in macrophage lineage-specific Mafb-deficient mice (C57BL/6J) using the ischemia-reperfusion injury model to analyze these mechanisms. Our results showed that MAFB regulates the expression of Alox15 (arachidonate 15-lipoxygenase) in macrophages during ischemic AKI. The expression of ALOX15 was significantly decreased at the mRNA and protein levels in macrophages that infiltrated the kidneys of macrophage-specific Mafb-deficient mice at 24 h after ischemia-reperfusion injury. ALOX15 promotes the resolution of inflammation under acute conditions by producing specialized proresolving mediators by oxidizing essential fatty acids. Therefore, MAFB in macrophages promotes the resolution of inflammation in ischemic AKI by regulating the expression of Alox15. Moreover, MAFB expression in macrophages is upregulated via the COX-2/PGE2/EP4 pathway in ischemic AKI. Our invitro assay showed that MAFB regulates the expression of Alox15 under the COX-2/PGE2/EP4 pathway in macrophages. PGE2 mediates the lipid mediator (LM) class switch from inflammatory LMs to specialized proresolving mediators. Therefore, MAFB plays a key role in the PGE2-mediated LM class switch by regulating the expression of Alox15. Our study identified a previously unknown mechanism by which MAFB in macrophages alleviates ischemic AKI and provides new insights into regulating the LM class switch in acute inflammatory conditions.

Therapeutic potential of Sertoli cells in vivo: alleviation of acute inflammation and improvement of sperm quality

BackgroundInflammation-induced testicular damage is a significant contributing factor to the increasing incidence of infertility. Traditional treatments during the inflammatory phase often fail to achieve the desired fertility outcomes, necessitating innovative interventions such as cell therapy.MethodsWe explored the in vivo properties of intravenously administered Sertoli cells (SCs) in an acute lipopolysaccharide (LPS)-induced inflammatory mouse model. Infiltrating and resident myeloid cell phenotypes were assessed using flow cytometry. The impact of SC administration on testis morphology and germ cell quality was evaluated using computer-assisted sperm analysis (CASA) and immunohistochemistry.ResultsSCs demonstrated a distinctive migration pattern, importantly they preferentially concentrated in the testes and liver. SC application significantly reduced neutrophil infiltration as well as preserved the resident macrophage subpopulations. SCs upregulated MerTK expression in both interstitial and peritubular macrophages. Applied SC treatment exhibited protective effects on sperm including their motility and kinematic parameters, and maintained the physiological testicular morphology.ConclusionOur study provides compelling evidence of the therapeutic efficacy of SC transplantation in alleviating acute inflammation-induced testicular damage. These findings contribute to the expanding knowledge on the potential applications of cell-based therapies for addressing reproductive health challenges and offer a promising approach for targeted interventions in male infertility.

Multigenic family 110 (1L-5-6L) of African swine fever virus modulate cytokine genes expression in vitro.

African swine fever (ASF) is a viral disease that affects pigs and wild boars providing economic burden in swine industry. In this study, we investigated the effect of deleting the ASFV multigene family 110 (MGF110) fragment (1L-5-6L) on apoptosis modulation and the expression of proinflammatory cytokines. Gene expression in swine peripheral blood macrophages infected with either the parental "Volgograd/14c" strain or the gene-deleted "Volgograd/D(1L-5-6L) MGF110" strain was analyzed. Caspase-3 activity was 1.15 times higher in macrophages infected with the parental ASFV strain compared to the gene-deleted strain. Gene expression analysis of Caspase-3 (Cas-3), Interferon-A (IFN-A), Tumor Necrosis Factor A (TNF-A), B-cell Lymphoma-2 (Bcl-2), Nuclear Factor Kappa B (NF-kB), Interleukin-12 (IL-12), and Heat Shock Protein-70 (HSP-70) using RT-qPCR at various time points after infection revealed significant differences in expression profiles between the strains. The peak expression of cytokines (except NF-kB) occurred at 24h post-infection with the "Volgograd/D(1L-5-6L) MGF110" strain. In samples infected with the ASFV "Volgograd/14c" strain, the most intense expression was observed at 72 and 96h, except for Bcl-2 and NF-kB, which peaked at 6h post-infection. The cytokine expression trend for the "Volgograd/D(1L-5-6L) MGF110" strain was more stable with higher expression values. The expression trend for the parental strain increased over time, reaching maximum values at 72 and 96h post-infection, but the overall expression level was lower than that of the gene-deleted strain. These findings suggest that deleting the multigene family 110 members (1L-5-6L) contributes to ASFV attenuation without affecting virus replication kinetics.

Abstract MP15: Macrophage PPARα is essential to increased immune function induced by angiotensin converting enzyme (ACE).

Mice with increased macrophage expression of angiotensin converting enzyme (ACE), called ACE 10/10 mice, have a profound increase of macrophage function in response to diverse immune challenges including tumors, infection, atherosclerosis, and Alzheimer’s disease. ACE 10/10 macrophages are highly efficient in oxidative ATP generation, and they express increased amounts of peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor that controls lipid metabolism. To pinpoint the role of PPARα in increasing macrophage immune function, we used LysM-Cre-LoxP system to generate ACE 10/10 mice selectively lacking macrophage PPARα (A10-PPARα-Cre mice). This reduced macrophage fatty acid metabolism, reduced oxidative metabolism, and lowered macrophage intracellular ATP. Functionally, A10-PPARα-Cre macrophage are impaired in both adaptive and innate immunity. A10-PPARα-Cre mice have larger tumor growth of B16-F10 melanoma, less intratumor macrophages, reduced anti-tumor cytokines, and reduced generation of tumor antigen-specific CD8 + T cells. The mice also have a very attenuated anti-bacterial response to methicillin-resistant Staphylococcus aureus (MRSA) infection, with more severe MRSA tissue colonization in vivo . In addition, increasing ACE expression or adding a PPARα agonist to the human monocytic cell line THP-1 enhances tumor cell cytotoxicity, phagocytosis of bacteria, and bacterial killing. Thus, we find that elevated macrophage PPARα is absolutely required for the increased immunity of ACE 10/10 mice. This may indicate a pathway to increasing human immunity.

Novel insights into vancomycin-loaded calcium sulfate and negative pressure wound therapy in preventing infections in open fractures

BackgroundOpen fractures are challenging due to susceptibility to Staphylococcus aureus infections. This study examines the impact of Vancomycin-Loaded Calcium Sulfate (VLCS) and negative pressure wound therapy (NPWT) on macrophage behavior in enhancing healing and infection resistance. Both VLCS and NPWT were evaluated individually and in combination to determine their effects on macrophage polarization and infection resistance in open fractures.MethodsThrough single-cell RNA sequencing, genomic expressions in macrophages from open fracture patients treated with VLCS and NPWT were compared to a control group. The analysis focused on MBD2 gene changes related to macrophage polarization.ResultsRemarkable modifications in MBD2 expression in the treatment group indicate a shift towards M2 macrophage polarization. Additionally, the combined treatment group exhibited greater improvements in infection resistance and healing compared to the individual treatments. This shift suggests a healing-promoting atmosphere with improved infection resilience.ConclusionsVLCS and NPWT demonstrate the ability to alter macrophage behavior toward M2 polarization, which is crucial for infection prevention in open fractures. The synergistic effect of their combined use shows even greater promise in enhancing outcomes in orthopedic trauma care.

Schizonepeta tenuifolia Briq-Saposhnikovia divaricata decoction alleviates atopic dermatitis via downregulating macrophage TRPV1.

Schizonepeta tenuifolia -Saposhnikovia divaricata (Jingjie-Fangfeng, JF) has been used for years to treat allergic inflammatory skin diseases like atopic dermatitis, but the specific effects and mechanisms of JF are still unclear. We aim to investigate the therapeutic effect and mechanism of JF in MC903-induced atopic dermatitis-like model. JF decoction was subjected to rigorous HPLC and GC analysis. The JF decoction was then freshly prepared and administered to MC903-induced atopic dermatitis -like mice models to investigate its therapeutic effects. Our evaluation focused on several markers of inflammation including the TEWL index, ear thickness, swelling, and specific inflammation indicators such as TSLP, IL33, IgE, and immune cell presence at the lesion sites. We measured Transient Receptor Potential Vanilloid 1 (TRPV1) expression levels through immunofluorescent staining in skin tissue from both atopic dermatitis patients and the MC903-treated mice. Furthermore, TRPV1 expression and macrophage activation markers were measured in LPS/IFN-γ-stimulated Raw264.7 and THP-1 cell models in vitro. Additionally, we developed cell lines that overexpress TRPV1 and investigated how JF treatment affects NF-κB p65 phosphorylation in these cells to understand better the role of TRPV1 in atopic dermatitis. The JF decoction met the standards outlined in the Chinese pharmacopeia. The JF decoction significantly alleviated inflammatory skin symptoms and helped restore skin barrier function. Additionally, it reduced the levels of IgE and pro-inflammatory cytokines TSLP, IL-33, and IL-4. There was also a noticeable decrease in mast cell infiltration and degranulation. Notably, JF decoction reduced infiltrated macrophages with limited affection on T cell infiltration. It also decreased F4/80+/TRPV1+ cells in atopic dermatitis mice and TRPV1 expression in LPS/IFNγ-stimulated microphages. Additionally, we observed that CD68+/TRPV1+ cells increased in human atopic dermatitis tissue. Further studies showed that JF water extract (JF-WE) suppressed TRPV1 expression in macrophages, potentially by affecting NF-κB p65 phosphorylation rather than the JAK-STAT6 pathway. This study offers initial evidence of the effectiveness of JF-WE in suppressing inflammation in atopic dermatitis. The therapeutic effect might stems from its ability to downregulate TRPV1 expression and subsequent NF-κB p65 phosphorylation in macrophages.