Monocytic THP-1 Cells Research Articles

Development and assessment of an intestinal tri-cellular model to investigate the pro/anti-inflammatory potential of digested foods

IntroductionImmunonutrition, defined as the potential of foods, nutrients and dietary patterns to modulate the immune system activity, has been proposed as a strategy to enhance the immune response in both metabolic and immune-mediated diseases. However, the anti-/pro-inflammatory role of foods and diets is far to be fully ascertained, and thus there is a continued needed for appropriate in vitro cell-culture models to investigate the role of foods in modulating cell-mediated inflammatory processes. This study aims to develop and test an in vitro tri-culture model, simulating the complexity of the intestinal tract and its multiple cell interactions.MethodsTo achieve this, the intestinal epithelial barrier was established by co-culturing human Caco-2 enterocyte-like and HT29-MTX-E12 mucus producing goblet-like colon cells, then adding human monocyte THP-1 cells to the basolateral compartment. The integrity and stability of the epithelial barrier were monitored and the inflammatory response of the model was assessed using various stressors at different concentrations, both individually and in combination (phorbol-12- myristate-13-acetate or PMA, and lipopolysaccharide or LPS), in terms of cytokines production. To test the model, different concentrations of in vitro digested broccoli (BD) were added to the apical section of the model.ResultsSupernatants from the basolateral compartment were collected and analyzed for cytokines production (IL-6, TNF-α, IL-12p70, IL-18 and IL-8) using automated ELISA (ELLA). Additionally, ZO-1 protein from the tight junctions of epithelial cells was analyzed by flow cytometry. The results indicated that 100 nM PMA added to the whole model for 20 h was the best stressor to simulate a mild-inflammatory status of the gut. Following treatment with BD, IL-6, TNF-α, IL-8 and IL-18 were significantly reduced compared to the control group, while ZO-1 expression increased at the lowest BD concentration.ConclusionsThese findings confirm the feasibility of the model for assessing the effects of food digesta on specific cytokines and permeability markers, representing a valuable strategy for investigating the role of foods in modulating the inflammatory response. The results obtained may support dietary strategies aimed at promoting wellbeing and preventing inflammatory-related metabolic diseases.

Liposomal encapsulation of cholecalciferol mitigates in vivo toxicity and delays tumor growth

IntroductionVitamin D3 (cholecalciferol) has demonstrated potential anticancer properties, but its clinical application is limited by associated toxicity at effective doses. This study investigated the use of liposomal encapsulation to increase the therapeutic efficacy of vitamin D3 while mitigating its toxicity.MethodsLiposomal vitamin D3 (VD-LP) was prepared via the film-hydration method and characterized for particle size, polydispersity index, encapsulation efficiency, and long-term stability. In vitro gene expression modulation was evaluated in monocytic THP-1 cells, and antiproliferative effects were assessed in HT29 (colorectal), BT474 (breast), and TRAMP-C1 (prostate) cancer cell lines. In vivo antitumor efficacy and toxicity were tested in a mouse model with subcutaneously implanted MC38 tumors. Tumor growth, survival rates, and serum calcium and phosphate levels were analyzed.ResultsVD-LP demonstrated high encapsulation efficiency and stability over 90 days, with a consistent particle size of approximately 83 nm. VD-LP modulated immune-related and metabolic gene expression in THP-1 cells, including upregulation of antimicrobial peptides and vitamin D receptor genes. VD-LP showed superior antiproliferative effects compared to free vitamin D3 in all tested cancer cell lines. In vivo, VD-LP delayed tumor growth and improved survival without causing hypercalcemia, highlighting its favorable toxicity profile.DiscussionLiposomal encapsulation of vitamin D3 significantly improves its anticancer efficacy while mitigating toxicity, making it a promising strategy for future cancer therapies. VD-LP shows potential for enhanced therapeutic applications with reduced adverse effects, warranting further clinical exploration.

Design and development of an isatin-1,2,3-triazole hybrid analogue as a potent anti-inflammatory agent with enhanced efficacy and gene expression modulation.

Isatin (1H-indole-2,3-dione) and its derivatives have been found to exhibit various biological activities, including anticancer and antidiabetic properties. In this study, a series of nine isatin-1,2,3-triazole conjugates were synthesized and evaluated for their anti-inflammatory potential via in vitro experiments. Their synthesis involved the propargylation of isatin 1 with propargyl bromide to obtain N-propargyl isatin 2, which was subjected to click reactions with different aromatic azides to yield isatin-N-1,2,3-triazoles (3a-i). The structures of all the compounds were confirmed via NMR and HR-MS. The final isatin analogues were tested for their ability to attenuate the production of proinflammatory cytokines in the lipopolysaccharide (LPS)-induced human leukemia monocytic THP-1 cells. Importantly, none of the compounds had any negative effect on THP-1 cell viability at the tested concentrations of 4 mM and 8 mM. LPS induced the production of the cytokines: Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) by 351.4, 7.9 and 14.3 fold, respectively, in THP-1 cells. However, treatment with compound 3e markedly attenuated the levels of TNF-α (by 6.6 fold and 1.5 fold), IL-6 (by 1.03 fold and 1.41 fold) and MCP-1 (by 3.3 fold and 1.7 fold) by several fold at concentrations of 4 mM and 8 mM, respectively. Furthermore, in the gene expression modulation studies, 3e was found to downregulate the genes responsible for the production of TNF-α (24 and 25 fold), IL-6 (148 and 502 fold) and MCP-1 (50 and 25 fold) at the two tested concentrations compared with their expression in the LPS-induced THP-1 cells (135 fold, 6612 fold, and 68.8 fold, respectively). Thus, 3e markedly attenuated the secretion of TNF-α, IL-6 and MCP-1 from LPS-treated THP-1 cells, and also the expression of the concerned genes. At the lowest dose tested, i.e., 4 mM, 3e had the greatest effect on both gene expression and marker secretion.

Genome-wide screen based on 2DG activated NLRP3 inflammasome reveals the priming signal of TLR2/4 to IKKβ but not IKKα

NLRP3 inflammasome activation is a pivotal area of research in innate immunity, yet the precise priming and activation signal remain unclear. In this study, we demonstrate that glycolysis inhibitor 2-Deoxy-D-glucose (2DG) triggers NLRP3-driven pyroptosis in human leukemia monocyte THP-1 cells by interfering glycosylation rather than glycolysis, which occurs independent of potassium efflux but requires the involvement of glycolysis rate-limiting enzyme PFKP. Using a CRISPR-Cas9 mediated large-scale screen, with 2DG as a new tool for probing NLRP3 activation, we identified that TLR2, rather than TLR4, initiates a rapid and robust priming signal for NLRP3 inflammasome activation. Importantly, both TLR2 and TLR4 depend entirely on MyD88, but not TRIF, for signal transduction. Furthermore, we discovered that TAK1, IKKβ and NEMO, but not IKKα, are essential for the priming signal. Additionally, we observed that deficiency in the linear ubiquitin assembly complex (LUBAC) subunits HOIP and HOIL-1, but not SHARPIN, is sufficient to inhibit 2DG-induced pyroptotic cell death. Collectively, our study reveals some common mechanism in the NLRP3 priming signals, as well as specific mechanisms upstream of NLRP3 triggered by 2DG, and underscores the potential of 2DG as a trigger to facilitate further detailed analysis of the underlying mechanisms of NLRP3 inflammasome activation.One Sentence Summary: Priming signal by IKKβ is essential for NLRP3 activation.

Anti-Endoglin monoclonal antibody prevents the progression of liver sinusoidal endothelial inflammation and fibrosis in MASH.

Liver sinusoidal endothelial inflammation/dysfunction and fibrosis are a crucial part of Metabolic Dysfunction Associated Steatohepatitis (MASH) development. TRC105 and M1043 are anti-endoglin (ENG) monoclonal antibodies that bind ENG. In this study, we hypothesized that treatment with anti-ENG antibodies would prevent the progression of LSECs inflammation and fibrosis in vivo and in vitro. MASH was induced in male C57BL/6 mice fed a choline-deficient L-amino acid-defined high-fat diet (CDAA-HFD) for 4 or 8 weeks. In the rescue study, mice were divided into three groups: a control group (chow diet), a MASH group (CDAA-HFD + IgG), and a rescue group (CDAA-HFD + M1043). Later, two groups received rat IgG1 (10 mg/kg) and M1043 (10 mg/kg). In in vitro experiments, inflammation was induced in human LSECs by ox-LDL (50 μg/mL) and treated with TRC105 (300 μg/mL). Liver sinusoidal endothelial inflammation/dysfunction in MASH animals was characterized by endothelial overexpression of ENG, VCAM-1, and ICAM-1 and reduced VE-cadherin and p-eNOS/eNOS expression. M1043 treatment prevented the overexpression of ENG, VCAM-1, and ICAM-1, the progression of liver fibrosis, and the increase of liver-to-body weight ratio. In vitro experiments with TRC105 confirmed the prevention of LSECs inflammation development by reduced ENG and VCAM-1 expression, as well as decreased THP-1 monocytic cell adhesion in ox-LDL activated LSECs. In conclusion, we demonstrate that anti-ENG antibody treatment can prevent LSECs inflammation and fibrosis progression in a MASH animal model and LSECs inflammation in vitro. Thus, we propose directly targeted ENG may represent a promising pharmacological approach for addressing LSECs inflammation and liver fibrosis.

Small Extracellular Vesicles Derived from Cord Blood Plasma and Placental Mesenchymal Stem Cells Attenuate Acute Lung Injury Induced by Lipopolysaccharide (LPS)

Sepsis is a risk factor associated with increasing neonatal morbidity and mortality, acute lung injury, and chronic lung disease. While stem cell therapy has shown promise in alleviating acute lung injury, its effects are primarily exerted through paracrine mechanisms rather than local engraftment. Accumulating evidence suggests that these paracrine effects are mediated by mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs), which play a critical role in immune system modulation and tissue regeneration. sEVs contain a diverse cargo of mRNA, miRNA, and proteins, contributing to their therapeutic potential. We hypothesize that sEVs derived from three distinct sources, cord blood plasma (CBP), Wharton jelly (WJ), and placental (PL) MSCs, may prevent the cytotoxicity induced by E. coli lipopolysaccharide (LPS) in lung alveolar epithelial cells. Objective: To determine the effects of CBP-, WJ-, and PL-MSCs-derived sEVs on cell viability, apoptosis, and proinflammatory cytokine production in alveolar epithelial cells and monocytes following LPS treatment. sEVs were collected from conditioned media of PL-MSCs, WJ-MSCs, and CBP using 50 nm membrane filters. sEVs were characterized based on nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blotting techniques. The protein concentration of isolated sEVs was used to standardize treatment doses. A549 cells and monocyte THP-1 cells were cultured and exposed to LPS in the presence or absence of sEVs for 72 h. Cell viability was measured using CellTiter-Glo 2.0 chemiluminescence-based assay. For cytokine analysis, A549 and THP-1 cells were pre-incubated for 24 h with or without PL- and CBP-sEVs, followed by exposure to LPS or control conditions for an additional 24 h. The conditioned media were collected, and interleukin-6 (IL-6) and interleukin-8 (IL-8) levels were quantified using ELISA. LPS treatment significantly reduced the viability of both A549 and THP-1 cells. The presence of CB- or WJ-sEVs significantly increased cell viability compared to controls. Cells treated with PL-sEVs showed increased cell viability but did not reach statistical significance. LPS-treated cells showed a significant increase in apoptosis and elevated levels of pro-inflammatory cytokines IL-6 and IL-8. All three sEVs types (CBP-, WJ-, and PL-sEVs) significantly reduced LPS-induced apoptosis and IL-6 release. Interestingly, while WJ-sEVs decreased IL-8, both CBP- and PL-sEVs led to an increase in IL-8 compared to their respective controls. CBP-, PL-, and WJ-derived sEVs demonstrated protective effects against LPS-induced injury in alveolar epithelial cells and monocytes, as evidenced by increased cell viability and modulation of pro-inflammatory cytokine release. These findings suggest that placenta-derived sEVs have the potential to modulate the immune response, mitigate inflammation, and prevent end-organ damage in neonatal sepsis.

Humanized anti-CD11d monoclonal antibodies suitable for basic research and therapeutic applications.

Immunomodulatory agents targeting the CD11d/CD18 integrin are in development for the treatment of several pathophysiologies including neurotrauma, sepsis, and atherosclerosis. Murine anti-human CD11d therapeutic antibodies have successfully improved neurological and behavioral recovery in rodent neurotrauma models. Here, we present the progression of CD11d-targeted agents with the development of humanized anti-CD11d monoclonal antibodies. Primary human leukocytes and the THP-1 monocytic cell line were used to determine the binding of the CD11d antibodies, determine binding affinities, and assess outside-in signaling induced by CD11d antibody binding. In addition, a rat model of spinal cord injury was employed to demonstrate that the humanized monoclonal antibodies retained their therapeutic function in vivo. These determinations were made using a combination of flow cytometry, western blotting, immunohistochemistry, biochemical assays, and a locomotor behavioral assessment. Flow cytometric analysis demonstrated that the humanized anti-CD11d clones bind both human monocytes and neutrophils. Using a THP-1 model, the humanized anti-CD11d-2 clone was then determined to bind both the active and inactive CD11d/CD18 conformations without inducing inflammatory cell signaling. Finally, an investigation using anti-CD11d-2 as a detection tool uncovered a mismatch between total and surface-level CD11d and CD18 expression that was not altered by CK2 inhibition. By developing humanized anti-CD11d monoclonal antibodies, new tools are now available to study CD11d biology and potentially treat inflammation arising from acute neurotrauma via CD11d targeting.

Distinct immune microenvironment of venous tumor thrombus in hepatocellular carcinoma at single-cell resolution.

Portal vein tumor thrombus (PVTT) worsens the prognosis of hepatocellular carcinoma by increasing intrahepatic dissemination and inducing portal vein hypertension. However, the immune characteristics of PVTT remain unclear. Therefore, this study aims to explore the immune microenvironment in PVTT. Time-of-flight mass cytometry (CyTOF) revealed that macrophages and monocytes were the dominant immune cell type in PVTT, with a higher proportion than in primary tumor (PT) and blood (54.1% vs. 26.3% and 9.1%, p<0.05). The differentially enriched clustering of inhibitory and regulatory immune cells in PVTT indicated an immune-suppressive environment. According to the single-cell RNA sequencing (scRNA-seq), TAM-C5AR1 was characterized by leukocyte chemotaxis and was the most common subpopulation in PVTT (36.7%). Multiple immunofluorescence staining showed that the C5aR+ TAM/Mφ were enriched in PVTT compared to both PT and liver, and positively correlated with C5a (r=0.559, p<0.001). Notably, THP-1 (monocyte cell line) was recruited by CSQT2 (PVTT cell line) and exhibited up-regulation of CD163, CD206, and PD-L1 upon stimulation. C5aR antagonist could reverse this. C5aR+ TAMs could also inhibit Granzyme B in CD8+ T cells. High infiltration of C5aR+ TAMs in PVTT correlated with poor differentiation (p<0.009), and was a risk factor for overall survival (p=0.003) and for re-formation of PVTT after resection (p=0.007). TAMs, especially C5aR+ TAMs, were enriched in PVTT. C5aR+ TAMs contribute to the development of PVTT and poor prognosis by reshaping the immunosuppressive environment.

Investigating the Immunomodulatory Impact of Fecal Bacterial Membrane Vesicles and Their IgA Coating Patterns in Crohn's Disease Patients.

The human intestinal tract contains trillions of bacteria that coexist in a symbiotic relationship with human cells. Imbalances in this interaction can lead to disorders such as Crohn's disease (CD). Bacteria membrane vesicles (MVs), which are released by almost all bacteria, have been demonstrated to play a crucial role in bacteria-host interactions. In this study, we assessed the physical characterizations, immunomodulatory effects, and IgA interactions of MVs derived from fecal samples of CD patients and healthy controls (HCs). MVs were isolated from the frozen fecal samples using a combination of ultrafiltration and size-exclusion chromatography. Using nanoparticle tracking analysis, we found that the MVs of the CD patients showed a significantly lower concentration compared to those of the HCs. Cryo-transmission electron microscopy revealed the larger size of the MVs in active CD (Ac-CD) compared to the MVs of remission CD (Re-CD) and HCs. Differentiated monocyte THP-1 cells released more TNF-a when exposed to MVs from the HCs compared to the CD patients. On the other hand, the MVs from the HCs and Re-CD patients but not the Ac-CD patients induced more anti-inflammatory IL-10. Intriguingly, bead-based flow cytometry analysis showed that the MVs of the HCs and Re-CD patients were more coated with IgA compared to those of the Ac-CD patients. These results suggest the potential role of MVs in the immunomodulatory impact on the pathophysiology of CD. Moreover, IgA seems to regulate these effects by direct binding, which was not the case for the Ac-CD patients. Finally, the IgA coating patterns of the MVs could be used as an additional disease biomarker, as they can clearly identify the exacerbation status of CD.

Chimeric antigen receptor macrophages targeting c-MET(CAR-M-c-MET) inhibit pancreatic cancer progression and improve cytotoxic chemotherapeutic efficacy

BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors. Macrophages are abundant in the tumor microenvironment, making them an attractive target for therapeutic intervention. While current immunotherapies, including immune checkpoint inhibition (ICI) and chimeric antigen receptor T (CAR-T) cells, have shown limited efficacy in pancreatic cancer, a novel approach involving chimeric antigen receptor macrophages (CAR-M) has, although promising, not been explored in pancreatic cancer. In this study, we first investigated the role of CAR-M cells targeting c-MET in pancreatic cancer.MethodsThe effectiveness and rationality of c-MET as a target for CAR-M in pancreatic cancer were validated through bioinformatic analyses and immunohistochemical staining of samples from pancreatic cancer patients. We utilized flow cytometry and bioluminescence detection methods to demonstrate the specific binding and phagocytic killing effect of CAR-M on pancreatic cancer cells. Additionally, we observed the process of CAR-M engulfing pancreatic cancer cells using confocal microscopy and a long-term fluorescence live cell imaging system. In an in situ tumor model transplanted into NOD/SCID mice, we administered intraperitoneal injections of CAR-M to confirm its inhibitory function on pancreatic cancer. Furthermore, we validated these findings in human monocyte-derived macrophages (hMDM).ResultsBioinformatics and tumor tissue microarray analyses revealed significantly higher expression levels of c-MET in tumor tissues, compared to the paired peritumoral tissues, and higher c-MET expression correlated with worse patient survival. CAR-M cells were engineered using human monocytic THP-1 cell line and hMDM targeting c-MET (CAR-M-c-MET). The CAR-M-c-MET cells demonstrated highly specific binding to pancreatic cancer cells and exhibited more phagocytosis and killing abilities than the pro-inflammatory polarized control macrophages. In addition, CAR-M-c-MET cells synergized with various cytotoxic chemotherapeutic drugs. In a NOD/SCID murine model, intraperitoneally injected CAR-M-c-MET cells rapidly migrated to tumor tissue and substantially inhibited tumor growth, which did not lead to obvious side effects. Cytokine arrays and mRNA sequencing showed that CAR-M-c-MET produced higher levels of immune activators than control macrophages.ConclusionsThis study provides compelling evidence for the safety and efficacy of CAR-M therapy in treating pancreatic cancer. The results demonstrate that CAR-M-c-MET significantly suppresses pancreatic cancer progression and enhances the effectiveness of cytotoxic chemotherapy. Remarkably, no discernible side effects occur. Further clinical trials are warranted in human pancreatic cancer patients.

The pyruvate dehydrogenase kinase inhibitor dichloroacetate mitigates alcohol-induced hepatic inflammation and metabolic disturbances in mice.

Dichloroacetate (DCA), a pan-pyruvate dehydrogenase kinase inhibitor, ameliorates multiple pathological conditions and tissue injury and shows strong potential for clinical applications. Here, we investigated the preventive effects of DCA in a murine model of alcohol-associated liver disease. C57BL/6J mice were subjected to the acute-on-chronic model of alcohol-associated liver disease and treated with DCA. Livers were assessed in liver histology, biochemistry, and gene expression. Mass spectrometry was used to compare protein expression and metabolite levels. DCA inhibited hepatic expression of inflammatory genes but did not prevent steatosis and hepatocellular injury in ethanol-fed mice. Consistently, DCA repressed the expression of mRNAs for inflammatory genes in LPS-stimulated murine bone-marrow-derived macrophages and human monocytic THP-1 cells and inhibited both gene expression and protein release of interleukin-1 beta. DCA prevented hepatic accumulation of isovaleric acid in ethanol-fed mice, a short-chain fatty acid primarily produced by gut microbiota. In vitro, isovaleric acid potentiated LPS's effects, while DCA prevented this proinflammatory action. Ethanol feeding increased the expression of proteins involved in diverse metabolic pathways, including branched-chain amino acid (BCAA) degradation. In ethanol-fed mice, hepatic Fischer's ratio (the molar ratio of BCAAs to aromatic amino acids Phe and Tyr) and BTR (the molar ratio of BCAAs to Tyr) showed a decrease compared to pair-fed mice; however, this decrease was not observed in DCA-treated ethanol-fed mice. DCA blunted the ethanol-induced increase of BCKDHA, the rate-limiting enzyme in BCAA catabolism, and cytochrome P450 2E1. Ethanol-induced hepatic inflammatory responses and metabolic disturbances were prevented by DCA in mice, indicating the potential to develop pyruvate dehydrogenase kinase inhibitors as an effective therapy to treat alcohol-associated liver disease.

Direct activation of Toll-like receptor 2 signaling stimulated by contact with the interfacial structures of chitin nanofibers

The innate immune system, which eliminates pathogens and abnormal cells, is involved in the pathogenesis of various diseases and infections, where Toll-like receptors (TLRs) play a critical regulatory role. In this study, we investigated the potential of chitin nanofiber (CtNF) to induce an immune response, which is expected to act as an agonist of TLR2. Crab-derived CtNF, surface-deacetylated CtNF, and surface-carboxylated cellulose NF were employed as TLR2-mediated immune stimulator, signal regulator, and cell adhesion promoter, respectively, to fabricate cell culture scaffolds for HEK293 cells with TLR2 and human monocyte THP-1 cells with or without TLR2. Surface deacetylation of CtNF drastically diminished the immunological response of HEK293 cells, suggesting that the N-acetyl groups on the solid CtNF surface were pivotal for TLR2-mediated stimulation. A comparison of wild-type and TLR2-KO THP-1 cells on cell culture substrates with N-acetyl groups ranging from 0 to 1.39 mmol g−1 revealed that immune signaling for nuclear factor-κB and interferon regulatory factor pathways was strongly dependent on the surface N-acetyl group content. The immunostimulatory level at the interface of solid CtNF and immune cells could be regulated by simply mixing CtNF and surface-deacetylated CtNF, which is a significant advantage for its potential use as a novel immunostimulant.

High Content Screening Assay of Inhibitors of the Legionella Pneumophila Histone Methyltransferase RomA in Infected Cells.

Resistance to anti-microbial agents is a world-wide health threat. Thus, there is an urgent need for new treatments. An alternative approach to disarm pathogens consists in developing drugs targeting epigenetic modifiers. Bacterial pathogens can manipulate epigenetic regulatory systems of the host to bypass defences to proliferate and survive. One example is Legionella pneumophila, a Gram-negative intracellular pathogen that targets host chromatin with a specific, secreted bacterial SET-domain methyltransferase named RomA. This histone methyltransferase specifically methylates H3 K14 during infection and is responsible for changing the host epigenetic landscape upon L. pneumophila infection. To inhibit RomA activity during infection, we developed a reliable high-content imaging screening assay, which we used to screen an in-house chemical library developed to inhibit DNA and histone methyltransferases. This assay was optimised using monocytic leukemic THP-1 cells differentiated into macrophages infected with L. pneumophila in a 96- or 384-well plate format using the Opera Phenix (Perkin Elmer) confocal microscope, combined with Columbus software for automated image acquisition and analysis. H3 K14 methylation was followed in infected, single cells and cytotoxicity was assessed in parallel. A first pilot screening of 477 compounds identified a potential starting point for inhibitors of H3 K14 methylation.

Preparation and Complex Characterisation of Stabilised Gold Nanoparticles: Biodistribution and Application for High Resolution In Vivo Imaging.

The Turkevich method was optimized to prepare gold nanoparticles (AuNP) stabilized by polyethyleneglycol (PEG) for µCT. Using various independent modalities, we thoroughly characterized the optimized PEG-AuNPs. Here, we show that PEG-AuNPs are retained in the blood and provide a high contrast in the high-resolution µCT imaging of blood vessels and inner organs. The biodistribution is characterized by prolonged circulation in the blood and accumulation in the liver, spleen and skin. The accumulation of AuNP in the skin resulted in the blue discoloration of eyes and the whole skin. In vitro experiments using a leukemic monocyte THP-1 cell line model expressing high levels of NLRP3 demonstrated that the NLRP3inflammasome was not activated by PEG AuNP. Over 9 months, the mice were scanned by µCT and were in good health. Scans in mice using PEG-stabilized AuNPs in this study were sharper, with a higher contrast, when compared to a commercial contrasting agent at the same dose. The PEG-AuNPs were morphologically and chemically stable for at least two years when stored in the refrigerator.

Potential probiotic Lactiplantibacillus plantarum strains alleviate TNF-α by regulating ADAM17 protein and ameliorate gut integrity through tight junction protein expression in in vitro model

BackgroundLactiplantibacillus species are extensively studied for their ability to regulate host immune responses and functional therapeutic potentials. Nevertheless, there is a lack of understanding on the mechanisms of interactions with the hosts during immunoregulatory activities.MethodsTwo Lactiplantibacillus plantarum strains MKMB01 and MKMB02 were tested for probiotic potential following Indian Council of Medical Research (ICMR) guidelines. Human colorectal adenocarcinoma cells such as HT-29, caco-2, and human monocytic cell THP-1 were also used to study the potential of MKMB01 and MKMB02 in regulating the host immune response when challenged with enteric pathogen Salmonella enterica typhimurium. Cells were pre-treated with MKMB01 and MKMB02 for 4 h and then stimulated with Salmonella. qRT-PCR and ELISA were used to analyze the genes and protein expression. Confocal microscopy and field emission scanning electron microscopy (FESEM) were used to visualize the effects. An Agilent Seahorse XF analyzer was used to determine real-time mitochondrial functioning.ResultsBoth probiotic strains could defend against Salmonella by maintaining gut integrity via expressing tight junction proteins (TJPs), MUC-2, and toll-like receptors (TLRs) negative regulators such as single Ig IL-1-related receptor (SIGIRR), toll-interacting protein (Tollip), interleukin-1 receptor-associated kinase (IRAK)-M, A20, and anti-inflammatory transforming growth factor-β and interleukin-10. Both strains also downregulated the expression of pro-inflammatory cytokines/chemokines interleukin-1β, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor-alpha (TNF-α), interleukin 6, and nitric oxide (NO). Moreover, TNF-α sheddase protein, a disintegrin and metalloproteinase domain 17 (ADAM17), and its regulator iRhom2 were downregulated by both strains. Moreover, the bacteria also ameliorated Salmonella-induced mitochondrial dysfunction by restoring bioenergetic profiles, such as non-mitochondrial respiration, spare respiratory capacity (SRC), basal respiration, adenosine triphosphate (ATP) production, and maximal respiration.ConclusionsMKMB01 and MKMB02 can reduce pathogen-induced gut-associated disorders and therefore should be further explored for their probiotic potential.

Malondialdehyde-specific natural IgM inhibit toll-like receptor 4 and peptidyl-arginine deiminase 4-dependent NETosis triggered by coronary extracellular vesicles of myocardial infarction patients

Abstract Background Neutrophil extracellular traps (NETs) are critical mediators of thromboinflammation during acute myocardial infarction (AMI). However, triggers and signalling pathways of NETosis in AMI remain incompletely understood. Levels of extracellular vesicles (EV) carrying oxidation-specific epitopes (OSE) originating from lipid peroxidation are increased at the culprit site in AMI. Importantly, natural IgM antibodies with specificity for OSE, such as malondialdehyde (MDA), have been shown to modulate functional effects of EV, and are associated with reduced cardiovascular risk. Purpose We investigated the stimulatory capacity of EV on neutrophil effector functions and specifically targeted key mediators of NET formation using pharmacological inhibitors and atheroprotective natural IgM to inhibit this process. Methods Patients were included after diagnosis of ST-segment elevation myocardial infarction and blood was aspirated from the culprit site and peripheral arterial site (n=28) during primary percutaneous coronary intervention (pPCI). Myocardial function was documented by cardiac magnetic resonance imaging 4±2 days and 195±15 days after pPCI. EV were isolated from cell culture supernatants and culprit site plasma for neutrophil stimulation in vitro. Pharmacological inhibitors were used to map NET signalling pathways of EV. Isolated EV were used for neutrophil stimulation in a murine injection model in the presence of the MDA-specific IgM LR04 or an isotype control. NET formation and other neutrophil functions were assessed by flow cytometry, ELISA and fluorescence microscopy. Results Levels of NET surrogate markers and CD45+ MDA+ EV were higher at the culprit site than in the peripheral circulation. EV generated by LPS-activated THP-1 monocytic cells induced in vitro NET formation, release of neutrophil elastase and IL-8, and degranulation of MPO and NGAL in primary human neutrophils, but not reactive oxygen species. Toll-like receptor 4 (TLR4) and peptidyl-arginine deiminase 4 (PAD4) were identified as key mediators of NET formation induced by in vitro-generated EV and EV isolated from the culprit site of AMI patients. Functionally, the MDA-specific monoclonal IgM antibody LR04, but not an isotype control, inhibited the ability of patient-derived and in vitro-generated EV to trigger release of NETs in primary human neutrophils and in mice. Titres of MDA-specific IgM antibodies were inversely associated with the NET marker citH3 in blood of AMI patients. Finally, we found that the concentration of CD45+ MDA+ EV per protective MDA-specific IgM at the culprit site showed an inverse association with left ventricular ejection fraction 72 hours and 6 months after AMI. Conclusions We show that EV can trigger several neutrophil effector functions. EV-induced NET formation is TLR4- and PAD4-dependent and can be inhibited by OSE-specific natural IgM potentially influencing cardiovascular outcomes after an acute event.

Loss of Y-chromosomal genes in macrophages induces paracrine phenotypic alterations in cardiac cells

Abstract Background At the intersection of gender medicine and ageing, mosaic loss of the Y chromosome (mLoY) in hematopoietic cells has emerged as a novel cardiovascular risk factor. As the most prevalent chromosomal aberration in men, mLoY is age-associated and characterised by interindividual varying frequencies of LoY cells in blood. It is associated with an increased risk for cardiovascular disease and mortality. A murine model of mLoY demonstrates myocardial fibrosis and reduced lifespan. However, the interactions between LoY hematopoietic and cardiac cells remain elusive. It is uncertain, whether the loss of single genes or combinations of multiple genes drive the observed effects, impeding the development of targeted therapies. Purpose We aimed to examine the impact of individual Y-chromosomal genes in macrophages concerning their paracrine effects on cardiac cells types. Methods and results To identify target genes, we analysed two single-nuclei RNA sequencing datasets of patient-derived PBMCs and THP-1 monocytic cells for their expression of Y-chromosomal genes. We identified nine genes that exhibited robust and concordant expression in both datasets. Seven were protein coding (RPS4Y, DDX3Y, EIF1AY, ZFY, UTY, USP9Y and KDM5D) and two were non-coding (TTTY14 and LINC00278). Using siRNA pools, we achieved &amp;gt;50% reductions in mRNA content in THP-1 M0 macrophages for all genes (p&amp;lt;0.05) and collected conditioned media (CM). As previous data suggested increased myocardial fibrosis in mLoY, we assessed the impact of CM on primary human cardiac fibroblasts. Notably, treatment with CM from ZFY, TTTY14 or LINC00278 silenced macrophages induced collagen 1A1 protein expression by 1.44-, 1.30- and 1.86-fold, respectively (all p&amp;lt;0.05), suggesting that loss of these genes might contribute to myocardial fibrosis. To explore potential effects on cardiomyocytes, neonatal rat cardiomyocytes were exposed to CM. We observed reduced beating frequencies upon treatment with CM from ZFY, TTTY14 or UTY silenced macrophages (relative fold-changes 0.45, 0.40, 0.53, respectively; all p&amp;lt;0.05). While suggestive of cardiomyocyte stress, we found no changes in the expression of the stress markers Nppa or Nppb, possibly indicating direct effects on ion transporters. Given the strong association of cardiovascular disease with endothelial cell dysfunction, we investigated the effects of CM on human umbilical vein endothelial cells (HUVEC). CM from ZFY and KDM5D silenced macrophages induced ICAM protein expression in HUVEC by 1.9- and 1.6-fold, respectively (both p&amp;lt;0.05). Conclusion Loss of individual Y-chromosomal genes in monocytic cells elicits distinct paracrine effects on various cardiac cell types. Particularly, silencing of ZFY in macrophages demonstrated profound effects on all investigated cell types, warranting further investigation. Additionally, two long non-coding RNAs, previously unexplored in cardiovascular disease, influenced paracrine activity of macrophages.

Impact of Senescent Cell-Derived Extracellular Vesicles on Innate Immune Cell Function.

Extracellular vesicles (EVs) are components of the senescence-associated secretory phenotype (SASP) that influence cellular functions via their cargo. Here, the interaction between EVs derived from senescent (SEVs) and non-senescent (N-SEVs) fibroblasts and the immune system is investigated. Via endocytosis, SEVs are phagocytosed by monocytes, neutrophils, and B cells. Studies with the monocytic THP-1 cell line find that pretreatment with SEVs results in a 32% (p < 0.0001) and 66% (p < 0.0001) increase in lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-α) production when compared to vehicle control or N-SEVs respectively. Interestingly, relative to vehicle control, THP-1 cells exposed to N-SEVs exhibit a 20% decrease in TNF-α secretion (p < 0.05). RNA sequencing reveals significant differences in gene expression in THP-1 cells treated with SEVs or N-SEVs, with vesicle-mediated transport and cell cycle regulation pathways featuring predominantly with N-SEV treatment, while pathways relating to SLITS/ROBO signaling, cell metabolism, and cell cycle regulation are enriched in THP-1 cells treated with SEVs. Proteomic analysis also reveals significant differences between SEV and N-SEV cargo. These results demonstrate that phagocytes and B cells uptake SEVs and drive monocytes toward a more proinflammatory phenotype upon LPS stimulation. SEVs may therefore contribute to the more proinflammatory immune response seen with aging.

α4 Nicotinic Acetylcholine Receptors in Lipopolysaccharide-Related Lung Inflammation

Sepsis remains an important healthcare challenge. The lungs are often affected in sepsis, resulting in acute lung injury characterized by inflammation. Mechanisms involving lipopolysaccharide (LPS) stimulation of toll-like receptor (TLR) signaling with induction of proinflammatory pathways have been implicated in this process. To date, however, studies targeting these pathways have failed to improve outcomes. We have found that LPS may also promote lung injury through the activation of α4 nicotinic acetylcholine receptors (α4 nAChRs) in immune cells. We observed increased expression of α4 nAChRs in human THP-1 monocytic cells exposed to LPS (100 ng/mL, 24 h). We also observed that LPS stimulated the expression of other relevant genes, including tumor necrosis factor-α, interleukin-1β, plasminogen activator inhibitor-1, the solute carrier family 7 member 11, extracellular superoxide dismutase, and transforming growth factor-β1. Of interest, dihydro-β-erythroidine hydrobromide (DHβE), a specific chemical inhibitor of α4 nAChRs, inhibited the LPS-induced expression of these genes. We generated mice with a global knockout mutation of the α4 nAChR subunit in the C57BL/6 background using CRISPR/Cas9 technology. The lungs of these LPS-treated animals demonstrated a reduction in the expression of the above-mentioned genes when compared with the lungs of wild-type animals. In support of the role of oxidative stress, we observed that LPS induced expression of the cystine transporter Slc7a11 in both THP-1 cells and in wild-type mouse lungs. The effects of LPS on THP-1 cells were blocked by the thiol antioxidant N-acetylcysteine and mimicked by redox stress. Importantly, the induction of IL-1β by redox stress was inhibited by the α4 nAChR inhibitor DHβE. Finally, we showed that LPS stimulated calcium influx in THP-1 cells, which was blocked by the α4 nAChR inhibitor. Our observations suggest that LPS promotes lung injury by stimulating redox stress, which activates α4 nAChR signaling and drives proinflammatory cytokine expression.

Pyrimidine Derivatives as Selective COX-2 Inhibitors with Anti-Inflammatory and Antioxidant Properties.

Pyrimidine derivatives exhibit a wide range of biological activities, including anti-inflammatory properties. The aim of this study was to investigate the effects of tested pyrimidine derivatives on the activity of cyclooxygenase isoenzymes (COX-1 and COX-2), antioxidant properties, and their ability to inhibit the growth of inflammatory cells. In vitro tests were conducted to assess the ability of pyrimidine derivatives L1-L4 to inhibit COX-1 and COX-2 activity using the TMPD oxidation assay (N,N,N',N'-tetramethyl-p-phenylenediamine). The compounds' ability to inhibit the growth of lipopolysaccharide (LPS)-stimulated THP-1 (human leukemia monocytic) monocyte cells and their impact on reactive oxygen species (ROS) levels in an inflammatory model were also evaluated. The binding properties of human serum albumin (HSA) were assessed using UV-Vis spectroscopy, circular dichroism (CD), and isothermal titration calorimetry (ITC). Among the tested pyrimidine derivatives, L1 and L2 showed high selectivity towards COX-2, outperforming piroxicam and achieving results comparable to meloxicam. In the sulforhodamine B (SRB) assay, L1 and L2 demonstrated dose-dependent inhibition of LPS-stimulated THP-1 cell growth. Additionally, ROS assays indicated that these compounds reduced free radical levels, confirming their antioxidant properties. Binding studies with albumin revealed that L1 and L2 formed stable complexes with HSA. These results suggest that these compounds could serve as a basis for further research into anti-inflammatory and anticancer drugs with reduced toxicity.