Human Monocytic Cell Research Articles

The Monocytic Cell Line THP-1 as a Validated and Robust Surrogate Model for Human Dendritic Cells.

We have implemented an improved, cost-effective, and highly reproducible protocol for a simple and rapid differentiation of the human leukemia monocytic cell line THP-1 into surrogates for immature dendritic cells (iDCs) or mature dendritic cells (mDCs). The successful differentiation of THP-1 cells into iDCs was determined by high numbers of cells expressing the DC activation markers CD54 (88%) and CD86 (61%), and the absence of the maturation marker CD83. The THP-1-derived mDCs are characterized by high numbers of cells expressing CD54 (99%), CD86 (73%), and the phagocytosis marker CD11b (49%) and, in contrast to THP-1-derived iDCs, CD83 (35%) and the migration marker CXCR4 (70%). Treatment of iDCs with sensitizers, such as NiSO4 and DNCB, led to high expression of CD54 (97%/98%; GMFI, 3.0/3.2-fold induction) and CD86 (64%/96%; GMFI, 4.3/3.2-fold induction) compared to undifferentiated sensitizer-treated THP-1 (CD54, 98%/98%; CD86, 55%/96%). Thus, our iDCs are highly suitable for toxicological studies identifying potential sensitizing or inflammatory compounds. Furthermore, the expression of CD11b, CD83, and CXCR4 on our iDC and mDC surrogates could allow studies investigating the molecular mechanisms of dendritic cell maturation, phagocytosis, migration, and their use as therapeutic targets in various disorders, such as sensitization, inflammation, and cancer.

Stress Granules Inhibit Coxsackievirus B3-Mediated Cell Death via Reduction of Mitochondrial Reactive Oxygen Species and Viral Extracellular Release.

Stress granules (SGs) are cytoplasmic aggregates of RNA-protein complexes that form in response to various cellular stresses and are known to restrict viral access to host translational machinery. However, the underlying molecular mechanisms of SGs during viral infections require further exploration. In this study, we evaluated the effect of SG formation on cellular responses to coxsackievirus B3 (CVB3) infection. Sodium arsenite (AS)-mediated SG formation suppressed cell death induced by tumor necrosis factor-alpha (TNF-a)/cycloheximide (CHX) treatment in HeLa cells, during which G3BP1, an essential SG component, contributed to the modulation of apoptosis pathways. SG formation in response to AS treatment blocked CVB3-mediated cell death, possibly via the reduction of mitochondrial reactive oxygen species. Furthermore, we examined whether AS treatment would affect small extracellular vesicle (sEV) formation and secretion during CVB3 infection and modulate human monocytic cell (THP-1) response. CVB3-enriched sEVs isolated from HeLa cells were able to infect and replicate THP-1 cells without causing cytotoxicity. Interestingly, sEVs from AS-treated HeLa cells inhibited CVB3 replication in THP-1 cells. These findings suggest that SG formation during CVB3 infection modulates cellular response by inhibiting the release of CVB3-enriched sEVs.

Sulfated polygalactofucan from triangular sea bell Turbinaria decurrens attenuates inflammatory cytokines on THP-1 human monocytic macrophages

Inflammation is one of the most significant causes of several chronic diseases, which includes the expression of cytokines activating immune cells to up-regulate the inflammatory cascade. Polysaccharides from marine macroalgae are promising anti-inflammatory agents because of their potential to attenuate inflammatory cytokines. The triangular sea bell Turbinaria decurrens (Sargassaceae) among marine macroalgae is ubiquitous in oceanic waters, and a sulfated polygalactofucan SPTd-2 [→3-(α-L-fucp-(2-OSO3−)-(1 → 4)-α-L-fucp-(3-OAc)-(1 → 4)-β-D-galp-(1→] was purified from the species. The studied polygalactofucan SPTd-2 exhibited anti-inflammatory activities against cyclooxygenase-2 (IC50 10.56 μM) and 5-lipoxygenase (IC50 3.36 μM) with a greater selectivity index (2.35) than ibuprofen (0.44), besides attenuating pro-inflammatory cytokine production, including tumor necrosis factor-α, transforming growth factor-β, interleukin-2, 1β, and interferon-γ. Quantitative real-time polymerase chain reaction displayed that SPTd-2 blocked the mRNA of interferon-γ and interleukin-2, in the human monocytic cell line THP-1. The results showed the potential of SPTd-2 to attenuate inflammation-associated disorders.

Rational design for MgO-modified porous carbon towards enhancing zoledronic acid adsorption

Nitrogen-containing bisphosphonates (N-BPs), namely zoledronic acid (ZA), are typically used as antiresorptive drugs by inhibiting osteoclast formation and functions. However, the long-term use of ZA may increase the risk of osteonecrosis of the jaw (ONJ) after tooth extraction. Hence, this study aims to develop a new sustainable adsorption material for capturing the exposed ZA. The porous activated carbon (AC) incorporated with MgO at various ratios was successfully developed and extensively characterized by several techniques. The adsorption behaviors correlated to their physicochemical properties for ZA removal were also carried out. Furthermore, density functional theory (DFT) was applied to investigate the adsorption mechanism of ZA adsorbed on a carbon surface functionalized with crystalline MgO. The results found that the well-dispersed MgO/AC provided a good adsorption capacity for ZA. The MgO with 15 % wt loading shows the highest performance (73 mg/g) on adsorbing ZA under a neutral condition compared to a bare AC (14 mg/g). The MgO/AC adsorbents were cytocompatible with human monocytic cells in vitro. The DFT result demonstrated that the MgO cluster is an active site for ZA adsorption. This evidence could imply that MgO/AC is a potential adsorbent for ZA removal in preventing ZA-related bone complications.

The Effect of Elasticity of Gelatin Nanoparticles on the Interaction with Macrophages.

Gelatin is a biocompatible, biodegradable, cheap, and nontoxic material, which is already used for pharmaceutical applications. Nanoparticles from gelatin (GNPs) are considered a promising delivery system for hydrophilic and macromolecular drugs. Mechanical properties of particles are recognized as an important parameter affecting drug carrier interaction with biological systems. GNPs offer the preparation of particles with different stiffness. GNPs were loaded with Fluorescein isothiocyanate-labeled 150 kDa dextran (FITC-dextran) yielding also different elastic properties. GNPs were visualized using atomic force microscopy (AFM), and force-distance curves from the center of the particles were evaluated for Young's modulus calculation. The prepared GNPs have Young's moduli from 4.12 MPa for soft to 9.8 MPa for stiff particles. Furthermore, cytokine release (IL-6 and TNF-α), cell viability, and cell uptake were determined on macrophage cell lines from mouse (RAW 264.7) and human (dTHP-1 cells, differentiated human monocytic THP-1 cells) origin for soft and stiff GNPs. Both particle types showed good cell compatibility and did not induce IL-6 and TNF-α release from RAW 264.7 and dTHP-1 cells. Stiffer GNPs were internalized into cells faster and to a larger extent.

Loss of the Immunomodulatory Transcription Factor BATF2 in Humans Is Associated with a Neurological Phenotype.

Epilepsy and mental retardation are known to be associated with pathogenic mutations in a broad range of genes that are expressed in the brain and have a role in neurodevelopment. Here, we report on a family with three affected individuals whose clinical symptoms closely resemble a neurodevelopmental disorder. Whole-exome sequencing identified a homozygous stop-gain mutation, p.Gln19*, in the BATF2 gene in the patients. The BATF2 transcription factor is predominantly expressed in macrophages and monocytes and has been reported to modulate AP-1 transcription factor-mediated pro-inflammatory responses. Transcriptome analysis showed altered base-level expression of interferon-stimulated genes in the patients' blood, typical for type I interferonopathies. Peripheral blood mononuclear cells from all three patients demonstrated elevated responses to innate immune stimuli, which could be reproduced in CRISPR-Cas9-generated BATF2-/- human monocytic cell lines. BATF2 is, therefore, a novel disease-associated gene candidate for severe epilepsy and mental retardation related to dysregulation of immune responses, which underscores the relevance of neuroinflammation for epilepsy.

Patient-specific monocyte-derived microglia as a screening tool for neurodegenerative diseases.

Microglia, the main driver of neuroinflammation, play a central role in the initiation and exacerbation of various neurodegenerative diseases and are now considered a promising therapeutic target. Previous studies on in vitro human microglia and in vivo rodent models lacked scalability, consistency, or physiological relevance, which deterred successful therapeutic outcomes for the past decade. Here we review human blood monocyte-derived microglia-like cells as a robust and consistent approach to generate a patient-specific microglia-like model that can be used in extensive cohort studies for drug testing. We will highlight the strength and applicability of human blood monocyte-derived microglia-like cells to increase translational outcomes by reviewing the advantages of human blood monocyte-derived microglia-like cells in addressing patient heterogeneity and stratification, the basis of personalized medicine.

Galactomannan-graft-poly(methyl methacrylate) nanoparticles induce an anti-inflammatory phenotype in human macrophages.

Macrophages are immune cells that can be activated into either pro-inflammatory M1 or anti-inflammatory M2 phenotypes. Attempts to modulate macrophage phenotype using drugs have been limited by targeting issues and systemic toxicity. This study investigates the effect of drug-free self-assembled hydrolyzed galactomannan-poly(methyl methacrylate) (hGM-g-PMMA) nanoparticles on the activation of the human monocyte-derived macrophage THP-1 cell line. Nanoparticles are cell compatible and are taken up by macrophages. RNA-sequencing analysis of cells exposed to NPs reveal the upregulation of seven metallothionein genes. Additionally, the secretion of pro-inflammatory and anti-inflammatory cytokines upon exposure of unpolarized macrophages and M1-like cells obtained by activation with lipopolysaccharide + interferon-γ to the NPs is reduced and increased, respectively. Finally, nanoparticle-treated macrophages promote fibroblast migration in vitro. Overall, results demonstrate that hGM-g-PMMA nanoparticles induce the release of anti-inflammatory cytokines by THP-1 macrophages, which could pave the way for their application in the therapy of different inflammatory conditions, especially by local delivery.

In vitro cytotoxicity of Mn(I) and Ru(II) carbonyls with a diphenyl pyridyl phosphine coligand towards leukaemia.

Human acute monocytic leukaemia cells were tested under both dark and light conditions for their susceptibility to Mn(I) and Ru(II) carbonyl complexes with a diphenyl pyridyl phosphine coligand. The Ru(II) complex (IC50 = 7.13 ± 0.8 μM) displayed higher outstanding potency against leukaemia than the Mn(I) analogue (54.58 ± 4.1 μM) in the dark and both complexes were completely harmless to healthy mouse bone marrow cells.

Investigating influences of intravenous fluids on HUVEC and U937 monocyte cell lines using the magnetic levitation method.

Intravenous fluids are being widely used in patients of all ages for preventing or treating dehydration in the intensive care units, surgeries in the operation rooms, or administering chemotherapeutic drugs at hospitals. Dextrose, Ringer, and NaCl solutions are widely received as intravenous fluids by hospitalized patients. Despite their widespread administration for over 100 years, studies on their influences on different cell types have been very limited. Increasing evidence suggests that treatment outcomes might be altered by the choice of the administered intravenous fluids. In this study, we investigated the influences of intravenous fluids on human endothelial (HUVEC) and monocyte (U937) cell lines using the magnetic levitation technique. Our magnetic levitation platform provides label-free manipulation of single cells without altering their phenotypic or genetic properties. It allows for monitoring and quantifying behavior of single cells by measuring their levitation heights, deformation indices, and areas. Our results indicate that HUVEC and U937 cell lines respond differently to different intravenous fluids. Dextrose solution decreased the viability of both cell lines while increasing the heterogeneity of areas, deformation, and levitation heights of HUVEC cells. We strongly believe that improved outcomes can be achieved when the influences of intravenous fluids on different cell types are revealed using robust, label-free, and efficient methods.

Glucocorticoids Impair the 7α-Hydroxycholesterol-Enhanced Innate Immune Response.

Glucocorticoids suppress the vascular inflammation that occurs under hypercholesterolemia, as demonstrated in an animal model fed a high-cholesterol diet. However, the molecular mechanisms underlying these beneficial effects remain poorly understood. Because cholesterol is oxidized to form cholesterol oxides (oxysterols) that are capable of inducing inflammation, we investigated whether glucocorticoids affect the immune responses evoked by 7α-hydroxycholesterol (7αOHChol). The treatment of human THP-1 monocytic cells with dexamethasone (Dex) and prednisolone (Pdn) downregulated the expression of pattern recognition receptors (PRRs), such as TLR6 and CD14, and diminished 7αOHChol-enhanced response to FSL-1, a TLR2/6 ligand, and lipopolysaccharide, which interacts with CD14 to initiate immune responses, as determined by the reduced secretion of IL-23 and CCL2, respectively. Glucocorticoids weakened the 7αOHChol-induced production of CCL2 and CCR5 ligands, which was accompanied by decreased migration of monocytic cells and CCR5-expressing Jurkat T cells. Treatment with Dex or Pdn also reduced the phosphorylation of the Akt-1 Src, ERK1/2, and p65 subunits. These results indicate that both Dex and Pdn impair the expression of PRRs and their downstream products, chemokine production, and phosphorylation of signaling molecules. Collectively, glucocorticoids suppress the innate immune response and activation of monocytic cells to an inflammatory phenotype enhanced or induced by 7αOHChol, which may contribute to the anti-inflammatory effects in hypercholesterolemic conditions.

Role of Serum C-C Motif Chemokine Ligand 2 Monocyte Chemotactic Activities in Patients with Non Small Cell Lung Cancer

To examine C-C motif chemokine ligand 2 chemotactic activities, expression and clinical relevance in the peripheral serum of non-small cell lung cancer patients is the objective of the study. The non-small cell lung cancer group consisted of 128 patients diagnosed with the disease in our institution between January 2018 and March 2022, while the healthy group consisted of 112 individuals. By using an enzyme-linked immunosorbent assay, the two group’s peripheral serum was examined for C-C motif chemokine ligand 2 expression levels. The monocyte chemotactic activity of blood plasma from the two groups was assessed using the Transwell chamber technique after human monocytic leukaemia cell line THP-1 cells were grown. Analysis was done on C-C motif chemokine ligand 2 expression levels and the relationship between monocyte chemotactic activity and histopathological features in non-small cell lung cancer patients. Age and gender did not significantly connect with the expression level of C-C motif chemokine ligand 2 or its monocyte chemotactic activity (p>0.05); however, smoking, pathological categorization, tumor, nodes and metastases stage, tumor stage, nodes stage and tumor diameter did (p<0.05). The expression level of C-C motif chemokine ligand 2 was 235.4±25.7 pg/ml in the peripheral serum of non-small cell lung cancer patients and 45.7±10.5 pg/ml in the healthy population; the monocyte chemotactic activity of non-small cell lung cancer patients was 236.5 % and that of healthy people was 86.5 %. They differed from one other in a statistically significant way (p<0.05). In comparison to the normal control group (r=0.87), the lung cancer group’s correlation coefficient between blood C-C motif chemokine ligand 2 and monocyte chemotactic activity was considerably lower (r=0.39). Patients with non-small cell lung cancer patients exhibit inadequate monocyte chemotactic activity, which may one day be targeted therapeutically.

The effect of ox-LDL and platelets on macrophages, M2 macrophage polarization, and foam cell formation.

The accumulation of oxidized LDL (ox-LDL) in macrophages in association with platelet activity leads to the formation of foam cells, which play a key role in the pathophysiology of atherosclerosis and coronary artery diseases (CAD). Here, in this study, we aimed to investigate the simultaneous effect of ox-LDL and platelets on foam cell formation, as well as modification in cell markers. First, the U937, a human monocytic cell line, was cultured in RPMI-1640. Then, isolated platelets were co-cultured with the U937 and exposed to ox-LDL (80 µg/ml) to evaluate the impact of ox-LDL on foam cell formation using Oil red O (ORO) staining. Also, the expression of foam cells' surface markers and CD36, ABCA1, SR-B1, ACAT1, and LXRα genes, which are involved in macrophage metabolism and ox-LDL uptake, was measured by flow cytometry and real-time PCR, respectively. Our findings suggest that platelets promoted foam cell formation (ORO-positive cells), accompanied by a higher level of CD163+ M2 macrophages. Furthermore, the expression of CD36, ABCA1, SR-B1, ACAT1, and LXRα genes, which are implicated in cholesterol accumulation in macrophages, was significantly upregulated in the ox-LDL+ platelets group compared to the control (P < 0.05). Moreover, the up-regulation of CD36, ABCA1, and SR-B1 genes in the ox-LDL+ platelets group was more accentuated compared to the ox-LDL group (P < 0.05). Owing to the positive effector role of platelets in the formation of foam cells and CD163+ cells, it could be assumed that platelets play a dual role in the development of these cells.

Follicle-Stimulating Hormone Provokes Macrophages to Secrete IL-1β Contributing to Atherosclerosis Progression.

Abnormally high follicle-stimulating hormone (FSH) has been reported to associate with cardiovascular diseases in prostate cancer patients with specific androgen deprivation therapy and in menopausal women. All of the cardiovascular diseases were involved in atherosclerosis. However, the pathogenic mechanism of FSH-associated atherosclerosis remains uncertain. Apolipoprotein E-deficient mice were chosen to develop atherosclerosis, of which the plaques were analyzed with administration of short- and long-term FSH imitating androgen deprivation therapy-induced and menopausal FSH elevation. The study showed that short- and long-term exposure of FSH significantly accelerated atherosclerosis progression in apolipoprotein E-deficient mice, manifested as strikingly increased plaques in the aorta and its roots, increased macrophage content, reduced fibrin, and an enlarged necrotic core, suggesting a decrease in plaque stability. Furthermore, expression profiles from the Gene Expression Omnibus GSE21545 dataset revealed that macrophage inflammation was tightly associated with FSH-induced atherosclerotic progression. The human monocyte cell line THP-1 was induced by PMA and worked as a macrophage model to detect inflammatory factors and cellular functions. FSH remarkably promoted the expression of IL-1β in macrophages and strikingly increased the chemotactic migratory capacity of macrophages toward MCP-1, but the promigratory capacity of FSH was attenuated in foam cells. Overall, we revealed that FSH significantly promoted the inflammatory response and migration of macrophages, thereby provoking atherosclerosis development.

Effect of Leishmania RNA virus 2 on virulence factors and cytokines gene expression in a human macrophage infected with Leishmania major: A preliminary study

Cutaneous leishmaniasis (CL) is one of the most important infectious parasitic diseases in the world caused by the Leishmania parasite. In recent decades, the presence of a virus from the Totiviridae family has been proven in some Leishmania species. Although the existence of LRV2 in the Old world Leishmania species has been confirmed, almost no studies have been done to determine the potential impact of LRV2 on the immunopathogenicity of the Leishmania parasite.In this preliminary study, we measured the expression of target genes, including Glycoprotein 63 (gp63), Heat Shock Protein 70 (hsp70), Cysteine Protease b (cpb), Interleukin 1 beta (IL-1β), IL8 and IL-12 in LRV2 positive Leishmania major strain (LRV2+L. major) and LRV2 negative L. major strain (LRV2-L. major). We exposed THP-1, a human leukemia monocytic cell line, to promastigotes of both strains. After the initial infection, RNA was extracted at different time points, and the relative gene expression was determined using a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Findings showed that the presence of LRV2 in L. major was able to increase the expression of gp63, hsp70, and cpb genes; also, we observed lower levels of expression in cytokine genes of IL-1β, IL-8, IL-12 in the presence of LRV2+, which are critical factors in the host's immune response against leishmaniasis. These changes could suggest that the presence of LRV2 in L. major parasite may change the outcome of the disease and increase the probability of Leishmania survival; nevertheless, further studies are needed to confirm our results.

Enteric-Coated Cologrit Tablet Exhibit Robust Anti-Inflammatory Response in Ulcerative Colitis-like In-Vitro Models by Attuning NFκB-Centric Signaling Axis

Ulcerative colitis (UC) is an inflammatory bowel disease that affects the patients' colorectal area culminating in an inflamed 'leaky gut.' The majority of UC treatments only provide temporary respite leading to its relapse. Therefore, this study investigated the efficacy of the enteric-coated 'Cologrit' (EC) tablet in alleviating UC-like inflammation. Cologrit is formulated using polyherbal extracts that have anti-inflammatory qualities according to ancient Ayurveda scriptures. Phytochemical profiling revealed the presence of gallic acid, rutin, ellagic acid, and imperatorin in Cologrit formulation. Cologrit treatment decreased inflammation in LPS-induced transformed THP-1 macrophages, and TNF-α-stimulated human colorectal (HT-29) cells through the modulation of NFκB activity, IL-6 production, and NFκB, IL-1β, IL-8, and CXCL5 mRNA expression levels. Cologrit also lessened human monocytic (U937) cell adhesion to HT29 cells. Methacrylic acid-ethylacrylate copolymer-coating of the enteric Cologrit tablets (EC) supported their dissolution, and the release of phytochemicals in the small intestine pH 7.0 environment in a simulated gastrointestinal digestion model. Small intestine EC digestae effectively abridged dextran sodium sulfate (2.5% w/v)-induced cell viability loss and oxidative stress in human colon epithelial Caco-2 cells. In conclusion, the enteric-coated Cologrit tablets demonstrated good small intestine-specific phytochemical delivery capability, and decreased UC-like inflammation, and oxidative stress through the regulation of TNF-α/NFκB/IL6 signaling axis.

Bystander effect of SARS-CoV-2 spike protein on human monocytic THP-1 cell activation and initiation of prothrombogenic stimulus representing severe COVID-19

BackgroundHypercoagulable state and thromboembolic complications are potential life-threatening events in COVID-19 patients. Our previous studies demonstrated that SARS-CoV-2 infection as well as viral spike protein expressed epithelial cells exhibit senescence with the release of inflammatory molecules, including alarmins.FindingsWe observed extracellular alarmins present in the culture media of SARS-CoV-2 spike expressing cells activate human THP-1 monocytes to secrete pro-inflammatory cytokines to a significant level. The release of THP-1 derived pro-inflammatory cytokine signature correlated with the serum of acute COVID-19 patient, but not in post-COVID-19 state. Our study suggested that the alarmins secreted by spike expressing cells, initiated phagocytosis property of THP-1 cells. The phagocytic monocytes secreted complement component C5a and generated an autocrine signal via C5aR1 receptor. The C5a-C5aR1 signal induced formation of monocyte mediated extracellular trap resulted in the generation of a prothrombogenic stimulus with activating platelets and increased tissue factor activity. We also observed an enhanced C5a level, platelet activating factor, and high tissue factor activity in the serum of acute COVID-19 patients, but not in recovered patients.ConclusionOur present study demonstrated that SARS-CoV-2 spike protein modulates monocyte responses in a paracrine manner for prothrombogenic stimulus by the generation of C5a complement component.

Binding to Iron Quercetin Complexes Increases the Antioxidant Capacity of the Major Birch Pollen Allergen Bet v 1 and Reduces Its Allergenicity.

Bet v 1 is the major allergen in birch pollen to which up to 95% of patients sensitized to birch respond. As a member of the pathogenesis-related PR 10 family, its natural function is implicated in plant defense, with a member of the PR10 family being reported to be upregulated under iron deficiency. As such, we assessed the function of Bet v 1 to sequester iron and its immunomodulatory properties on human immune cells. Binding of Bet v 1 to iron quercetin complexes FeQ2 was determined in docking calculations and by spectroscopy. Serum IgE-binding to Bet v 1 with (holoBet v1) and without ligands (apoBet v 1) were assessed by ELISA, blocking experiments and Western Blot. Crosslinking-capacity of apo/holoBet v 1 were assessed on human mast cells and Arylhydrocarbon receptor (AhR) activation with the human reporter cellline AZ-AHR. Human PBMCs were stimulated and assessed for labile iron and phenotypic changes by flow cytometry. Bet v 1 bound to FeQ2 strongly with calculated Kd values of 1 nm surpassing affinities to quercetin alone nearly by a factor of 1000. Binding to FeQ2 masked IgE epitopes and decreased IgE binding up to 80% and impaired degranulation of sensitized human mast cells. Bet v 1 facilitated the shuttling of quercetin, which activated the anti-inflammatory AhR pathway and increased the labile iron pool of human monocytic cells. The increase of labile iron was associated with an anti-inflammatory phenotype in CD14+monocytes and downregulation of HLADR. To summarize, we reveal for the first time that FeQ2 binding reduces the allergenicity of Bet v 1 due to ligand masking, but also actively contributes anti-inflammatory stimuli to human monocytes, thereby fostering tolerance. Nourishing immune cells with complex iron may thus represent a promising antigen-independent immunotherapeutic approach to improve efficacy in allergen immunotherapy.

Cerium Nitrate Stiffens In Vitro Skin Models and Reduces Pseudomonas aeruginosa Pathogenicity and Penetration Through Skin Models.

Objective: Cerium nitrate (CeN) plus silver sulfadiazine (SSD) cream has been used for 40-plus years to manage burns. CeN produces a hardened eschar believed to resist bacterial colonization/infection. To evaluate this potential mechanism, we treated in vitro skin models or Pseudomonas aeruginosa with CeN and measured mechanical properties of the models and bacterial virulence, respectively. Approach: We treated three-dimensional-collagen matrix and ex-vivo-burned porcine skin with CeN and evaluated stiffness and P. aeruginosa penetration. In addition, we treated P. aeruginosa with CeN and evaluated the bacteria's motility, skin model penetration, susceptibility to be phagocytized by the human monocytic cell line THP-1, and ability to stimulate this cell line to produce cytokines. Results: CeN treatment of skin models stiffened them and made them resistant to P. aeruginosa penetration. Inversely, CeN treatment of P. aeruginosa reduced their motility, penetration through skin models (ex-vivo-burned porcine skin), and ability to stimulate cytokine production (tumor necrosis factor-α [TNF-α] and interleukin 8 [IL-8]) by THP-1 cells. In addition, CeN-treated Pseudomonas was more readily phagocytized by THP-1 cells. Finally, P. aeruginosa inoculated on CeN-treated ex-vivo-burned porcine skin was more susceptible to killing by a silver dressing. Innovation: In vitro skin models offer a platform for screening drugs that interfere with bacterial penetration into wounded tissue. Conclusion: CeN treatment reduced P. aeruginosa virulence, altered the mechanical properties of ex-vivo-burned porcine skin and collagen matrix, retarded penetration of P. aeruginosa through the skin models, and resulted in increased vulnerability of P. aeruginosa to killing by antimicrobial wound dressings. These data support the use of CeN in burn management.

Application of deep generative model for design of Pyrrolo[2,3-d] pyrimidine derivatives as new selective TANK binding kinase 1 (TBK1) inhibitors

The deep conditional transformer neural network SyntaLinker was applied to identify compounds with pyrrolo[2,3-d]pyrimidine scaffold as potent selective TBK1 inhibitor. Further medicinal chemistry optimization campaign led to the discovery of the most potent compound 7l, which exhibited strong enzymatic inhibitory activity against TBK1 with an IC50 value of 22.4 nM 7l had a superior inhibitory activity in human monocytic THP1-Blue cells reporter gene assay than MRT67307. Furthermore, 7l significantly inhibited TBK1 downstream target genes cxcl10 and ifnβ expression in THP1 and RAW264.7 cells induced by poly (I:C) and lipopolysaccharide, respectively. This study suggested that combination of deep conditional transformer neural network SyntaLinker and transfer learning could be a powerful tool for scaffold hopping in drug discovery.