Green (Ulva fenestrata) and Brown (Saccharina latissima) Macroalgae Similarly Modulate Inflammatory Signaling by Activating NF-κB and Dampening IRF in Human Macrophage-Like Cells.

Macroalgae are considered healthy food ingredients due to their content in numerous bioactive compounds, and the traditional use of whole macroalgae in Asian cuisine suggests a contribution to longevity. Although much information is available about the bioactivity of pure algal compounds, such as different polyphenols and polysaccharides, documentation of potential effects of whole macroalgae as part of Western diets is limited. Lifestyle- and age-related diseases, which have a high impact on population health, are closely connected to underlying chronic inflammation. Therefore, we have studied crude extracts of green (Ulva fenestrata) and brown (Saccharina latissima) macroalgae, as two of the most promising food macroalgae in the Nordic countries for their effect on inflammation in vitro. Human macrophage-like reporter THP-1 cells were treated with macroalgae extracts and stimulated with lipopolysaccharide (LPS) to induce inflammatory signalling. Effects of the macroalgae extracts were assessed on transcription factor activity of NF-κB and IRF as well as secretion and/or expression of the cytokines TNF-α and IFN-ß and chemokines IL-8 and CXCL10. The crude macroalgae extracts were further separated into polyphenol-enriched and polysaccharide-enriched fractions, which were also tested for their effect on transcription factor activity. Interestingly, we observed a selective activation of NF-κB, when cells were treated with macroalgae extracts. On the other hand, pretreatment with macroalgae extracts selectively repressed IRF activation when inflammatory signaling was subsequently induced by LPS. This effect was consistent for both tested species as well as for polyphenol- and polysaccharide-enriched fractions, of which the latter had more pronounced effects. Overall, this is the first indication of how macroalgae could modulate inflammatory signaling by selective activation and subsequent repression of different pathways. Further in vitro and in vivo studies of this mechanism would be needed to understand how macroalgae consumption could influence the prevention of noncommunicable, lifestyle- and age-related diseases that are highly related to unbalanced inflammatory processes.

The non-pathogenic protozoon Leishmania tarentolae interferes with the activation of NLRP3 inflammasome in human cells: new perspectives in the control of inflammation.

Background: Innate immune responses against infectious agents can act as triggers of inflammatory diseases. On the other hand, various pathogens have developed mechanisms for the evasion of the immune response, based on an inhibition of innate immunity and inflammatory responses. Inflammatory diseases could thus be controlled through the administration of pathogens or pathogen-derived molecules, capable of interfering with the mechanisms at the basis of inflammation. In this framework, the NLRP3 inflammasome is an important component in innate antimicrobial responses and a major player in the inflammatory disease. Parasites of the genus Leishmania are master manipulators of innate immune mechanisms, and different species have been shown to inhibit inflammasome formation. However, the exploitation of pathogenic Leishmania species as blockers of NLRP3-based inflammatory diseases poses safety concerns. Methods: To circumvent safety issues associated with pathogenic parasites, we focused on Leishmania tarentolae, a species of Leishmania that is not infectious to humans. Because NLRP3 typically develops in macrophages, in response to the detection and engulfment microorganisms, we performed our experiments on a monocyte-macrophage cell line (THP-1), either wild type or knockout for ASC, a key component of NLRP3 formation, with determination of cytokines and other markers of inflammation. Results: L. tarentolae was shown to possess the capability of dampening the formation of NLRP3 inflammasome and the consequent expression of pro-inflammatory molecules, with minor differences compared to effects of pathogenic Leishmania species. Conclusion: The non-pathogenic L. tarentolae appears a promising pro-biotic microbe with anti-inflammatory properties or a source of immune modulating cellular fractions or molecules, capable of interfering with the formation of the NLRP3 inflammasome.

Non-invasive Physical Plasma Modulates Macrophage Polarization: A Potential Strategy for Tumor Microenvironment Remodeling.

BACKGROUND/AIM: Non-invasive physical plasma (NIPP) has shown promise in the treatment of cancer. However, conflicting results have been reported regarding the effect of NIPP on macrophage polarization. As tumor-associated macrophages (TAMs) are essential in the regulation of cancer development, this study aimed to determine the role of NIPP treatment in macrophage polarization and tumor-microenvironment (TME) remodeling. MATERIALS AND METHODS: A portable NIPP device, Plasma Care (Terraplasma Medical, Garching, Germany), was employed as the source of NIPP. The human monocytic cell line THP-1 was adopted as the cell model for macrophage differentiation and polarization. The effects of NIPP treatment on temperature, pH value, and oxidative stress induction of the culture medium were examined to validate the feasibility of applying the NIPP device in subsequent cell treatment. The changes in morphology, viability, and proliferation of THP-1 cells after NIPP treatment were determined. The expression of M1/M2 macrophage markers was examined by real-time quantitative polymerase chain reaction. RESULTS: No significant changes were observed in temperature and pH value after NIPP treatment, while the formation of hydrogen peroxide was promoted in a time-dependent manner. Cell morphology, viability, and proliferation were not affected by up to 6 minutes of NIPP treatment. In monocytes, 6 minutes of NIPP treatment significantly increased the expression of M1 markers (TNF-α and IL-6) and suppressed the M2 marker (CD206), findings which were consistent in the monocyte-derived macrophages. Furthermore, NIPP treatment also significantly promoted M1 polarization in the monocyte-derived macrophages induced by phorbol 12-myristate 13-acetate. CONCLUSION: NIPP is a safe and robust oxidative stress inducer and showed potential in TAM regulation by promoting M1 macrophage polarization.

Ampelopsin facilitates diabetic wound healing and keratinocyte cell progression by inhibiting the NLRP3 inflammasome pathway in macrophages.

Ampelopsin (AMP) had a wound-healing effect in rat skin wounds with or without purulent infection. However, the role of AMP in diabetic wound healing remains poorly defined. Wounds were created on the dorsal skin of type 2 diabetic mouse model, and the histological features of wounds were examined by hematoxylin and eosin (HE) staining. Caspase-1 activity and the secretion of inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). Cell viability and migration were examined through cell counting kit-8 (CCK-8) and wound healing assays, respectively. AMP facilitated wound healing in vivo. AMP notably facilitated platelet endothelial cell adhesion molecule-31 (CD31), collagen type I alpha 1 chain (COL1A1), and alpha-smooth muscle actin (α-SMA), and inhibited matrix metallopeptidase 9 (MMP9) and cyclooxygenase 2 (Cox2) expression in diabetic wounds. The inflammasome pathway was implicated in skin injury. AMP inhibited pro-inflammatory factor secretions and NLR family pyrin domain containing 3 (NLRP3) inflammasome pathway in diabetic wounds and high glucose-treated THP-1 macrophages. AMP-mediated NLRP3 inflammasome inhibition in THP-1 macrophages increased cell viability and migratory capacity in HaCaT cells. AMP facilitated diabetic wound healing and increased keratinocyte cell viability and migratory ability by inhibiting the NLRP3 inflammasome pathway in macrophages.

Synthetic silica fibers of different length, diameter and shape: synthesis and interaction with rat (NR8383) and human (THP-1) macrophages in vitro, including chemotaxis and gene expression profile.

BACKGROUND: Inhalation of biopersistent fibers like asbestos can cause strong chronic inflammatory effects, often resulting in fibrosis or even cancer. The interplay between fiber shape, fiber size and the resulting biological effects is still poorly understood due to the lack of reference materials. RESULTS: We investigated how length, diameter, aspect ratio, and shape of synthetic silica fibers influence inflammatory effects at doses up to 250 µg cm-2. Silica nanofibers were prepared with different diameter and shape. Straight (length ca. 6 to 8 µm, thickness ca. 0.25 to 0.35 µm, aspect ratio ca. 17:1 to 32:1) and curly fibers (length ca. 9 µm, thickness ca. 0.13 µm, radius of curvature ca. 0.5 µm, aspect ratio ca. 70:1) were dispersed in water with no apparent change in the fiber shape during up to 28 days. Upon immersion in aqueous saline (DPBS), the fibers released about 5 wt% silica after 7 days irrespectively of their shape. The uptake of the fibers by macrophages (human THP-1 and rat NR8383) was studied by scanning electron microscopy and confocal laser scanning microscopy. Some fibers were completely taken up whereas others were only partially internalized, leading to visual damage of the cell wall. The biological effects were assessed by determining cell toxicity, particle-induced chemotaxis, and the induction of gene expression of inflammatory mediators. CONCLUSIONS: Straight fibers were only slightly cytotoxic and caused weak cell migration, regardless of their thickness, while the curly fibers were more toxic and caused significantly stronger chemotaxis. Curly fibers also had the strongest effect on the expression of cytokines and chemokines. This may be due to the different aspect ratio or its twisted shape.

Inflammatory corpuscle AIM2 facilitates macrophage foam cell formation by inhibiting cholesterol efflux protein ABCA1.

The inflammatory corpuscle recombinant absents in melanoma 2 (AIM2) and cholesterol efflux protein ATP binding cassette transporter A1(ABCA1) have been reported to play opposing roles in atherosclerosis (AS) plaques. However, the relationship between AIM2 and ABCA1 remains unclear. In this study, we explored the potential connection between AIM2 and ABCA1 in the modulation of AS by bioinformatic analysis combined with in vitro experiments. The GEO database was used to obtain AS transcriptional profiling data; screen differentially expressed genes (DEGs) and construct a weighted gene co-expression network analysis (WGCNA) to obtain AS-related modules. Phorbol myristate acetate (PMA) was used to induce macrophage modelling in THP-1 cells, and ox-LDL was used to induce macrophage foam cell formation. The experiment was divided into Negative Control (NC) group, Model Control (MC) group, AIM2 overexpression + ox-LDL (OE AIM2 + ox-LDL) group, and AIM2 short hairpin RNA + ox-LDL (sh AIM2 + ox-LDL) group. The intracellular cholesterol efflux rate was detected by scintillation counting; high-performance liquid chromatography (HPLC) was used to detect intracellular cholesterol levels; apoptosis levels were detected by TUNEL kit; levels of inflammatory markers (IL-1ß, IL-18, ROS, and GSH) were detected by ELISA kits; and levels of AIM2 and ABCA1 proteins were detected by Western blot. Bioinformatic analysis revealed that the turquoise module correlated most strongly with AS, and AIM2 and ABCA1 were co-expressed in the turquoise module with a trend towards negative correlation. In vitro experiments demonstrated that AIM2 inhibited macrophage cholesterol efflux, resulting in increased intracellular cholesterol levels and foam cell formation. Moreover, AIM2 had a synergistic effect with ox-LDL, exacerbating macrophage oxidative stress and inflammatory response. Silencing AIM2 ameliorated the above conditions. Furthermore, the protein expression levels of AIM2 and ABCA1 were consistent with the bioinformatic analysis, showing a negative correlation. AIM2 inhibits ABCA1 expression, causing abnormal cholesterol metabolism in macrophages and ultimately leading to foam cell formation. Inhibiting AIM2 may reverse this process. Overall, our study suggests that AIM2 is a reliable anti-inflammatory therapeutic target for AS. Inhibiting AIM2 expression may reduce foam cell formation and, consequently, inhibit the progression of AS plaques.

Phytochemical study of Magonia pubescens A. St.-Hil. and cytotoxicity of branches aqueous extract on breast cancer and leukemia cells.

Magonia pubescens is a natural species from the Brazilian cerrado biome. Its fruits and seeds are used in the treatment of seborrheic dermatitis, a common inflammatory skin disease. In this work, the known compounds lapachol, stigmasterol, maniladiol and scopoletin were isolated from hexane and dichloromethane extracts of M. pubescens branches. The aqueous extract of this material was fractioned through a liquid-liquid partition and the obtained fractions were analyzed by UHPLC-MS/MS. The results obtained were compared with data from three databases, leading to the putative identification of 51 compounds from different classes, including flavonoids, saponins and triterpenes. The cytotoxicity of aqueous fractions was assayed against breast cancer (MDA-MB-231) and leukemia (THP-1 and K562) cells. The best activity was observed for fraction AE3 against MDA-MB-231 cells (IC50 30.72 µg.mL-1).

The amoeboid migration of monocytes in confining channels requires the local remodeling of the cortical actin cytoskeleton by cofilin-1.

Within the bloodstream, monocytes must traverse the microvasculature to prevent leukostasis, which is the entrapment of monocytes within the confines of the microvasculature. Using the model cell line, THP-1, and VCAM-1 coated channels to simulate the microvasculature surface, we demonstrate that monocytes predominantly adopt an amoeboid phenotype, which is characterized by the formation of blebs. As opposed to cortical actin flow in leader blebs, cell movement is correlated with myosin contraction at the cell rear. It was previously documented that cofilin-1 promotes cortical actin turnover at leader bleb necks in melanoma cells. In monocytes, our data suggest that cofilin-1 promotes the local upregulation of myosin contractility through actin cytoskeleton remodeling. In support of this concept, cofilin-1 is found to localize to a single cell edge. Moreover, the widespread upregulation of myosin contractility was found to inhibit migration. Thus, monocytes within the microvasculature may avoid entrapment by adopting an amoeboid mode of migration.

Spleen tyrosine kinase inhibitor R406 has both antiviral and anti-inflammatory effects on severe influenza A infection.

Death due to severe influenza is usually a fatal complication of a dysregulated immune response more than the acute virulence of an infectious agent. Although spleen tyrosine kinase (SYK) as a critical immune signaling molecule and therapeutic target plays roles in airway inflammation and acute lung injury, the role of SYK in influenza virus infection is not clear. Here, we investigated the antiviral and anti-inflammatory effects of SYK inhibitor R406 on influenza infection through a coculture model of human alveolar epithelial (A549) and macrophage (THP-1) cell lines and mouse model. The results showed that R406 treatment increased the viability of A549 and decreased the pathogenicity and mortality of lethal influenza virus in mice with influenza A infection, decreased levels of intracellular signaling molecules under the condition of inflammation during influenza virus infection. Combination therapy with oseltamivir further ameliorated histopathological damage in the lungs of mice and further delayed the initial time to death compared with R406 treatment alone. This study demonstrated that phosphorylation of SYK is involved in the pathogenesis of influenza, and R406 has antiviral and anti-inflammatory effects on the treatment of the disease, which may be realized through multiple pathways, including the already reported SYK/STAT/IFNs-mediated antiviral pathway, as well as TNF-α/SYK- and SYK/Akt-based immunomodulation pathway.

Itaconic acid inhibits nontuberculous mycobacterial growth in pH dependent manner while 4-octyl-itaconic acid enhances THP-1 clearance of nontuberculous mycobacteria in vitro.

Increasingly prevalent, nontuberculous mycobacteria (NTM) infections affect approximately 20% of people with cystic fibrosis (CF). Previous studies of CF sputum identified lower levels of the host metabolite itaconate in those infected with NTM. Itaconate can inhibit the growth of M. tuberculosis (MTB) in vitro via the inhibition of the glyoxylate cycle enzyme (ICL), but its impact on NTM is unclear. To test itaconic acid's (IA) effect on NTM growth, laboratory and CF clinical strains of Mycobacterium abscessus and Mycobacterium avium were cultured in 7H9 minimal media supplemented with 1-10 mM of IA and short-chain fatty acids (SCFA). M. avium and M. abscessus grew when supplemented with SCFAs, whereas the addition of IA (≥ 10 mM) completely inhibited NTM growth. NTM supplemented with acetate or propionate and 5 mM IA displayed slower growth than NTM cultured with SCFA and ≤ 1 mM of IA. However, IA's inhibition of NTM was pH dependent; as similar and higher quantities (100 mM) of pH adjusted IA (pH 7) did not inhibit growth in vitro, while in an acidic minimal media (pH 6.1), 1 to 5 mM of non-pH adjusted IA inhibited growth. None of the examined isolates displayed the ability to utilize IA as a carbon source, and IA added to M. abscessus isocitrate lyase (ICL) decreased enzymatic activity. Lastly, the addition of cell-permeable 4-octyl itaconate (4-OI) to THP-1 cells enhanced NTM clearance, demonstrating a potential role for IA/itaconate in host defense against NTM infections.

Quantifying NF-κB Activation by Flow Cytometry of IκBα Degradation.

Nuclear factor-κB (NF-κB) is a crucial pro-inflammatory transcription factor whose activation is of immense interest to immunology research. Estimation of NF-κB activation through flow cytometry is not possible due to the unavailability of robust flow cytometry antibodies that can bind to its phosphorylated, active, nuclear form. In this protocol, we describe a flow cytometry assay that measures the activation of the pro-inflammatory transcription factor NF-κB in stimulated immune cells by quantifying the degradation of its upstream regulator IκBα. We demonstrate the utility of this protocol by assessment of intracellular IκBα in human primary regulatory T cells experiencing TNFR2 agonism, a process previously reported to activate NF-κB in these cells. We also show that this assay may be applied to study NF-κB activation in other cell types, such as human primary T cells and THP-1 cell-derived macrophages, when induced by their corresponding inflammatory cues. Thus, this robust and reproducible protocol will be of interest to a wide range of scientists who aim to measure NF-κB activity in medium-to-high-throughput assays. © 2024 Wiley Periodicals LLC. Basic Protocol: Quantifying inflammatory activation by flow cytometry of IκBα degradation Support Protocol 1: Isolating and expanding human regulatory T cells Support Protocol 2: Calculating IC50 from flow cytometry data using Excel.

Total glucosides of paeony alleviates cGAS-STING-mediated diseases by blocking the STING-IRF3 interaction.

In the realm of autoimmune and inflammatory diseases, the cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) signaling pathway has been thoroughly investigated and established. Despite this, the clinical approval of drugs targeting the cGAS-STING pathway has been limited. The Total glucosides of paeony (TGP) is highly anti-inflammatory and is commonly used in the treatment of rheumatoid arthritis (RA), emerged as a subject of our study. We found that the TGP markedly reduced the activation of the cGAS-STING signaling pathway, triggered by various cGAS-STING agonists, in mouse bone marrow-derived macrophages (BMDMs) and Tohoku Hospital Pediatrics-1 (THP-1) cells. This inhibition was noted alongside the suppression of interferon regulatory factor 3 (IRF3) phosphorylation and the expression of interferon-beta (IFN-ß), C-X-C motif chemokine ligand 10 (CXCL10), and inflammatory mediators such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). The mechanism of action appeared to involve the TGP's attenuation of the STING-IRF3 interaction, without affecting STING oligomerization, thereby inhibiting the activation of downstream signaling pathways. In vivo, the TGP hindered the initiation of the cGAS-STING pathway by the STING agonist dimethylxanthenone-4-acetic acid (DMXAA) and exhibited promising therapeutic effects in a model of acute liver injury induced by lipopolysaccharide (LPS) and D-galactosamine (D-GalN). Our findings underscore the potential of the TGP as an effective inhibitor of the cGAS-STING pathway, offering a new treatment avenue for inflammatory and autoimmune diseases mediated by this pathway.

Profiling of Early Immune Responses to Vaccination Using THP-1-Derived Dendritic Cells.

The COVID-19 pandemic has made assessing vaccine efficacy more challenging. Besides neutralizing antibody assays, systems vaccinology studies use omics technology to reveal immune response mechanisms and identify gene signatures in human peripheral blood mononuclear cells (PBMCs). However, due to their low proportion in PBMCs, profiling the immune response signatures of dendritic cells (DCs) is difficult. Here, we develop a predictive model for evaluating early immune responses in dendritic cells. We establish a THP-1-derived dendritic cell (TDDC) model and stimulate their maturation in vitro with an optimal dose of attenuated yellow fever 17D (YF-17D). Transcriptomic analysis reveals that type I interferon (IFN-I)-induced immunity plays a key role in dendritic cells. IFN-I regulatory biomarkers (IRF7, SIGLEC1) and IFN-I-inducible biomarkers (IFI27, IFI44, IFIT1, IFIT3, ISG15, MX1, OAS2, OAS3) are identified and validated in vitro and in vivo. Furthermore, we apply this TDDC approach to various types of vaccines, providing novel insights into their early immune response signatures and their heterogeneity in vaccine recipients. Our findings suggest that a standardizable TDDC model is a promising predictive approach to assessing early immunity in DCs. Further research into vaccine efficacy assessment approaches on various types of immune cells could lead to a systemic regimen for vaccine development in the future.

Krüppel-like Factor-4-Mediated Macrophage Polarization and Phenotypic Transitions Drive Intestinal Fibrosis in THP-1 Monocyte Models In Vitro.

Background and Objectives: Despite the fact that biologic drugs have transformed inflammatory bowel disease (IBD) treatment, addressing fibrosis-related strictures remains a research gap. This study explored the roles of cytokines, macrophages, and Krüppel-like factors (KLFs), specifically KLF4, in intestinal fibrosis, as well as the interplay of KLF4 with various gut components. Materials and Methods: This study examined macrophage subtypes, their KLF4 expression, and the effects of KLF4 knockdown on macrophage polarization and cytokine expression using THP-1 monocyte models. Co-culture experiments with stromal myofibroblasts and a conditioned medium from macrophage subtype cultures were conducted to study the role of these cells in intestinal fibrosis. Human-induced pluripotent stem cell-derived small intestinal organoids were used to confirm inflammatory and fibrotic responses in the human small intestinal epithelium. Results: Each macrophage subtype exhibited distinct phenotypes and KLF4 expression. Knockdown of KLF4 induced inflammatory cytokine expression in M0, M2a, and M2c cells. M2b exerted anti-fibrotic effects via interleukin (IL)-10. M0 and M2b cells showed a high migratory capacity toward activated stromal myofibroblasts. M0 cells interacting with activated stromal myofibroblasts transformed into inflammatory macrophages, thereby increasing pro-inflammatory cytokine expression. The expression of IL-36α, linked to fibrosis, was upregulated. Conclusions: This study elucidated the role of KLF4 in macrophage polarization and the intricate interactions between macrophages, stromal myofibroblasts, and cytokines in experimental in vitro models of intestinal fibrosis. The obtained results may suggest the mechanism of fibrosis formation in clinical IBD.

The mechanism of Traditional Mongolian medicine Daruqi particles on inflammation.

Daruqi is a Traditional Mongolian medicine with anti-inflammatory, anti-bacterial, and immune-regulatory effects. However, the mechanisms of its activity were unclear. In the present study, we confirmed the anti-inflammation effect of Daruqi on inflammation induced by LPS using animal models. Then, THP-1 cells treated with LPS was used as a positive control to explore the effective component of Daruqi on inflammation. We identified that Oxymatrine was the essential effector of Daruqi. Furthermore, the mechanism of Oxymatrine on inflammation was verified through proteomics analyses and validation assays. Our results demonstrated that Oxymatrine significantly reduced the levels of inflammatory cytokine, including IL-8, IL-1α, and IL-1ß, in LPS induced THP-1 cells. Based on tandem mass tag -labeled quantitative proteomics, 428 differentially expressed proteins were screened, involved in TNF signaling pathway, Ferroptosis, IL-17 signaling pathway, etc. Among these differential expressed proteins (DEPs), 23 proteins were verified with parallel reaction monitoring analysis. The results showed that LPS treatment potentiated the protein level of PLEK, ACSL5 and CYBB, which could be reversed by Oxymatrine. By contrast, the protein expression of SPRYD4 and EMR2 was suppressed after LPS treatment, which could be rescued by Oxymatrine. In summary, Oxymatrine has excellent protective effects in LPS induced THP-1 cells. The five proteins, including PLEK, ACSL5, CYBB, SPRYD4 and EMR2, might serve as the targets of Oxymatrine, and as candidates regulating inflammation in future therapies.

Chemokine receptor hetero-oligomers regulate monocyte chemotaxis.

It is known that stress influences immune cell function. The underlying molecular mechanisms are unclear. We recently reported that many chemokine receptors (CRs) heteromerize with α1-adrenoceptors (α1-ARs) through which CRs are regulated. Here, we show that arginine vasopressin receptor 1A (AVPR1A) heteromerizes with all human CRs, except chemokine (C-X-C motif) receptor (CXCR)1, in recombinant systems and that such heteromers are detectable in THP-1 cells and human monocytes. We demonstrate that ligand-free AVPR1A differentially regulates the efficacy of CR partners to mediate chemotaxis and that AVPR1A ligands disrupt AVPR1A:CR heteromers, which enhances chemokine (C-C motif) receptor (CCR)1-mediated chemotaxis and inhibits CCR2-, CCR8-, and CXCR4-mediated chemotaxis. Using bioluminescence resonance energy transfer to monitor G protein activation and CRISPR/Cas9 gene-edited THP-1 cells lacking AVPR1A or α1B-AR, we show that CRs that share the propensity to heteromerize with α1B/D-ARs and AVPR1A exist and function within interdependent hetero-oligomeric complexes through which the efficacy of CRs to mediate chemotaxis is controlled. Our findings suggest that hetero-oligomers composed of CRs, α1B/D-ARs, and AVPR1A may enable stress hormones to regulate immune cell trafficking.

HHLA2 deficiency inhibits pancreatic cancer progression and THP-1 macrophage M2 polarization via EGFR/MAPK/ERK and mTOR/AKT pathway.

BACKGROUND: Human endogenous retrovirus subfamily H long terminal repeat associating protein 2, (HHLA2), a member of B7 family, exhibits heightened expression in various malignant tumors. However, the exact functions of HHLA2 in pancreatic cancer (PC) remain incompletely elucidated. METHODS: We initially conducted an analysis of the B7 family members' expression pattern in pancreatic tumor samples and adjacent normal tissues using The Cancer Genome Atlas (TCGA) database. Subsequently, immunohistochemistry, RT-qPCR and western blot methods were used to assess HHLA2 expression levels in PC tissues and cell lines. Furthermore, after silencing HHLA2 in PC cell lines, cell migration and proliferation of PC cells were detected by wound healing and CCK-8 assays, and cell invasion of PC cells was detected by transwell assays. We also investigated the regulation of epithelial-mesenchymal transition (EMT) markers and levels of EGFR, MEK, ERK1/2, mTOR and AKT via western blot analysis. Finally, the correlation between HHLA2 expression and immune infiltration was further explored. RESULTS: Silencing of HHLA2 resulted in the inhibition of PC cell proliferation, migration and invasion, potentially through the suppression of the EGFR/MAPK/ERK and mTOR/AKT signaling pathway. Additionally, silencing HHLA2 led to the inhibition of M2-type polarization of tumor associated macrophages (TAMs). CONCLUSION: The knockdown of HHLA2 was observed to inhibit the migration and invasion of PC cells through the regulation of the EMT process and EGFR/MAPK/ERK and mTOR/AKT pathway. Furthermore, silencing HHLA2 was found to modulate M2 polarization of TAMs. These finding suggest that HHLA2 could be a promising therapeutic target for Pancreatic cancer.

LPS and ATP-induced Death of PMA-differentiated THP-1 Macrophages and its Validation.

Cell death is a fundamental process in all living organisms. The protocol establishes a lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced phorbol-12-myristate-13-acetate (PMA)-differentiated lipid deposition in human monocyte (THP-1) macrophage model to observe cell death. LPS combined with ATP is a classic inflammatory induction method, often used to study pyroptosis, but apoptosis and necroptosis also respond to stimulation by LPS/ATP. Under normal circumstances, phosphatidylserine is only localized in the inner leaflet of the plasma membrane. However, in the early stages of pyroptosis, apoptosis, and necroptosis, the cell membrane remains intact and exposed to phosphatidylserine, and in the later stages, the cell membrane loses its integrity. Here, flow cytometry was used to analyze Annexin V and 7-Aminoactinomycin D (AAD) double staining to detect the cell death from the whole cells. The results show that substantial cells died after stimulation with LPS/ATP. Using scanning electron microscopy, we observe the possible forms of cell death in individual cells. The results indicate that cells may undergo pyroptosis, apoptosis, or necroptosis after stimulation with LPS/ATP. This protocol focuses on observing the death of macrophages after stimulation with LPS/ATP. The results showed that cell death after LPS and ATP stimulation is not limited to pyroptosis and that apoptosis and necrotic apoptosis can also occur, helping researchers better understand cell death after LPS and ATP stimulation and choose a better experimental method.

Determining the toxicological effects of indoor air pollution on both a healthy and an inflammatory-comprised model of the alveolar epithelial barrier in vitro.

Exposure to indoor air pollutants (IAP) has increased recently, with people spending more time indoors (i.e. homes, offices, schools and transportation). Increased exposures of IAP on a healthy population are poorly understood, and those with allergic respiratory conditions even less so. The objective of this study, therefore, was to implement a well-characterised in vitro model of the human alveolar epithelial barrier (A549 + PMA differentiated THP-1 incubated with and without IL-13, IL-5 and IL-4) to determine the effects of a standardised indoor particulate (NIST 2583) on both a healthy lung model and one modelling a type-II (stimulated with IL-13, IL-5 and IL-4) inflammatory response (such as asthma).Using concentrations from the literature, and an environmentally appropriate exposure we investigated 232, 464 and 608ng/cm2 of NIST 2583 respectively. Membrane integrity (blue dextran), viability (trypan blue), genotoxicity (micronucleus (Mn) assay) and (pro-)/(anti-)inflammatory effects (IL-6, IL-8, IL-33, IL-10) were then assessed 24 h post exposure to both models. Models were exposed using a physiologically relevant aerosolisation method (VitroCell Cloud 12 exposure system).No changes in Mn frequency or membrane integrity in either model were noted when exposed to any of the tested concentrations of NIST 2583. A significant decrease (p < 0.05) in cell viability at the highest concentration was observed in the healthy model. Whilst cell viability in the "inflamed" model was decreased at the lower concentrations (significantly (p < 0.05) after 464ng/cm2). A significant reduction (p < 0.05) in IL-10 and a significant increase in IL-33 was seen after 24 h exposure to NIST 2583 (464, 608ng/cm2) in the "inflamed" model.Collectively, the results indicate the potential for IAP to cause the onset of a type II response as well as exacerbating pre-existing allergic conditions. Furthermore, the data imposes the importance of considering unhealthy individuals when investigating the potential health effects of IAP. It also highlights that even in a healthy population these particles have the potential to induce this type II response and initiate an immune response following exposure to IAP.

Mechanistic insights into SARS-CoV-2 spike protein induction of the chemokine CXCL10.

During a SARS-CoV-2 infection, macrophages recognize viral components resulting in cytokine production. While this response fuels virus elimination, overexpression of cytokines can lead to severe COVID-19. Previous studies suggest that the spike protein (S) of SARS-CoV-2 can elicit cytokine production via the transcription factor NF-κB and the toll-like receptors (TLRs). In this study, we found that: (i) S and the S2 subunit induce CXCL10, a chemokine implicated in severe COVID-19, gene expression by human macrophage cells (THP-1); (ii) a glycogen synthase kinase-3 inhibitor attenuates this induction; (iii) S and S2 do not activate NF-κB but do activate the transcription factor IRF; (iv) S and S2 do not require TLR2 to elicit CXCL10 production or activate IRF; and (v) S and S2 elicit CXCL10 production by peripheral blood mononuclear cells (PBMCs). We also discovered that the cellular response, or lack thereof, to S and S2 is a function of the recombinant S and S2 used. While such a finding raises the possibility of confounding LPS contamination, we offer evidence that potential contaminating LPS does not underly induced increases in CXCL10. Combined, these results provide insights into the complex immune response to SARS-CoV-2 and suggest possible therapeutic targets for severe COVID-19.