Role In Activation Research Articles

Exploiting the damaging effects of ROS for therapeutic use by deactivating cell-free chromatin: the alchemy of resveratrol and copper.

Cell-free chromatin particles (cfChPs) that circulate in blood, or those that are released locally from dying cells, have myriad pathological effects. They can horizontally transfer themselves into healthy cells to induce DNA damage and activate inflammatory and apoptotic pathways. It has been proposed that repeated and lifelong assault on healthy cells by cfChPs may be the underlying cause of ageing and multiple age related disorders including cancer. The damaging effects of cfChPs can be minimized by deactivating them via the medium of ROS generated by admixing the nutraceuticals resveratrol (R) and copper (Cu). The antioxidant R acts as a pro-oxidant in the presence of Cu by its ability to catalyse the reduction of Cu(II) to Cu(I) with the generation of ROS via a Fenton-like reaction which can deactivate extra-cellular cfChPs. This perspective article explores the possibility of using the damaging potential of ROS for therapeutic purposes. It discusses the ability of ROS generating nutraceuticals R-Cu to deactivate the extracellular cfChPs without damaging effects on the genomic DNA. As cfChPs play a key role in activation of various disease associated pathways, R-Cu mediated deactivation of these pathways may open up multiple novel avenues for therapy. These findings have considerable translational implications which deserve further investigation by the way of well-designed randomised clinical trials.

Unraveling the crystal structure of the HpaA adhesin: insights into cell adhesion function and epitope localization of a Helicobacter pylori vaccine candidate.

Helicobacter pylori is a bacterium that can cause chronic gastritis, peptic ulcers, and gastric cancers. The bacterium adheres to the lining of the stomach using proteins called adhesins. One of these proteins, HpaA, is particularly important for H. pylori colonization and is considered a promising vaccine candidate against H. pylori infections. In this work, we determined the atomic structure of HpaA, identifying a characteristic protein fold to the Helicobacter family and delineating specific amino acids that are crucial to support the attachment to the gastric cells. Additionally, we discovered that HpaA can trigger the production of TNF-α, a proinflammatory molecule, in macrophages. These findings provide valuable insights into how H. pylori causes disease and suggest that HpaA has a dual role in both attachment and immune activation. This knowledge could contribute to the development of improved vaccine strategies for preventing H. pylori infections.

TET1 inhibits liver fibrosis by blocking hepatic stellate cell activation.

Hepatic stellate cells (HSCs) are critical regulator contributing to the onset and progression of liver fibrosis. Chronic liver injury triggers HSCs to undergo vast changes and trans-differentiation into a myofibroblast HSCs, the mechanism remains to be elucidated. This study investigated that the involvement of hydroxymethylase TET1 (ten-eleven translocation 1) in HSC activation and liver fibrosis. It is revealed that TET1 levels were downregulated in the livers in mouse models of liver fibrosis and patients with cirrhosis, as well as activated HSCs in comparison to quiescent HSCs. In vitro data showed that the inhibition of TET1 promoted the activation HSC, whereas TET1 overexpression inhibited HSC activation. Moreover, TET1 could regulate KLF2 (Kruppel-like transcription factors) transcription by promoting hydroxymethylation of its promoter, which in turn suppressed the activation of HSCs. In vivo, it is confirmed that liver fibrosis was aggravated in Tet1 knockout mice after CCl4 injection, accompanied by excessive activation of primary stellate cells, in contrast to wild-type mice. In conclusion, we suggested that TET1 plays a significant role in HSC activation and liver fibrosis, which provides a promising target for anti-fibrotic therapies.

Trehalose promotes atherosclerosis regression in female mice.

Atherosclerosis is a chronic inflammatory disease caused by the deposition of lipids within the artery wall. During atherogenesis, efficient autophagy is needed to facilitate efferocytosis and cholesterol efflux, limit inflammation and lipid droplet buildup, and eliminate defective mitochondria and protein aggregates. Central to the regulation of autophagy is the transcription factor EB (TFEB), which coordinates the expression of lysosomal biogenesis and autophagy genes. In recent years, trehalose has been shown to promote TFEB activation and protect against atherogenesis. Here, we sought to investigate the role of autophagy activation during atherosclerosis regression. Atherosclerosis was established in C57BL/6N mice by injecting AAV-PCSK9 and 16 weeks of Western diet feeding, followed by switching to a chow diet to induce atherosclerosis regression. During the regression period, mice were either injected with trehalose concomitant with trehalose supplementation in their drinking water or injected with saline for 6 weeks. Female mice receiving trehalose had reduced atherosclerosis burden, as evidenced by reduced plaque lipid content, macrophage numbers and IL-1β content in parallel with increased plaque collagen deposition, which was not observed in their male counterparts. In addition, trehalose-treated female mice had lower levels of circulating leukocytes, including inflammatory monocytes and CD4+ T cells. Lastly, we found that autophagy flux in male mice was basally higher than in female mice during atherosclerosis progression. Our data demonstrate a sex-specific effect of trehalose in atherosclerosis regression, whereby trehalose reduced lipid content, inflammation, and increased collagen content in female mice but not in male mice. Furthermore, we discovered inherent differences in the autophagy flux capacities between the sexes: female mice exhibited lower plaque autophagy than males, which rendered the female mice more responsive to atherosclerosis regression. Our work highlights the importance of understanding sex differences in atherosclerosis to personalize the development of future therapies to treat cardiovascular diseases.

Effective chromium mitigation using phosphorous doped bio carbon electrode via capacitive deionisation

ABSTRACT Capacitive deionisation (CDI) is an emerging eco-economic water reclamation technology that can remove inorganic salts and heavy metals. Biomass-derived carbon electrodes have attracted the scientific communities in recent years due to their economic feasibility and sustainability. However, electrochemical performance needs to be improved to achieve durability and reusability. Hence, the present study develops rice straw-derived phosphorous-doped (P-doped) carbon as an electrode for mitigating Cr(VI) ions. Phosphorus doping of biocarbon electrodes enhances their electrochemical properties, including increased electrical conductivity, improved charge storage capacity, and enhanced ion adsorption capabilities. Here, Phosphoric acid plays a dual role of activation and doping that enhances the physico-electrochemical properties. The synthesised material was found to be P-doped carbon with better pore distribution, which was confirmed through FESEM-EDX analysis. Further, the physicochemical properties of the electrode material are enriched with carbon and possess an enhanced surface area of 753 m2/g. The cyclic voltammetry shows the specific capacitance of 67 F/g for the Cr(VI) ions, which was found to be 15 times more than the non-doped carbon. CDI studies were performed with optimisation of operational parameters and found that mitigation of Cr(VI) ions was efficient at pH 2 for the applied voltage of 2V. The electrode’s performance with real-time chrome wash effluent confirms its potentiality and has better scope upon optimisation. The experimental data fits well with pseudo first-order kinetics, which ensures the nature of electrosorption is physisorption.

A16 ALTERATIONS TO BOTH INTESTINAL BARRIER INTEGRITY AND THE MICROBIOTA CONSPIRE DURING AGING TO PROMOTE DISEASE PROGRESSION IN A MOUSE MODEL OF MULTIPLE SCLEROSIS

Abstract Background Multiple sclerosis (MS) is a chronic, inflammatory condition impacted by both genetic and environmental factors. Aged individuals have an increased risk of progressive multiple sclerosis (pMS), as well as altered microbiota community composition and elevated levels of circulating gut microbiota-derived metabolites due to compromised gut barrier function. Fecal microbiota transplantation (FMT) studies confirm that an MS-associated microbiome can potentiate disease onset and enhance neuroinflammation in experimental autoimmune encephalomyelitis (EAE), a murine model of MS. Aims 1) Assess whether an aged microbiota alone is sufficient to promote age-associated progressive-like disease in our mouse model of EAE 2) Determine whether altered intestinal barrier integrity results in central nervous system-specific immune changes and/or disease course during EAE Methods To assess the impact of an aged microbiota on EAE outcomes we performed age-disparate human-derived FMT from young vs aged healthy co-habiting, first degree relatives into recipient mice. Then, to further interrogate the role of the gut-brain axis in the association of age and pMS we isolated the compromised intestinal barrier seen in aged individuals as a variable via two methods – Muc2-/- mice, which exhibit a defective mucus barrier, and DSS treated mice. Results Following adoptive transfer of young EAE-primed T cells, ‘young’ FMT recipients exhibited disease resolution while an ‘aged’ FMT lead to severe, non-remitting EAE relative to both controls and ‘young’ FMT recipients. This difference in outcomes was not seen in all donor pairs, suggesting that worsened EAE is not a universal feature of the aged microbiota. We collected cecal material, blood, and central nervous system (CNS) tissue from an age-differential FMT mouse pair and performed metabolomic analysis. We found robust differences in the metabolomic profile of young vs aged FMT recipients before and after EAE induction. Further, in both models of altered barrier integrity, we observed altered myeloid cell trafficking to and immune activation in the CNS, suggesting that the intestinal barrier itself plays a critical role in immune activation during EAE. Conclusions These findings suggest specific age-related microbiota-derived metabolites, which have increased access to the host system due to a leaky intestinal barrier, may be associated with increased risk of progressive disease and may represent promising therapeutic targets for MS. Funding Agencies CIHRMS Canada

A184 HCPE CONTRIBUTES TO THE HOST INFLAMMATORY RESPONSE TO HELICOBACTER PYLORI

Abstract Background Helicobacter pylori (HP) colonizes chronically 50% of the world population, leading to gastric ulcers or cancers in 2-10 % of infections. Due to rising antibiotic resistance, curtailing HP-induced diseases requires the identification of new anti-HP molecules that can reduce HP viability or its ability to elicit inflammation. Amongst HP’s virulence factors are the Helicobacter Cysteine-rich Proteins (Hcp) that are secreted outside the bacteria and contain Sel-Like Repeats (SLR) which support protein / protein interactions involved in signal transduction across kingdoms. Several SLR-containing bacterial proteins including HcpA are involved in bacteria / host interactions. Thus, Hcps may affect HP’s virulence via interaction of their SLRs with host proteins. Aims We aim to elucidate the role of Hcps in HP’s virulence. Hcps were considered as immune decoys since anti-Hcp antibodies made in infected patients are unable to clear the infection. However, recent data suggest that Hcps interact with host components and may modulate the function of immune cells. However, their effects on gastric cells remain unknown and functional differences between Hcps remain to be explored. Methods This work uses knockout mutagenesis, interactions with gastric cells, transcriptomics, and microscopy. Results We focus on HcpE, the largest Hcp that may interact with many host proteins via its 9 SLRs motifs. We showed that HcpE is secreted outside HP in 2 lab strains and that ~ 30% of secreted HcpE was comprised in outer membrane vesicles that may deliver HcpE into eukaryotic cells by membrane fusion. We also showed that the DiSulfide Bond forming protein DsbK is essential for HcpE production and secretion. Here, we demonstrate the production and secretion of HcpE by clinical isolates in vitro, and its production in situ in infected patients. Using our HcpE and DsbK knockout mutants, we investigate the role of HcpE and other Hcps in interactions with human gastric cells in vitro and in ex vivo gastric explants, showing a role in inflammation activation. Finally, we demonstrate their role in murine gastric colonization and in murine splenocytes activation. Overall, our data show a role of Hcps in host / pathogen interactions largely due to immuno-modulatory functions and a role in gastric colonization, with a predominant role of HcpE over other Hcps. Conclusions The findings open up possibilities to use Hcps or the gate keeper DsbK that controls their production as novel therapeutic targets to alleviate the burden of HP-associated disease.This could benefit the ~6 million patients who develop gastric ulcers or cancers each year worldwide due to HP infection, also saving billions of annual health care costs. Funding Agencies Western University

A62 EXAMINING THE ACTIVATION OF XENOBIOTIC RECEPTORS PXR AND AHR IN COLONOIDS USING MICROBIAL METABOLITES AND CHEMICAL LIGANDS

Abstract Background The Aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) are vital xenobiotic receptors activated by foreign substances, playing pivotal roles in regulating chemical metabolism. Traditionally, these receptors have been closely linked to their roles in mediating responses to toxic compounds. However, recent findings have revealed their newfound significance in maintaining gut homeostasis and regulating inflammatory processes. Aims We investigated the dual roles of AhR and PXR activation. We started with dosage response experiments to determine optimal treatment conditions, such as treatment concentration and exposure time. Subsequently, we compared transcriptomic responses induced by chemical ligands with those from microbial metabolites, aiming to understand how AhR and PXR activation can yield both adverse and beneficial effects. Methods Using mouse 3D colonoids and 2D monolayer cultures, PXR and AhR were activated using the microbial metabolites indole-3-propionic acid (IPA) and indole-3-pyruvic acid (IPyA), respectively. Concentrations were determined through dosage response experiments. Changes to PXR and AhR target gene expression were measured using qPCR. We compared the gene induction by IPA and IPyA to responses driven by the chemical ligands pregnenolone 16α-carbonitrile (PCN) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), respectively. Results In 3D cell culture, PCN induced PXR target genes Cyp2c55 and Abcb1a, while IPA had no significant effect. Cyp3a11 was absent. Both IPyA and TCDD induced AhR genes, Cyp1a1 and Cyp1b1, with varying induction, and Cyp1a2 showed no response. In 2D cell culture, PCN significantly increased Cyp2c55 gene expression, but neither PCN nor IPA significantly induced Abcb1a. In 3D culture, TCDD significantly induced Cyp1a1 and Cyp1b1, while IPyA only induced Cyp1a1, revealing differences in AhR gene induction between 2D and 3D cell culture models. Conclusions Our research reveals contrasting gene induction patterns following AhR and PXR activation through microbial metabolites and chemical ligands. These varied responses highlight the multifaceted roles these receptors play within the gut environment. This study enhances our understanding of xenobiotic receptors' contributions to maintaining gut homeostasis and regulating inflammatory processes, shedding light on the interplay between ligands and receptors. Methods First, we isolate the crypts of mice to create 3D organoids, were we have access to the basolateral side. To capture the true biological system, we convert the 3D culture to 2D. This enables us to explore both the apical and basolateral sides, retaining the crucial polarity of the cells. Funding Agencies CIHR

Cu2O/WO3 S-scheme heterojunctions for photocatalytic degradation of levofloxacin based on coordination activation

Heterogeneous photocatalytic degradation of antibiotic involves the activation of antibiotic molecules and the photocatalytic oxidation process. However, the simultaneous improvement of these processes is still a challenge. Herein, S-scheme heterojunctions consisted of Cu2O nanocluster with defective WO3 nanosheets were constructed for efficient photocatalytic degradation of levofloxacin (LVX). The typical CNS-5 composite (5 wt% Cu2O/WO3) achieves an optimal LVX degradation efficiency of 97.9% within 80 min. The spatial charge separation and enhancement of redox capacity were realized by the formation of S-scheme heterojunction between Cu2O and WO3. Moreover, their interfacial interaction would lead to the loss of lattice oxygen and the generation of W5+ sites. It is witnessed that the C–N of piperazine ring and CO of carboxylic acid in LVX are coordinated with W5+ sites to build the electronic bridge to activate LVX, greatly promoting the further degradation. This work highlights the important role of selective coordination activation cooperated with S-type heterojunctions for the photocatalytic degradation and offers a new view to understand the degradation of antibiotics at molecular level.

Delayed CCL23 response is associated with poor outcomes after cardiac arrest

Chemokines, a family of chemotactic cytokines, mediate leukocyte migration to and entrance into inflamed tissue, contributing to the intensity of local inflammation. We performed an analysis of chemokine and immune cell responses to cardiac arrest (CA). Forty-two patients resuscitated from cardiac arrest were analyzed, and twenty-two patients who underwent coronary artery bypass grafting (CABG) surgery were enrolled. Quantitative antibody array, chemokines, and endotoxin quantification were performed using the patients blood. Analysis of CCL23 production in neutrophils obtained from CA patients and injected into immunodeficient mice after CA and cardiopulmonary resuscitation (CPR) were done using flow cytometry. The levels of CCL2, CCL4, and CCL23 are increased in CA patients. Temporal dynamics were different for each chemokine, with early increases in CCL2 and CCL4, followed by a delayed elevation in CCL23 at forty-eight hours after CA. A high level of CCL23 was associated with an increased number of neutrophils, neuron-specific enolase (NSE), worse cerebral performance category (CPC) score, and higher mortality. To investigate the role of neutrophil activation locally in injured brain tissue, we used a mouse model of CA/CPR. CCL23 production was increased in human neutrophils that infiltrated mouse brains compared to those in the peripheral circulation. It is known that an early intense inflammatory response (within hours) is associated with poor outcomes after CA. Our data indicate that late activation of neutrophils in brain tissue may also promote ongoing injury via the production of CCL23 and impair recovery after cardiac arrest.

DNA-methylome-derived epigenetic fingerprint as an immunophenotype indicator of durable clinical immunotherapeutic benefits in head and neck squamous cell carcinoma.

Cancer immunotherapy provides durable response and improves survival in a subset of head and neck squamous cell carcinoma (HNSC) patients, which may due to discriminative tumor microenvironment (TME). Epigenetic regulations play critical roles in HNSC tumorigenesis, progression, and activation of functional immune cells. This study aims to identify an epigenetic signature as an immunophenotype indicator of durable clinical immunotherapeutic benefits in HNSC patients. Unsupervised consensus clustering approach was applied to distinguish immunophenotypes based on five immune signatures in The Cancer Genome Atlas (TCGA) HNSC cohort. Two immunophenotypes (immune 'Hot' and immune 'Cold') that had different TME features, diverse prognosis, and distinct DNA methylation patterns were recognized. Immunophenotype-related methylated signatures (IPMS) were identified by the least absolute shrinkage and selector operation algorithm. Additionally, the IPMS score by deconvolution algorithm was constructed as an immunophenotype classifier to predict clinical outcomes and immunotherapeutic response. The 'Hot' HNSC immunophenotype had higher immunoactivity and better overall survival (p = 0.00055) compared to the 'Cold' tumors. The immunophenotypes had distinct DNA methylation patterns, which was closely associated with HNSC tumorigenesis and functional immune cell infiltration. 311 immunophenotype-related methylated CpG sites (IRMCs) was identified from TCGA-HNSC dataset. IPMS score model achieved a strong clinical predictive performance for classifying immunophenotypes. The area under the curve value (AUC) of the IPMS score model reached 85.9% and 89.8% in TCGA train and test datasets, respectively, and robustness was verified in five HNSC validation datasets. It was also validated as an immunophenotype classifier for predicting durable clinical benefits (DCB) in lung cancer patients who received anti-PD-1/PD-L1 immunotherapy (p = 0.017) and TCGA-SKCM patients who received distinct immunotherapy (p = 0.033). This study systematically analyzed DNA methylation patterns in distinct immunophenotypes to identify IPMS with clinical prognostic potential for personalized epigenetic anticancer approaches in HNSC patients. The IPMS score model may serve as a reliable epigenome prognostic tool for clinical immunophenotyping to guide immunotherapeutic strategies in HNSC.

Microglia measured by TSPO PET are associated with Alzheimer's disease pathology and mediate key steps in a disease progression model.

Evidence suggests microglial activation precedes regional tau and neurodegeneration in Alzheimer's disease (AD). We characterized microglia with translocator protein (TSPO) positron emission tomography (PET) within an AD progression model where global amyloid beta (Aβ) precedes local tau and neurodegeneration, resulting in cognitive impairment. Florbetaben, PBR28, and MK-6240 PET, T1 magnetic resonance imaging, and cognitive measures were performed in 19 cognitively unimpaired older adults and 22 patients with mild cognitive impairment or mild AD to examine associations among microglia activation, Aβ, tau, and cognition, adjusting for neurodegeneration. Mediation analyses evaluated the possible role of microglial activation along the AD progression model. Higher PBR28 uptake was associated with higher Aβ, higher tau, and lower MMSE score, independent of neurodegeneration. PBR28 mediated associations between tau in early and middle Braak stages, between tau and neurodegeneration, and between neurodegeneration and cognition. Microglia are associated with AD pathology and cognition and may mediate relationships between subsequent steps in AD progression.

Abstract TP245: Identifying Ischemic Stroke Etiology Through Cytokine Biomarkers

Background: Ischemic stroke can arise from various etiologies, such as cardioembolism, atherosclerosis, small vessel disease or cryptogenic. Accurate identification of stroke etiology is vital for secondary stroke prevention. Accumulating evidence suggests that an imbalance of neuroprotective and neuroinflammatory cytokines may contribute to stroke outcomes. Interleukin-2 receptor subunit α (IL-2Rα), a cell surface protein that regulates lymphocyte activation, has been shown to have either pro-atherosclerotic or atheroprotective roles through activation of lymphocytes or regulatory T cells, respectively. We hypothesized that distinct cytokine profiles, and in particular IL-2Rα, may correlate with specific stroke etiology. Methods: Plasma samples were collected from patients with ischemic stroke that were admitted to Memorial Hermann Hospital, Houston by UTHealth biobank. ELISA was used to analyze the plasma samples for levels of IL-2Rα. The relationship between stroke etiology (TOAST criteria) and IL-2Rα was assessed using ANOVA and then adjusted for co-morbidities using multilinear regression models. Results: The mean age of patients was 63.4 years, 35.2% were women, 87% had hypertension, 48.1% had diabetes mellitus, and 53.7% had hyperlipidemia. IL-2Rα levels were significantly elevated in patients with ischemic stroke due to large-artery atherosclerosis (53.5±4.7 pg/ml) as compared to cardioembolic (35.6±6.5 pg/ml), small vessel disease (38.2±7.4pg/ml) or cryptogenic etiology 32±7.8; p<0.01). Conclusions: Our study suggests that IL-2Rα is significantly elevated in ischemic strokes caused by atherosclerosis compared to other ischemic etiologies. This suggests the role of lymphocytic activation in strokes from intracranial and extracranial atherosclerotic disease, which may be used as a therapeutic target. It also identifies a novel biomarker for ischemic strokes from atherosclerosis. Future studies identifying the upstream and downstream pathways that lead to IL-2Rα activation and stroke in atherosclerotic lesions, will further add to our understanding of the characteristics of atherosclerotic lesions that lead to ischemic strokes.

Abstract 21: Similarity in the Changes of Brain Myeloid Transcriptome Signature is Shared Between Ischemic Stroke and Chronic Inflammation Caused by Diabetes Mellitus

Introduction: Ischemic stroke (IS) is a pressing global health concern. Diabetes mellitus not only heightens the risk of IS but also aggravates its outcomes. There is established evidence that neutrophil infiltration is involved in inflammation after stroke through various mechanisms, such as activating neutrophil extracellular traps. We aimed to examine the factors that contribute to the deterioration of IS in diabetic mice focusing on mechanisms underlying immune cell infiltration by single cell RNA sequencing (scRNAseq) of brain before and after stroke. Methods: Experimental stroke was induced using the distal middle cerebral artery occlusion (dMCAO) model. db/db mice were used to model type 2 diabetes and obesity, while db/+ mice served as euglycemic controls. Mononuclear cells from ipsilateral mouse brains were isolated 3 days post-dMCAO or sham surgery with the Percoll gradient following enzymatic digestion. Transcriptomic analysis was performed using scRNAseq from db/+ sham, db/db sham, db/+ stroke, and db/db stroke. Fluorescence-activated cell sorting (FACS) and immunofluorescence (IF) staining were conducted to validate the changes detected in the transcriptome results. Results: Prior to the onset of stroke, db/db mice exhibited changes in gene expression in endothelial cells and myeloid cells including macrophages, monocytes, and microglia, mirroring patterns of changes after stroke. Among the macrophage subpopulation in particular, db/db sham and db/+ stroke mice shared an overlap of 638/901 (70.8%) differentially expressed genes compared to db/+ sham. Gene enrichment analysis indicated predominant upregulation of genes linked to leukocyte migration and neutrophil chemotaxis. FACS revealed a heightened neutrophil presence in the brain parenchyma of diabetic mice before stroke, and further elevated after stroke compared to control mice. Specifically, the increased expression of anaphylatoxin receptor C3aR and complement C3 shown by IF corroborated with the transcriptomic signature, supporting a role of complement activation and myeloid cell transmigration. Conclusions: Our findings provide valuable insights into the mechanisms whereby diabetes potentially escalates neutrophil infiltration post-stroke.

Macrophage CREBZF Orchestrates Inflammatory Response to Potentiate Insulin Resistance and Type 2 Diabetes.

Chronic adipose tissue inflammation accompanied by macrophage accumulation and activation is implicated in the pathogenesis of insulin resistance and type 2 diabetes in humans. The transcriptional coregulator CREBZF is a key factor in hepatic metabolism, yet its role in modulating adipose tissue inflammation and type 2 diabetes remains elusive. The present study demonstrates that overnutrition-induced CREBZF links adipose tissue macrophage (ATM) proinflammatory activation to insulin resistance. CREBZF deficiency in macrophages, not in neutrophils, attenuates macrophage infiltration in adipose, proinflammatory activation, and hyperglycemia in diet-induced insulin-resistant mice. The coculture assays show that macrophage CREBZF deficiency improves insulin sensitivity in primary adipocytes and adipose tissue. Mechanistically, CREBZF competitively inhibits the binding of IκBα to p65, resulting in enhanced NF-κB activity. In addition, bromocriptine is identified as a small molecule inhibitor of CREBZF in macrophages, which suppresses the proinflammatory phenotype and improves metabolic dysfunction. Furthermore, CREBZF is highly expressed in ATM of obese humans and mice, which is positively correlated with proinflammatory genes and insulin resistance in humans. This study identifies a previously unknown role of CREBZF coupling ATM activation to systemic insulin resistance and type 2 diabetes.

Radiofrequency ablation plays double role in immunosuppression and activation of PBMCs in recurrent hepatocellular carcinoma.

Radiofrequency ablation (RFA) is the primary curative treatment for hepatocellular carcinoma (HCC) patients who are not eligible for surgery. However, the effects of RFA on the global tumor immune response remain unclear. In this study, we examined the phenotypic and functional changes in peripheral blood mononuclear cells (PBMCs) from recurrent HCC patients who had undergone two RFA treatments using mass cytometry and high-throughput mRNA assays. We observed significant increase in monocytes and decrease in T cell subpopulations three days after the first RFA treatment and three days after the second RFA treatment. The down-regulation of GZMB, GZMH, GZMK, and CD8A, which are involved in the cytotoxic function of T cells, was observed following RFA. Furthermore, the population of CD8 effector and memory T cells (CD8 Teff and CD8 Tem) significantly decreased after RFA. The expression of CD5 and CD161 in various T cell subpopulations also showed significant reductions. Additionally, elevated secretion of VEGF was observed in monocytes, B cells, regulatory T cells (Tregs), and CD4 naive T cells. In recurrent HCC patients, serum components derived from radiofrequency therapy can enhance the antigen-presenting capacity of monocytes. However, they also inhibit the anti-cancer immune response by reducing the population of CD8 effector and memory T cells and suppressing the activation of T cells, as well as down-regulating the expression of CD161 and CD5 in various T cell subpopulations. These tumor-derived components also contribute to an immunosuppressive microenvironment by promoting the secretion of VEGF in monocytes, Tregs, B cells, and CD4 naive T cells.

New insight into prurigo nodularis: Proadrenomedullin N-terminal 20 peptide mediates mouse mast cell activation via Mrgprb2.

Prurigo nodularis (PN) is a chronic inflammatory skin disorder that is characterized by extremely itchy nodules. Proadrenomedullin N-terminal 20 (PAMP) activates mast cell degranulation via Mas-related G protein-coupled receptor X2 (MRGPRX2), which is associated with pruritus in allergic contact dermatitis. However, the mechanisms underlying the action of PAMP and MRGPRX2 in PN remain unclear. To determine the role of PAMP-induced mast cell activation via MRGPRX2 (mouse homologous Mrgprb2) in PN. The expression of PAMP and the number of MRGPRX2-expressing mast cells in the skin biopsies of patients with PN, atopic dermatitis (AD), and healthy participants were analyzed using immunohistochemistry and immunofluorescence, respectively. The biphasic response of PAMP9-20 mediated by Mrgprb2 in mouse peritoneal mast cells (PMC) was validated in vitro using qRT-PCR, ELISA, flow cytometry, and siRNA techniques. PAMP expression and the number of MRGPRX2+ mast cells in lesional PN skin, but not in AD, were elevated compared to healthy skin. PAMP9-20 mediates the immediate and delayed phase responses of PMC, such as degranulation, histamine and β-hexosaminidase release, and secretion of inflammatory factors such as CCL2, TNF-α, and GM-CSF. These effects were inhibited when Mrgprb2 expression was silenced. Silencing Mrgprb2 did not affect the biphasic response of PMC that was induced by IgE-FcεRI activation. The results show that PAMP mediates mouse mast cell activation via Mrgprb2, which may be involved in the pathogenesis of PN. The PAMP/ Mrgprb2 pathway, independent of classical IgE signaling, could be developed as a candidate drug target for treating PN.

CD133-Dependent Activation of Phosphoinositide 3-Kinase /AKT/Mammalian Target of Rapamycin Signaling in Melanoma Progression and Drug Resistance.

Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.

Photocatalytic ethylene production by oxidative dehydrogenation of ethane with dioxygen on ZnO-supported PdZn intermetallic nanoparticles

The selective oxidative dehydrogenation of ethane (ODHE) is attracting increasing attention as a method for ethylene production. Typically, thermocatalysts operating at high temperatures are needed for C–H activation in ethane. In this study, we describe a low temperature ( < 140 °C) photocatalytic route for ODHE, using O2 as the oxidant. A photocatalyst containing PdZn intermetallic nanoparticles supported on ZnO is prepared, affording an ethylene production rate of 46.4 mmol g–1 h–1 with 92.6% ethylene selectivity under 365 nm irradiation. When we employ a simulated shale gas feed, the photocatalytic ODHE system achieves nearly 20% ethane conversion while maintaining an ethylene selectivity of about 87%. The robust interface between the PdZn intermetallic nanoparticles and ZnO support plays a crucial role in ethane activation through a photo-assisted Mars-van Krevelen mechanism, followed by a rapid lattice oxygen replenishment to complete the reaction cycle. Our findings demonstrate that photocatalytic ODHE is a promising method for alkane-to-alkene conversions under mild conditions.

“I’m Not Worthless, I Do Help Society”: Exploring the Lived Experience of Community Placement in Activation Schemes

Abstract Activation schemes are widely criticised, with the negative experiences of ‘the activated’ featuring prominently in the literature. This article presents the findings of a constructivist grounded theory study concerning the lived experience of long-term unemployment, welfare recipiency and community placement in activation schemes in Ireland, with a focus on the positive effects that participating in such schemes had on participants’ subjective well-being. For the participants in this research, community placement signified change, respite, and recovery that improved their subjective well-being by creating an experience that counteracted the draining experience of long-term unemployment and welfare recipiency. This study brings new elements to the discussion on the role of activation in promoting/diminishing the subjective well-being of the long-term unemployed.