Activator Protein Research Articles

Regulatory Effects of Copper on Ghrelin Secretion in Rat Fundic Glands.

Copper (Cu) is an effective additive in feed for promoting growth. Growth dan axis comprising growth hormone (GH), somatostatin (SS) and GH-releasing hormone (GHRH), with ghrelin regulating their release. The growth-promoting effects of Cu are closely related to ghrelin, but the specific mechanism behind the relationship remains unknown. We investigated the adjustment of ghrelin synthesis and secretion by Cu. Sprague-Dawley rats were fed basal diets with an addition of 0, 120 or 240 mg/kg Cu sulfate for 28 day to establish a growth-promoting model. Signalling molecules relevant to ghrelin synthesis and secretion were detected and mechanistically explored using enzyme-linked immunosorbent assay, quantitative reverse-transcription polymerase chain reaction and Western blot analysis. The 120 mg/kg supplement improved growth performance; significantly increased the serum levels of ghrelin, ghrelin O-acyltransferase (GOAT), acylated ghrelin (AG), GH, and reactive oxygen species (ROS) and decreased those of SS; significantly increased the mRNA and protein expression of ghrelin, GOAT, ghrelin receptor (GHS-R1α), and activator protein 1 (AP-1); increased the phosphorylation ratio of JNK and p38 MAPK; and inhibited the mRNA and protein expression of SS and SS receptor subtype 2 (SSTR2) in gastric fundic gland tissues. Thus, Cu may affect gastric ghrelin synthesis at the transcriptional level by activating the JNK/p38 MAPK pathway through increased ROS levels and regulating the activation of the downstream redox-sensitive transcription factor AP-1. SS plays a crucial determinant role in ghrelin regulation via intragastric Cu. Cu promotes GOAT activity and ghrelin secretion by inhibiting SS secretion, affecting AG levels, and promoting ghrelin acylation through ghrelin/GOAT/GHS-R1α system, modulating ghrelin secretion.

Echinochrome A inhibits HMGB1-induced vascular smooth muscle cell migration by suppressing osteopontin expression.

Echinochrome A (Ech A) isolated from marine organisms is a therapeutic effector for various cardiovascular diseases, but its precise mechanisms are unclear. This study identified the role and mechanisms mediating the effects of Ech A on the migration of vascular smooth muscle cells (VSMCs) induced by high-mobility group box 1 (HMGB1). Compared to the control cells, the migration of VSMCs stimulated with HMGB1 (100 ng/ml) was markedly increased, which was significantly attenuated in cells pretreated with MPIIIB10 (100 ng/ml), a neutralizing monoclonal antibody for osteopontin (OPN). In VSMCs stimulated with HMGB1, the increased expression of OPN mRNA and protein was accompanied by an increased OPN promoter activity. In reporter gene assays using OPN promoter-luciferase constructs, the promoter region 538-234 bp of the transcription start site containing the binding sites for activator protein 1 (AP-1) was shown to be responsible for the increased transcriptional activity by HMGB1. In addition, the binding activity of AP-1 was increased in HMGB1-stimulated cells, highlighting the pivotal role of AP-1 on OPN expression in HMGB1-stimulated VSMCs. An examination of the vascular effects of Ech A showed that the increased AP-1 binding/promoter activities and OPN expression induced by HMGB1 were attenuated in cells pretreated with Ech A (3 or 10 μM). Similarly, Ech A inhibited HMGB1-induced VSMC migration in a concentration-dependent manner. These findings suggest that Ech A inhibits VSMC migration by suppressing OPN expression. Hence, Ech A is suggested as a potential therapeutic strategy for vascular remodeling in the injured vasculatures.

The JNK signalling pathway gene BmJun is involved in the regulation of egg quality and production in the silkworm, Bombyx mori.

The Jun N-terminal kinase (JNK) signalling pathway has a key role in tissue remodelling during insect metamorphosis by regulating programmed cell death. However, multiple members of the JNK pathway in Lepidoptera remain uncharacterized. In this study, two key genes of the JNK pathway, BmJun and BmFos, were cloned from the silkworm Bombyx mori, a lepidopteran model insect, and their effects on reproductive development were investigated. BmJun and BmFos encode 239 and 380 amino acids, respectively. Both proteins have typical basic leucine zipper domains and form a BmJUN-BmFOS dimer activator protein to exert transcriptional regulation. During the wandering stage of silkworm development, interference in BmJun expression had no effect on pupation, whereas B. mori vitellogenin (BmVg) expression, which is essential for egg development, was suppressed in the fat body and egg laying was significantly reduced. Additionally, numerous eggs appeared shrivelled and deformed, suggesting that they were nutritionally stunted. Inhibition of the JNK pathway caused abnormal pupal metamorphosis, an increase in shrivelled, unfertilized eggs, a decrease in fat body synthesis, and accumulation of BmVg in the ovaries of female B. mori. The results indicated that BmJUN and BmFOS can form an AP-1 dimer. Interfering with BmJun or inhibiting the phosphorylation of BmJUN leads to a reduction in the synthesis of BmVg in the fat body and its accumulation in the ovaries, thereby affecting the quality and production of the progeny eggs. These findings suggest that regulating Jun in the JNK pathway could be a potential way to inhibit female reproduction in Lepidoptera.

Optogenetic Control of Phosphate-Responsive Genes Using Single-Component Fusion Proteins in Saccharomyces cerevisiae.

Blue light illumination can be detected by light-oxygen-voltage (LOV) photosensing proteins and translated into a range of biochemical responses, facilitating the generation of novel optogenetic tools to control cellular function. Here, we develop new variants of our previously described VP-EL222 light-dependent transcription factor and apply them to study the phosphate-responsive signaling (PHO) pathway in the budding yeast Saccharomyces cerevisiae, exemplifying the utilities of these new tools. Focusing first on the VP-EL222 protein itself, we quantified the tunability of gene expression as a function of light intensity and duration and demonstrated that this system can tolerate the addition of substantially larger effector domains without impacting function. We further demonstrated the utility of several EL222-driven transcriptional controllers in both plasmid and genomic settings, using the PHO5 and PHO84 promoters in their native chromosomal contexts as examples. These studies highlight the utility of light-controlled gene activation using EL222 tethered to either artificial transcription domains or yeast activator proteins (Pho4). Similarly, we demonstrate the ability to optogenetically repress gene expression with EL222 fused to the yeast Ume6 protein. We finally investigated the effects of moving EL222 recruitment sites to different locations within the PHO5 and PHO84 promoters, as well as determining how this artificial light-controlled regulation could be integrated with the native controls dependent on inorganic phosphate (Pi) availability. Taken together, our work expands the applicability of these versatile optogenetic tools in the types of functionalities that they can deliver and the biological questions that can be probed.

PNSC5325 prevents acute respiratory distress syndrome by alleviating inflammation and inhibiting extracellular matrix degradation of alveolar macrophages

BackgroundAcute respiratory distress syndrome (ARDS) is characterized by severe inflammation and significant extracellular matrix (ECM) degradation in the lungs. Our prior research identified the CtBP2-p300-NF-κB (C-terminal-binding protein 2-histone acetyltransferase p300-nuclear factor kappa B) transcriptional complex as critical in ARDS by activating pro-inflammatory cytokine genes. MethodsAn ARDS mouse model was established using intratracheal instillation of lipopolysaccharide (LPS). Small molecules that inhibit the CtBP2-p300 interaction were identified through AlphaScreen. RNA sequencing (RNA-Seq) was conducted to determine differential gene expression. Immunoprecipitation and co-immunoprecipitation analyzed protein interactions. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunoblotting detected gene and protein expression. Histological staining evaluated tissue damage. ResultsThrough AlphaScreen, two natural compounds, PNSC2477 and PNSC5325, were identified for their ability to inhibit the CtBP2-p300 interaction. While PNSC2477 demonstrated toxicity and was deemed unsuitable for further research, PNSC5325 exhibited minimal toxicity. PNSC5325 effectively inhibited the CtBP2-p300 interaction and reduced pro-inflammatory cytokine gene expression. RNA-Seq analysis of PNSC5325-treated cells indicated significant suppression of pro-inflammatory cytokine genes and matrix metalloproteinases (MMPs). Further molecular studies revealed that the CtBP2-p300 complex, in conjunction with activator protein 1 (AP1), activates MMP expression. PNSC5325 simultaneously suppressed both pro-inflammatory cytokines and MMPs by targeting the CtBP2-p300 complex. In LPS-injected mice, PNSC5325 administration significantly reduced ARDS incidence by inhibiting inflammatory and MMP genes. ConclusionThese findings suggest that PNSC5325 protects against ARDS by inhibiting key inflammatory and ECM degradation pathways, highlighting its potential as a novel therapeutic agent for ARDS and paving the way for further clinical investigations.

Systematic identification and expression profiling of calmodulin-binding transcription activator genes reveal insights into their functional diversity against pathogens in sugarcane

The calmodulin-binding transcription activator (CAMTA) proteins in plants play significant roles in signal-transduction, activation of regulatory networks, and defense response against environmental stressors. In this study we systematically identified a total 17 CAMTA genes (named as SsnpCAMTAs) in Saccharum spontaneum Np-X genome. Moreover, SsnpCAMTAs exhibited diverse physio-chemical and gene structural attributes. Notably, eight SsnpCAMTA gene pairs displayed segmental duplication events, while CAMTA genes from S. spontaneum Np-X and Arabidopsis thaliana shared homology relationship. In-vitro interaction networking showed that SsnpCAMTA1 and SsnpCAMTA2 were the core protein which interacted with each other as well as with other four different proteins (SsnpCAMTA5/7/13/17). To check functional variability, the expression profiles of SsnpCAMTAs were quantified in transcriptomic and proteomic datasets triggered by Xanthomonas albilineans (Xa) and Acidovorax avenae subsp. avenae (Aaa). The temporal expression of SsnpCAMTA4/5 was ranged between 1.7–3.5 folds in sugarcane cultivars triggered by Xa infection. Most of the SsnpCAMTAs exhibited irregular expression profile in sugarcane cultivars triggered by Aaa infection. Additionally, transcript expression profiles of eight candidate genes SsnpCAMTA1/2/5/7/8/12/13/17 were determined by RT-qPCR assay in sugarcane cultivars Zhongtang3 (resistant to smut) and ROC22 (susceptible to smut) under Sporisorium scitamineum pathogen infection. Interestingly, the transcript expression of SsnpCAMTA5 was upregulated from 1.4 to 10.8 folds as compared to control in both cultivars, while SsnpCAMTA8 was downregulated in both cultivars. Overall, our results provide valuable candidate gene resources for the development of disease-resistant sugarcane cultivars in the face of current climate change scenarios.

Targeting GM2 Ganglioside Accumulation in Dementia: Current Therapeutic Approaches and Future Directions.

Dementia in neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and dementia with Lewy bodies (DLB) is a progressive neurological condition affecting millions worldwide. The amphiphilic molecule GM2 gangliosides are abundant in the human brain and play important roles in neuronal development, intercellular recognition, myelin stabilization, and signal transduction. GM2 ganglioside's degradation requires hexosaminidase A (HexA), a heterodimer composed of an α subunit encoded by HEXA and a β subunit encoded by HEXB. The hydrolysis of GM2 also requires a non-enzymatic protein, the GM2 activator protein (GM2-AP), encoded by GM2A. Pathogenic mutations of HEXA, HEXB, and GM2A are responsible for autosomal recessive diseases known as GM2 gangliosidosis, caused by the excessive intralysosomal accumulation of GM2 gangliosides. In AD, PD and DLB, GM2 ganglioside accumulation is reported to facilitate Aβ and α-synuclein aggregation into toxic oligomers and plaques through activation of downstream signaling pathways, such as protein kinase C (PKC) and oxidative stress factors. This review explored the potential role of GM2 ganglioside alteration in toxic protein aggregations and its related signaling pathways leading to neurodegenerative diseases. Further review explored potential therapeutic approaches, which include synthetic and phytomolecules targeting GM2 ganglioside accumulation in the brain, holding a promise for providing new and effective management for dementia.

Effects of intrauterine extracellular vesicle microRNAs on embryonic gene expression in low-fertility cows.

Embryo survival and pre-implantation development depend on uterine luminal fluid, which is believed to play a role in early embryonic death and infertility in cows. Extracellular vesicles (EVs) in the uterine luminal fluid contain microRNAs (miRNAs), crucial mediators of intercellular communication. miRNAs regulate conceptus-maternal interactions and participate in embryonic development by suppressing gene expression. Therefore, we hypothesized that miRNAs in the intrauterine EVs of low-fertility cows would hinder embryonic survival and development. EVs were collected from the bovine uterine luminal fluid of both normal- and low-fertility cows 7 days post-estrus. Small RNA-sequencing analysis of miRNAs isolated from these EVs identified eight miRNAs that were highly expressed in normal-fertility cows (normal-fertility miRNAs) and eight with elevated expression in low-fertility cows (low-fertility miRNAs). These two sets of miRNAs were transfected into hatched blastocysts via lipofection. RNA-seq following lipofection with low-fertility miRNAs identified 424 differentially expressed genes (DEGs) relative to the control; in contrast, following lipofection with normal-fertility miRNAs, seven DEGs were identified. Pathway analysis of the DEGs identified following lipofection with low-fertility miRNAs revealed substantial enrichment of mitogen-activated protein kinase (MAPK) signaling. Expression of activator protein 1 (AP1) and interferon-tau (IFNT) mRNA was significantly lower in the low-fertility miRNA transfection group than in the control. IFNT is essential for maternal pregnancy recognition. Therefore, miRNAs in intrauterine EVs from low-fertility cows at 7 days post-estrus may inhibit embryo development and suppress IFNT expression by altering MAPK signaling.

Blockade of foam cell formation by an AP-1 inhibitor attenuates atherosclerosis in diabetes

Abstract Background Atherosclerosis is a major contributor to cardiovascular disease (CVD) related premature deaths in people with diabetes. Residual increased risk of CVD remains even after treatment of standard risk factors including hyperglycaemia. Therefore, there is an unmet clinical need of novel therapies that can directly target the intrinsic pathobiology of atherosclerotic plaque development. Macrophage associated pro-atherosclerotic processes including impaired cholesterol efflux resulting in foam cell formation are important therapeutic targets in atherosclerosis. Expression of genes linked to impaired cholesterol efflux can be regulated by multiple factors including transcription factors (TFs) such as activator protein 1 (AP-1) complex. Although, previous studies have implicated the role of foam cells in atherosclerosis, the role of AP-1 TF complex in foam cell formation in diabetes induced atherosclerosis is not known. Methods Diabetes was induced with streptozotocin (STZ) in atheroprone Apoe-/- mice and 10 weeks later aortae were subjected to single cell RNA sequencing (scRNA-seq) analysis using 10X Genomics platform. In vitro model mimicking diabetes-induced foam cell formation was established in human monocytes THP-1 derived macrophages using high glucose (25mM) and ox-LDL ± a small molecular inhibitor of AP-1, T-5224. AP-1 activity, gene expression and foam cell formation were assessed with activity assay, RT PCR and Oil Red O staining respectively in this setting. Complementary in vitro AP-1 knockdown experiments using shRNA were also performed. Furthermore, preclinical intervention studies were also performed where Apoe-/- mice made diabetic with STZ were treated 5-weeks post diabetes with T-5224 (30 mg/kg body weight daily for 5 weeks). Results scRNA-seq analysis identified a well-defined cluster of foam cells within macrophages with a diabetes specific proatherogenic transcriptomic profile. Differential gene expression analysis showed increased expression of AP-1 members cFos, Atf3, Atf4 and Junb exclusively in foam cell cluster in diabetes (cut off = FDR<0.05, Log2FC -2/2). Comparison with the ENCODE dataset for AP-1 target genes using Harmonizome version 3 showed that indeed multiple differentially expressed genes in diabetes were targets of AP-1. AP-1 members were also upregulated in the THP-1-based in vitro model of high glucose induced foam cell formation. THP-1 derived foam cells showed increased AP-1 activity and lipid uptake. Interestingly, AP-1 inhibition by T-5224 attenuated foam cell formation. AP-1 knockdown experiments validated experimental findings of AP-1 inhibition studies in THP-1 derived macrophages. Importantly, T-5224 treatment blocked foam cell formation resulting in reduced atherosclerosis in diabetic Apoe-/- mice in our intervention study design. Conclusion This study identified the AP-1 inhibition with T-5224 as a potential treatment for the diabetes induced foam cell formation and associated atherosclerosis.

Immunostimulation Signaling via Toll-like Receptor 2 Activation: A Molecular Mechanism of Lactococcus lactis OTG1204 In Vitro and In Vivo.

The immune system's defense against pathogens involves innate and adaptive responses, crucial in maintaining overall health. Immunosuppressed states render individuals more susceptible to potential diseases, indicating the need for effective strategies to bolster immune functions. Although the immunostimulatory effects of various probiotics have been studied, the specific effects and molecular mechanisms of Lactococcus lactis OTG1204 (OTG1204) remain unknown. In this study, the aim was to investigate the molecular mechanisms of OTG1204 in RAW 264.7 macrophages, the key effector cells of the innate immune system involved in host defense and inflammatory responses. Additionally, in this study, the effects of OTG1204 on cyclophosphamide (CTX)-induced immunosuppression states were investigated, thereby demonstrating its potential as an immune stimulant. To assess the macrophage activation ability and underlying mechanisms of OTG1204, RAW 264.7 cells were utilized with transfection, enzyme-linked immunosorbent assay, and quantitative real-time PCR analyses. Furthermore, to evaluate the immunostimulatory effects under immunosuppressed conditions, CTX-induced immunosuppression mice model was employed, and analyses were performed using hematoxylin and eosin staining, flow cytometry, and microbiota examination. OTG1204 activated RAW 264.7 macrophages, leading to increased production of nitric oxide, prostaglandin E2, and cytokines. This immune activation was mediated through the upregulation of toll-like receptor 2, which subsequently activated the nuclear factor-κB (NF-kB) and mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) pathways, thereby stimulating the immune response. In CTX-treated mice, OTG1204 recovered body weight, spleen, and mesenteric lymph node indices, and natural killer cell activity. It re-established populations of innate and adaptive immune cells and activated T cells to secrete cytokines. We also examined the gut barrier integrity and microbiota composition to assess OTG1204's impact on intestinal health, as these factors play a significant role in immune enhancement. OTG1204 enhanced gut barrier integrity by upregulating mucin 2 and tight junction proteins and modulated the gut microbiota by restoring the Firmicutes/Bacteroidetes balance and reducing the abundance of Actinobacteria and Tenericutes. These results suggest that OTG1204 may serve as an effective probiotic for immune enhancement and gut health management by targeting the NF-κB and MAPK/AP-1 pathways, with minimal side effects.

Postoperative Innate Immune Dysregulation, Proteomic, and Monocyte Epigenomic Changes After Colorectal Surgery: A Substudy of a Randomized Controlled Trial.

Colorectal surgery is associated with moderate-to-severe postoperative complications in over 25% of patients, predominantly infections. Monocyte epigenetic alterations leading to immune tolerance could explain postoperative increased susceptibility to infections. This research explores whether changes in monocyte DNA accessibility contribute to postoperative innate immune dysregulation. Damage-associated molecular patterns (DAMPs) and ex vivo cytokine production capacity were measured in a randomized controlled trial (n = 100) in colorectal surgery patients, with additional exploratory subgroup proteomic (proximity extension assay; Olink) and epigenomic analyses (Assay for Transposase-Accessible Chromatin [ATAC sequencing]). Monocytes of healthy volunteers were used to study the effect of high-mobility group box 1 (HMGB1) and heat shock protein 70 (HSP70) on cytokine production capacity in vitro. Plasma DAMPs were increased after surgery. HMGB1 showed a mean 235% increase from before- (preop) to the end of surgery (95% confidence interval [CI] [166 - 305], P < .0001) and 90% increase (95% CI [63-118], P = .0004) preop to postoperative day 1 (POD1). HSP70 increased by a mean 12% from preop to the end of surgery (95% CI [3-21], not significant) and 30% to POD1 (95% CI [18-41], P < .0001). Nuclear deoxyribonucleic acid (nDNA) increases by 66% (95% CI [40-92], P < .0001) at the end of surgery and 94% on POD1 (95% CI [60-127], P < .0001). Mitochondrial DNA (mtDNA) increases by 370% at the end of surgery (95% CI [225-515], P < .0001) and by 503% on POD1 (95% CI [332-673], P < .0001). In vitro incubation of monocytes with HSP70 decreased cytokine production capacity of tumor necrosis factor (TNF) by 46% (95% CI [29-64], P < .0001), IL-6 by 22% (95% CI [12-32], P = .0004) and IL-10 by 19% (95% CI [12-26], P = .0015). In vitro incubation with HMGB1 decreased cytokine production capacity of TNF by 34% (95% CI [3-65], P = .0003), interleukin 1β (IL-1β) by 24% (95% CI [16-32], P < .0001), and IL-10 by 40% (95% CI [21-58], P = .0009). Analysis of the inflammatory proteome alongside epigenetic shifts in monocytes indicated significant changes in gene accessibility, particularly in inflammatory markers such as CXCL8 (IL-8), IL-6, and interferon-gamma (IFN-γ). A significant enrichment of interferon regulatory factors (IRFs) was found in loci exhibiting decreased accessibility, whereas enrichment of activating protein-1 (AP-1) family motifs was found in loci with increased accessibility. These findings illuminate the complex epigenetic modulation influencing monocytes' response to surgical stress, shedding light on potential biomarkers for immune dysregulation. Our results advocate for further research into the role of anesthesia in these molecular pathways and the development of personalized interventions to mitigate immune dysfunction after surgery.

Effective Assessment of Rheumatoid Arthritis Disease Activity and Outcomes Using Monocyte Chemotactic Protein-1 (MCP-1) and Disease Activity Score 28-MCP-1.

The effectiveness of monocyte chemotactic protein-1 (MCP-1) and Disease Activity Score 28 (DAS28)-MCP-1 (DAS28-MCP-1) in assessing rheumatoid arthritis (RA) disease activity is unclear, although some studies have demonstrated their potential usefulness. The present study investigated relationships between MCP-1 and different DAS28 measures, the occurrence of residual swollen joints in different DAS28 remission statuses, changes in medication dosage in relation to the 2005 modified American Rheumatism Association and 2011 American College of Rheumatology/European League against Rheumatism (ACR/EULAR) remission definitions, and the correlations between different DAS28-related scores and Health Assessment Questionnaire Disability Index (HAQ-DI) scores in two RA patient cohorts. The results revealed that the MCP-1 level was correlated with five disease activity measures (DAS28-erythrocyte sedimentation rate [DAS28-ESR], DAS28-C-reactive protein [CRP], Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), and DAS28-MCP-1) in multivariable regression analysis (all p < 0.05; ESR, CRP, and MCP-1 as independent variables). However, ESR was not significantly associated with SDAI and CDAI scores (p = 0.343 and 0.323, respectively). Residual swollen joints were more frequently observed in patients who met the DAS28-ESR remission criteria (<2.6) compared with those meeting the other four remission criteria, with a difference ranging from 71% to 94%. Among patients meeting the DAS28-ESR remission criteria (<2.6), medication changes (dose increase by ≥30% or new medications prescribed) were less frequent in those who also met the 2011 ACR/EULAR remission criteria than in those who did not meet them (p = 0.006). Moreover, the correlation coefficients for the relationship between DAS28-ESR and HAQ-DI scores were the lowest among the five disease activity measures. In conclusion, MCP-1 and DAS28-MCP-1 are effective in assessing RA disease activity, with less residual joint swelling and less frequent medication increases observed in the DAS28-MCP-1 remission < 2.2 subgroup.

Targeting immune-fibroblast cell communication in heart failure.

Inflammation and tissue fibrosis co-exist and are causally linked to organ dysfunction1,2. However, the molecular mechanisms driving immune-fibroblast cell communication in human cardiac disease remain unexplored and there are at present no approved treatments that directly target cardiac fibrosis3,4. Here we performed multiomic single-cell gene expression, epitope mapping and chromatin accessibility profiling in 45 healthy donor, acutely infarcted and chronically failing human hearts. We identified a disease-associated fibroblast trajectory that diverged into distinct populations reminiscent of myofibroblasts and matrifibrocytes, the latter expressing fibroblast activator protein (FAP) and periostin (POSTN). Genetic lineage tracing of FAP+ fibroblasts in vivo showed that they contribute to the POSTN lineage but not the myofibroblast lineage. We assessed the applicability of experimental systems to model cardiac fibroblasts and demonstrated that three different in vivo mouse models of cardiac injury were superior compared with cultured human heart and dermal fibroblasts in recapitulating the human disease phenotype. Ligand-receptor analysis and spatial transcriptomics predicted that interactions between C-C chemokine receptor type 2(CCR2) macrophages and fibroblasts mediated by interleukin-1β (IL-1β) signalling drove the emergence of FAP/POSTN fibroblasts within spatially defined niches. In vivo, we deleted the IL-1 receptor on fibroblasts and the IL-1β ligand in CCR2+ monocytes and macrophages, and inhibited IL-1β signalling using a monoclonal antibody, and showed reduced FAP/POSTN fibroblasts, diminished myocardial fibrosis and improved cardiac function. These findings highlight the broader therapeutic potential of targeting inflammation to treat tissue fibrosis and preserve organ function.

Lack of AMP-activated protein kinase-α1 reduces nitric oxide synthesis in thoracic aorta perivascular adipose tissue

ObjectivePerivascular adipose tissue (PVAT) releases anti-contractile bioactive molecules including NO. PVAT anti-contractile activity is attenuated in mice lacking AMPKα1 (AMP-activated protein kinase-α1). As AMPK regulates endothelial NO synthase (eNOS) activity in cultured cells, NO synthesis was examined in PVAT from AMPKα1 knockout (KO) mice. Methods and resultsEndothelium-denuded thoracic or abdominal aortic rings were isolated from wild type (WT) and KO mice. NOS inhibition enhanced vasoconstriction in PVAT-intact thoracic aortic rings from mice of either genotype yet had no effect on abdominal rings as assessed by wire myography. Thoracic aorta PVAT exhibited increased NO production, NOS activity and levels of the brown adipose tissue marker uncoupling protein-1 (UCP1) compared to abdominal PVAT. In KO mice, NO production was significantly reduced in thoracic but not abdominal PVAT. Reduced NO production in KO thoracic PVAT was not due to altered levels or phosphorylation of eNOS but was associated with increased caveolin-1:eNOS association and caveolin-1 Tyr14 phosphorylation. A peptide that disrupts eNOS:caveolin-1 association increased NO synthesis and reduced vasoconstriction of PVAT-intact thoracic but not abdominal aortic rings. KO thoracic PVAT also exhibited reduced UCP1 levels. ConclusionsMurine thoracic aorta PVAT exhibits higher NO synthesis and UCP1 levels than abdominal aortic PVAT. Downregulation of AMPK suppresses NO synthesis which may contribute to the reduced anticontractile activity and reduced brown adipose tissue phenotype of KO thoracic PVAT. The mechanism underlying the effect of AMPK downregulation likely results from increased caveolin-1:eNOS association associated with caveolin-1 Tyr14 phosphorylation.

Unraveling the Pathogenesis of Calcinosis in Systemic Sclerosis: A Molecular and Clinical Insight.

Dystrophic calcinosis, which is the accumulation of insoluble calcified crystalline materials within tissues with normal circulating calcium and phosphorus levels, is a frequent finding in systemic sclerosis (SSc) and represents a major burden for patients. In SSc, calcinosis poses significant challenges in management due to the associated risk of severe complications such as infection, ulceration, pain, reduction in functional capacity and quality of life, and lack of standardized treatment choices. The exact pathogenesis of calcinosis is still unknown. There are multifaceted factors contributing to calcinosis development, including osteogenic differentiation of cells, imbalance between promoter and inhibitors of mineralization, local disturbance in calcium and phosphate levels, and extracellular matrix as a template for mineralization. Several pathophysiological changes observed in SSc such as ischemia, exacerbated production of excessive reactive oxygen species, inflammation, production of inflammatory cytokines, acroosteolysis, and increased extracellular matrix production may promote the development of calcinosis in SSc. Furthermore, mitochondrial dynamics, particularly fission function through the activity of dynamin-related protein-1, may have an effect on the dystrophic calcinosis process. In-depth investigations of cellular mechanisms and microenvironmental influences can offer valuable insights into the complex pathogenesis of calcinosis in SSc, providing potential targeting pathways for calcinosis treatment.

Selective activation of PPARα by pemafibrate mitigates peritoneal inflammation and fibrosis through suppression of NLRP3 inflammasome and modulation of inflammation

Peritoneal inflammation and fibrosis remain major challenges to the long-term maintenance of peritoneal dialysis. Pemafibrate, a selective peroxisome proliferator-activated receptor α (PPARα) modulator, has been implicated in the management of fibrosis-related disorders. We investigated whether pemafibrate ameliorates peritoneal inflammation and fibrosis and explored the underlying mechanisms in mice with methylglyoxal (MGO)-induced peritoneal fibrosis (MGO mice). MGO mice exhibited peritoneal fibrosis with increased expression of mesenchymal markers, transforming growth factor-β1 (TGF-β1), and substantial deposition of extracellular matrix (ECM) proteins. Additionally, MGO mice exhibited peritoneal inflammation as indicated by elevated tumor necrosis factor-α expression and macrophage infiltration in peritoneal tissue. These effects were mitigated by pemafibrate treatment, which also restored peritoneal membrane function. Furthermore, pemafibrate promoted anti-inflammatory macrophage polarization in both mice and THP-1 cells. In human peritoneal mesothelial cells (HPMCs), pemafibrate effectively inhibited interferon-γ-induced production of TGF-β1 and ECM while suppressing the proinflammatory cytokines nuclear factor-κB (NF-κB) and activator protein 1. The NF-κB inhibitory effect of pemafibrate involved stabilization of the NF-κB inhibitory protein IkBα. Notably, pemafibrate hindered activation of the NLR family pyrin domain containing 3/caspase-1 axis in interferon-γ-stimulated THP-1 cells. These findings suggest that pemafibrate ameliorates peritoneal inflammation and fibrosis, making it a promising candidate for peritoneal fibrosis therapy.

Interleukin 11 therapy causes acute left ventricular dysfunction.

Interleukin 11 (IL11) was initially thought important for platelet production, which led to recombinant IL11 being developed as a drug to treat thrombocytopenia. IL11 was later found to be redundant for haematopoiesis and its use in patients is associated with unexplained and severe cardiac side effects. Here we aim to identify, for the first time, direct cardiomyocyte toxicities associated with IL11, which was previously believed cardioprotective. We injected recombinant mouse lL11 (rmIL11) into mice and studied its molecular effects in the heart using immunoblotting, qRT-PCR, bulk RNA-seq, single nuclei RNA-seq (snRNA-seq) and ATAC-seq. The physiological impact of IL11 was assessed by echocardiography in vivo and using cardiomyocyte contractility assays in vitro. To determine the activity of IL11 specifically in cardiomyocytes we made two cardiomyocyte-specific Il11ra1 knockout (CMKO) mouse models using either AAV9-mediated and Tnnt2-restricted (vCMKO) or Myh6 (m6CMKO) Cre expression and an Il11ra1 floxed mouse strain. In pharmacologic studies, we studied the effects of JAK/STAT inhibition on rmIL11-induced cardiac toxicities. Injection of rmIL11 caused acute and dose-dependent impairment of left ventricular ejection fraction (saline: 62.4% ± 1.9; rmIL11: 32.6% ± 2.9, p<0.001, n=5). Following rmIL11 injection, myocardial STAT3 and JNK phosphorylation were increased and bulk RNA-seq revealed upregulation of pro-inflammatory pathways (TNFα, NFκB and JAK/STAT) and perturbed calcium handling. snRNA-seq showed rmIL11-induced expression of stress factors (Ankrd1, Ankrd23, Xirp2), activator protein-1 (AP-1) transcription factor genes and Nppb in the cardiomyocyte compartment. Following rmIL11 injection, ATAC-seq identified the Ankrd1 and Nppb genes and loci enriched for stress-responsive, AP-1 transcription factor binding sites. Cardiomyocyte-specific effects were examined in vCMKO and m6CMKO mice, which were both protected from rmIL11-induced left ventricular impairment and molecular pathobiologies. In mechanistic studies, inhibition of JAK/STAT signalling with either ruxolitinib or tofacitinib prevented rmIL11-induced cardiac dysfunction. Injection of IL11 directly activates IL11RA/JAK/STAT3 in cardiomyocytes to cause acute heart failure. Our data overturn the earlier assumption that IL11 is cardioprotective and explain the serious cardiac side effects associated with IL11 therapy.

Oncological Aspects of Lysosomal Storage Diseases.

Lysosomal storage diseases (LSDs) are caused by the deficient activity of a lysosomal hydrolase or the lack of a functional membrane protein, transporter, activator, or other protein. Lysosomal enzymes break down macromolecular compounds, which contribute to metabolic homeostasis. Stored, undegraded materials have multiple effects on cells that lead to the activation of autophagy and apoptosis, including the toxic effects of lyso-lipids, the disruption of intracellular Ca2+ ion homeostasis, the secondary storage of macromolecular compounds, the activation of signal transduction, apoptosis, inflammatory processes, deficiencies of intermediate compounds, and many other pathways. Clinical observations have shown that carriers of potentially pathogenic variants in LSD-associated genes and patients affected with some LSDs are at a higher risk of cancer, although the results of studies on the frequency of oncological diseases in LSD patients are controversial. Cancer is found in individuals affected with Gaucher disease, Fabry disease, Niemann-Pick type A and B diseases, alfa-mannosidosis, and sialidosis. Increased cancer prevalence has also been reported in carriers of a potentially pathogenic variant of an LSD gene, namely CLN3, SGSH, GUSB, NEU1, and, to a lesser extent, in other genes. In this review, LSDs in which oncological events can be observed are described.

Punicalagin as a novel selective aryl hydrocarbon receptor (AhR) modulator upregulates AhR expression through the PDK1/p90RSK/AP-1 pathway to promote the anti-inflammatory response and bactericidal activity of macrophages

Aryl hydrocarbon receptor (AhR) plays an important role in inflammation and immunity as a new therapeutic target for infectious disease and sepsis. Punicalagin (PUN) is a Chinese herbal monomer extract of pomegranate peel that has beneficial anti-inflammatory, antioxidant and anti-infective effects. However, whether PUN is a ligand of AhR, its effect on AhR expression, and its signaling pathway remain poorly understood. In this study, we found that PUN was a unique polyphenolic compound that upregulated AhR expression at the transcriptional level, and regulated the AhR nongenomic pathway. AhR expression in lipopolysaccharide-induced macrophages was upregulated by PUN in vitro and in vivo in a time- and dose-dependent manner. Using specific inhibitors and siRNA, induction of AhR by PUN depended on sequential phosphorylation of 90-kDa ribosomal S6 kinase (p90RSK), which was activated by the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphoinositide-dependent protein kinase (PDK)1 pathways. PUN promoted p90RSK-mediated activator protein-1 (AP-1) activation. AhR knockout or inhibitors reversed suppression of interleukin (IL)-6 and IL-1β expression by PUN. PUN decreased Listeria load and increased macrophage survival via AhR upregulation. In conclusion, we identified PUN as a novel selective AhR modulator involved in AhR expression via the MEK/ERK and PDK1 pathways targeting p90RSK/AP-1 in inflammatory macrophages, which inhibited macrophage inflammation and promoted bactericidal activity.

FOS+ B cells: Key mediators of immunotherapy resistance in diverse cancer types

While immunotherapy has marked significant advances in cancer treatment, resistance remains a challenge. The complexity of the tumor microenvironment, particularly the role of B cell subpopulations, is a critical factor affecting treatment efficacy. In this study, we conducted analyses of single-cell RNA sequencing data from immunotherapy patients (n = 25) to explore the biomarker of immunotherapy resistance. Spatial transcriptome analysis, immunofluorescence analysis and multi-cancer immunotherapy transcriptome analysis (n = 1253) were used to validate our finding, and the potential mechanisms were explored. FOS+ B cells, identified across multiple cancer types, were associated with poor response to immunotherapy. FOS may form AP-1 (activator protein 1) with JUNB, thereby promoting the expression of Blimp-1 and subsequently facilitating the differentiation of B cells into immunosuppressive plasma cells. Furthermore, FOS+ B cells were linked to altered TNF signaling pathways, suggesting a mechanism for their immunosuppressive effects. Our findings highlight FOS+ B cells as important players in immunotherapy resistance, providing a novel biomarker for predicting treatment response. This study not only deepens our understanding of the immunological landscape influencing immunotherapy efficacy but also opens avenues for targeted interventions to overcome resistance.