CCAAT/enhancer-binding protein delta promotes intracellular lipid accumulation in M1 macrophages of vascular lesions

CEBPD is a pivotal factor for the activation of NLRP3 inflammasome in traumatic brain injury

Traumatic brain injury (TBI) is a significant global health concern and a leading cause of mortality and disability worldwide. Neuroinflammation is a pivotal pathological mechanism underlying secondary brain injury following TBI. CCAAT enhancer-binding protein-delta (CEBPD), a transcription factor necessary for regulating immune and inflammatory responses, plays an important role in the progression of neuroinflammatory disorders. However, the role of CEBPD in the prognosis of TBI needs to be determined. We found that the expression of CEBPD increased significantly in TBI patients and animal models, as well as in the HT-22 neuron mechanical scratch injury model. The inhibition of CEBPD by in vivo siRNA effectively suppressed neuronal death, brain edema, and brain contusion volume and alleviated neurofunctional deficits. Knocking down CEBPD considerably inhibited the activation of the neuronal NLRP3 inflammasome, downregulated the expression of the GSDMD N-terminal fragment, and reduced the production of IL-1β and IL-18, significantly mitigating neuronal pyroptosis after TBI. Increasing CEBPD levels led to the activation of the NLRP3 inflammasome and neuronal pyroptosis in the mechanical scratch injury cell model. We also determined that the NLRP3 inflammasome activated by nigericin depended on the CEBPD pathway following TBI. Our results suggested that CEBPD may serve as a pivotal factor in promoting neuronal pyroptosis and that inhibiting CEBPD might be a promising strategy for treating TBI.

The Complementary Role of Morphology in Understanding Microglial Functional Heterogeneity

A search of the PubMed database for publications on microglia reveals an intriguing shift in scientific interest over time. Dividing microglia into categories such as "resting" and "activated" or M1 versus M2 is nowadays obsolete, with the current research focusing on unraveling microglial heterogeneity. The onset of transcriptomics, especially single-cell RNA sequencing (scRNA-seq), has profoundly reshaped our understanding of microglia heterogeneity. Conversely, microglia morphology analysis can offer important insights regarding their activation state or involvement in tissue responses. This review explores microglial heterogeneity under homeostatic conditions, developmental stages, and disease states, with a focus on integrating transcriptomic data with morphological analysis. Beyond the core gene expression profile, regional differences are observed with cerebellar microglia exhibiting a uniquely immune-vigilant profile. During development, microglia express homeostatic genes before birth, yet the bushy appearance is a characteristic that appears later on. In neurodegeneration, microglia alternate between proinflammatory and neuroprotective roles, influenced by regional factors and disease onset. Understanding these structural adaptations may help identify specific microglial subpopulations for targeted therapeutic strategies.

The emerging role of E3 ubiquitin ligases and deubiquitinases in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, with a prevalence as high as 32.4%. MASLD encompasses a spectrum of liver pathologies, ranging from steatosis to metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, and, in some cases, progression to end-stage liver disease (cirrhosis and hepatocellular carcinoma). A comprehensive understanding of the pathogenesis of this highly prevalent liver disease may facilitate the identification of novel targets for the development of improved therapies. E3 ubiquitin ligases and deubiquitinases (DUBs) are key regulatory components of the ubiquitin‒proteasome system (UPS), which plays a pivotal role in maintaining intracellular protein homeostasis. Emerging evidence implicates that aberrant expression of E3 ligases and DUBs is involved in the progression of MASLD. Here, we review abnormalities in E3 ligases and DUBs by (1) discussing their targets, mechanisms, and functions in MASLD; (2) summarizing pharmacological interventions targeting these enzymes in preclinical and clinical studies; and (3) addressing challenges and future therapeutic strategies. This review synthesizes current evidence to highlight the development of novel therapeutic strategies based on the UPS for MASLD and progressive liver disease.

Basic biology and roles of CEBPD in cardiovascular disease

CCAAT/enhancer-binding protein delta (CEBPD), as an evolutionarily conserved protein in mammals, belongs to the CEBP transcription factor family, which modulates many biological processes. The diversity of CEBPD functions partly depends on the cell type and cellular context. Aberrant CEBPD expression and activity are associated with multiple organ diseases, including cardiovascular diseases. In this review, we describe the basic molecular biology of CEBPD to understand its expression regulation, modifications, and functions. Here, we summarize the recent advances in genetically modified animals with CEBPD. Finally, we discuss the contribution of CEBPD to cardiovascular diseases and highlight the strategies for developing novel therapies targeting CEBPD.

Comprehensive analysis of lipid metabolic signatures identified CEBPD promotes breast cancer cell proliferation

Breast cancer (BRCA) remains the leading cause of cancer-related mortality worldwide, with lipid metabolism emerging as a critical factor in tumor progression that influences cell proliferation, migration, and immune response. Insights into lipid metabolism signatures and associated genes may offer new prognostic and therapeutic avenues. In this study, we leveraged scRNA-seq and bulk transcriptome data to assess the expression patterns and prognostic significance of lipid metabolism-related genes in BRCA. Through single-cell transcriptomic analysis of primary BRCA samples, we identified a specific set of lipid metabolism signature genes and constructed a prognostic risk model based on these signatures. This model enables patient stratification by risk scores, supporting an integrated analysis of lipid metabolism, immune landscape, and clinical outcomes. Importantly, we identified CEBPD, ABCA1, and CYP27A1 as independent prognostic genes linked to lipid metabolism, with functional assays revealing an inhibitory role for CEBPD in BRCA cell proliferation. Our findings underscore the influence of adipocytes in BRCA progression and propose CEBPD as a potential target for therapeutic intervention. This study provides a foundation for further exploration of metabolism-based strategies to enhance BRCA outcomes.

Identification of immune-associated biomarkers of diabetes nephropathy tubulointerstitial injury based on machine learning: a bioinformatics multi-chip integrated analysis

BACKGROUND

Diabetic nephropathy (DN) is a major microvascular complication of diabetes and has become the leading cause of end-stage renal disease worldwide. A considerable number of DN patients have experienced irreversible end-stage renal disease progression due to the inability to diagnose the disease early. Therefore, reliable biomarkers that are helpful for early diagnosis and treatment are identified. The migration of immune cells to the kidney is considered to be a key step in the progression of DN-related vascular injury. Therefore, finding markers in this process may be more helpful for the early diagnosis and progression prediction of DN.

METHODS

The gene chip data were retrieved from the GEO database using the search term ' diabetic nephropathy '. The ' limma ' software package was used to identify differentially expressed genes (DEGs) between DN and control samples. Gene set enrichment analysis (GSEA) was performed on genes obtained from the molecular characteristic database (MSigDB. The R package 'WGCNA' was used to identify gene modules associated with tubulointerstitial injury in DN, and it was crossed with immune-related DEGs to identify target genes. Gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on differentially expressed genes using the 'ClusterProfiler' software package in R. Three methods, least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE) and random forest (RF), were used to select immune-related biomarkers for diagnosis. We retrieved the tubulointerstitial dataset from the Nephroseq database to construct an external validation dataset. Unsupervised clustering analysis of the expression levels of immune-related biomarkers was performed using the 'ConsensusClusterPlus 'R software package. The urine of patients who visited Dongzhimen Hospital of Beijing University of Chinese Medicine from September 2021 to March 2023 was collected, and Elisa was used to detect the mRNA expression level of immune-related biomarkers in urine. Pearson correlation analysis was used to detect the effect of immune-related biomarker expression on renal function in DN patients.

RESULTS

Four microarray datasets from the GEO database are included in the analysis : GSE30122, GSE47185, GSE99340 and GSE104954. These datasets included 63 DN patients and 55 healthy controls. A total of 9415 genes were detected in the data set. We found 153 differentially expressed immune-related genes, of which 112 genes were up-regulated, 41 genes were down-regulated, and 119 overlapping genes were identified. GO analysis showed that they were involved in various biological processes including leukocyte-mediated immunity. KEGG analysis showed that these target genes were mainly involved in the formation of phagosomes in Staphylococcus aureus infection. Among these 119 overlapping genes, machine learning results identified AGR2, CCR2, CEBPD, CISH, CX3CR1, DEFB1 and FSTL1 as potential tubulointerstitial immune-related biomarkers. External validation suggested that the above markers showed diagnostic efficacy in distinguishing DN patients from healthy controls. Clinical studies have shown that the expression of AGR2, CX3CR1 and FSTL1 in urine samples of DN patients is negatively correlated with GFR, the expression of CX3CR1 and FSTL1 in urine samples of DN is positively correlated with serum creatinine, while the expression of DEFB1 in urine samples of DN is negatively correlated with serum creatinine. In addition, the expression of CX3CR1 in DN urine samples was positively correlated with proteinuria, while the expression of DEFB1 in DN urine samples was negatively correlated with proteinuria. Finally, according to the level of proteinuria, DN patients were divided into nephrotic proteinuria group (n = 24) and subrenal proteinuria group. There were significant differences in urinary AGR2, CCR2 and DEFB1 between the two groups by unpaired t test (P < 0.05).

CONCLUSIONS

Our study provides new insights into the role of immune-related biomarkers in DN tubulointerstitial injury and provides potential targets for early diagnosis and treatment of DN patients. Seven different genes ( AGR2, CCR2, CEBPD, CISH, CX3CR1, DEFB1, FSTL1 ), as promising sensitive biomarkers, may affect the progression of DN by regulating immune inflammatory response. However, further comprehensive studies are needed to fully understand their exact molecular mechanisms and functional pathways in DN.

Single-Cell Gene-Regulatory Networks of Advanced Symptomatic Atherosclerosis

BACKGROUND

While our understanding of the single-cell gene expression patterns underlying the transformation of vascular cell types during the progression of atherosclerosis is rapidly improving, the clinical and pathophysiological relevance of these changes remains poorly understood.

METHODS

Single-cell RNA sequencing data generated with SmartSeq2 (≈8000 genes/cell) in 16 588 single cells isolated during atherosclerosis progression in Ldlr-/-Apob100/100 mice with human-like plasma lipoproteins and from humans with asymptomatic and symptomatic carotid plaques was clustered into multiple subtypes. For clinical and pathophysiological context, the advanced-stage and symptomatic subtype clusters were integrated with 135 tissue-specific (atherosclerotic aortic wall, mammary artery, liver, skeletal muscle, and visceral and subcutaneous, fat) gene-regulatory networks (GRNs) inferred from 600 coronary artery disease patients in the STARNET (Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task) study.

RESULTS

Advanced stages of atherosclerosis progression and symptomatic carotid plaques were largely characterized by 3 smooth muscle cells (SMCs), and 3 macrophage subtype clusters with extracellular matrix organization/osteogenic (SMC), and M1-type proinflammatory/Trem2-high lipid-associated (macrophage) phenotypes. Integrative analysis of these 6 clusters with STARNET revealed significant enrichments of 3 arterial wall GRNs: GRN33 (macrophage), GRN39 (SMC), and GRN122 (macrophage) with major contributions to coronary artery disease heritability and strong associations with clinical scores of coronary atherosclerosis severity. The presence and pathophysiological relevance of GRN39 were verified in 5 independent RNAseq data sets obtained from the human coronary and aortic artery, and primary SMCs and by targeting its top-key drivers, FRZB and ALCAM in cultured human coronary artery SMCs.

CONCLUSIONS

By identifying and integrating the most gene-rich single-cell subclusters of atherosclerosis to date with a coronary artery disease framework of GRNs, GRN39 was identified and independently validated as being critical for the transformation of contractile SMCs into an osteogenic phenotype promoting advanced, symptomatic atherosclerosis.

Adipose tissue macrophage dysfunction is associated with a breach of vascular integrity in NASH

BACKGROUND & AIMS

In non-alcoholic fatty liver disease (NAFLD), monocytes infiltrate visceral adipose tissue promoting local and hepatic inflammation. However, it remains unclear what drives inflammation and how the immune landscape in adipose tissue differs across the NAFLD severity spectrum. We aimed to assess adipose tissue macrophage (ATM) heterogeneity in a NAFLD cohort.

METHODS

Visceral adipose tissue macrophages from lean and obese patients, stratified by NAFLD phenotypes, underwent single-cell RNA sequencing. Adipose tissue vascular integrity and breaching was assessed on a protein level via immunohistochemistry and immunofluorescence to determine targets of interest.

RESULTS

We discovered multiple ATM populations, including resident vasculature-associated macrophages (ResVAMs) and distinct metabolically active macrophages (MMacs). Using trajectory analysis, we show that ResVAMs and MMacs are replenished by a common transitional macrophage (TransMac) subtype and that, during NASH, MMacs are not effectively replenished by TransMac precursors. We postulate an accessory role for MMacs and ResVAMs in protecting the adipose tissue vascular barrier, since they both interact with endothelial cells and localize around the vasculature. However, across the NAFLD severity spectrum, alterations occur in these subsets that parallel an adipose tissue vasculature breach characterized by albumin extravasation into the perivascular tissue.

CONCLUSIONS

NAFLD-related macrophage dysfunction coincides with a loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver.

IMPACT AND IMPLICATIONS

Our study describes for the first time the myeloid cell landscape in human visceral adipose tissue at single-cell level within a cohort of well-characterized patients with non-alcoholic fatty liver disease. We report unique non-alcoholic steatohepatitis-specific transcriptional changes within metabolically active macrophages (MMacs) and resident vasculature-associated macrophages (ResVAMs) and we demonstrate their spatial location surrounding the vasculature. These dysfunctional transcriptional macrophage states coincided with the loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver. Our study provides a theoretical basis for new therapeutic strategies to be directed towards reinstating the endogenous metabolic, homeostatic and cytoprotective functions of ResVAMs and MMacs, including their role in protecting vascular integrity.

Identification of key biomarkers for predicting CAD progression in inflammatory bowel disease via machine-learning and bioinformatics strategies

The study aimed to identify the biomarkers for predicting coronary atherosclerotic lesions progression in patients with inflammatory bowel disease (IBD). Related transcriptome datasets were seized from Gene Expression Omnibus database. IBD-related modules were identified via Weighted Gene Co-expression Network Analysis. The 'Limma' was applied to screen differentially expressed genes between stable coronary artery disease (CAD) and acute myocardial infarction (AMI). Subsequently, we employed protein-protein interaction (PPI) network and three machine-learning strategies to further screen for candidate hub genes. Application of the receiver operating characteristics curve to quantitatively evaluate candidates to determine key diagnostic biomarkers, followed by a nomogram construction. Ultimately, we performed immune landscape analysis, single-gene GSEA and prediction of target-drugs. 3227 IBD-related module genes and 570 DEGs accounting for AMI were recognized. Intersection yielded 85 shared genes and mostly enriched in immune and inflammatory pathways. After filtering through PPI network and multi-machine learning algorithms, five candidate genes generated. Upon validation, CTSD, CEBPD, CYP27A1 were identified as key diagnostic biomarkers with a superior sensitivity and specificity (AUC > 0.8). Furthermore, all three genes were negatively correlated with CD4+ T cells and positively correlated with neutrophils. Single-gene GSEA highlighted the importance of pathogen invasion, metabolism, immune and inflammation responses during the pathogenesis of AMI. Ten target-drugs were predicted. The discovery of three peripheral blood biomarkers capable of predicting the risk of CAD proceeding into AMI in IBD patients. These identified biomarkers were negatively correlated with CD4+ T cells and positively correlated with neutrophils, indicating a latent therapeutic target.

Pentraxin 3: A promising therapeutic target for cardiovascular diseases

Cardiovascular disease (CVD) is the primary global cause of death, and inflammation is a crucial factor in the development of CVDs. The acute phase inflammatory protein pentraxin 3 (PTX3) is a biomarker reflecting the immune response. Recent research indicates that PTX3 plays a vital role in CVDs and has been investigated as a possible biomarker for CVD in clinical trials. PTX3 is implicated in the progression of CVDs through mechanisms such as exacerbating vascular endothelial dysfunction, affecting angiogenesis, and regulating inflammation and oxidative stress. This review summarized the structure and function of PTX3, focusing on its multifaceted effects on CVDs, such as atherosclerosis, myocardial infarction, and hypertension. This may help in explaining the varying PTX3 functions and usage, as well as in utilizing target organs to manage diseases. Moreover, elucidating the opposite role of PTX3 in the cardiovascular system will demonstrate the therapeutic and predictive potential in human diseases.

The Multifunction of TRIM26: From Immune Regulation to Oncology

Ubiquitination, a crucial post-translational modification, plays a role in nearly all physiological processes. Its functional execution depends on a series of catalytic reactions involving numerous proteases. TRIM26, a protein belonging to the TRIM family, exhibits E3 ubiquitin ligase activity because of its RING structural domain, and is present in diverse cell lineages. Over the last few decades, TRIM26 has been documented to engage in numerous physiological and pathological processes as a controller, demonstrating a diverse array of biological roles. Despite the growing research interest in TRIM26, there has been limited attention given to examining the protein's structure and function in existing reviews. This review begins with a concise overview of the composition and positioning of TRIM26 and then proceeds to examine its roles in immune response, viral invasion, and inflammatory processes. Simultaneously, we demonstrate the contribution of TRIM26 to the progression of various diseases, encompassing numerous malignancies and neurologic conditions. Finally, we have investigated the potential areas for future research on TRIM26.

Tripartite motif containing 26 prevents steatohepatitis progression by suppressing C/EBPδ signalling activation

Currently potential preclinical drugs for the treatment of nonalcoholic steatohepatitis (NASH) and NASH-related pathopoiesis have failed to achieve expected therapeutic efficacy due to the complexity of the pathogenic mechanisms. Here we show Tripartite motif containing 26 (TRIM26) as a critical endogenous suppressor of CCAAT/enhancer binding protein delta (C/EBPδ), and we also confirm that TRIM26 is an C/EBPδ-interacting partner protein that catalyses the ubiquitination degradation of C/EBPδ in hepatocytes. Hepatocyte-specific loss of Trim26 disrupts liver metabolic homeostasis, followed by glucose metabolic disorder, lipid accumulation, increased hepatic inflammation, and fibrosis, and dramatically facilitates NASH-related phenotype progression. Inversely, transgenic Trim26 overexpression attenuates the NASH-associated phenotype in a rodent or rabbit model. We provide mechanistic evidence that, in response to metabolic insults, TRIM26 directly interacts with C/EBPδ and promotes its ubiquitin proteasome degradation. Taken together, our present findings identify TRIM26 as a key suppressor over the course of NASH development.

Drug resistance and new therapies in gallbladder cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy, which poses significant challenges for timely diagnosis, resulting in a dismal prognosis. Chemotherapy serves as a primary treatment option in cases where surgery is not feasible. However, the emergence of chemoresistance poses a significant challenge to the effectiveness of chemotherapy, ultimately resulting in a poor prognosis. Despite extensive research on mechanisms of chemotherapeutic resistance in oncology, the underlying mechanisms of chemoresistance in GBC remain poorly understood. In this review, we present the findings from the last decade on the molecular mechanisms of chemotherapeutic resistance in GBC. We hope that these insights may provide novel therapeutic and experimental targets for further investigations into this lethal disease.

Analysis of the microglia transcriptome across the human lifespan using single cell RNA sequencing

BACKGROUND

Microglia are tissue resident macrophages with a wide range of critically important functions in central nervous system development and homeostasis.

METHOD

In this study, we aimed to characterize the transcriptional landscape of ex vivo human microglia across different developmental ages using cells derived from pre-natal, pediatric, adolescent, and adult brain samples. We further confirmed our transcriptional observations using ELISA and RNAscope.

RESULTS

We showed that pre-natal microglia have a distinct transcriptional and regulatory signature relative to their post-natal counterparts that includes an upregulation of phagocytic pathways. We confirmed upregulation of CD36, a positive regulator of phagocytosis, in pre-natal samples compared to adult samples in situ. Moreover, we showed adult microglia have more pro-inflammatory signature compared to microglia from other developmental ages. We indicated that adult microglia are more immune responsive by secreting increased levels of pro-inflammatory cytokines in response to LPS treatment compared to the pre-natal microglia. We further validated in situ up-regulation of IL18 and CXCR4 in human adult brain section compared to the pre-natal brain section. Finally, trajectory analysis indicated that the transcriptional signatures adopted by microglia throughout development are in response to a changing brain microenvironment and do not reflect predetermined developmental states.

CONCLUSION

In all, this study provides unique insight into the development of human microglia and a useful reference for understanding microglial contribution to developmental and age-related human disease.

The biological impacts of CEBPD on urothelial carcinoma development and progression

Urothelial carcinoma (UC), which includes urinary bladder urothelial carcinoma (UBUC) and upper tract urothelial carcinoma (UTUC), is one of the most common malignancies worldwide. Accordingly, a comprehensive understanding of the underlying mechanism governing UC development is compulsory. Aberrant CCAAT/enhancer-binding protein delta (CEBPD), a transcription factor, displays an oncogene or tumor suppressor depending on tumor type and microenvironments. However, CEBPD has been reported to possess a clear oncogenic function in UC through multiple regulation pathways. Genomic amplification of CEBPD triggered by MYC-driven genome instability is frequently examined in UC that drives CEBPD overexpression. Upregulated CEBPD transcriptionally suppresses FBXW7 to stabilize MYC protein and further induces hexokinase II (HK2)-related aerobic glycolysis that fuels cell growth. Apart from the MYC-dependent pathway, CEBPD also downregulates the level of hsa-miR-429 to enhance HK2-associated glycolysis and induce angiogenesis driven by vascular endothelial growth factor A (VEGFA). Additionally, aggressive UC is attributed to the tumor metastasis regulated by CEBPD-induced matrix metalloproteinase-2 (MMP2) overexpression. Furthermore, elevated CEBPD induced by cisplatin (CDDP) is identified to have dual functions, namely, CDDP-induced chemotherapy resistance or drive CDDP-induced antitumorigenesis. Given that the role of CEBPD in UC is getting clear but pending a more systemic reappraisal, this review aimed to comprehensively discuss the underlying mechanism of CEBPD in UC tumorigenesis.

Pentraxin 3 regulates tyrosine kinase inhibitor-associated cardiomyocyte contraction and mitochondrial dysfunction via ERK/JNK signalling pathways

BACKGROUND

Hepatocellular carcinoma (HCC) patients suffer varying degrees of heart dysfunction after tyrosine kinase inhibitor (TKI) treatment. Interestingly, HCC patients often have higher levels of pentraxin 3 (PTX3), and PTX3 inhibition was found to improve left ventricular dysfunction in animal models.

OBJECTIVES

We sought to assess the therapeutic potential of PTX3 inhibition on TKI-associated cardiotoxicity.

METHODS

We used a human embryonic stem cell line, RUES2, to generate cardiomyocyte cultures (RUES2-CM) for functional testing. We also assessed heart function and PTX3 expression levels in 16 HCC patients who received TKI treatment, 3 HCC patients who did not receive TKIs, and 7 healthy volunteers.

RESULTS

Significantly higher PTX3 expression was noted in HCC patients with TKI treatment versus those without, and 38% of male and 33% of female patients had QTc prolongation after TKI treatment. Treatment of cardiomyocyte cultures with sorafenib also increased PTX3 expression and induced cytoskeletal remodelling, contraction reduction, sodium current inhibition, and mitochondrial respiratory dysfunction. PTX3 colocalised with CD44 in cardiomyocytes, and cardiomyocyte contraction, mitochondrial respiratory function, and regular cytoskeletal and apoptotic protein expression were restored with PTX3 inhibition. CD44 knockdown confirmed PTX3/CD44 signalling. These results suggest a possible mechanism in which sorafenib treatment increases PTX3 expression, thereby resulting in reduced extracellular signal-regulated kinase (ERK) 1/2 expression that affects cardiomyocyte contraction, while also activating c-Jun N-terminal kinase (JNK) downstream pathways to disrupt mitochondrial respiration and trigger apoptosis.

CONCLUSIONS

TKI-induced cardiotoxicity may be partly mediated by the upregulation of PTX3, and thus PTX3 inhibition has potential as a therapeutic strategy.

Pentraxin 3 Facilitates Shrimp-Allergic Responses in IgE-Activated Mast Cells

BACKGROUND

Since food avoidance is currently the only way to prevent allergic reactions to shrimp, a better understanding of molecular events in the induction and progression of allergy, including food allergy, is needed for developing strategies to inhibit allergic responses. Pentraxin 3 (PTX3) is rapidly produced directly from inflammatory or damaged tissues and is involved in acute immunoinflammatory responses. However, the role of PTX3 in the development of immediate IgE-mediated shrimp allergy remains unknown.

METHODS

Wild-type BALB/c mice were immunized intraperitoneally and were challenged with shrimp extract. Serum IgE and PTX3 levels were analyzed. RBL-2H3 cells were stimulated with either dinitrophenyl (DNP) or serum of shrimp-allergic mice, and markers of degranulation, proinflammatory mediators, and phosphorylation of signal proteins were analyzed. We further examined the effect of PTX3 in shrimp extract-induced allergic responses in vitro and in vivo.

RESULTS

Mice with shrimp allergy had increased PTX3 levels in the serum and small intestine compared with healthy mice. PTX3 augmented degranulation, the production of proinflammatory mediators, and activation of the Akt and MAPK signaling pathways in mast cells upon DNP stimulation. Furthermore, the expression of transcription factor CCAAT/enhancer-binding protein delta (CEBPD) was elevated in PTX3-mediated mast cell activation. Finally, the PTX3 inhibitor RI37 could attenuate PTX3-induced degranulation, proinflammatory mediator expression, and phosphorylation of the Akt and MAPK signaling.

CONCLUSIONS

The results suggested that PTX3 can facilitate allergic responses. Our data provide new insight to demonstrate that PTX3 is a cause of allergic inflammation and that RI37 can serve as a therapeutic agent in shrimp allergy.

CEBPD modulates the airway smooth muscle transcriptomic response to glucocorticoids

BACKGROUND

CCAAT/Enhancer Binding Protein D (CEBPD), a pleiotropic glucocorticoid-responsive transcription factor, modulates inflammatory responses. Of relevance to asthma, expression of CEBPD in airway smooth muscle (ASM) increases with glucocorticoid exposure. We sought to characterize CEBPD-mediated transcriptomic responses to glucocorticoid exposure in ASM by measuring changes observed after knockdown of CEBPD and its impact on asthma-related ASM function.

METHODS

Primary ASM cells derived from four donors were transfected with CEBPD or non-targeting (NT) siRNA and exposed to vehicle control, budesonide (100 nM, 18 h), TNFα (10 ng/ml, 18 h), or both budesonide and TNFα. Subsequently, RNA-Seq was used to measure gene expression levels, and pairwise differential expression results were obtained for exposures versus vehicle and knockdown versus control conditions. Weighted gene co-expression analysis was performed to identify groups of genes with similar expression patterns across the various experimental conditions (i.e., CEBPD knockdown status, exposures).

RESULTS

CEBPD knockdown altered expression of 3037 genes under at least one exposure (q-value < 0.05). Co-expression analysis identified sets of 197, 152 and 290 genes that were correlated with CEBPD knockdown status, TNFα exposure status, and both, respectively. JAK-STAT signaling pathway genes, including IL6R and SOCS3, were among those influenced by both TNFα and CEBPD knockdown. Immunoblot assays revealed that budesonide-induced IL-6R protein expression and augmented IL-6-induced STAT3 phosphorylation levels were attenuated by CEBPD knockdown in ASM.

CONCLUSIONS

CEBPD modulates glucocorticoid responses in ASM, in part via modulation of IL-6 receptor signaling.

CCAAT/enhancer binding protein (C/EBP) delta promotes the expression of PTX3 and macrophage phagocytosis during A. fumigatus infection

Given the increasing incidence of pulmonary aspergillosis, it is important to understand the natural defense mechanisms by which the body can kill Aspergillus fumigatus conidia. Pentraxin 3 (PTX3) plays a nonredundant role in resistance to A. fumigatus. Here, we found that the key predicted PTX3 transcription factor, CCAAT/enhancer-binding protein δ (CEBPD), was up-regulated during A. fumigatus conidia infection. Functionally, CEBPD significantly promoted the expression of PTX3 and the phagocytic ability of macrophages. Mechanistically, CEBPD activated the PTX3 by directly binding to the promoter region of the PTX3 gene. We also showed that the RNA-binding protein human antigen R promoted CEBPD expression. These findings provide new insights into the crucial role of CEBPD in the phagocytosis of A. fumigatus conidia by macrophages and highlight this protein as a potential therapeutic target for invasive pulmonary aspergillosis.

Genetic deficiency of Phactr1 promotes atherosclerosis development via facilitating M1 macrophage polarization and foam cell formation

Genetic variants in phosphatase and actin regulator-1 (Phactr1) are reported to be associated with arteriosclerotic cardiovascular disease (ASCVD). However, the function of Phactr1 in atherosclerosis remains unclear. Patients with acute coronary syndrome (ACS) who underwent coronary angiography and optical coherence tomography (OCT) were enrolled and divided into non-ST segment elevation (NST-ACS) group and ST-ACS group. The expression of Phactr1 on monocytes was higher in NST-ACS and ST-ACS groups as compared with control group. Furthermore, NST-ACS patients who have more vulnerable features including thin-cap fibroatheroma (TCFA) and large lipid area showed higher levels of Phactr1 on monocytes than those with stable plaques. Through mouse models of atherosclerosis, Phactr1-/-Apoe-/- mice (double knockout mice, DKO) developed more severe atherosclerotic plaques, recruiting more macrophages into subendothelium and having elevated levels of proinflammatory cytokines in plaques. Similarly, Apoe knockout mice (Apoe-/-) receiving DKO bone marrow (BM) exhibited elevated plaque burden compared with Apoe-/- mice receiving Apoe-/- BM, indicating the protective effect of Phactr1 in hematopoietic cells. We found that depletion of Phactr1 in BM-derived macrophages (BMDMs) tended to differentiate into M1 phenotype, produced more proatherogenic cytokines and eventually converted into foam cells driven by oxidized low-density lipoprotein (ox-LDL). Mechanistically, Phactr1 activated CREB signaling via directly binding to CREB, up-regulating CREB phosphorylation and inducing KLF4 expression. Finally, overexpression of KLF4 partly rescued the excessive inflammation response and foam cell formation induced by deficiency of Phactr1. In conclusion, our study demonstrates that elevated Phactr1 in monocytes is a promising biomarker for vulnerable plaques, while increased Phactr1 attenuates atherosclerotic development via activation of CREB and M2 macrophage differentiation.

Metformin Resensitizes Sorafenib-Resistant HCC Cells Through AMPK-Dependent Autophagy Activation

Despite the activation of autophagy may enable residual cancer cells to survive and allow tumor relapse, excessive activation of autophagy may eventually lead to cell death. However, the details of the association of autophagy with primary resistance in hepatocellular carcinoma (HCC) remain less clear. In this study, cohort analysis revealed that HCC patients receiving sorafenib with HBV had higher mortality risk. We found that high epidermal growth factor receptor (EGFR) expression and activity may be linked to HBV-induced sorafenib resistance. We further found that the resistance of EGFR-overexpressed liver cancer cells to sorafenib is associated with low activity of AMP-activated protein kinase (AMPK) and CCAAT/enhancer binding protein delta (CEBPD) as well as insufficient autophagic activation. In response to metformin, the AMPK/cAMP-response element binding protein (CREB) pathway contributes to CEBPD activation, which promotes autophagic cell death. Moreover, treatment with metformin can increase sorafenib sensitivity through AMPK activation in EGFR-overexpressed liver cancer cells. This study suggests that AMPK/CEBPD-activated autophagy could be a potent strategy for improving the efficacy of sorafenib in HCC patients.

Metformin Resensitizes Sorafenib-Resistant HCC Cells Through AMPK-Dependent Autophagy Activation

Despite the activation of autophagy may enable residual cancer cells to survive and allow tumor relapse, excessive activation of autophagy may eventually lead to cell death. However, the details of the association of autophagy with primary resistance in hepatocellular carcinoma (HCC) remain less clear. In this study, cohort analysis revealed that HCC patients receiving sorafenib with HBV had higher mortality risk. We found that high epidermal growth factor receptor (EGFR) expression and activity may be linked to HBV-induced sorafenib resistance. We further found that the resistance of EGFR-overexpressed liver cancer cells to sorafenib is associated with low activity of AMP-activated protein kinase (AMPK) and CCAAT/enhancer binding protein delta (CEBPD) as well as insufficient autophagic activation. In response to metformin, the AMPK/cAMP-response element binding protein (CREB) pathway contributes to CEBPD activation, which promotes autophagic cell death. Moreover, treatment with metformin can increase sorafenib sensitivity through AMPK activation in EGFR-overexpressed liver cancer cells. This study suggests that AMPK/CEBPD-activated autophagy could be a potent strategy for improving the efficacy of sorafenib in HCC patients.

CCAAT/Enhancer-binding protein delta mediates glioma stem-like cell enrichment and ATP-binding cassette transporter ABCA1 activation for temozolomide resistance in glioblastoma

Glioblastoma (GBM) is the most aggressive brain tumor and relapses after chemo- or radiotherapy in a short time. The anticancer drug temozolamide (TMZ) is commonly used for GBM treatment, but glioma stem-like cells (GSCs) often lead to drug resistance and therapeutic failure. To date, the mechanism of GSC formation in TMZ-treated GBM remains largely unknown. CCAAT/Enhancer-binding protein delta (CEBPD) is an inflammation-responsive transcription factor and is proposed to be oncogenic in the context of drug resistance, prompting us to clarify its role in TMZ-resistant GBM. In this study, we first found that the CEBPD protein levels in GBM patients were significantly increased and further contributed to TMZ resistance by promoting GSC formation. Accordingly, the protein levels of stemness transcription factors, namely, SRY-box transcription factor 2 (SOX2), octamer-binding transcription factor 4 (OCT4), NANOG, and ATP-binding cassette subfamily A member 1 (ABCA1), were increased in GSCs and TMZ-treated GBM cells. Increased binding of CEBPD to promoter regions was observed in GSCs, indicating the direct regulation of these GSC-related genes by CEBPD. In addition, an ABCA1 inhibitor increased the caspase 3/7 activity of TMZ-treated GSCs, suggesting that TMZ efflux is controlled by ABCA1 activity and that the expression levels of the ABCA1 gene are an indicator of the efficiency of TMZ treatment. Together, we revealed the mechanism of CEBPD-mediated GSC drug resistance and proposed ABCA1 inhibition as a potential strategy for the treatment of TMZ-resistant GBM.

Perspectives on long pentraxin 3 and rheumatoid arthritis: several potential breakthrough points relying on study foundation of the past

Rheumatoid arthritis (RA) is a systemic chronic autoimmune inflammatory disease which is mainly characterized by synovitis and results in a severe burden for both the individual and society. To date, the underlying mechanisms of RA are still poorly understood. Pentraxin 3 (PTX3) is a typical long pentraxin protein which has been highly conserved during evolution. Meanwhile, functions as well as properties of PTX3 have been extensively studied. Several studies identified that PTX3 plays a predominate role in infection, inflammation, immunity and tumor. Interestingly, PTX3 has also been verified to be closely associated with development of RA. We therefore accomplished an elaboration of the relationships between PTX3 and RA. Herein, we mainly focus on the associated cell types and cognate cytokines involved in RA, in combination with PTX3. This review infers the insight into the interaction of PTX3 in RA and aims to provide novel clues for potential therapeutic target of RA in clinic.

Maternal Influenza A Virus Infection Restricts Fetal and Placental Growth and Adversely Affects the Fetal Thymic Transcriptome

Maternal influenza A viral infections in humans are associated with low birth weight, increased risk of pre-term birth, stillbirth and congenital defects. To examine the effect of maternal influenza virus infection on placental and fetal growth, pregnant C57BL/6 mice were inoculated intranasally with influenza A virus A/CA/07/2009 pandemic H1N1 or phosphate-buffered saline (PBS) at E3.5, E7.5 or E12.5, and the placentae and fetuses collected and weighed at E18.5. Fetal thymuses were pooled from each litter. Placentae were examined histologically, stained by immunohistochemistry (IHC) for CD34 (hematopoietic progenitor cell antigen) and vascular channels quantified. RNA from E7.5 and E12.5 placentae and E7.5 fetal thymuses was subjected to RNA sequencing and pathway analysis. Placental weights were decreased in litters inoculated with influenza at E3.5 and E7.5. Placentae from E7.5 and E12.5 inoculated litters exhibited decreased labyrinth development and the transmembrane protein 150A gene was upregulated in E7.5 placentae. Fetal weights were decreased in litters inoculated at E7.5 and E12.5 compared to controls. RNA sequencing of E7.5 thymuses indicated that 957 genes were downregulated ≥2-fold including Mal, which is associated with Toll-like receptor signaling and T cell differentiation. There were 28 upregulated genes. It is concluded that maternal influenza A virus infection impairs fetal thymic gene expression as well as restricting placental and fetal growth.

The Role of ROCK in Platelet-Monocyte Collaborative Induction of Thromboinflammation during Acute Coronary Syndrome

BACKGROUND

 Arterial thrombosis is initiated by atherosclerotic plaque damage, prothrombotic material release and platelet aggregation. Platelets are primary mediators involved in thrombosis and cooperate with vascular and immune cells.

OBJECTIVE

 Herein, we investigated how activated platelets interacted with monocytes in atherothrombosis.

METHODS AND RESULTS

 We collected patients' blood from coronary arteries during percutaneous coronary intervention and measured platelet activity. Platelets from coronary arteries had higher pseudopodium expression and activity in patients with acute coronary syndrome (ACS). Ribosome profiling of platelets from coronary blood mapped a vigorous upregulation of Rho GTPases and their downstream effectors. RhoA activated downstream Rho-associated coiled-coil containing protein kinase (ROCK), and ROCK increased surface P-selectin in coronary blood platelets. The interaction between platelets and monocytes was observed in vitro, and was found in ruptured coronary plaques of ACS. Further we found that activated platelets promoted monocytes transmigration, which could be suppressed in the presence of ROCK inhibitors. The increased surface P-selectin on thrombin-induced platelets interacted with monocytes to upregulate monocyte chemokine receptor 2 (CCR2) expression via the ROCK pathway. The expression of CCR2 was higher in monocyte-platelet aggregates than in monocytes without platelets. Finally, using the Asian Screening Array BeadChip, we identified single-nucleotide polymorphism (SNP) associated with cardiovascular events. Notably, patients having homozygous major alleles of the RHOA SNP rs11706370 presented with higher risks of cardiovascular events.

CONCLUSION

 Through ROCK-activated cytoskeleton remodeling and P-selectin expression, platelets were recruited and interacted synergistically with high CCR2-expressing monocytes to induce thromboinflammation in atherothrombosis.

CCAAT/enhancer-binding protein delta regulates the stemness of glioma stem-like cells through activating PDGFA expression upon inflammatory stimulation

Background

The small population of glioma stem-like cells (GSCs) contributes to tumor initiation, malignancy, and recurrence in glioblastoma. However, the maintenance of GSC properties in the tumor microenvironment remains unclear. In glioma, non-neoplastic cells create an inflammatory environment and subsequently mediate tumor progression and maintenance. Transcriptional factor CCAAT/enhancer-binding protein delta (CEBPD) is suggested to regulate various genes responsive to inflammatory cytokines, thus prompting us to investigate its role in regulating GSCs stemness after inflammatory stimulation.

Methods

Stemness properties were analyzed by using spheroid formation. Oncomine and TCGA bioinformatic databases were used to analyze gene expression. Western blotting, quantitative real-time polymerase chain reaction, luciferase reporter assay, and chromatin immunoprecipitation assay were used to analyze proteins and gene transcript levels. The glioma tissue microarrays were used for CEBPD and PDGFA expression by immunohistochemistry staining.

Results

We first found that IL-1β promotes glioma spheroid formation and is associated with elevated CEBPD expression. Using microarray analysis, platelet-derived growth factor subunit A (PDGFA) was confirmed as a CEBPD-regulated gene that mediates IL-1β-enhanced GSCs self-renewal. Further analysis of the genomic database and tissue array revealed that the expression levels between CEBPD and PDGFA were coincident in glioma patient samples.

Conclusion

This is the first report showing the activation of PDGFA expression by CEBPD through IL-1β treatment and a novel CEBPD function in maintaining the self-renewal feature of GSCs.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1535-z) contains supplementary material, which is available to authorized users.

Transcriptome analysis of regeneration during Xenopus laevis experimental twinning

Animal embryos have the remarkable property of self-organization. Over 125 years ago, Hans Driesch separated the two blastomeres of sea urchin embryos and obtained twins, in what was the foundation of experimental embryology. Since then, embryonic twinning has been obtained experimentally in many animals. In a recent study, we developed bisection methods that generate identical twins reliably from Xenopus blastula embryos. In the present study, we have investigated the transcriptome of regenerating half-embryos after sagittal and dorsal-ventral (D-V) bisections. Individual embryos were operated at midblastula (stage 8) with an eyelash hair and cultured until early gastrula (stage 10.5) or late gastrula (stage 12) and the transcriptome of both halves were analyzed by RNA-seq. Since many genes are activated by wound healing in Xenopus embryos, we resorted to stringent sequence analyses and identified genes up-regulated in identical twins but not in either dorsal or ventral fragments. At early gastrula, cell division-related transcripts such as histones were elevated, whereas at late gastrula, pluripotency genes (such as sox2) and germ layer determination genes (such as eomesodermin, ripply2 and activin receptor ACVRI) were identified. Among the down-regulated transcripts, sizzled, a regulator of Chordin stability, was prominent. These findings are consistent with a model in which cell division is required to heal damage, while maintaining pluripotency to allow formation of the organizer with a displacement of 90 ⁰ from its original site. The extensive transcriptomic data presented here provides a valuable resource for data mining of gene expression during early vertebrate development.

CCAAT/enhancer binding protein δ is a transcriptional repressor of α-synuclein

α-Synuclein is the main component of Lewy bodies, the intracellular protein aggregates representing the histological hallmark of Parkinson's disease. Elevated α-synuclein levels and mutations in SNCA gene are associated with increased risk for Parkinson's disease. Despite this, little is known about the molecular mechanisms regulating SNCA transcription. CCAAT/enhancer binding protein (C/EBP) β and δ are b-zip transcription factors that play distinct roles in neurons and glial cells. C/EBPβ overexpression increases SNCA expression in neuroblastoma cells and putative C/EBPβ and δ binding sites are present in the SNCA genomic region suggesting that these proteins could regulate SNCA transcription. Based on these premises, the goal of this study was to determine if C/EBPβ and δ regulate the expression of SNCA. We first observed that α-synuclein CNS expression was not affected by C/EBPβ deficiency but it was markedly increased in C/EBPδ-deficient mice. This prompted us to characterize further the role of C/EBPδ in SNCA transcription. C/EBPδ absence led to the in vivo increase of α-synuclein in all brain regions analyzed, both at mRNA and protein level, and in primary neuronal cultures. In agreement with this, CEBPD overexpression in neuroblastoma cells and in primary neuronal cultures markedly reduced SNCA expression. ChIP experiments demonstrated C/EBPδ binding to the SNCA genomic region of mice and humans and luciferase experiments showed decreased expression of a reporter gene attributable to C/EBPδ binding to the SNCA promoter. Finally, decreased CEBPD expression was observed in the substantia nigra and in iPSC-derived dopaminergic neurons from Parkinson patients resulting in a significant negative correlation between SNCA and CEBPD levels. This study points to C/EBPδ as an important repressor of SNCA transcription and suggests that reduced C/EBPδ neuronal levels could be a pathogenic factor in Parkinson's disease and other synucleinopathies and C/EBPδ activity a potential pharmacological target for these neurological disorders.

Hyperlipidemias and Obesity

The organs require oxygen and other types of nutrients (amino acids, sugars, and lipids) to function, the heart consuming large amounts of fatty acids for oxidation and adenosine triphosphate (ATP) generation.