AP-1 Transcription Factor Research Articles

Network pharmacology and experimental validation methods to reveal the active compounds and hub targets of Curculigo orchioides Gaertn in rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is an autoimmune disease that can lead to joint destruction and deformity. Curculigo orchioides Gaertn (CO) was previously revealed to play a significant role in RA treatment. However, the main active ingredients and molecular mechanisms of CO in regulating RA are still unclear.MethodsThe active ingredients of CO were obtained from the Traditional Chinese Medicine Systems Pharmacology database and published literature. The targets corresponding to these compounds and the targets linked to RA were collected from public databases. The “ingredient-target” and “protein–protein interaction” networks were constructed to screen the main active ingredients and hub targets of CO in the treatment of RA. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment assays were used to elucidate the potential pharmacological mechanism of CO in RA. Molecular docking was performed to detect the binding between the main active ingredients and hub targets. Collagen-induced arthritis rats were used to validate the hub targets of CO against RA.ResultsNetwork pharmacological topology analysis showed that caffeine, 2,4-dichloro-5-methoxy-3-methylphenol, curculigoside, orcinol glucoside, and orcin were the main active ingredients of CO, and matrix metalloproteinase 9 (MMP9), transcription factor AP-1 (JUN), prostaglandin-endoperoxide synthase 2 (PTGS2), brain-derived neurotrophic factor, and receptor-type tyrosine-protein phosphatase C were the hub targets of CO for RA treatment. Molecular docking revealed that curculigoside and orcinol glucoside had effective binding potential with MMP9, JUN, and PTGS2, respectively. In vivo experiments demonstrated that CO alleviated RA symptoms and inhibited the expression of MMP9, JUN, and PTGS2 proteins.ConclusionsOur study demonstrates the main active ingredients and potential targets of CO against RA, laying an experimental foundation for the development and application of CO as an anti-RA drug.

The CRTC-1 transcriptional domain is required for COMPASS complex-mediated longevity in C. elegans.

Loss of function during aging is accompanied by transcriptional drift, altering gene expression and contributing to a variety of age-related diseases. CREB-regulated transcriptional coactivators (CRTCs) have emerged as key regulators of gene expression that might be targeted to promote longevity. Here we define the role of the Caenorhabditis elegans CRTC-1 in the epigenetic regulation of longevity. Endogenous CRTC-1 binds chromatin factors, including components of the COMPASS complex, which trimethylates lysine 4 on histone H3 (H3K4me3). CRISPR editing of endogenous CRTC-1 reveals that the CREB-binding domain in neurons is specifically required for H3K4me3-dependent longevity. However, this effect is independent of CREB but instead acts via the transcription factor AP-1. Strikingly, CRTC-1 also mediates global histone acetylation levels, and this acetylation is essential for H3K4me3-dependent longevity. Indeed, overexpression of an acetyltransferase enzyme is sufficient to promote longevity in wild-type worms. CRTCs, therefore, link energetics to longevity by critically fine-tuning histone acetylation and methylation to promote healthy aging.

Plasmodial Transcription Factors and Chromatin Modifiers as Drug Targets

The complex life cycle of the malaria parasite Plasmodium requires the parasite to adequately adapt to different conditions. For this reason, Plasmodium strictly controls its gene expression, and given its evolutionary distance from the human host, the involved factors may figure as attractive potential drug targets. In recent years, several unique transcription factors and chromatin modifiers have been identified and partially characterized in Plasmodium falciparum and in the murine species P. yoelii and P. berghei. This review unites data from studies focusing on drug development against enigmatic plant-like AP2-transcription factors and chromatin modifiers, such as histone acetyl transferases and deacetylases and histone methyltransferases and demethylases. Considering the reported success of inhibition of both factors, these may be included as targets to effectively combat the parasite by perturbing its control of gene expression.

Calcitriol reverses age-related hypertension via downregulating renal AP1/AT1R pathway through regulating mitochondrial function

ABSTRACT Background The vitamin D level in the blood is associated with the incidence of hypertension. The present study investigated whether or not calcitriol, an active form of vitamin D, reverses age-related hypertension. Methods Young (3-month-old) and aged (12-month-old) C57BL/6 male mice were administered with or without calcitriol at 150 ng/kg per day by oral gavage for 8 weeks. Blood pressure was measured by tail-cuff plethysmography and telemetry, and superoxide production in renal tissue was assessed by fluorescence imaging, and the protein expression of AP1/AT1R signaling pathway was examined by Western blot. Results We showed that 24-hour renal sodium excretion was impaired and blood pressure was increased in aged mice, which was related to the enhancement of renal AT1R expression and function. In addition, the expression of transcription factor AP1 (a dimer of c-Fos and c-Jun) and the binding of AP1 to the AT1R promoter region was significantly enhanced, accompanied by decreased nuclear translocation of Nrf2, abnormal mitochondrial function including decreased ATP production, NAD+/NADH ratio and mtDNA copy numbers, and increased reactive oxygen species. Calcitriol increased 24-hour urinary sodium excretion and reduced blood pressure in aged mice. Mechanically, calcitriol increased the nuclear translocation of Nrf2, improved mitochondrial function, reduced AP1 binding ability to AT1R promoter, which reversed enhanced AT1R expression and function, and lowered blood pressure in aged mice. Conclusions Our findings indicated that calcitriol reversed age-related hypertension via downregulating renal AP1/AT1R pathway through regulating mitochondrial function. Thus, calcitriol may be a valuable therapeutic strategy for age-related hypertension.

Upregulation of human GD3 synthase (hST8Sia I) gene expression during serum starvation-induced osteoblastic differentiation of MG-63 cells.

In this study, we have firstly elucidated that serum starvation augmented the levels of human GD3 synthase (hST8Sia I) gene and ganglioside GD3 expression as well as bone morphogenic protein-2 and osteocalcin expression during MG-63 cell differentiation using RT-PCR, qPCR, Western blot and immunofluorescence microscopy. To evaluate upregulation of hST8Sia I gene during MG-63 cell differentiation by serum starvation, promoter area of the hST8Sia I gene was functionally analyzed. Promoter analysis using luciferase reporter assay system harboring various constructs of the hST8Sia I gene proved that the cis-acting region at -1146/-646, which includes binding sites of the known transcription factors AP-1, CREB, c-Ets-1 and NF-κB, displays the highest level of promoter activity in response to serum starvation in MG-63 cells. The -731/-722 region, which contains the NF-κB binding site, was proved to be essential for expression of the hST8Sia I gene by serum starvation in MG-63 cells by site-directed mutagenesis, NF-κB inhibition, and chromatin immunoprecipitation (ChIP) assay. Knockdown of hST8Sia I using shRNA suggested that expressions of hST8Sia I and GD3 have no apparent effect on differentiation of MG-63 cells. Moreover, the transcriptional activation of hST8Sia I gene by serum starvation was strongly hindered by SB203580, a p38MAPK inhibitor in MG-63 cells. From these results, it has been suggested that transcription activity of hST8Sia I gene by serum starvation in human osteosarcoma MG-63 cells is regulated by p38MAPK/NF-κB signaling pathway.

DNA-binding protein PfAP2-P regulates parasite pathogenesis during malaria parasite blood stages.

Malaria-associated pathogenesis such as parasite invasion, egress, host cell remodelling and antigenic variation requires concerted action by many proteins, but the molecular regulation is poorly understood. Here we have characterized an essential Plasmodium-specific Apicomplexan AP2 transcription factor in Plasmodium falciparum (PfAP2-P; pathogenesis) during the blood-stage development with two peaks of expression. An inducible knockout of gene function showed that PfAP2-P is essential for trophozoite development, and critical for var gene regulation, merozoite development and parasite egress. Chromatin immunoprecipitation sequencing data collected at timepoints matching the two peaks of pfap2-p expression demonstrate PfAP2-P binding to promoters of genes controlling trophozoite development, host cell remodelling, antigenic variation and pathogenicity. Single-cell RNA sequencing and fluorescence-activated cell sorting revealed de-repression of most var genes in Δpfap2-p parasites. Δpfap2-p parasites also overexpress early gametocyte marker genes, indicating a regulatory role in sexual stage conversion. We conclude that PfAP2-P is an essential upstream transcriptional regulator at two distinct stages of the intra-erythrocytic development cycle.

MICA: a multi-omics method to predict gene regulatory networks in early human embryos.

Recent advances in single-cell omics have transformed characterisation of cell types in challenging-to-study biological contexts. In contexts with limited single-cell samples, such as the early human embryo inference of transcription factor-gene regulatory network (GRN) interactions is especially difficult. Here, we assessed application of different linear or non-linear GRN predictions to single-cell simulated and human embryo transcriptome datasets. We also compared how expression normalisation impacts on GRN predictions, finding that transcripts per million reads outperformed alternative methods. GRN inferences were more reproducible using a non-linear method based on mutual information (MI) applied to single-cell transcriptome datasets refined with chromatin accessibility (CA) (called MICA), compared with alternative network prediction methods tested. MICA captures complex non-monotonic dependencies and feedback loops. Using MICA, we generated the first GRN inferences in early human development. MICA predicted co-localisation of the AP-1 transcription factor subunit proto-oncogene JUND and the TFAP2C transcription factor AP-2γ in early human embryos. Overall, our comparative analysis of GRN prediction methods defines a pipeline that can be applied to single-cell multi-omics datasets in especially challenging contexts to infer interactions between transcription factor expression and target gene regulation.

A TGF-β signaling-related lncRNA signature for prediction of glioma prognosis, immune microenvironment, and immunotherapy response.

The dysregulation of TGF-β signaling is a crucial pathophysiological process in tumorigenesis and progression. LncRNAs have diverse biological functions and are significant participants in the regulation of tumor signaling pathways. However, the clinical value of lncRNAs related to TGF-β signaling in glioma is currently unclear. Data on glioma's RNA-seq transcriptome, somatic mutation, DNA methylation data, and clinicopathological information were derived from the CGGA and TCGA databases. A prognostic lncRNA signature was constructed by Cox and LASSO regression analyses. TIMER2.0 database was utilized to deduce immune infiltration characteristics. "ELMER v.2" was used to reconstruct TF-methylation-gene regulatory network. Immunotherapy and chemotherapy response predictions were implemented by the TIDE algorithm and GDSC database, respectively. Invitro and invivo experiments were conducted to verify the results and clarify the regulatory mechanism of lncRNA. In glioma, a TGF-β signaling-related 15-lncRNA signature was constructed, including AC010173.1, HOXA-AS2, AC074286.1, AL592424.1, DRAIC, HOXC13-AS, AC007938.1, AC010729.1, AC013472.3, AC093895.1, AC131097.4, AL606970.4, HOXC-AS1, AGAP2-AS1, and AC002456.1. This signature proved to be a reliable prognostic tool, with high risk indicating an unfavorable prognosis and being linked to malignant clinicopathological and genomic mutation traits. Risk levels were associated with different immune infiltration landscapes, where high risk was indicative of high levels of macrophage infiltration. In addition, high risk also suggested better immunotherapy and chemotherapy response. cg05987823 was an important methylation site in glioma progression, and AP-1 transcription factor family participated in the regulation of signature lncRNA expression. AGAP2-AS1 knockdown in invitro and invivo experiments inhibited the proliferation, migration, and invasion of glioma cells, as well as the growth of glioma, by downregulating the expression levels of NF-κB and ERK 1/2 in the TGF-β signaling pathway. A prognostic lncRNA signature of TGF-β signaling was established in glioma, which can be used for prognostic judgment, immune infiltration status inference, and immunotherapy response prediction. AGAP2-AS1 plays an important role in glioma progression.

MiR-199a-5p Decreases Esophageal Cancer Cell Proliferation Partially through Repression of Jun-B.

MicroRNA (miR)-199a-5p has been shown to function as a tumor suppressor in some malignancies but its role in esophageal cancer is poorly understood. To further explore its role in esophageal cancer, we sought to investigate the interaction between miR-199a-5p and Jun-B, an important component of the AP1 transcription factor, which contains a potential binding site for miR-199a-5p in its mRNA. We found that levels of miR-199a-5p are reduced in both human esophageal cancer specimens and in multiple esophageal cancer cell lines compared to esophageal epithelial cells. Jun-B expression is correspondingly elevated in these tumor specimens and in several cell lines compared to esophageal epithelial cells. Jun-B mRNA expression and stability, as well as protein expression, are markedly decreased following miR-199a-5p overexpression. A direct interaction between miR-199a-5p and Jun-B mRNA was confirmed by a biotinylated RNA-pull down assay and luciferase reporter constructs. Either forced expression of miR-199a-5p or Jun-B silencing led to a significant decrease in cellular proliferation as well as in AP-1 promoter activity. Our results provide evidence that miR-199a-5p functions as a tumor suppressor in esophageal cancer cells by regulating cellular proliferation, partially through repression of Jun B.

Bone marrow fibrosis is associated with non-response to CD19 CAR T-cell therapy in B-acute lymphoblastic leukemia.

CD19 directed CAR T-cell therapy is used to treat relapsed/refractory B-cell acute lymphoblastic leukemia. The role of the pre-CAR bone marrow (BM) stromal microenvironment in determining response to CAR T-cell therapy has been understudied. We performed whole transcriptome analysis, reticulin fibrosis assessment and CD3 T-cell infiltration on BM core biopsies from pre- and post-CAR timepoints for 61 patients, as well as on a cohort of 54 primary B-ALL samples. Pathways of fibrosis, extracellular matrix development, and associated transcription factors AP1 and TGF-β3, were enriched and upregulated in nonresponders (NR) even prior to CAR T cell therapy. NR showed significantly higher levels of BM fibrosis compared to complete responders by both clinical reticulin assessment and AI-assisted digital image scoring. CD3+ T cells showed a trend toward lower infiltration in NR. NR had significantly higher levels of pre-CAR fibrosis compared to primary B-ALL. High levels of fibrosis were associated with lower overall survival after CAR T-cell therapy. In conclusion, BM fibrosis is a novel mechanism mediating nonresponse to CD19-directed CAR T-cell therapy in B-ALL. A widely used clinically assay for quantitating myelofibrosis can be repurposed to determine patients at high risk of non-response. Genes and pathways associated with BM fibrosis are a potential target to improve response.

Shock drives a STAT3 and JunB-mediated coordinated transcriptional and DNA methylation response in the endothelium.

Endothelial dysfunction is a crucial factor in promoting organ failure during septic shock. However, the underlying mechanisms are unknown. Here, we show that kidney injury after lipopolysaccharide (LPS) insult leads to strong endothelial transcriptional and epigenetic responses. Furthermore, SOCS3 loss leads to an aggravation of the responses, demonstrating a causal role for the STAT3-SOCS3 signaling axis in the acute endothelial response to LPS. Experiments in cultured endothelial cells demonstrate that IL-6 mediates this response. Furthermore, bioinformatics analysis of in vivo and in vitro transcriptomics and epigenetics suggests a role for STAT, AP1 and interferon regulatory family (IRF) transcription factors. Knockdown of STAT3 or the AP1 member JunB partially prevents the changes in gene expression, demonstrating a role for these transcription factors. In conclusion, endothelial cells respond with a coordinated response that depends on overactivated IL-6 signaling via STAT3, JunB and possibly other transcription factors. Our findings provide evidence for a critical role of IL-6 signaling in regulating shock-induced epigenetic changes and sustained endothelial activation, offering a new therapeutic target to limit vascular dysfunction.

Global expression analysis of endometrial cancer cells in response to progesterone identifies new therapeutic targets

Progesterone prevents development of endometrial cancers through its receptor (PR) although the molecular mechanisms have yet to be fully characterized. In this study, we performed a global analysis of gene regulation by progesterone using human endometrial cancer cells that expressed PR endogenously or exogenously. We found progesterone strongly inhibits multiple components of the platelet derived growth factor receptor (PDGFR), Janus kinase (JAK), signal transducer and activator of transcription (STAT) pathway through PR. The PDGFR/JAK/STAT pathway signals to control numerous downstream targets including AP-1 transcription factors Fos and Jun. Treatment with inhibitors of the PDGFR/JAK/STAT pathway significantly blocked proliferation in multiple novel patient-derived organoid models of endometrial cancer, and activation of this pathway was found to be a poor prognostic signal for the survival of patients with endometrial cancer from The Cancer Genome Atlas. Our study identifies this pathway as central to the growth-limiting effects of progesterone in endometrial cancer and suggests that inhibitors of PDGFR/JAK/STAT should be considered for future therapeutic interventions.

Gene Expression Analysis of Different Organs and Identification of AP2 Transcription Factors in Flax (Linum usitatissimum L.).

Flax (Linum usitatissimum L.) is an important oilseed crop widely cultivated for its oil and fiber. This study conducted transcriptome analysis to analyze the gene expression profiles of roots, leaves, stamens, pistils, and fruits in the flax cultivar Longya10. A total of 43,471 genes were detected in the RNA-seq data, with 34,497 genes showing differential expression levels between different organs. Gene expression patterns varied across different organs, with differences observed in expression-regulating genes within specific organs. However, 23,448 genes were found to be commonly expressed across all organs. Further analysis revealed organ-specific gene expressions, with 236, 690, 544, 909, and 1212 genes identified in pistils, fruits, leaves, roots, and stamens, respectively. Gene Ontology (GO) enrichment analysis was performed on these organ-specific genes, and significant enrichment was observed in various biological processes, cellular components, and molecular functions, providing new insights for the specific growth patterns of flax organs. Furthermore, we investigated the expression differences of AP2 transcription factors in various tissues and organs of Longya10. We identified 96 AP2 genes that were differentially expressed in different organs and annotated them into various biological pathways. Our results suggest that AP2 transcription factors may play important roles in regulating the growth and development of flax organs including stress response. In summary, our study provides a comprehensive analysis of gene expression patterns in different organs and tissues of flax plant and identifies potential critical regulators of flax organ growth and development. These findings contribute to a better understanding of the molecular mechanisms underlying flax organ development and may have important implications for the genetic improvement of flax crops.

Predictive value of DNA methylation in the efficacy of chemotherapy for gastric cancer.

Gastric cancer (GC) is one of the most common causes of cancer-related death. Drug resistance in chemotherapy often occurs in patients with GC, leading to tumor recurrence and poor survival. DNA methylation is closely related to the development of cancer. To investigate the role of DNA methylation in chemotherapy resistance in GC patients, we conducted a comprehensive analysis using DNA methylation data and survival information obtained from The Cancer Genome Atlas. Univariate Cox analysis was performed to screen for differential DNA methylation of chemotherapy response in patients who did and did not receive chemotherapy. Multivariate Cox analysis was then performed to identify the independent prognostic genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were used to explore the biological function of the signature genes. Patients receiving adjuvant chemotherapy for GC survived longer. 308 differentially methylated genes were demonstrated to be associated with prognosis. Six genes were optimally chosed for establisehing the risk model, including C6orf222, CCNL1, CREBZF, GCKR, TFCP2, and VIPR2. It was constructed based on the DNA methylation levels of these six genes: risk score = 0.47123374*C6orf222 + 9.53554803*CCNL1 + 10.40234138* CREBZF + 0.07611856* GCKR + 18.87661557*TFCP2 - 0.46396254* VIPR2. According to the risk score, patients receiving chemotherapy were divided into high- and low-risk groups, and the prognosis of the two groups was compared. The high-risk group had a shorter survival; however, this association was not present in patients without chemotherapy. The accuracy and predictive efficacy of the risk score in predicting the 1-, 3-, and 5-year survival of patients was evaluated with the receiver operating characteristic curve. In patients receiving chemotherapy, the area under the curve of the risk score for 1-, 3-, and 5-year survival was 0.841, 0.72, and 0.734, respectively. In patients who did not receive chemotherapy, the area under the curve was 0.406, 0.585, and 0.585, respectively. A nomogram model was constructed based on the risk score and clinical indicators. The model showed good consistency in the predicted probabilities and actual probabilities. Gene Ontology functional enrichment of these candidate methylated genes showed the following molecular functions: RNA binding, protein binding, mRNA binding, and nucleic acid binding; that they were mediated mainly through the following cell components: nuclear speck, nucleoplasm, nucleus, catalytic step 2 spliceosome, and the transcription factor AP-1 complex; and that they were involved in the following biological processes: mRNA processing, mRNA splicing, and RNA polymerase II promoter transcription. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment results revealed that the signaling pathways mainly enriched were transcriptional misregulation in cancer, spliceosome, and the IL-17 signaling pathway. Our work identifies a six DNA methylated expression signature as a promising biomarker of chemo-resistance in GC, which provides new insights into the development of new strategies to overcome chemo-resistance in GC.

Insights into the physiological, molecular, and genetic regulators of albinism in Camellia sinensis leaves.

Introduction: Yanling Yinbiancha, a cultivar of Camellia sinensis (L.) O. Kuntze, is an evergreen woody perennial with characteristic albino leaves. A mutant variant with green leaves on branches has been recently identified. The molecular mechanisms underlying this color variation remain unknown. Methods: We aimed to utilize omics tools to decipher the molecular basis for this color variation, with the ultimate goal of enhancing existing germplasm and utilizing it in future breeding programs. Results and discussion: Albinotic leaves exhibited significant chloroplast degeneration and reduced carotenoid accumulation. Transcriptomic and metabolomic analysis of the two variants revealed 1,412 differentially expressed genes and 127 differentially accumulated metabolites (DAMs). Enrichment analysis for DEGs suggested significant enrichment of pathways involved in the biosynthesis of anthocyanins, porphyrin, chlorophyll, and carotenoids. To further narrow down the causal variation for albinotic leaves, we performed a conjoint analysis of metabolome and transcriptome and identified putative candidate genes responsible for albinism in C. sinensis leaves. 12, 7, and 28 DEGs were significantly associated with photosynthesis, porphyrin/chlorophyll metabolism, and flavonoid metabolism, respectively. Chlorophyllase 2, Chlorophyll a-Binding Protein 4A, Chlorophyll a-Binding Protein 24, Stay Green Regulator, Photosystem II Cytochrome b559 subunit beta along with transcription factors AP2, bZIP, MYB, and WRKY were identified as a potential regulator of albinism in Yanling Yinbiancha. Moreover, we identified Anthocyanidin reductase and Arabidopsis Response Regulator 1 as DEGs influencing flavonoid accumulation in albino leaves. Identification of genes related to albinism in C. sinensis may facilitate genetic modification or development of molecular markers, potentially enhancing cultivation efficiency and expanding the germplasm for utilization in breeding programs.

Modular pooled discovery of synthetic knockin sequences to program durable cell therapies

Chronic stimulation can cause Tcell dysfunction and limit the efficacy of cellular immunotherapies. Improved methods are required to compare large numbers of synthetic knockin (KI) sequences to reprogram cell functions. Here, we developed modular pooled KI screening (ModPoKI), an adaptable platform for modular construction of DNA KI libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors (SRs). Over 30 ModPoKI screens across human TCR- and CAR-T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically stimulated CAR-T cells and anti-cancer function invitro and invivo. ModPoKI's modularity allowed us to generate an ∼10,000-member library of TF combinations. Non-viral KI of a combined BATF-TFAP4 polycistronic construct enhanced fitness. Overexpressed BATF and TFAP4 co-occupy and regulate key gene targets to reprogram Tcell function. ModPoKI facilitates the discovery of complex gene constructs to program cellular functions.

AP-1 Transcription Factor Complex Members FOSB and FOS are Linked With CNS Infiltration and Inferior Prognosis in Childhood T-ALL.

AP-1 Transcription Factor Complex Members FOSB and FOS are Linked With CNS Infiltration and Inferior Prognosis in Childhood T-ALL.

Translocator protein is a marker of activated microglia in rodent models but not human neurodegenerative diseases

Microglial activation plays central roles in neuroinflammatory and neurodegenerative diseases. Positron emission tomography (PET) targeting 18 kDa Translocator Protein (TSPO) is widely used for localising inflammation in vivo, but its quantitative interpretation remains uncertain. We show that TSPO expression increases in activated microglia in mouse brain disease models but does not change in a non-human primate disease model or in common neurodegenerative and neuroinflammatory human diseases. We describe genetic divergence in the TSPO gene promoter, consistent with the hypothesis that the increase in TSPO expression in activated myeloid cells depends on the transcription factor AP1 and is unique to a subset of rodent species within the Muroidea superfamily. Finally, we identify LCP2 and TFEC as potential markers of microglial activation in humans. These data emphasise that TSPO expression in human myeloid cells is related to different phenomena than in mice, and that TSPO-PET signals in humans reflect the density of inflammatory cells rather than activation state.

TaAP2-10, an AP2/ERF transcription factor, contributes to wheat resistance against stripe rust

The AP2/ERF TF (transcription factor) family is involved in regulating plant responses to various biotic and abiotic stresses. Nevertheless, understanding of the function of AP2/ERF TFs in wheat (Triticum aestivum L.) resistance against the obligate biotrophic stripe rust fungus (Puccinia striiformis f. sp tritici, Pst) remains limited. From a wheat–Pst incompatible interaction cDNA library, the transcript of TaAP2-10 was identified to be significantly induced during Pst infection. TaAP2-10, encodes an AP2 TF with two typical AP2-binding domains. There are three homologues of TaAP2-10 in the wheat genome, located on chromosome 6A, 6B and 6D. TaAP2-10 is localized in the nucleus of wheat protoplasts. A transactivation assay in yeast revealed that TaAP2-10 had transcriptional activation activity that was dependent on its C-terminal region. Quantitative real-time PCR (qRT-PCR) analyses verified that the expression of TaAP2-10 was specifically upregulated by avirulent Pst infection but not by virulent Pst, suggesting its role in wheat resistance to Pst. Furthermore, TaAP2-10 is also induced by abiotic stresses and hormone treatments, particularly under PEG4000 and abscisic acid (ABA) treatments, indicating its potential role in facilitating wheat adaptation to environmental stresses. Silencing TaAP2-10 by barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) significantly reduced wheat resistance against Pst, resulting in a decreased reactive oxygen species (ROS) burst, and promoted Pst growth and development. These findings suggest that TaAP2-10, as a nuclear-localized transcription factor, positively regulates wheat resistance to Pst.

M1 polarization of chicken macrophage HD11 can be activated by duck Tembusu virus via MyD88-NF-κB-mediated signaling pathway

Duck Tembusu virus (DTMUV) has caused significant economic losses to the global duck industry since its outbreak in 2010. The macrophages act as the key immune cell, and its polarization in different functional states is very important for host’s immune responses and microbial infections. Avian macrophages are the main target cells of DTMUV, its polarization induced by DTMUV and the underlying mechanisms were explored in this study. Through quantitative real-time PCR, nitrite assay, and flow cytometry analysis, we found that DTMUV caused severe inflammatory responses in chicken macrophage line HD11 by reprogramming the expression of M1- and M2-associated genes, leading to the polarization of HD11 macrophage to M1-type. In term of mechanism, transcriptomics was performed to analyze the M1-type polarization triggered by DTMUV, it was found that most differential genes were implicated in biological processes, and DTMUV infection significantly activated innate immune signaling pathways, including cytokine-cytokine receptor interaction, MAPK signaling pathway. Moreover, transcription factors NF-κB and AP1 also be activated after viral infection. However, further validation analysis by inhibitors and siRNAs of NF-κB and AP1 showed that NF-κB molecule was essential for DTMUV-induced M1 polarization in HD11 cell, but not AP1. Additionally, the inhibiting assays targeting MyD88 and TRIF molecules were conducted to determine their effect on NF-κB and M1-associated genes upregulated by DTMUV. The results showed that although the inhibition of both MyD88 and TRIF significantly downregulated the mRNA level of NF-κB, but the expression of M1-associated genes such as CD86 was lower in MyD88 inhibition group than in the other group, indicating that the role of MyD88 in mediating M1 polarization induced by DTMUV was more important. Overall, these results demonstrated that DTMUV infection induces M1-type polarization in chicken macrophage HD11 through MyD88-NF-κB signaling pathways. This finding will lay the foundation for further study the pathogenesis of DTMUV, and provide new insights into the prevention and control of this disease.