Function Of Transcription Factors Research Articles

LkERF6 enhances drought and salt tolerance in transgenic tobacco by regulating ROS homeostasis

The transcription factor Ethylene Responsive Factor (ERF) is crucial for responding to various environmental stressors. Proteins containing the ERF-associated amphiphilic repression (EAR) motif often inhibit gene expression. However, the functions of LkERF, an EAR motif-containing protein from Larix kaempferi, especially in reactive oxygen species (ROS) homeostasis, are not well understood. In the present research, we introduce a novel transcription factor, LkERF6, which contains an EAR motif and positively regulates gene expression, thereby enhancing drought and salt tolerance in tobacco. LkERF6 is classified within the ERF-B1 subfamily due to its conserved AP2/ERF domain and EAR motif. Subcellular localization assays demonstrated LkERF6 is primarily localized in the nucleus. Further analysis revealed that LkERF6 interacts with GCC and DRE elements and is significantly induced by NaCl and PEG6000. Moreover, LkERF6 transgenic tobacco plants exhibit lower ROS accumulation and higher levels of antioxidant enzyme activities. Additionally, correlation analysis identified a strong association between LkERF6 and three genes: LkSOD, LkCCS, and LkCAT. Y1H, EMAS, and DLR assays confirmed that LkERF6 directly interacts with the promoters of these genes through GCC-box and DRE-box to activate their expression. These findings shed new light on the function of EAR motif-containing transcription factors and highlight LkERF6’s crucial role in enhancing abiotic stress resistance by activating multiple ROS clearance genes.

Binding profiles for 961 Drosophila and C. elegans transcription factors reveal tissue-specific regulatory relationships.

A catalog of transcription factor (TF) binding sites in the genome is critical for deciphering regulatory relationships. Here we present the culmination of the efforts of the Model Organism ENCyclopedia Of DNA Elements (modENCODE) and the model organism Encyclopedia of Regulatory Networks (modERN) consortia to systematically assay TF binding events in vivo in two major model organisms, Drosophila melanogaster (fly) and Caenorhabditis elegans (worm). These datasets comprise 605 TFs identifying 3.6M sites in the fly and 356 TFs identifying 0.9 M sites in the worm and represent the majority of the regulatory space in each genome. We demonstrate that TFs associate with chromatin in clusters termed "metapeaks", that larger metapeaks have characteristics of high occupancy target (HOT) regions, and that the importance of consensus sequence motifs bound by TFs depends on metapeak size and complexity. Combining ChIP-seq data with single cell RNA-seq data in a machine learning model identifies TFs with a prominent role in promoting target gene expression in specific cell types, even differentiating between parent-daughter cells during embryogenesis. These data are a rich resource for the community that should fuel and guide future investigations into TF function. To facilitate data accessibility and utility, all strains expressing GFP-tagged TFs are available at the stock centers for each organism. The chromatin immunoprecipitation sequencing data are available through the ENCODE Data Coordinating Center, GEO, and through a direct interface that provides rapid access to processed data sets and summary analyses, as well as widgets to probe the cell type-specific TF-target relationships.

Ionising radiation exposure-induced regulation of selected biomarkers and their impact in cancer and treatment

Ionising radiation (IR) is a form of energy that travels as electromagnetic waves or particles. While it is vital in medical and occupational health settings, IR can also damage DNA, leading to mutations, chromosomal aberrations, and transcriptional changes that disrupt the functions of certain cell regulators, genes, and transcription factors. These disruptions can alter functions critical for cancer development, progression, and treatment response. Additionally, IR can affect various cellular proteins and their regulators within different cell signalling pathways, resulting in physiological changes that may promote cancer development, progression, and resistance to treatment. Understanding these impacts is crucial for developing strategies to mitigate the harmful effects of IR exposure and improve cancer treatment outcomes. This review focuses on specific genes and protein biomarkers regulated in response to chronic IR exposure, and how their regulation impacts disease onset, progression, and treatment response.

A High-Throughput Screen for Antiproliferative Peptides in Mammalian Cells Identifies Key Transcription Factor Families.

Transcription factors (TFs) are a promising therapeutic target for a multitude of diseases. TFs perform their cellular roles by participating in multiple specific protein-protein interactions. For example, homo- or heterodimerization of some TFs controls DNA binding, while interactions between TFs and components of basal transcriptional machinery or chromatin modifiers can also be critical. While, in theory, small molecules could be used to disrupt specific protein-protein interfaces required for TF function, in practice, it is difficult to identify small molecules with the necessary specificity and efficacy, likely due to the extensive protein-protein interfaces that often underlie TF function. However, in contrast to small molecules, peptides have the potential to provide both the specificity and efficacy required to disrupt such interfaces. Here, we identified ∼15 peptides that inhibit the proliferation of leukemia cells using a high-throughput pooled screen of a library of 80-mer protein regions (peptides) derived from human nuclear-localized proteins. The antiproliferative peptides were enriched for regions known to be involved in specific TF dimerization, including the basic leucine zipper (bZIP) domain family. One of these bZIP domains, JDP2;bZIP_1, from the TF JDP2, was the top antiproliferative peptide, reducing the proliferation of K562 cells by 2-fold. JDP2;bZIP_1 inhibited AP-1 transcriptional activity and phenocopied JDP2 overexpression, suggesting that the peptide affected proliferation through a native JDP2 mechanism. Unexpectedly, given the strong conservation of the bZIP domain, residues outside of the annotated dimerization domain were critical for the peptide's antiproliferative potency. The peptide-mediated antiproliferative effect initiated erythrocyte differentiation in K562 cells and increased G0/G1 cells across multiple cell line models. We also found that many of the antiproliferative peptides identified in this study, including JDP2;bZIP_1, did not require a nuclear localization signal to function, a potential benefit for delivering these peptides in therapeutic applications.

Transcription factor ASCL1 targets SLC6A13 to inhibit the progression of hepatocellular carcinoma via the glycine-inflammasome signaling.

Hepatocellular carcinoma (HCC), the most common primary liver cancer, typically arises from chronic liver conditions such as hepatitis, cirrhosis, or other chronic liver diseases, and is characterized by its aggressive nature and poor prognosis. The purpose of this research was to clarify the function of achaete-scute family bHLH transcription factor 1 (ASCL1) and solute carrier family 6 member 13 (SLC6A13) in influencing tumor cell behavior, inflammatory responses, and the regulation of inflammasomes. We analyzed the differentially expressed genes (DEGs) in the Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) database, as well as in the GSE14520 and GSE67764 datasets, to identify the expression changes of SLC6A13 in liver cancer. The prognostic significance of SLC6A13 in LIHC was assessed through Kaplan-Meier survival curve analysis. Transcriptional regulation of SLC6A13 by ASCL1 was explored using the Joint Annotation of the Human Genome and other species by the Systematic Pipeline for the Annotation of Regulatory Regions (JASPAR) database and dual-luciferase assays. In vitro experiments investigated the impact of ASCL1 and SLC6A13 overexpression on HCC cell growth. Additionally, the effects of ethanol treatment and glycine modulation on the inflammatory response in HCC cell lines were evaluated. HCC samples showed reduced levels of SLC6A13, which correlates with a better prognosis for liver metastases. Elevated SLC6A13 expression correlated with improved overall survival (OS), progression-free survival (PFS), recurrence-free survival (RFS), and disease-specific survival (DSS). ASCL1 upregulated SLC6A13 and inhibited proliferation, migration, and invasion of HCC cells. Ethanol induced the production of inflammatory cytokines, which was enhanced by overexpression of SLC6A13 but counteracted by glycine. This study highlighted elevated expression of SLC6A13 in LIHC which has been correlated with improved OS, PFS, RFS, and DSS. Overexpression of SLC6A13 and ASCL1 in HCC cells enhanced inflammasome activation, which was exacerbated by ethanol and attenuated by glycine.

Transcriptional coactivator MED15 is required for beta cell maturation

Mediator, a co-regulator complex required for RNA Polymerase II activity, interacts with tissue-specific transcription factors to regulate development and maintain homeostasis. We observe reduced Mediator subunit MED15 expression in endocrine hormone-producing pancreatic islets isolated from people living with type 2 diabetes and sought to understand how MED15 and Mediator control gene expression programs important for the function of insulin-producing β-cells. Here we show that Med15 is expressed during mouse β-cell development and maturation. Knockout of Med15 in mouse β-cells causes defects in β-cell maturation without affecting β-cell mass or insulin expression. ChIP-seq and co-immunoprecipitation analyses found that Med15 binds β-cell transcription factors Nkx6-1 and NeuroD1 to regulate key β-cell maturation genes. In support of a conserved role during human development, human embryonic stem cell-derived β-like cells, genetically engineered to express high levels of MED15, express increased levels of maturation markers. We provide evidence of a conserved role for Mediator in β-cell maturation and demonstrate an additional layer of control that tunes β-cell transcription factor function.

Diverse functions of DEAD-box proteins in oligodendrocyte development, differentiation, and homeostasis.

Oligodendrocytes, a type of glial cell in the central nervous system, have a critical role in the formation of myelin around axons, facilitating saltatory conduction, and maintaining the integrity of nerve axons. The dysregulation of oligodendrocyte differentiation and homeostasis have been implicated in a wide range of neurological diseases, including dysmyelinating disorders (e.g., Pelizaeus-Merzbacher disease), demyelinating diseases (e.g., multiple sclerosis), Alzheimer's disease, and psychiatric disorders. Therefore, unraveling the mechanisms of oligodendrocyte development, differentiation, and homeostasis is essential for understanding the pathogenesis of these diseases and the development of therapeutic interventions. Numerous studies have identified and analyzed the functions of transcription factors, RNA metabolic factors, translation control factors, and intracellular and extracellular signals involved in the series of processes from oligodendrocyte fate determination to terminal differentiation. DEAD-box proteins, multifunctional RNA helicases that regulate various intracellular processes, including transcription, RNA processing, and translation, are increasingly recognized for their diverse roles in various aspects of oligodendrocyte development, differentiation, and maintenance of homeostasis. This review introduces the latest insights into the regulatory networks of oligodendrocyte biology mediated by DEAD-box proteins.

Genome-wide characterization and expression analysis of WRKY transcription factors reveals biotic stress response potential mechanisms in Panax notoginseng

WRKY transcription factors (TFs), among the largest families of transcriptional regulators, are essential players in defense responses in plants. Panax notoginseng, a traditional and precious herbal medicine in China, is widely cultivated due to its excellent medicinal and edible value. However, P. notoginseng is frequently affected by various diseases (like Black blot disease, Root rot disease and Viral diseases). Therefore, the present study aimed to identify and characterize PnWRKYs in the P. notoginseng genome, reveal their structural attributes, regulatory elements, and potential functions in defense responses. 68 PnWRKY TFs that have conserved domains and different physicochemical characteristics were identified in the genome. They can be divided into four groups according to phylogenetic relationships and conserved domain structures. Furthermore, Group II WRKY TFs can be classified into five subgroups (IIa, IIb, IIc, IId, and IIe) according to their zinc finger-like motif. The PnWRKY family expands mainly via segmental duplication. Additionally, the promoter regions of PnWRKYs contain many hormone-responsive and stress-responsive elements. Expression patterns under different hormones (salicylic acid, methyl jasmonate, and melatonin) and disease (root rot disease, black blot disease, and virus disease) treatment analysis highlighted their wide involvement in plant hormone-induced disease defense responses. These findings affirmed the potential functions of PnWRKY TFs in disease-mediated defense responses and provided valuable insights for future agricultural applications.

Transcription factor ZmNAC19 promotes embryo development in Arabidopsis thaliana.

Overexpression of ZmNAC19, a NAC transcription factor gene from maize, improves embryo development in transgenic Arabidopsis. NAC proteins are plant-specific transcription factors that are involved in multiple aspects of plant growth, development and stress response. Although functions of many NAC transcription factors have been elucidated, little is known about their roles in seed development. In this study, we report the function of a maize NAC transcription factor ZmNAC19 in seed development. ZmNAC19 is highly expressed in embryos of developing maize seeds. ZmNAC19 localizes to nucleus and exhibits transactivation activity in yeast cells. Overexpression of ZmNAC19 in Arabidopsis significantly increases seed size and seed yield. During 3 to 7days after flowering, embryos of ZmNAC19-overexpression Arabidopsis lines developed faster compared to Col-0, while no visible differences were detected for their endosperms. Furthermore, overexpression of ZmNAC19 in Arabidopsis leads to increased transcription levels of two embryo development-related genes YUC1 and RGE1, and several elements proven to be binding sites of NAC transcription factors were observed in promoters of these two genes. Taken together, these results suggest that ZmNAC19 acts as a positive regulator in plant embryo development.

Integration of metabolomic and transcriptomic analyses reveals novel regulatory functions of the ChREBP transcription factor in energy metabolism.

Carbohydrate Response Element-Binding Protein (ChREBP) is a transcription factor that activates key genes involved in glucose, fructose, and lipid metabolism in response to carbohydrate feeding, but its other potential roles in metabolic homeostasis have not been as well studied. We used liver-selective GalNAc-siRNA technology to suppress expression of ChREBP in rats fed a high fat/high sucrose diet and characterized hepatic and systemic responses by integrating transcriptomic and metabolomic analyses. GalNAc-siChREBP-treated rats had lower levels of multiple short-chain acyl CoA metabolites compared to rats treated with GalNAc-siCtrl containing a non-targeting siRNA sequence. These changes were related to a sharp decrease in free CoA levels in GalNAc-siChREBP treated-rats, accompanied by lower expression of transcripts encoding enzymes and transporters involved in CoA biosynthesis. These activities of ChREBP likely contribute to its complex effects on hepatic lipid and energy metabolism. While core enzymes of fatty acid (FA) oxidation are induced by ChREBP knockdown, accumulation of liver acylcarnitines and circulating ketones indicate diversion of acetyl CoA to ketone production rather than complete oxidation in the TCA cycle. Despite strong suppression of pyruvate kinase and activation of pyruvate dehydrogenase, pyruvate levels were maintained, likely via increased expression of pyruvate transporters, and decreased expression of lactate dehydrogenase and alanine transaminase. GalNAc-siChREBP treatment increased hepatic citrate and isocitrate levels while decreasing levels of distal TCA cycle intermediates. The drop in free CoA levels, needed for the 2-ketoglutarate dehydrogenase reaction, as well as a decrease in transcripts encoding the anaplerotic enzymes pyruvate carboxylase, glutamate dehydrogenase, and aspartate transaminase likely contributed to these effects. GalNAc-siChREBP treatment caused striking increases in PRPP and ZMP/AICAR levels, and decreases in GMP, IMP, AMP, NaNM, NAD(P), and NAD(P)H levels, accompanied by reduced expression of enzymes that catalyze late steps in purine and NAD synthesis. ChREBP suppression also increased expression of a set of plasma membrane amino acid transporters, possibly as an attempt to replenish TCA cycle intermediates. In sum, combining transcriptomic and metabolomic analyses has revealed regulatory functions of ChREBP that go well beyond its canonical roles in control of carbohydrate and lipid metabolism to now include mitochondrial metabolism and cellular energy balance.

Involvement of BRD4 in Alcoholic Liver Injury: Autophagy Modulation via Regulation of the SIRT1/Beclin1 Axis

Alcoholic liver disease (ALD) caused by chronic alcohol abuse involves complex processes from steatosis to fibrosis, cirrhosis, and hepatocellular carcinoma, posing a global health issue. Bromodomain protein 4 (BRD4) typically serves as a “reader” modulating the functions of transcription factors involved in various biological processes and disease progression. However, the specific mechanisms underlying alcoholic liver injury remain unclear. In this study, we detected aberrant BRD4 expression in the alcohol-induced ALD mouse model of chronic and binge ethanol feeding developed by the National Institute on Alcohol Abuse and Alcoholism, consistent with the in vitro results in Aml-12 mouse hepatocytes. Blocking and inhibiting BRD4 restored the impaired autophagic flux and lysosomal functions in alcohol-treated Aml-12 cells, whereas BRD4 overexpression reduced the expression levels of autophagy marker and lysosomal genes. Furthermore, mouse BRD4 knockdown, mediated by a short hairpin RNA carried by the adeno-associated virus serotype 8, significantly attenuated the alcohol-induced hepatocyte damage, including lipid deposition and inflammatory cell infiltration. Mechanistically, BRD4 overexpression in alcoholic liver injury inhibited the expression of sirtuin (SIRT)1 in Aml-12 cells. Chromatin immunoprecipitation and dual-luciferase reporter assays revealed that BRD4 functions as a transcription factor and suppressor, actively binding to the SIRT1 promoter region and inhibiting its transcription. SIRT1 activated autophagy, which was suppressed in alcoholic liver injury via Beclin1 deacetylation. In conclusion, our study revealed that BRD4 negatively regulated the SIRT1/Beclin1 axis and that its deficiency alleviated alcohol-induced liver injury in mice, thus providing a new strategy for ALD treatment.

SUMOylation and DeSUMOylation: Tug of War of Pain Signaling.

SUMOylation is a post-translational modification that attaches a small ubiquitin-like modifier (SUMO) group to a target protein via SUMO ligases, while deSUMOylation refers to the removal of this SUMO group by sentrin-specific proteases (SENPs). Although the functions of these processes have been well described in the nucleus, the role of SUMOylation and deSUMOylation in regulating ion channels is emerging as a novel area of study. Despite this, their contributions to pain signaling remain less clear. Therefore, this review consolidates the current evidence on the link(s) between SUMOylation, deSUMOylation, and pain, with a specific focus on ion channels expressed in the sensory system. Additionally, we explore the role of SUMOylation in the expression and function of kinases, vesicle proteins, and transcription factors, which result in the modulation of certain ion channels contributing to pain. Altogether, this review aims to highlight the relationship between SUMOylation and deSUMOylation in the modulation of ion channels, ultimately exploring the potential therapeutic role of these processes in chronic pain.

BHLHE41, a transcriptional repressor involved in physiological processes and tumor development.

BHLHE41 is a nuclear transcriptional repressor that belongs to the basic helix-loop-helix protein superfamily. BHLHE41 expression tends to be restricted to specific tissues and is regulated by environmental cues and biological events. BHLHE41 homodimerizes or heterodimerizes with various partners, influencing its transcription factor function. BHLHE41 is involved in the regulation of many physiological processes implicated in tissue/organ homeostasis, such as myogenesis, adipogenesis, circadian rhythms and DNA repair. At cellular level, BHLHE41 is involved in the regulation of mesenchymal stem cell properties, tissue-specific macrophage functions and lymphoid lineage physiology. In several cancer types, BHLHE41 modulates the expression of different transcriptional programs influencing cell cycle control, apoptosis, invasiveness, epithelial to mesenchymal transition and hypoxia response in the tumor environment. Depending on the cancer cell type, BHLHE41 can act as a tumor suppressor or an oncogene, and could be a target for innovative therapies. This review summarizes the available knowledge on BHLHE41 structure, biological functions, regulation and potential partners, as well as its role in physiological processes, and its implication in major cancer steps.

Genome-Wide Identification of MsICE Gene Family in Medicago sativa and Expression Analysis of the Response to Abiotic Stress

To predict the role of the MsICE gene family in the response to abiotic stress, in this study, bioinformatics analysis and real-time fluorescence quantitative PCR were performed. Alfalfa (Medicago sativa) is one of the most economically valuable crops globally. Inducer of CBF expression (ICE), which is part of the basic helix–loop–helix (bHLH) transcription factor (TF) family, acts as a key regulator of cold tolerance. Despite this, there is little information available about ICE genes in alfalfa. Therefore, we studied the function of ICE TFs in alfalfa. We identified 11 MsICE genes from the alfalfa genome and classified them into two groups. Analysis of the protein motif and gene structure revealed relatively high conservation among subgroups of the tightly clustered MsICE genes. Through synteny analysis, we detected duplication events in the MsICE gene family, suggesting that the ICE gene family was formed through fragment duplications. All the MsICE proteins were located in the nucleus according to subcellular localization predictions. The promoter cis-regulatory elements of MsICE genes are largely involved in light (Box 4), hormone (ABRE), and stress (MYB) responses. The MsICE01/MsICE07/MsICE09/MsICE10/MsICE11 genes contained MYB- and MYC-binding motifs, indicating an association with abiotic stress. The specific expression patterns of MsICE genes in leaves were revealed by examining their expression patterns in different tissues. These findings suggest that these genes may sense external environmental changes through leaves. Abiotic stress can cause striking upregulation of MsICE07 (PCA score: −4.03) and MsICE10 (PCA score: −4.05) expression. In this study, candidate genes associated with cold stress were identified, and subsequent molecular biological analyses allowed elucidation of the biological functions of these genes in alfalfa. This research provides a theoretical foundation for enhancing alfalfa yield and quality under cold conditions.

A LBD transcription factor from moso bamboo, PheLBD12, regulates plant height in transgenic rice.

The regulation mechanism of bamboo height growth has always been one of the hotspots in developmental biology. In the preliminary work of this project, the function of LBD transcription factor regulating height growth was firstly studied. Here, a gene PheLBD12 regulating height growth was screened. PheLBD12-overexpressing transgenic rice had shorter internodes, less bioactive gibberellic acid (GA3), and were more sensitive to GA3 than wild-type (WT) plants, which implied that PheLBD12 involve in gibberellin (GA) pathway. The transcript levels of OsGA2ox3, that encoding GAs deactivated enzyme, was significantly enhanced in PheLBD12-overexpressing transgenic rice. The transcript levels of OsAP2-39, that directly regulating the expression of EUI1 to reduce GA levels, was also significantly enhanced in PheLBD12-overexpressing transgenic rice. Expectedly, yeast one-hybrid assays, Dual-luciferase reporter assay and EMSAs suggested that PheLBD12 directly interacted with the promoter of OsGA2ox3 and OsAP2-39. Together, our results reveal that PheLBD12 regulates plant height growth by modulating GA catabolism. Through the research of this topic, it enriches the research content of LBD transcription factors and it will theoretically enrich the research content of height growth regulation.

Exonic splice variant discovery using in vitro models of inherited retinal disease

Correct identification of the molecular consequences of pathogenic genetic variants is essential to the development of allele-specific therapies. However, such molecular effects may remain ambiguous following genetic sequence analysis alone. Here, we identify exonic codon-altering variants that are also predicted to disrupt normal RNA splicing in the context of inherited retinal disease. NR2E3 c.932G>A (p.Arg311Gln) is a variant commonly associated with Enhanced S Cone Syndrome (ESCS). Previous studies using mutagenized cDNA constructs have shown that the arginine to glutamine substitution at position 311 of NR2E3 does not meaningfully diminish function of the rod-specific transcription factor. Using retinal organoids, we explored the molecular consequences of NR2E3 c.932G>A when expressed endogenously during human rod photoreceptor cell development. Retinal organoids carrying the NR2E3 c.932G>A allele expressed a transcript containing a 186-nucleotide deletion of exon 6 within the ligand binding domain. This short transcript was not detected in control organoids or control human donor retina samples. A minigene containing exons 5 and 6 of NR2E3 showed sufficiency of the c.932G>A variant to cause the observed splicing defect. These results support the hypothesis that the pathogenic NR2E3 c.932G>A variant leads to photoreceptor disease by causing a splice defect and not through an amino acid substitution as previously supposed. They also explain the relatively mild effect of Arg311Gln on NR2E3 function in vitro. We also used in silico prediction tools to show that similar changes are likely to affect other inherited retinal disease variants in genes such as CEP290, ABCA4, and BEST1.

BZIP transcription factor responds to changes in light quality and affects saponins synthesis in Eleutherococcus senticosus

Light quality considerably influences plant secondary metabolism, yet the precise mechanism underlying its impact on Eleutherococcus senticosus remains elusive. Comprehensive metabolomic and transcriptomic analyses revealed that varying light quality alters the biosynthesis of triterpene saponins by modulating the expression of genes involved in the process in E. senticosus. Through correlation analysis of gene expression and saponin biosynthesis, we identified four light-responsive transcription factors, namely EsbZIP1, EsbZIP2, EsbZIP4, and EsbZIP5. EsbZIP transcription factors function in the nucleus, with light quality-dependent promoter activity. Except for EsbZIP2, the other EsbZIP transcription factors exhibit transcriptional self-activation. Furthermore, EsbZIP can bind to the promoter areas of genes that encode important enzymes (EsFPS, EsSS, and EsSE) involved in triterpene saponin biosynthesis, thereby regulating their expression. Overexpression of EsbZIP resultes in significant down-regulation of most downstream target genes，which leads to a decrease in saponin content. Overall, varying light quality enhances the content of triterpene saponins by suppressing the expression of EsbZIP. This study thus elucidates the molecular mechanism by which E. senticosus adjusts triterpene saponin levels in response to changes in light quality.

The C/EBPβ-SESN2 Axis Promotes M2b Macrophage Polarization Induced by T.cp-MIF to Suppress Inflammation in Thelazia Callipaeda Infection.

Infection by the conjunctival sucking nematode Thelazia callipaeda results in ocular inflammation and immune impairment. T.cp-MIF, a macrophage migration inhibitor factor of T. callipaeda, can induce macrophage polarization and is involved in the host innate immune response, but little is known about the regulatory mechanisms and the actual immune effect. Understanding the immunoregulatory mechanisms carries significant clinical relevance for the development of novel preventative and therapeutic strategies. The macrophages were induced by T.cp-MIF in vitro, and the polarization direction at different times and the expression of inflammatory factors were detected by flow cytometry analysis, qPCR and western blotting. The key transcription factors and target genes were screened through transcriptome data, and the functions of transcription factors were verified by inhibition experiments in vitro. T.cp-MIF and T. callipaeda adult worms can cause inflammation of the ocular conjunctiva and macrophage infiltration. T.cp-MIF activated macrophages presenting M2b polarization after 48h and played a role in inhibiting inflammation. Furthermore, based on the results of transcriptome data analysis and inhibition experiments, we demonstrate that this polarization is dependent on the involvement of the transcription factor C/EBPβ and its target gene SESN2. Our results demonstrated that the C/EBPβ-SESN2 axis plays an important regulatory role in T.cp-MIF-induced macrophage M2b polarization and it provides a new perspective for understanding the immune escape of ocular parasite infection.

Regulation of transcription factor function by purinergic signalling in cardiovascular diseases.

Cardiovascular diseases (CVDs), including hypertension, atherosclerosis, myocardial ischemia, and myocardial infarction, constitute the primary cause of mortality worldwide. Transcription factors play critical roles in the development of CVDs and contribute to the pathophysiology of these diseases by coordinating the transcription of many genes involved in inflammation, oxidative stress, angiogenesis, and glycolytic metabolism. One important regulator of hemostasis in both healthy and pathological settings has been identified as a purinergic signalling pathway. Research has demonstrated that several signalling networks implicated in the pathophysiology of CVDs are formed by transcription factors that are regulated by purinergic substances. Here, we briefly summarize the roles and mechanisms of the transcription factors regulated by purinergic pathways in various types of CVD. This information will be essential for discovering novel approaches for CVD treatment and prevention.

YY1-controlled regulatory connectivity and transcription are influenced by the cell cycle.

Few transcription factors have been examined for their direct roles in physically connecting enhancers and promoters. Here acute degradation of Yin Yang 1 (YY1) in erythroid cells revealed its requirement for the maintenance of numerous enhancer-promoter loops, but not compartments or domains. Despite its reported ability to interact with cohesin, the formation of YY1-dependent enhancer-promoter loops does not involve stalling of cohesin-mediated loop extrusion. Integrating mitosis-to-G1-phase dynamics, we observed partial retention of YY1 on mitotic chromatin, predominantly at gene promoters, followed by rapid rebinding during mitotic exit, coinciding with enhancer-promoter loop establishment. YY1 degradation during the mitosis-to-G1-phase interval revealed a set of enhancer-promoter loops that require YY1 for establishment during G1-phase entry but not for maintenance in interphase, suggesting that cell cycle stage influences YY1's architectural function. Thus, as revealed here for YY1, chromatin architectural functions of transcription factors can vary in their interplay with CTCF and cohesin as well as by cell cycle stage.