关键词： AP‐1   ATF3   chromatin accessibility   IARs   DNA methylation   heterochromatin   DARs   senescence   DNA METHYLATION   CELL SENESCENCE   EXPRESSION   PROLIFERATION   AMELIORATION   COMPACTION   LANDSCAPE   PHENOTYPE   HALLMARKS   PROTEINS  

摘要： Chromatin organization and transcriptional profiles undergo tremendous reordering during senescence. However, uncovering the regulatory mechanisms between chromatin reconstruction and gene expression in senescence has been elusive. Here, we depicted the landscapes of both chromatin accessibility and gene expression to reveal gene regulatory networks in human umbilical vein endothelial cell (HUVEC) senescence and found that chromatin accessibilities are redistributed during senescence. Particularly, the intergenic chromatin was massively shifted with the increased accessibility regions (IARs) or decreased accessibility regions (DARs), which were mainly enhancer elements. We defined AP-1 transcription factor family as being responsible for driving chromatin accessibility reconstruction in IARs, where low DNA methylation improved binding affinity of AP-1 and further increased the chromatin accessibility. Among AP-1 transcription factors, we confirmed ATF3 was critical to reconstruct chromatin accessibility to promote cellular senescence. Our results described a dynamic landscape of chromatin accessibility whose remodeling contributes to the senescence program, we identified that AP-1 was capable of reorganizing the chromatin accessibility profile to regulate senescence.

关键词： ATF3   Migration   Invasion   Stemness   Epithelial mesenchymal transition   Gastric cancer cell line   Mouse  

摘要： Background Gastric cancer (GC) is one of the most common cancers and the third leading cause of cancer related mortality worldwide. The 5-year survival rate is rather low owing to advanced unresectable and distant metastasis. The EMT has been widely implicated in the stemness, metastatic dormancy, and chemoresistance of different solid tumors. Given the fact that activating transcription factor-3 (ATF3) is a member of the ATF/CREB family of transcription factors and its role in regulation of GC recurrence and metastasis remain poorly understood, the aim of the present study was to investigate its potential impact in epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties and GC aggression. Methods To elucidate the potential role of ATF3 in gastric cancer, we utilized SGC-7901 and MGC-803 gastric cancer cell lines as research models and constructed stable cell lines overexpressing ATF3. We conducted a series of assays including cell proliferation, colony formation, cell migration, tumorsphere formation, and invasion to investigate the functional roles of ATF3 in stemness of gastric cancer. The possible effect of ATF3 on epithelial-mesenchymal transition (EMT) was assessed through flow cytometry and qRT-PCR. In vivo functional effect of upregulation of ATF3 on tumor growth was examined in a mouse xenograft model. Results We found that overexpression of ATF3 inhibited cell proliferation, colony formation, cell migration and invasion. In addition, up-regulation of ATF3 attenuated tumorsphere formation, cell stemness, and potentially decreased expression of EMT markers. Moreover, ATF3 overexpression inhibited tumorigenesis in mouse xenograft model. Conclusion Our data suggest a suppressive role of ATF3 in gastric cancer development. Our findings will provide a potential therapeutic strategy and novel drug target for gastric cancer.

关键词： Nonalcoholic fatty liver disease   Ginsenoside-Rg1   RNA-seq   Atf3   Acox2   OXIDATIVE STRESS   GUT MICROBIOTA   RG1   IMPACT   NAFLD  

摘要： Aims: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease and lacks for safe and effective drug to therapy completely. Ginsenoside-Rg1 is one of the main components of ginseng and has been proved to counteract a variety of diseases. However, there is currently a lack of sufficient evidence to support the efficacy of ginsenoside-Rg1 in the treatment of NAFLD. Our aim was to investigate whether Ginsenoside-Rg1 is a potential drug for NAFLD. Main methods: NAFLD model in rats was established by giving a high-fat diet (HFD), ginsenoside-Rg1 was intragastrically administered 100 mg/kg/d for 8 weeks in NAFLD rat. Serum biochemical indices were measured. Liver tissues were stained with hematoxylin and eosin (HE) and oil red O. Total RNA was extracted from liver and was used for high throughput sequencing to identify the changes of transcriptome. The relevant hub genes were verified by quantitative real-time PCR and western blot. Key findings: Serum biochemical analysis indicated that ginsenoside-Rg1 improved liver function. Additionally, the staining of HE and oil red O indicated ginsenoside-Rg1 could remit pathology process of NAFLD. The transcriptome changes also support this result and reveals Atf3 and Acox2 were key genes. Significance: Taken together, these results suggest that the efficiency of ginsenoside-Rg1 against NAFLD and confirmed that ginsenoside-Rg1 is a potential effective drug in treatment of NAFLD.

关键词： ACTIVATING TRANSCRIPTION FACTOR-3   DEPENDENT KINASE 2   GENE   CDK2   EXPRESSION   STRESS   ATF3   PHOSPHORYLATION   INHIBITORS   DISCOVERY  

摘要： The prediction of drug-target interaction (DTI) is a key step in drug repositioning. In recent years, many studies have tried to use matrix factorization to predict DTI, but they only use known DTIs and ignore the features of drug and target expression profiles, resulting in limited prediction performance. In this study, we propose a new DTI prediction model named AdvB-DTI. Within this model, the features of drug and target expression profiles are associated with Adversarial Bayesian Personalized Ranking through matrix factorization. Firstly, according to the known drug-target relationships, a set of ternary partial order relationships is generated. Next, these partial order relationships are used to train the latent factor matrix of drugs and targets using the Adversarial Bayesian Personalized Ranking method, and the matrix factorization is improved by the features of drug and target expression profiles. Finally, the scores of drug-target pairs are achieved by the inner product of latent factors, and the DTI prediction is performed based on the score ranking. The proposed model effectively takes advantage of the idea of learning to rank to overcome the problem of data sparsity, and perturbation factors are introduced to make the model more robust. Experimental results show that our model could achieve a better DTI prediction performance.

关键词： 转录激活因子3   急性肾损伤   慢性肾脏病   作用机制  

摘要： 肾功能不全依据肾功恶化的速度及病因可分为急性肾损伤(AKI)及慢性肾脏病(CKD)。在我国,每年约有140~290万AKI患者入院,院内死亡率高达12.4%[1];经流行病学调查,2017年全球CKD平均患病率为9.1%,较1990年增加了29%,其中近六分之一CKD患者在中国,我国患病总人数高达1.32亿[2],可见AKI及CKD发病率逐渐升高,威胁人群健康,增加社会医疗负担,是亟待解决的健康问题。

关键词： Ferroptosis   Quercetin   Activation transcription factor 3   Macrophages   Acute kidney injury   TUBULAR EPITHELIAL-CELLS   N-ACETYLCYSTEINE   HEME OXYGENASE-1   RENAL-FAILURE   DEATH   PROTECTS   ATF3   REGULATOR  

摘要： Introduction: Ferroptosis is an iron-dependent regulated necrosis and has been proven to contribute to the progress of acute kidney injury (AKI). Quercetin (QCT), a natural flavonoid which is commonly found in numerous fruits and vegetables, has extensive pharmacological effects, such as anti-oxidant, antiinflammatory and anti-senescence effects. Objectives: This study aims to explain whether ferroptosis is a therapeutic strategy to AKI, and to explore the effect of QCT on AKI ferroptosis. Methods: NRK-52E cells and HK-2 cells were used for in vitro ferroptosis studies. Morphology of cells was detected by transmission electron microscopy. Lipid ROS was assayed using flow cytometry. In vivo, AKI was induced by ischemia-reperfusion (I/R) or folic acid (FA). To explore the molecular mechanisms, RNA-sequence analysis was performed. Transwell was used to detect macrophage migration. Results: We discovered that quercetin (QCT), a natural flavonoid, inhibited ferroptosis in renal proximal tubular epithelial cells. QCT blocked the typical morphologic changes of ferroptotic cells by reducing the levels of malondialdehyde (MDA) and lipid ROS and increasing the levels of glutathione (GSH). Moreover, QCT ameliorated AKI induced by I/R or FA. RNA-sequence analysis highlighted activation transcription factor 3 (ATF3), as it was the dominant one among all the 299 down-regulated genes by QCT. Knockdown of ATF3 could significantly increase the levels of SLC7A11, GPX4 and increased the cell viability. In addition, ferroptotic cells were found to be extremely pro-inflammatory by recruiting macrophages through CCL2, while QCT inhibited the chemotaxis of macrophages induced by ferroptosis in AKI. Conclusions: Collectively, these results identify QCT as a ferroptosis inhibitor and provide new therapeutic strategies for diseases related to ferroptosis. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of Cairo University. This is an open access article under the CC BY-NC-ND licen

关键词： ACTIVATING TRANSCRIPTION FACTOR-3   TRAIL-INDUCED APOPTOSIS   ADAPTIVE-RESPONSE   GENE-EXPRESSION   CANCER   INTERFERON   DIFFERENTIATION   G1P3   PATHOGENESIS   HYPERPLASIA  

摘要： Activating transcription factor 3 (ATF3) is a key transcription factor involved in regulating cellular stress responses, with different expression levels and functions in different tissues. ATF3 has also been shown to play crucial roles in regulating tumor development and progression, however its potential role in oral squamous cell carcinomas has not been fully explored. In this study, we examined biopsies of tongue squamous cell carcinomas (TSCCs) and found that the nuclear expression level of ATF3 correlated negatively with the differentiation status of TSCCs, which was validated by analysis of the ATGC database. By using gain- or loss- of function analyses of ATF3 in four different TSCC cell lines, we demonstrated that ATF3 negatively regulates the growth and migration of human TSCC cells in vitro. RNA-seq analysis identified two new downstream targets of ATF3, interferon alpha inducible proteins 6 (IFI6) and 27 (IFI27), which were upregulated in ATF3-deleted cells and were downregulated in ATF3-overexpressing cells. Chromatin immunoprecipitation assays showed that ATF3 binds the promoter regions of the IFI6 and IFI27 genes. Both IFI6 and IFI27 were highly expressed in TSCC biopsies and knockdown of either IFI6 or IFI27 in TSCC cells blocked the cell growth and migration induced by the deletion of ATF3. Conversely, overexpression of either IFI6 or IFI27 counteracted the inhibition of TSCC cell growth and migration induced by the overexpression of ATF3. Finally, an in vivo study in mice confirmed those in vitro findings. Our study suggests that ATF3 plays an anti-tumor function in TSCCs through the negative regulation of its downstream targets, IFI6 and IFI27. Author summary Activating transcription factor 3 (ATF3), a stress response gene, has been shown to play either tumor promoting or tumor suppressing functions depending on the type of tumor cell and the stromal context. Here we discovered that ATF3 plays an anti-tumor role in tongue squamous cell carcinoma (

关键词： apoptosis   ATF   fluorizoline   ISR   NOXA   prohibitins   BH3-ONLY PROTEIN NOXA   CELL-DEATH   ER STRESS   MITOCHONDRIAL-FUNCTION   BCL-2 FAMILY   APOPTOSIS   EXPRESSION   INHIBITOR   PROLIFERATION   INDUCTION  

摘要： Fluorizoline is a new synthetic molecule that induces p53-independent apoptosis, in several tumor cell lines and in primary leukemia cells, by selectively targeting prohibitins (PHBs). In this study, we describe how fluorizoline induces BCL-2 homology 3-only protein NOXA, without modulating the protein levels of anti-apoptotic B-cell lymphoma-2 (BCL-2) family members prior to caspase activation, as well as how it synergizes with the BCL-2 and BCL-X(L)inhibitor ABT-737 to induce apoptosis. Interestingly, fluorizolinetreatment triggers the activation of the integrated stress response (ISR) in HeLa and HAP1 cells, with increased eukaryotic translation initiation factor 2 alpha phosphorylation, and induction of ATF3, ATF4, and CHOP. Moreover, PHB downregulation induces similar ISR activation and apoptosis as with fluorizoline treatment. In addition, we studied the essential role of the pro-apoptotic protein NOXA in fluorizoline-induced apoptosis and we describe its mechanism of induction in HeLa and HAP1 cells. Moreover, we identified ATF3 and ATF4 as the transcription factors that bind to NOXA promoter upon fluorizoline treatment. Furthermore, usingATF3andATF4CRISPR HeLa and HAP1 cells, we confirmed that both factors mediate the induction of NOXA and apoptosis by fluorizoline. In conclusion, fluorizoline treatment triggers the activation of the ISR that results in the induction of ATF3 and ATF4, important regulators of NOXA transcription in fluorizoline-induced apoptosis.

关键词： Cardiac remodeling   Hypertrophy   Heart failure   Pressure overload   Cardiomyocytes fibroblasts   Conditional knockout  

摘要： Background: Activating transcription 3 (ATF3) is a member of the basic leucine zipper family of transcription factors. ATF3 is an immediate early gene expressed following various cellular stresses. ATF3 acts through binding to cyclic AMP response elements found in the promoters of key regulatory proteins that determine cell fate. In the heart, multiple cardiac stresses result in chronic ATF3 expression. Transgenic mice with ATF3 expression in cardiomyocytes clearly demonstrate that ATF3 serves a leading role in heart hypertrophy, cardiac fibrosis, cardiac dysfunction and death. In contrast, the use of ATF3 whole body knockout mice resulted non-conclusive results. The heart is composed of various cell types such as cardiomyocytes, fibroblasts, endothelial and immune cells. The question that we addressed in this study is whether ablation of ATF3 in unique cell types in the heart results in diverse cardiac phenotypes. Methods: ATF3-flox mice were crossed with alpha MHC and Postn specific promoters directing CRE expression and thus ATF3 ablation in cardiomyocytes and myofibroblast cells. Mice were challenged with transverse aortic constriction (TAC) for eight weeks and heart function, ventricle weight, hypertrophic markers, fibrosis markers and ATF3 expression were assessed by qRT-PCR. Results: The results of the study show that ATF3 deletion in cardiomyocytes followed by TAC resulted in reduced heart growth and dampened fibrosis response while ATF3 ablation in myofibroblasts displayed a reduced hypertrophic gene program. Conclusions: TAC-operation results in increased ATF3 expression in both myofibroblasts and cardiomyocytes that promotes a hypertrophic program and fibrotic cardiac growth, respectively. (C) 2020 The Authors. Published by Elsevier B.V.

关键词： ATF3   Hepatocellular carcinoma   Database mining   Prognostic value   Functional network analysis  

摘要： BackgroundThe abnormal expression of activating transcription factor 3 (ATF3), a member of the basic leucine zipper (bZIP) family of transcription factors, is associated with carcinogenesis. However, the expression pattern and exact role of ATF3 in the development and progression of hepatocellular carcinoma (HCC) remain *** used UALCAN, ONCOMINE, Kaplan-Meier plotter, and cBioPortal databases to investigate the prognostic value of ATF3 expression in ***3 was found to be expressed at low levels in multiple HCC tumor tissues. Moreover, low ATF3 expression was significantly associated with clinical cancer stage and pathological tumor grade in patients with HCC. Therefore, low expression of ATF3 was significantly associated with poor overall survival in patients with HCC. Functional network analysis showed that ATF3 regulates cytokine receptors and signaling pathways via various cancer-related kinases, miRNAs, and transcription factors. ATF3 expression was found to be correlated with macrophage infiltration levels and with macrophage immune marker sets in HCC *** data mining methods, we clarified the role of ATF3 expression and related regulatory networks in HCC, laying a foundation for further functional research. Future research will validate our findings and establish clinical applications of ATF3 in the diagnosis and treatment of HCC.