关键词： autism   dendiritic spines   mTOR   protein synthesis   translation   ACTIVATING TRANSCRIPTION FACTOR-3   DIFFERENTIAL EXPRESSION ANALYSIS   TRANSLATIONAL PROFILING APPROACH   ASSEMBLY PROTEIN AP180   CNS CELL-TYPES   SYNAPSE FORMATION   MESSENGER-RNA   NERVOUS-SYSTEM   MOUSE MODEL   AUTISM  

摘要： Hyperactivation of the mechanistic target of rapamycin (mTOR) kinase, as a result of loss-of-function mutations in tuberous sclerosis complex 1 (TSC1) or TSC2 genes, causes protein synthesis dysregulation, increased cell size, and aberrant neuronal connectivity. Dys-regulated synthesis of synaptic proteins has been implicated in the pathophysiology of autism spectrum disorder (ASD) associated with TSC and fragile X syndrome. However, cell type-specific translational profiles in these disease models remain to be investigated. Here, we used high-fidelity and unbiased Translating Ribosome Affinity Purification (TRAP) methodology to purify ribosome-associated mRNAs and identified translational alterations in a rat neuronal culture model of TSC. We find that expression of many stress and/or activity-dependent proteins is highly induced while some synaptic proteins are repressed. Importantly, transcripts for the activating transcription factor-3 (Atf3) and mitochondrial uncoupling protein-2 (Ucp2) are highly induced in Tsc2-deficient neurons, as well as in a neuron-specific Tsc1 conditional knock-out mouse model, and show differential responses to the mTOR inhibitor rapamycin. Gelsolin, a known target of Atf3 transcriptional activity, is also upregulated. shRNA-mediated block of Atf3 induction suppresses expression of gelsolin, an actin-severing protein, and rescues spine deficits found in Tsc2-deficient neurons. Together, our data demonstrate that a cell-autonomous program consisting of a stress-induced Atf3-gelsolin cascade affects the change in dendritic spine morphology following mTOR hyperactivation. This previously unidentified molecular cascade could be a therapeutic target for treating mTORopathies.

关键词： activating transcription factor 3   computational network   Huh7 cell line   hepatitis C virus-infected Huh7 cell line   NEGATIVE REGULATOR   ATF3   EXPRESSION   PROTEIN   KINASE   CANCER   MICROARRAY   APOPTOSIS   PROSTATE   ROLES  

摘要： Activating transcription factor 3 (ATF3) is an adaptive-response gene of the ATF family. ATF3 activity may be induced in response to a number of different stress-associated signals and ATF3 is involved in a variety of cellular processes. However, the functions of ATF3 and its molecular networks in human hepatoma cells lines and hepatitis C virus-infected Huh7 (HCV-Huh7) cells are not well understood. In the present study, ATF3 regulatory networks in Huh7 and HCV-Huh7 cell lines were established using the linear programming-based GRNinfer software and molecule annotation system 3.0 software. The gene expression omnibus dataset, GSE20948, was analyzed. The resulting network consisted of clusters located upstream and downstream of ATF3 in Huh7 and HCV-Huh7 cell lines. Using the annotation, visualization and integrated discovery (DAVID) software, 10 activation and 2 inhibition enriched functional annotation clusters were identified downstream of ATF3 in HCV-Huh7 cells. However, there were no enriched functional annotation clusters identified upstream of ATF3 in HCV-Huh7 cells. Furthermore, no clusters were identified downstream nor upstream of ATF3 in Huh7 cells. Gene ontology term and Kyoto encyclopedia of genes and genomes pathway analyses demonstrated that ATF3 may be involved in a number of biological processes, in particular, in metabolism regulation in HCV-Huh7 cells. It is hypothesized that the ATF3 pathway may be activated in Huh7 cells following HCV infection and that it is a potential hub' in the network of HCV-Huh7 cells.

关键词： TRANSCRIPTION factors   INFLAMMATION   AORTIC valve -- Diseases   CALCIFICATION   MEDICAL research  

关键词： apoptosis   DNA transcription   DNA-protein interaction   endoplasmic reticulum stress (ER stress)   oxidative stress   unfolded protein response (UPR)   ATF3   ATF4   CEBP   CHAC1   ENDOPLASMIC-RETICULUM STRESS   ASPARAGINE SYNTHETASE GENE   ER-STRESS   ENDOTHELIAL-CELLS   INDUCIBLE GENE   EXPRESSION   APOPTOSIS   CHOP   ANTIOXIDANT   ACTIVATION  

摘要： Using an unbiased systems genetics approach, we previously predicted a role for CHAC1 in the endoplasmic reticulum stress pathway, linked functionally to activating transcription factor 4 (ATF4) following treatment with oxidized phospholipids, a model for atherosclerosis. Mouse and yeast CHAC1 homologs have been shown to degrade glutathione in yeast and a cell-free system. In this report, we further defined the ATF4-CHAC1 interaction by cloning the human CHAC1 promoter upstream of a luciferase reporter system for in vitro assays in HEK293 and U2OS cells. Mutation and deletion analyses defined two major cis DNA elements necessary and sufficient for CHAC1 promoter-driven luciferase transcription under conditions of ER stress or ATF4 coexpression: the -267 ATF/cAMP response element (CRE) site and a novel -248 ATF/CRE modifier (ACM) element. We also examined the ability of the CHAC1 ATF/CRE and ACM sequences to bind ATF4 and ATF3 using immunoblot-EMSA and confirmed ATF4, ATF3, and CCAAT/enhancer-binding protein binding at the human CHAC1 promoter in the proximity of the ATF/CRE and ACM using ChIP. To further validate the function of CHAC1 in a human cell model, we measured glutathione levels in HEK293 cells with enhanced CHAC1 expression. Overexpression of CHAC1 led to a robust depletion of glutathione, which was alleviated in a CHAC1 catalytic mutant. These results suggest an important role for CHAC1 in oxidative stress and apoptosis with implications for human health and disease.

关键词： 子宫颈肿瘤   鳞癌   病理学   激活转录因子3   免疫组织化学  

摘要： 目的探讨激活转录因子3(activating transcription factor 3,ATF3)在子宫颈鳞癌组织的表达及其临床意义。方法采用免疫组化SP法分别检测72例子宫颈鳞癌组织和48例子宫颈正常组织中ATF3的表达。结果 ATF3在子宫颈鳞癌组织中的阳性率(77.8%,56/72)明显高于正常子宫颈组织(25.0%,12/48),二者比较差异有统计学意义(P<0.05)。ATF3表达与子宫颈鳞癌临床分期、浸润深度和淋巴结转移相关(P<0.05),与患者年龄、鳞癌分化程度无关(P>0.05)。结论 ATF3在子宫颈鳞癌组织中高表达,并且与临床分期、浸润深度和淋巴结转移密切相关,可能作为反映子宫颈鳞癌生物行为的有效指标之一。

关键词： stem   cell   ATF  

摘要： One of the major problems of modern neurobiology is how to replace dead or damaged neurons in the human brain or spinal cord after injury or as a consequence of neurodegenerative dis- eases. In fact, because adult mammalian neurons are post-mi- totic cells that cannot divide to replace dead cells, loss due to lesion or disease is permanent. Furthermore, surviving neurons have modest capacity to regenerate their damaged axons and re-establish functional connections. Thus, a gradual neurode- generative scenario with certain similarities in stroke, brain or spinal cord injuries and neurological diseases like Alzheimer＇s disease is produced. These conditions represent the major disease burden of the modern world in terms of mortality, dis- ability, productivity loss and health-care costs （World Health Organization, 2008）. While much effort has been directed to understand the molecular and cellular mechanisms involved in the pathology of these diseases to set new effective treatments, many neuroprotective and regenerative approaches, although showing positive results in preclinical studies, have so far failed to provide strong benefit to patients.

关键词： ACTIVATING TRANSCRIPTION FACTOR-3   DOUBLE-STRAND BREAKS   INDUCED APOPTOSIS   COLON-CANCER   DOXORUBICIN   RESISTANCE   ICRF-187   CARDIOPROTECTION   PHARMACOLOGY   GAMMA-H2AX  

摘要： Background and PurposeThe catalytic topoisomerase II inhibitor dexrazoxane has been associated not only with improved cancer patient survival but also with secondary malignancies and reduced tumour response. Experimental ApproachWe investigated the DNA damage response and the role of the activating transcription factor 3 (ATF3) accumulation in tumour cells exposed to dexrazoxane. Key ResultsDexrazoxane exposure induced topoisomerase II (TOP2A)-dependent cell death, -H2AX accumulation and increased tail moment in neutral comet assays. Dexrazoxane induced DNA damage responses, shown by enhanced levels of -H2AX/53BP1 foci, ATM (ataxia telangiectasia mutated), ATR (ATM and Rad3-related), Chk1 and Chk2 phosphorylation, and by p53 accumulation. Dexrazoxane-induced -H2AX accumulation was dependent on ATM. ATF3 protein was induced by dexrazoxane in a concentration- and time-dependent manner, which was abolished in TOP2A-depleted cells and in cells pre-incubated with ATM inhibitor. Knockdown of ATF3 gene expression by siRNA triggered apoptosis in control cells and diminished the p53 protein level in both control and dexrazoxane -treated cells. This was accompanied by increased -H2AX accumulation. ATF3 knockdown also delayed the repair of dexrazoxane -induced DNA double-strand breaks. Conclusions and ImplicationsAs with other TOP2A poisons, dexrazoxane induced DNA double-strand breaks followed by activation of the DNA damage response. The DNA damage-triggered ATF3 controlled p53 accumulation and generation of double-strand breaks and is proposed to serve as a switch between DNA damage and cell death following dexrazoxane treatment. These findings suggest a mechanistic explanation for the diverse clinical observations associated with dexrazoxane.

关键词： ATF3   Nitric oxide   iNOS   NF-kappa B: macrophages   NITRIC-OXIDE SYNTHASE   TRANSCRIPTION FACTOR-3   ADAPTIVE-RESPONSE   CELL APOPTOSIS   KAPPA-B   GENE   MECHANISMS   MODULATION   DISEASES   SEPSIS  

摘要： Macrophage-associated nitric oxide (NO) production plays a crucial role in the pathogenesis of tissue damage. However, negative factors that regulate NO production remains poorly understood despite its significance of NO homeostasis. Here, we show that activating transcription factor 3 (ATF3), a transcriptional regulator of cellular stress responses, was strongly induced in activated macrophages and its depletion resulted in pronounced enhancement of inducible nitric oxide synthase (iNOS) gene expression and subsequently the induction of high levels of NO production. In response to lipopolysaccharide (LPS) and IFN-gamma, ATF3 inhibited transcriptional activity of NF-kappa B by interacting with the N-terminal (1-200 amino acids) of p65 and was bound to the NF-kappa B promoter, leading to suppression of iNOS gene expression. In addition, inhibitory effects of ATF3 on iNOS and NO secretion were suppressed by inhibitor of casein kinase II (CK2) activity or its knockdown. Moreover, the levels of ATF3 were highly elevated in established cecal ligation and puncture or LPS-injected mice, a model of endotoxemia. ATF3 is also elevated in peritoneal macrophages. Collectively, our findings suggest that ATF3 regulates NO homeostasis by associating with NF-kappa B component, leading to the repression of its transcriptional activity upon inflammatory signals and points to its potential relevance for the control of cell injuries mediated by NO during macrophage activation.

关键词： Neuropathic pain   Hydrogen sulfide   Microglia   Inflammatory cytokine   ROOT GANGLION NEURONS   EXPRESSION   MONONEUROPATHY   ATF3   RAT   INTERLEUKIN-6   HYPERALGESIA   INFLAMMATION   MODULATION   ALLODYNIA  

摘要： Increasing evidence suggests that the pathogenesis of neuropathic pain is mediated through activation of microglia in the spinal cord. Hydrogen sulfide attenuates microglial activation and central nervous system inflammation; however, the role of hydrogen sulfide in neuropathic pain is unclear. In this study, we examined the effects of hydrogen sulfide breathing on neuropathic pain in mice. C57BL/6J mice were subjected to chronic constriction injury (CCI) of the sciatic nerve. After CCI, mice breathed air alone or air mixed with hydrogen sulfide at 40 ppm for 8 h on 7 consecutive days. The expression levels of inflammatory cytokines including interleukin 6 (IL-6) were measured in the spinal cord. Effects of hydrogen sulfide on IL-6-induced activation of microglia were examined in primary rat microglia. Mice that breathed air alone exhibited the neuropathic pain behavior including mechanical allodynia and thermal hyperalgesia and increased mRNA levels of IL-6 and chemokine CC motif ligand 2 (CCL2) after CCI. Inhaled hydrogen sulfide prevented the neuropathic pain behavior and attenuated the upregulation of inflammatory cytokines. Sodium sulfide inhibited IL-6-induced activation of primary microglia. These results suggest that inhaled hydrogen sulfide prevents the development of neuropathic pain in mice possibly via inhibition of the activation of microglia in the spinal cord. (C) 2014 Elsevier Inc. All rights reserved.