关键词： MOUSE GENITAL TUBERCLE   EXTERNAL GENITALIA   ESTROGEN-RECEPTORS   INDUCED APOPTOSIS   URETHRAL SEAM   ATF3   EXPRESSION   CELLS   DIFFERENTIATION   MUTATIONS  

摘要： Introduction: Hypospadias is a common inborn error of the genital development, whose complex etiology remains elusive. Defects of the androgen metabolism and activity have been found in a subset of boys with hypospadias. Moreover, the balance between androgens and estrogens seems to be important to the proper male genital development. Activating transcription factor 3 (ATF3), an estrogen responsive gene, has been reported to be expressed during sexual development and up-regulated in hypospadic genital skin. We investigated ATF3 as a candidate gene for hypospadias. Material and methods: Genotyping of eight-tagged single nucleotide polymorphisms (SNP)s was performed in 330 boys with hypospadias and in 380 healthy controls. Screening for mutations in ATF3 was conducted in a subset of boys with hypospadias. ATF3 expression was evaluated in the foreskin of boys with hypospadias and in healthy controls and in the human fetal genitalia by immunohistochemistry. Results: Three common SNPs, spanning a region of about 16 kb in intron 1 of ATF3, are associated with hypospadias. These SNPs are not linked and their effects Eire independent. Thecombination of the three risk SNPs yields the highest significance. Mutation screening identified the gene variant c536 A > G in one patient and c817C>T in the 3'-UTR in two other patients. ATF3 expression was evidenced in the developing male urethra. Conclusions: ATF3 gene variants influence the risk of hypospadias. Its hormonal responsiveness may underlie this risk effect. But also other ATF3-dependent biological aspects, such as cell survival and death, response to stress stimuli. or the control of epithelial-mesenchymal interactions, may be of importance.

关键词： ATF3   transcriptional regulation   cancer cell dichotomy   cell motility   breast cancer   adaptive response   ACTIVATING TRANSCRIPTION FACTOR-3   RNA-POLYMERASE-II   BREAST-CANCER   BETA   CELLS   EXPRESSION   IDENTIFICATION   AMPLIFICATION   METASTASIS   SUPPRESSOR  

摘要： Activating transcription factor 3 (ATF3) is a member of the ATF/cyclic AMP response element-binding family of transcription factors. We present evidence that ATF3 has a dichotomous role in cancer development. By both gain- and loss-of-function approaches, we found that ATF3 enhances apoptosis in the untransformed MCF10A mammary epithelial cells, but protects the aggressive MCF10CA1a cells and enhances its cell motility. Array analyses indicated that ATF3 upregulates the expression of several genes in the tumor necrosis factor pathway in the MCF10A cells but upregulates the expression of several genes implicated in tumor metastasis, including TWIST1, fibronectin (FN)-1, plasminogen activator inhibitor-1, urokinase-type plasminogen activator, caveolin-1 and Slug, in the MCF10CA1a cells. We present evidence that ATF3 binds to the endogenous promoters and regulates the transcription of the TWIST1, FN-1, Snail and Slug genes. Furthermore, conditioned medium experiments indicated that ATF3 has a paracrine/autocrine effect, consistent with its upregulation of genes encoding secreted factors. Finally, ATF3 gene copy number is > 2 in similar to 80% of the breast tumors examined (N = 48) and its protein level is elevated in similar to 50% of the tumors. These results provided a correlative argument that it is advantageous for the malignant cancer cells to express ATF3, consistent with its oncogenic roles suggested by the MCF10CA1a cell data.

摘要： Abstract PURPOSE ATF3, an estrogen-responsive gene expressed during genital development, is a strong candidate gene in the development of hypospadias. It is indeed the most upregulated gene in hypospadiac skin and it is implicated in cell cycling suppression that may interfere with urethral cell growth. We thus investigated the sequence and the expression of ATF3 in hypospadias. MATERIAL AND METHODS Direct sequencing of coding exons and splicing sites of ATF3 was performed in 41 boys with hypospadias and 30 controls. ATF3 expression in the genital tubercle of fetuses with and without hypospadias was also studied by immunochemistry. RESULTS -A missense mutation (Leu23Met) was identified in a boy with anterior hypospadias. This aminoacid is highly conserved through species and may be of functional interest. -3 mutations (C53616T, C54177A, Ins54489A) were found in or close to exon 6. This important exon includes splicing sites for an alternative transcript (ATF3ΔZip) implicated in the regulation of the function of ATF3. The phenotypes associated with these mutations were perineal, penoscrotal and anterior hypospadias. None of these mutations were present in controls. -Immunochemistry revealed that ATF3, which is undetectable around the urethra in normal fetus, is overexpressed in the urethral plate and subcutaneous tissue of hypospadiac specimen, especially around the ectopic orifice of urethra. CONCLUSIONS This first report of ATF3 mutations in hypospadias, coupled with its particular expression pattern in hypospadiac fetus, highlight the role of ATF3 in this frequent malformation. These results further support the importance of estrogen responsive genes in the development of hypospadias.

关键词： 尿道下裂/病理学   尿激酶   基因表达  

摘要： 目的研究激活转录因子3(Activating transcription factor 3,ATF3)在尿道下裂包皮组织中的表达情况,探索ATF3与散发的单纯性尿道下裂之间的关系。方法采用免疫组织化学方法,在蛋白质水平检测ATF3蛋白在散发的单纯性尿道下裂患者和对照组之间的表达情况。采用RT-PCR的方法,在RNA水平检测ATF3mRNA在两组之间的表达差异。结果ATF3蛋白在散发的单纯性尿道下裂中的阳性表达率为90%(27/30),在对照组中为10%(2/20),两组比较,差异有统计学意义(P<0.05)。散发的单纯性尿道下裂患者ATF3mRNA的相对表达量为0.5375±0.0591,对照组相对表达量为0.4193±0.0678,两组比较,差异有统计学意义。从数据上看,重型组中ATF3mRNA相对表达量高于其它两组。结论正常人包皮组织中ATF3表达量很少,散发的单纯性尿道下裂患者包皮组织中ATF3的表达明显增多,提示ATF3和散发的单纯性尿道下裂关系密切。进一步研究尿道下裂中ATF3产生的分子基础和ATF3相关的信号转导通路,有可能揭示散发的单纯性尿道下裂的病因。

关键词： protein - protein interaction   liver regeneration   cell proliferation   transcription factor   matrix mating Y2H assay   ATF3   EXPRESSION   INDUCTION   GROWTH   GENE   MAP   IDENTIFICATION   ACTIVATION   DOMAIN   MODEL  

摘要： Liver regeneration is a complex process that involves a multitude of cellular functions, including primarily cell proliferation, apoptosis, inflammation, and metabolism. A number of signaling pathways that control these processes have been identified, and cross communication between them by direct protein-protein interactions has been shown to be crucial in orchestrating liver regeneration. Previously, we have identified a group of transcription factors capable of regulating liver cell growth and that may be involved in liver cancer development. The expression of some of their mouse counterpart genes was altered dramatically after liver injury and regeneration induced by CCl4 in mice. In an effort to elucidate the molecular basis for liver regeneration through protein-protein interactions (PPI), a matrix mating Y2H approach was produced to generate a PPI network between a set of 32 regulatory proteins. Sixty-four interactions were identified, including 4 that had been identified previously. Ten of the interactions were further confirmed with GST pull-down and coimmunoprecipitation assays. Information provided by this PPI network may shed further light on the molecular mechanisms that regulate liver regeneration at the protein interaction level and ultimately identify regulatory factors that may serve as candidate drug targets for the treatment of liver diseases. (c) 2007 Elsevier Inc. All rights reserved.

关键词： ACTIVATING TRANSCRIPTION FACTOR-3   NERVE GROWTH-FACTOR   AXOTOMIZED FACIAL MOTONEURONS   AXONAL REGENERATION   ENDOPEPTIDASE DINE   PERIPHERIN GENE   TRANSGENIC MICE   IN-VIVO   EXPRESSION   PROMOTER  

摘要： Nerve injury requires the expression of large ensembles of genes. The key molecular mechanism for this gene transcription regulation in injured neurons is poorly understood. Among many nerve injury-inducible genes, the gene encoding damage-induced neuronal endopeptidase (DINE) showed most marked expression response to various kinds of nerve injuries in central and peripheral nervous system neurons. This unique feature led us to examine the promoter region of the DINE gene and clarify both the injury-responsive element within the promoter and its related transcriptional machinery. This study showed that DINE promoter was activated by leukemia inhibitory factor and nerve growth factor withdrawal, which were pivotal for the up-regulation of DINE mRNA after nerve injury. The injury-inducible transcription factors such as activating transcription factor 3 (ATF3), c-Jun, and STAT3, which were located at the downstream of leukemia inhibitory factor and nerve growth factor withdrawal, seemed to be involved in the activation of the DINE promoter. Surprisingly, these transcription factors did not bind to the DINE promoter directly. Instead, the general transcription factor, Sp1, bound to a GC box within the promoter. ATF3, c-Jun, and STAT3 interacted with Sp1 and are associated with the GC box region of the DINE gene in injured neurons. These findings suggested that Sp1 recruit ATF3, c-Jun, and STAT3 to obtain the requisite synergistic effect. Of these transcription factors, ATF3 may be the most critical, because ATF3 is specifically expressed after nerve injury.

关键词： Fra1   ATF3   MAP kinases   DNA damage   apoptosis   cell cycle   ACTIVATING TRANSCRIPTION FACTOR-3   CISPLATIN-INDUCED APOPTOSIS   JUN NH2-TERMINAL KINASE   TUMOR-NECROSIS-FACTOR   C-JUN   CELL-PROLIFERATION   MOUSE DEVELOPMENT   CYCLIN D1   AP-1   GENE  

摘要： JNK and ERK MAP kinases regulate cellular responses to genotoxic stress in a cell type and cell context- dependent manner. However, the factors that determine and execute JNK- and ERK-controlled stress responses are only partly known. In this study, we investigate the roles of the AP-1 components ATF3 and Fra1 in JNK- and ERK-dependent cell cycle arrest and apoptosis. We show that the anti-cancer drug cisplatin or UV light activates both JNK and ERK in human glioblastoma cells lacking functional p53. Inhibition experiments of JNK or ERK activities revealed that the ERK pathway strongly promotes cisplatin- and UV-induced apoptosis in these glioblastoma cells. Furthermore, JNK but not ERK is required for ATF3 induction, and both ERK and JNK are necessary for post-transcriptional induction of Fra1 in response to cisplatin or UV. Knock-down of ATF3 and Fra1 results in increased and decreased cisplatin-induced apoptosis, respectively, indicating that ATF3 is an anti-apoptotic JNK effector and Fra1 is a pro- apoptotic ERK/JNK effector. Knock-down experiments also revealed that ATF3 and Fra1, respectively, enhance and reduce S-phase arrest through differential modulation of the Chk1-Cdk2 pathway. Thus, we identify novel reciprocal functions of ATF3 and Fra1 in JNK- and ERK-dependent DNA damage responses. (c) 2007 Elsevier B.V. All rights reserved.

关键词： ACTIVATING TRANSCRIPTION FACTOR-3   INSULIN-RECEPTOR SUBSTRATE-2   LIVER DYSFUNCTION   EXPRESSION   CREB   DISRUPTION   SURVIVAL   DEFECTS   PATHWAY   PROTEIN  

摘要： OBJECTIVE-P-Cell failure is an essential component of all types of diabetes, and the insulin receptor substrate 2 (IRS2) branch of signaling plays a key role in beta-cell survival and function. We tested the hypothesis that activating transcription factor 3 (ATF3), a stress-inducible proapoptotic gene, downregulates the expression of IRS2 in beta-cells. RESEARCH DESIGN AND METHODS-We used both the gain- and loss-of-function approaches to test the effects of ATF3 on IRS2 gene expression. We also analyzed the binding of ATF3 to the IRS2 promoter by chromatin immunoprecipitation assay and the transcription of the IRS2 gene by polymerase II occupancy assay. Furthermore, we tested the ability of IRS2 to alleviate the proapoptotic effects of ATF3 in cultured beta-cells and in transgenic mice using the rat insulin promoter to drive the transgenes. RESULTS-Expression of ATF3 is sufficient to reduce IRS2 gene expression; in contrast, knockdown or knockout of ATF3 reduces the ability of stress signals to downregulate IRS2 expression. ATF3 binds to the IRS2 promoter in vivo, and the binding of ATF3 correlates with decreased IRS2 gene transcription. Functionally, expression of IRS2 protects beta-cells from ATF3-induced apoptosis. CONCLUSIONS-IRS2 is a target gene of ATF3, and its repression by ATF3 contributes, at least partly, to the apoptosis induced by ATF3. Because ATF3 is a stress-inducible gene, our work provides a direct link to explain how environmental stress factors can modulate IRS2 gene transcription.

关键词： elevated plus maze   anhedonia   porsolt   forced swim test   addiction   anxiety   drugs of abuse   stimulants   CREB   CREM   striatum   sucrose preference   neophobia   behavior   CRE-BP1   CREB2   ELEMENT-BINDING PROTEIN   GENE-EXPRESSION   C-JUN   CREB   STRESS   AMPHETAMINE   RESPONSES   DOPAMINE   COCAINE   BRAIN  

摘要： Previous research has shown that cAMP response element ( CRE) binding protein ( CREB) in the nucleus accumbens gates behavioral responses to emotional stimuli. For example, overexpression of CREB decreases anxiety, sucrose preference, and sensitivity to drugs of abuse and increases depression-like behavior, whereas blocking CREB via overexpression of inducible cAMP early repressor ( ICER) or other dominant-negative inhibitors of CRE-mediated transcription has the opposite effects. However, CREB and ICER are but two members of a larger family of leucine zipper-containing transcription factors composed of multiple products of the creb, crem ( cAMP response element modulator), and atf ( activating transcription factor) genes. We demonstrate here that ATF2, ATF3, and ATF4 are each robustly induced in the nucleus accumbens and dorsal striatum by restraint stress or by amphetamine administration. In contrast, little induction is seen for ATF1 or CREM. Using viral-mediated gene transfer, we show that ATF2 overexpression in nucleus accumbens produces increases in emotional reactivity and antidepressant-like responses, a behavioral phenotype similar to that caused by dominant-negative antagonists of CREB. In contrast, ATF3 or ATF4 overexpression in nucleus accumbens decreases emotional reactivity and increases depression-like behavior, consistent with the behavioral phenotype induced by CREB. Because amphetamine and stress induce ATF2, ATF3, and ATF4 in nucleus accumbens, and overexpression of these transcription factors in this brain region in turn alters behavioral responsiveness to amphetamine and stress, our findings support novel roles for these ATF family members in regulating emotional behavior.