关键词： Pancreatic and duodenal homeobox factor-1 (PDX-1)   Activating transcription factor 3 (ATF3)   Promoter   ATF/CREB responsive element (ATF/CRE)   Hyperglycemia   Hyperlipidemia  

摘要： The downregulation of PDX-1 expression plays an important role in development of type 2 diabetes. However, the negative regulator of PDX-1 expression is not well known. In this study, we analyzed the mouse PDX-1 promoter to characterize the effects of ATF3 on PDX-1 expression in pancreatic beta-cells. Both thapsigargin treatment, an inducer of ER stress, and ATF3 expression decreased PDX-1 expression in pancreatic beta-cells, MIN6N8. Furthermore, they also repressed the activity of -4.5 Kb promoter of mouse PDX-1 gene. Transfection studies with 5' deleted-reporters showed that ATF3 repressed the activity of 0.9 Kb PDX-1 promoter, whereas it did not affect the activity of 0.7 Kb PDX-1 promoter, suggesting that ATF3 responsive element is located between the -903 and -702. An electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 binds directly to the promoter region spanning from -759 to -738. Moreover, mutation of the putative ATF/CRE site between -752 and -745 abrogated ATF3-mediated transrepression of the PDX-1 promoter. PDX-1 was decreased in MIN6N8 cells treated with high glucose or high palmitate, whereas ATF3 was increased, indicating that ATF3 plays a role in hyperglycemia or hyperlipidemia-mediated downregulation of PDX-1 expression. Collectively, these results demonstrate that ATF3 represses PDX-1 expression via binding to an ATF3-responsive element in its promoter, which plays an important role in suppression of pancreatic beta-cells function. (C) 2011 Elsevier Inc. All rights reserved.

关键词： 支气管哮喘   激活转录因子3   氧化应激  

摘要： 目的探讨支气管哮喘(简称哮喘)急性发作期激活转录因子-3(ATF3)的表达及作用。方法 30只健康雄性豚鼠,按随机数字表法分为对照组(A组)、哮喘组(B组)及地塞米松治疗组(C组),每组10只。卵清蛋白致敏法复制哮喘模型。收集支气管肺泡灌洗液(BALF)并进行细胞总数及分类计数;观察豚鼠肺组织病理学改变;检测豚鼠肺组织及BALF中ROS含量;采用免疫组织化学和Westernblot法测定豚鼠肺组织中ATF3蛋白的表达和量的变化;原位杂交、RT-PCR法检测ATF3 mRNA的表达变化;免疫细胞化学检测豚鼠BALF细胞中ATF3蛋白的表达。结果①哮喘组豚鼠BALF中炎细胞总数、嗜酸粒细胞百分比(EOS%)显著高于对照组(P<0.01),哮喘组豚鼠肺组织可见大量炎症细胞浸润及明显气道重塑改变,且哮喘组ROS含量显著升高,而地塞米松治疗组上述变化明显减低(P值均<0.01);②ATF3蛋白及mRNA表达哮喘组明显高于对照组(P值均<0.01);③ATF3蛋白及mRNA的表达变化与ROS含量及BALF炎细胞总数、EOS%变化均呈正相关。结论哮喘急性发作期豚鼠肺组织及BALF细胞中ATF3的表达升高,可能与气道炎症反应和氧化应激有关;给予地塞米松治疗后ATF3表达下降,可能在哮喘的防治中起重要作用。

关键词： Psychiatry   Inflammation   Monocytes   TREM-1   EGR3   ATF3  

摘要： Introduction: Immune activation is a characteristic of schizophrenia (SCZ), bipolar disorder (BD) and unipolar major depressive disorder (MDD). The triggering receptor expressed on myeloid cells 1 (TREM-1), its' adaptor molecule DAP12 and their transcription factor (TF) PU.1 are important key genes in inflammation and expressed in activated monocytes and microglia. Aim: To test: (1) if the expressions of TREM-1, DAP12 and PU.1 are increased in monocytes of patients with severe psychiatric disorders and (2) if PU.1 and the TFs ATF3 and EGR3 (which have been found as prominent increased monocyte genes in previous studies) are involved in the regulation of TREM-1 and DAP12 expression. Methods: Using Q-PCR, we studied the gene expression of TREM-1, DAP12, PU.1, ATF3 and EGR3 in the monocytes of 73 patients with severe psychiatric disorders (27 recent onset SCZ patients, 22 BD patients and 24 MDD patients) and of 79 healthy controls (HC). Using in silico TF binding site prediction and in vivo chromatin immunoprecipitation (ChIP), we studied the actual binding of EGR3, ATF3 and PU.1 to the promoter regions of TREM-1 and DAP12. Results: 1. TREM-1 gene expression was increased in the monocytes of SCZ and BD patients and tended to be increased in the monocytes of MDD patients. 2. DAP12 gene levels were neither increased in the monocytes of SCZ, BD, nor MDD patients. 3. PU.1 expression levels were increased in the monocytes of MDD patients, but not in those of SCZ and BD patients. 4. TREM-1 expression levels correlated in particular to ATF3 and EGR3 expression levels, DAP12 expression levels correlated in particular to PU.1 expression levels. 5. We found using binding site prediction and ChIP assays that the TFs EGR3 and ATF3 indeed bound to the TREM-1 promoter, PU.1 bound to both the TREM-1 and DAP12 promoter. Conclusion: In this study, we provide evidence that TREM-1 gene expression is significantly increased in monocytes of SCZ and BD patients and that the TREM-1 gene is a

关键词： Sublytic C5b-9   ATF3   Gadd45 alpha   KLF6   PCNA  

摘要： The sublytic C5b-9 complexes can result in glomerular mesangial cells (GMCs) apoptosis, which involved in the initiation and development of rat Thy-1 nephritis. Activating transcription factor 3 (ATF3) is an immediate early gene for cells to cope with a variety of stress signals, and our previous study revealed that ATF3 could promote GMCs apoptosis attacked by sublytic C5b-9. But the mechanism of ATF3 promoting GMCs apoptosis triggered by sublytic C5b-9 attack has not been elucidated. In this study, the data showed that the expression of ATF3, growth arrest and DNA damage-45 alpha (Gadd45 alpha.), Kruppel-like factor 6 (KLF6) and proliferating cell nuclear antigen (PCNA) in the GMCs in response to sublytic C5b-9 stimulation for the indicated time was significantly increased, and ATF3 expression could lead to GMCs apoptosis through up-regulation of Gadd45 alpha and KLF6, but not up-regulation of PCNA. Furthermore, Gadd45 alpha was identified as a downstream target gene regulated by ATF3 directly, and KLF6 might be regulated by ATF3 in an indirect manner. Crown Copyright (C) 2011 Published by Elsevier GmbH. All rights reserved.

关键词： Chromatin Immunoprecipitation (ChIP)   NF-kB Transcription Factor   Transcription Regulation   Tumor Metastases   Tumor Suppressor   Molecular Mechanism Of Metastasis   Tumor Metastasis Diagnosis  

摘要： NDRG1 and KAI1 belong to metastasis suppressor genes, which impede the dissemination of tumor cells from primary tumors to distant organs. Previously, we identified the metastasis promoting transcription factor, ATF3, as a downstream target of NDRG1. Further analysis revealed that the KAI1 promoter contained a consensus binding motif of ATF3, suggesting a possibility that NDRG1 suppresses metastasis through inhibition of ATF3 expression followed by activation of the KAI1 gene. In this report, we found that ectopic expression of NDRG1 was able to augment endogenous KAI1 gene expression in prostate cancer cell lines, whereas silencing NDRG1 was accompanied with significant decrease in KAI1 expression in vitro and in vivo. In addition, our results of ChIP analysis indicate that ATF3 indeed bound to the promoter of the KAI1 gene. Importantly, our promoter-based analysis revealed that ATF3 modulated KAI1 transcription through cooperation with other endogenous transcription factor as co-activator (ATF3-JunB) or co-repressor (ATF3-NF kappa B). Moreover, loss of KAI1 expression significantly abrogated NDRG1-mediated metastatic suppression in vitro as well as in a spontaneous metastasis animal model, indicating that KAI1 is a functional downstream target of the NDRG1 pathway. Our result of immunohistochemical analysis showed that loss of NDRG1 and KAI1 occurs in parallel as prostate cancer progresses. We also found that a combined expression status of these two genes serves as a strong independent prognostic marker to predict metastasis-free survival of prostate cancer patients. Taken together, our result revealed a novel regulatory network of two metastasis suppressor genes, NDRG1 and KAI1, which together concerted metastasis-suppressive activities through an intrinsic transcriptional cascade.

关键词： ATF3 gene   Gene association study   Polymorphism   C reactive protein   Haplotype   Interaction  

摘要： Objective: ATF3 has traditionally been related to various inflammatory processes. Our aim was to test the statistical association between variations in the ATF3 gene and levels of nine serum inflammatory markers, including C reactive protein (CRP), in a Taiwanese population using interaction analysis. Methods: A sample population of 604 Taiwanese subjects was enrolled. Five tagging single nucleotide polymorphisms of the ATF3 gene from the Han Chinese HapMap Database were selected and genotyped. Results: With or without adjustment for clinical covariates, ATF3 genotypes were found to be associated with CRP levels but not with other inflammatory marker levels. Minor alleles of 2 of the 5 ATF3 SNPs were associated with decreased CRP levels predominantly in non-obese subjects (Bonferoni P = 0.018, and P = 0.002 for rs11571530, and rs10475, respectively). Two haplotypes inferred from the 5 SNPs, GATTA and TACCA, were also associated with increased or decreased CRP levels, respectively, in non-obese subjects (Bonferoni P = 0.012 and P = 0.01, respectively) but not in obese subjects. Interaction analysis revealed interaction of obesity with an ATF3 genotype associated with a high CRP level (interaction P = 0.006 for SNP rs10475). An effect of obesity on CRP level was also noted in haplotype interaction analysis (interaction P = 0.019 for haplotype TACCA). Conclusions: ATF3 polymorphisms are independently associated with CRP levels in Taiwanese subjects. Further, ATF3 genotypes/haplotypes interact with obesity to set CRP levels. These findings may have implications for the prediction of atherosclerotic disease. (C) 2011 Elsevier B.V. All rights reserved.

关键词： 转录激活因子3   糖皮质激素   邻苯二甲酸二丁酯   尿道下裂  

摘要： 目的利用糖皮质激素与邻苯二甲酸二丁酯（DBP）联合作用致大鼠尿道下裂，观察转录激活因子3（ATF3）在正常大鼠生殖结节（GT）与不同严重程度尿道下裂大鼠生殖结节中的差异表达，并探讨ATF3在尿道下裂发生中的作用机制。方法将sD孕鼠40只随机均分为4组，在妊娠14～18d（GD14～18）分别给予：A组：大豆油灌胃2ml／d；B组：地塞米松（DXM）O．1mg／（kg·d）皮下注射；c组：DBP700mg／（kg·d）灌胃；D组：DXM0．1mg／（kg·d）皮下注射加DBP700mg／（kg·d）灌胃。GDl9将各组孕鼠处死剖腹统计雄性仔鼠出生体质量（BW）及肛门生殖器间距离（AGD），取雄性仔鼠生殖结节，运用免疫印迹法和免疫组织化学方法分析ATF3的表达。结果DXM单独作用于孕鼠仅表现为仔鼠BW下降，但与DBP组合作用却能显著增强DBP的致畸作用，导致雄性仔鼠BW及AGD／BW明显减少。ATF3在A组的蛋白相对表达量为0．351±0．012，B组为0．336±0．015，C组为0．603±0．014，D组为0．851±0．016，C组或D组与A组，以及C组与D组之间的差异均有统计学意义（P〈0．05）；免疫组织化学结果显示ATF3主要定位于生殖结节的尿道上皮和侧翼间质，C组和D组免疫组织化学染色强度明显强于A组，而D组染色强于C组。结论DXM联合DBP进一步增强了DBP的致畸作用，提示尿道下裂的发生是环境中多因素协同作用的结果，ATF3在对照组与实验组生殖结节中的表达有明显变化，且随着尿道下裂程度的加重而表达增高，ATF3的高表达影响了生殖结节的发育及尿生殖褶的融合，这可能是尿道下裂发生的机制之一。

关键词： Angiotensin II   Nrf2   ATF3   TCMK-1   Fibrosis  

摘要： Angiotensin II (ATII), a physiologically active mediator of the renin-angiotensin system, has been shown to be associated with renal fibrosis pathophysiology. In our current study with murine renal epithelial TCMK-1 cells, ATII inhibited the expression of NF-E2-related factor 2 (Nrf2)-target antioxidant genes such as NAD(P)H: quinone oxidoreductase-1 and gamma-glutamate cysteine ligase (GCL). In accord to the reduced expression of GCL, a GSH biosynthesis enzyme, ATII treatment reduced intracellular GSH content and increased the levels of reactive oxygen species (ROS). While, there was no significant changes in nuclear protein levels of Nrf2 following ATII treatment, implying the potential alterations in the expression of partner proteins of Nrf2. Our measurement of Nrf2 partner bZIP transcription factors, including Bach1, small Maf proteins, and activating transcription factor 3 (ATF3) showed that the expression level for ATF3 was enhanced in ATII-treated TCMK cells. Presumably through ATII-induced oxidative stress, ATII treatment was found to enhance the inducible level of TGF beta-mediated alpha-smooth muscle actin (alpha-SMA) expression, which is one of molecular markers of renal fibrosis. In conclusion, our results indicate that ATII suppresses Nrf2-GSH signaling in murine renal epithelial cells. Elevated ROS levels in ATII exposed epithelial cells might be a causing factor contributing to renal fibrosis pathology.

关键词： Epigenetic therapy   kidney injury   ATF3   deacetylation  

摘要： The incidence of mortality in acute renal failure (ARF) induced by ischemia-reperfusion (I/R) injury or septic shock is high. Previous studies using animal models of ARF reported that inflammation-induced macrophage recruitment in endothelial cells, along with I/R-induced production of inflammatory cytokines and chemokines in tubule epithelial cells, results in macrophage and neutrophil accumulation, and that both ultimately lead to irreversible kidney injury. Recent studies suggest that ARF may also induce a beneficial stress response program and express many transcriptional regulators, including activating transcription factor 3 (ATF3). ATF3 is a member of the ATF/CREB subfamily of the basic-region leucine zipper (bZIP) family. Recent research has shed new light on the protective role of the ATF3 signaling pathway in attenuating inflammation and I/R-induced tubular cell death and nephrotoxicity. A recent clinical study also reported that ATF3 can serve as an indicator of acute kidney injury (AKI). AKI is associated with a robust inflammatory effect with increased levels of cytokines, including IL-6, IL-12, and IFN gamma. By inhibiting these cytokines, the ATF3 molecule may hold the potential to provide future epigenetic therapy against inflammation-induced renal injury.