关键词： 人参   大黄芪汤   肺癌   ATF3   B7-H3  

摘要： 目的:研究大黄芪汤抑制化疗所致lewis肿瘤肺转移的作用及机制。方法:40只C57BL/6小鼠随机分为对照组、中药组、化疗组、联合中药组,每组各10只。对照组单予生理盐水腹腔注射,中药组用生理盐水腹腔注射联合大黄芪汤灌胃,化疗组小鼠予顺铂腹腔注射,联合中药组予顺铂腹腔注射联合大黄芪汤灌胃。化疗末次后4 d,对所有小鼠尾静脉注射lewis细胞。20 d后检测小鼠肺内转移病灶数、瘤重,并分析瘤周肺组织ATF3、瘤体B7-H3表达。结果:1.肺内转移病灶数:对照组、中药组、化疗组、联合中药组、分别为4.7、4.9、7.6、5.5个,化疗组与其余三组分别比较显著升高,P<0.01。2.瘤重:对照组、中药组、化疗组、联合中药组分别为1.41、1.47、1.92、1.43g,化疗组与其余三组分别比较显著升高,P<0.01。3.瘤周正常肺组织ATF3、瘤体B7-H3表达:化疗组均高于对照组,联合中药后其表达均降低。结论:大黄芪汤可以抑制化疗所致的lewis肿瘤肺转移,其机制可能与其降低正常肺组织ATF3及肿瘤组织B7-H3表达有关。

关键词： Cloning   Cell polarity   Eyes   Drosophila melanogaster   Cell differentiation   Imaginal discs   Gene expression   Mutant genotypes  

摘要： Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or DIg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from DIg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity.

关键词： Atf3   D3R   Methamphetamine   Pde4b   Sensitization  

摘要： The role of the D3 dopamine receptor (D3R) and the specific molecular mechanisms underlying the regulation of D3R via the CAMP signaling pathway in methamphetamine (METH) addiction are still unclear. Here, we measured changes in Pde4b and Atf3 in the cAMP signaling pathway of dopaminergic system components, including the nucleus accumbens (NAc), caudate putamen (CPu) and hippocampus (Hip), in D3R knockout mice(D3R-/-) 1 h and 24 h after METH-induced behavioral sensitization. We found that knocking out D3R attenuated METH induced behavioral sensitization, and Pde4b and Atf3 exhibited different expression patterns in brain regions in response to METH. Knocking out D3R suppressed the METH-induced increase in Pde4b in the Hip of mice 24 h after the final METH injection and augmented the METH-induced increase in Atf3 in the CPu of mice 1 h after the final METH injection. Our study suggests that D3R knockout controls METH-induced behavioral sensitization via regulation of Pde4b and Atf3 in different brain regions. Furthermore, the responses of Pde4b and Atf3 to METH exposure depend on the specific region of the brain involved.

关键词： Indoxyl sulfate   Cannabinoid type 1 receptor   ATF3   C-Jun   Oxidative stress   Uremic cardiomyopathy  

摘要： Background: The risk of cardiovascular disease is notably increased in patients with chronic kidney disease (CKD) and cannabinoid receptor type 1 (CB1R) plays an important role in the development of uremic cardiomyopathy. However, the molecular mechanism underlying the uremic toxin-induced upregulation of CBI R remains elusive. Methods: The expression of the ATF3/c-Jun complex and CB1R in both in vivo and in vitro models of CKD were measured. We also determined the impact of the ATF3/c-Jun complex on CB1R expression by transfecting H9c2 cells with dominant negative mutants of ATF3 or c-Jun. Inhibitors of organic anion transport, specific MAPK pathways and oxidative DNA damage were also used to assess the pathways mediating the effects of indoxyl sulfate (IS). Results: CB1R upregulation was associated with increased ATF3 expression and c-Jun phosphorylation in CKD both in vivo and in vitro. Expression of dominant-negative ATF3 or c-Jun mutants in IS-treated cells significantly reduced CB1R mRNA levels. Moreover, Co-IP revealed that the ATF3/c-Jun complex is formed and ChIP confirmed its binding to the CB1R promoter, suggesting that this complex directly stimulates CB1R transcription in CKD. Blocking the cellular entry of IS using an organic anion transport inhibitor, as well as inhibiting the ERK1/2 and/or JNK pathways, abrogated the effects of IS on CB1R, ATF3, and c Jun expression. The IS-induced reactive oxygen species (ROS) was observed in the mitochondria. Conclusions: We demonstrate that uremic toxins induce ATF3/c-Jun complex-mediated CBIR expression both in vivo and in vitro, possibly by modulating the ERK1/2 and JNK signaling pathways and ROS. (C) 2017 Elsevier B.V. All rights reserved.

关键词： liver   ATF4 transcription   histone modification   AAR   UPR  

摘要： Activating transcription factor 3 (ATF3) is a highly regulated protein that is implicated in a wide range of pathological conditions including inflammation and transformation. Transcription from the ATF3 gene is induced by several stress-induced signaling pathways, including amino acid limitation (amino acid response, AAR) and ER stress (unfolded protein response, UPR). Induction of ATF3 transcription by these pathways is mediated by ATF4 and cJUN recruitment to enhancer elements within the ATF3 gene. Although a canonical promoter (promoter A) has been studied by numerous laboratories, a second promoter activity (promoter Al), 43 kb upstream of the first, has been reported to respond to stress-induced signaling and to be critical for ATF3 expression in certain transformed cells. The results of the present study show that in normal human hepatocytes and HepG2 human hepatoma cells both basal as well as AAR- and UPR-induced transcription occurs almost exclusively from promoter A. This selectivity between the two promoters correlated with increased binding of ATF4, recruitment of RNA polymerase II, and the expected histone modifications in the promoter A region of the gene. Time course studies of ATF3 transcription activity revealed that the temporal kinetics for ATF3 induction differ between the AAR and UPR, with the former being more transient than the latter. Collectively, the results document that ATF3 expression in normal and transformed human liver originates from the canonical promoter A that responds to multiple stress signals.

摘要： 623

关键词： Anticancer   ATF3   Cinnamomum cassia   Cyclin D1   Human colorectal cancer   NF-kappa B   ROS   Twigs of Cinnamomum cassia  

摘要： Background: Because twigs of Cinnamomum cassia (TC) have been reported to exert anti-cancer activity, the mechanistic study for TC's anti-cancer activity is required. Thus, we elucidated the potential molecular mechanism of TC's anti-proliferative effect and the induction of apoptosis in human colorectal cancer cells. Methods: How water extracts form TC (TC-HW) was used in this study. Anti-cell proliferative effect of TC-HW was evaluated by MTT assay. The change of protein or mRNA level by TC-HW was evaluated by Western blot and RT-RCR, respectively. The promoter construct for ATF3, NF-kappa B, TOP-FLASH or FOP-FLASH was used for the investigation of the transcriptional activity for ATF3, NF-kappa B or Wnt. siRNA for ATF3 or p65 was used for the knockdown of ATF3 and p65. Results: TC-HW reduced the cell viability in human colorectal cancer cells. TC-HW decreased cyclin D1 protein level through cyclin D1 degradation via GSK3 beta-dependent threonine-286 (T286) phosphorylation of cyclin D1, indicating that cyclin D1 degradation may contribute to TC-HW-mediated decrease of cyclin D1 protein level. TC-HW downregulated the expression of cyclin D1 mRNA level and inhibited Wnt activation through the downregulation of beta-catenin and TCF4 expression, indicating that inhibition of cyclin D1 transcription may also result in TC-HW-mediated decrease of cyclin D1 protein level. In addition, TC-HW was observed to induce apoptosis through ROS-dependent DNA damage. TC-HWinduced ROS increased NF-kappa B and ATF3 activation, and inhibition of NF-kappa B and ATF3 activation attenuated TC- HWmediated apoptosis. Conclusions: Our results suggest that TC-HW may suppress cell proliferation through the downregulation of cyclin D1 via proteasomal degradation and transcriptional inhibition, and may induce apoptosis through ROSdependent NF-kappa B and ATF3 activation. These effects of TC-HW may contribute to the reduction of cell viability in human colorectal cancer cells. From these findings

关键词： Silica   Silicosis   Inflammation   ATF3   RNA-Seq  

摘要： Background: Millions of workers are exposed to dust containing silica. Chronic and over-exposure to silica will lead to silicosis, which is an irreversible and sometimes fatal lung disease. The disordered physiological processes of silicosis consist of accumulation of silica particles in the alveoli of the lung. Then, the ingestion of the silica particles by macrophages was followed by an inflammatory response. Up till now, the chest radiographs remain the key tool in diagnosing and assessing the extent of silicosis. However, concerns exist regarding the sensitivity and specificity of the technique. Therefore, there is still a need to develop a biomarker for silicosis for early detection of silicosis. Method: In this study, RNA-Seq was applied to detect the gene expression changes when silica was exposed to macrophages at different time intervals. RNA-Seq provides a broader dynamic range, increased specificity and sensitivity, and easier detection of rare and low-abundance transcripts. Bioinformatics tools such as the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Gene Functional Classification Tool and Search Tool for the Retrieval of Interacting Genes (STRING) were applied for data analysis. Quantitative PCR was used to validate the results. Results: Our results showed that regulation of transcription factors was the dominant activated pathway in early exposure of silica to macrophages, followed by inflammatory responses which were the main mechanisms in silicosis. One of the findings was the upregulation of activating transcription factor 3 (ATF3) during silica exposure. When ATF3 expression was inhibited by siRNA, the production of cytokines IL-1 beta, IL-6 and TNF was further increased. Conclusion: This indicated that ATF3 may be a potential early diagnostic biomarker for silicosis and ATF3 acts as a repressor in inflammatory responses induced by silica.

摘要： Mice lacking genes involving in the DNA-damage response (DDR) are often tumor prone owing to genome instability caused by oncogenic challenges. Previous studies demonstrate that activating transcription factor 3 (ATF3), a common stress sensor, can activate the tumor suppressor p53 and regulate expression of p53 target genes upon DNA damage. However, whether ATF3 contributes to the maintenance of genome stability and tumor suppression remains unknown. Here we report that Atf3-deficient (Atf3(-/-)) mice developed spontaneous tumors, and died significantly earlier than wild-type (Atf3(+/+)) mice. Consistent with these results, Atf3(-/-) mouse embryonic fibroblasts (MEFs) had more aberrant chromosomes and micronuclei, and were genetically unstable. Whereas we demonstrated that ATF3 activated p53 and promoted its pro-apoptotic activity in mouse thymi and small intestines, the chromosomal instability caused by Atf3 deficiency was largely dependent on the regulation of p53 by ATF3. Interestingly, loss of Atf3 also promoted spontaneous tumorigenesis in Trp53(+/-) mice, but did not affect tumor formation in Trp53(-/-) mice. Our results thus provide the first genetic evidence linking ATF3 to the suppression of the early development of cancer, and underscore the importance of ATF3 in the maintenance of genome integrity.

关键词： 结肠癌   ATF3基因   Wnt/β-catenin信号通路   上皮-间质转化  

摘要： 目的激活转录因子3(activating transcription factor 3,ATF3)是转录因子ATF/CREB(cyclic AMP-responsive element binding protein)家族中的一员,在正常细胞中表达低,但是通过信号刺激可以诱导其短时间快速表达发挥作用。本研究旨在探讨ATF3在结肠癌中的表达及临床病理特征相关性,揭示ATF3过表达对结肠癌HCT116细胞Wnt/β-catenin信号通路和EMT的影响。方法利用免疫组化法分析ATF3在结肠癌组织中的表达及其临床病理特征相关性。分别向HCT116细胞转染空载和ATF3过表达质粒:采用细胞增殖检测试剂盒8(cell counting kit 8,CCK8)法检测ATF3对细胞增殖的影响;利用划痕实验观察ATF3对细胞迁移的影响;采用蛋白质印迹法检测ATF3过表达对Wnt/β-catenin信号通路和EMT过程中蛋白的影响。结果 ATF3在正常结肠黏膜上皮中高表达,在癌组织及转移癌中低表达,χ~2=27.2,P<0.001。细胞实验显示,转染前两组细胞增殖差异无统计学意义,t=0.60,P=0.566;与对照组相比,观察组48h的吸光度值降低,t=4.21,P=0.003。转染质粒48h观察组划痕愈合速度变慢;转染48h观察组ATF3蛋白表达量明显多于对照组;观察组β-catenin、c-myc、Cyclin D1、TCF7L2和N-cadherin蛋白表达减少,GSK-3β和E-cadherin增多。结论 ATF3过表达可以抑制结肠癌细胞的增殖和迁移;ATF3过表达可以抑制Wnt/β-catenin信号通路和上皮-间质转化,抑制结肠癌的发生及转移;ATF3可能在结肠癌的发生发展起着重要的作用。