关键词： 尿道下裂   ATF3   包皮  

摘要： 目的:检测散发性单纯性尿道下裂患者包皮组织中激活转录因子3(Activating transcription factor 3,ATF3)的表达情况,探索ATF3与散发性单纯性尿道下裂之间的关系。方法:1、标本收集:实验组标本为散发性单纯性尿道下裂患者在尿道成形术中的多余的包皮组织(共35例,其中轻度10例,中度15例,重度10例),对照组标本为单纯包皮过长(包括包茎)患者在包皮环切术中去除的多余的包皮组织(共20例)。2、通过反转录聚合酶链反应(RT-PCR)方法检测实验组和对照组ATF3mRNA的表达情况。3、通过免疫组织化学方法检测实验组和对照组ATF3蛋白的表达情况。4、统计学处理:实验过程中采集的数据均进行了严格检查,重复测量对偏出均值3个标准差的数据进行删除。采用SPSS12.0统计学软件进行数据录入,构建数据库。计数资料使用(均值±标准差)的形式表示,计量资料之间的比较采用F/t检验。计数资料用阳性例数或阳性率(%)表示,阳性率之间的比较用卡方检验。检验水准α取值0.05,检验概率为双侧概率。结果:通过RT-PCR方法测得散发性单纯性尿道下裂患者包皮组织中ATF3 mRNA的相对表达量为:0.54±0.06,对照组的包皮组织中ATF3 mRNA的相对表达量为:0.44±0.07,从结果中可以得出在散发性单纯性尿道下裂患者的包皮组织中ATF3的表达情况比正常的包皮组织中明显增加,两组结果比较(t=5.89,P=0.00),差异有统计学意义。比较不同严重程度中尿道下裂患者ATF3mRNA相对表达量,不同严重程度相对表达量差异并不显著(F=0.13,P=0.88)。通过免疫组织化学方法测得ATF3蛋白在散发的单纯性尿道下裂中的阳性表达率为:85.7%(30/35),对照组中阳性率为:15.0%(3/20),两组人群比较,ATF3蛋白阳性表达率差异显著(χ2=7.95,P=0.01),具有统计学意义。比较不同严重程度中尿道下裂患者免疫组化检测ATF3蛋白阳性表达率情况发现,不同严重患者ATF3蛋白阳性表达率呈现递增关系,但是统计学分析差异不明显(χ2=0.65,P=0.72)。结论:在散发性单纯性尿道下裂患者的包皮组织中ATF3的表达比单纯包皮过长(包括包茎)患者的包皮组织中明显增多,提示ATF3和散发性单纯性尿道下裂存在着密切的关系。为将来研究ATF3在尿道下裂中产生的相关信号转导通路提供相关实验基础,及研究尿道下裂的发病机制提供理论依据。

关键词： Activating Transcription Factor 3/biosynthesis   Active Transport, Cell Nucleus   Animals   Aorta/metabolism   Apoptosis   Caspase 3/metabolism   Cells, Cultured   Endothelial Cells/metabolism   Humans   Lipolysis   Lipoproteins/genetics   Lipoproteins/metabolism   Mice   Phosphorylation   Receptors, Transforming Growth Factor beta/metabolism   RNA, Messenger/genetics   RNA, Messenger/metabolism   Signal Transduction   Smad2 Protein/metabolism   Smad4 Protein/metabolism   Stress, Physiological   Transforming Growth Factor beta1/metabolism   Triglycerides/genetics   Triglycerides/metabolism   Tumor Suppressor Protein p53/metabolism  

摘要： Studies have suggested a link between the transforming growth factor beta 1 (TGF-beta 1) signaling cascade and the stress-inducible activating transcription factor 3 (ATF3). We have demonstrated that triglyceride-rich lipoproteins (TGRL) lipolysis products activate MAP kinase stress associated JNK/c-Jun pathways resulting in up-regulation of ATF3, pro-inflammatory genes and induction of apoptosis in human aortic endothelial cells. Here we demonstrate increased release of active TGF-beta at 15 min, phosphorylation of Smad2 and translocation of co-Smad4 from cytosol to nucleus after a 1.5 h treatment with lipolysis products. Activation and translocation of Smad2 and 4 was blocked by addition of SB431542 (10 mu M), a specific inhibitor of TGF-beta-activin receptor ALKs 4, 5, 7. Both ALK receptor inhibition and anti TGF-beta 1 antibody prevented lipolysis product induced up-regulation of ATF3 mRNA and protein. ALK inhibition prevented lipolysis product-induced nuclear accumulation of ATF3. ALKs 4, 5, 7 inhibition also prevented phosphorylation of c-Jun and TGRL lipolysis product-induced p53 and caspase-3 protein expression. These findings demonstrate that TGRL lipolysis products cause release of active TGF-beta and lipolysis product-induced apoptosis is dependent on TGF-beta signaling. Furthermore, signaling through the stress associated JNK/c-Jun pathway is dependent on TGF-beta signaling suggesting that TGF-beta signaling is necessary for nuclear accumulation of the ATF3/cJun transcription complex and induction of pro-inflammatory responses.

关键词： VENTRICULAR remodeling   HEART cells   MACROPHAGES   CARDIAC hypertrophy   PHENYLEPHRINE (Drug)   GENE expression  

关键词： VENTRICULAR remodeling   MACROPHAGES   MANUSCRIPTS   PHENYLEPHRINE (Drug)   CARDIAC hypertrophy   MICE as laboratory animals  

关键词： Macrophage activation   PHYSIOLOGY   Transcription factors -- Physiological aspects   Interleukin receptors -- Therapeutic use   Interleukins -- Therapeutic use   Macrophages  

摘要： Cytokines and IFNs downstream of innate immune pathways are critical for mounting an appropriate immune response to microbial infection. However, the expression of these inflammatory mediators is tightly regulated, as uncontrolled production can result in tissue damage and lead to chronic inflammatory conditions and autoimmune diseases. Activating transcription factor 3 (ATF3) is an important transcriptional modulator that limits the inflammatory response by controlling the expression of a number of cytokines and chemokines. However, its role in modulating IFN responses remains poorly defined. In this study, we demonstrate that ATF3 expression in macrophages is necessary for governing basal IFN-beta expression, as well as the magnitude of IFN-beta cytokine production following activation of innate immune receptors. We found that ATF3 acted as a transcriptional repressor and regulated IFN-beta via direct binding to a previously unidentified specific regulatory site distal to the Ifnb1 promoter. Additionally, we observed that ATF3 itself is a type I IFN-inducible gene, and that ATF3 further modulates the expression of a subset of inflammatory genes downstream of IFN signaling, suggesting it constitutes a key component of an IFN negative feedback loop. Consistent with this, macrophages deficient in Atf3 showed enhanced viral clearance in lymphocytic choriomeningitis virus and vesicular stomatitis virus infection models. Our study therefore demonstrates an important role for ATF3 in modulating IFN responses in macrophages by controlling basal and inducible levels of IFN beta, as well as the expression of genes downstream of IFN signaling.

关键词： Pressure overload   Cardiac remodeling   Macrophages   Bone marrow transplantation   Cardiac hypertrophy  

摘要： Rationale: Pressure overload induces adaptive remodeling processes in the heart. However, when pressure overload persists, adaptive changes turn into maladaptive alterations leading to cardiac hypertrophy and heart failure. ATF3 is a stress inducible transcription factor that is transiently expressed following neuroendocrine stimulation. However, its role in chronic pressure overload dependent cardiac hypertrophy is currently unknown. Objective: The objective of the study was to study the role of ATF3 in chronic pressure overload dependent cardiac remodeling processes. Methods and results: Pressure overload was induced by phenylephrine (PE) mini-osmotic pumps in various mice models of whole body, cardiac specific, bone marrow (BM) specific and macrophage specific ATF3 ablations. We show that ATF3-KO mice exhibit a significantly reduced expression of cardiac remodeling markers following chronic pressure overload. Consistently, the lack of ATF3 specifically in either cardiomyocytes or BM derived cells blunts the hypertrophic response to PE infusion. A unique cross-talk between cardiomyocytes and macrophages was identified. Cardiomyocytes induce an ATF3 dependent induction of an inflammatory response leading to macrophage recruitment to the heart. Adoptive transfer of wild type macrophages, but not ATF3-KO derived macrophages, into wild type mice potentiates maladaptive response to PE infusion. Conclusions: Collectively, this study places ATF3 as a key regulator in promoting pressure overload induced cardiac hypertrophy through a cross-talk between cardiomyocytes and macrophages. Inhibiting this cross-talk may serve as a useful approach to blunt maladaptive remodeling processes in the heart. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

关键词： Chaetocin   SUV39H1   CHOP   ATF3   DR5   Apoptosis  

摘要： Epigenetic abnormalities are associated with non-small cell lung cancer (NSCLC) initiation and progression. Epigenetic drugs are being studied and in clinical trials. However, the molecular mechanism underlying the apoptosis by the epigenetic agents remains unclear. SUV39H1 is an important methyl-transferase for lysine 9 on histone H3 and usually related to gene transcriptional suppression, and chaetocin acts as the inhibitor of SUV39H1. We demonstrated here that chaetocin effectively suppressed the growth of multiple lung cancer cells through inducing apoptosis in a death receptor 5 (DR5)-dependent manner. Chaetocin treatment activated endoplasmic reticulum (ER) stress which gave rise to the up-regulation of ATF3 and CHOP. Furthermore, ATF3 and CHOP contributed to the induction of DR5 and subsequent apoptosis. When SUV39H1 was silenced with siRNA, the expression of ATF3, CHOP and DR5 was elevated. Thereafter, knockdown of SUV39H1 induced apoptosis in NSCLC cells. In summary, chaetocin pharmacologically inhibits the activity of SUV39H1 which provokes ER stress and results in up-regulation of ATF3 and CHOP, leading to DR5-dependent apoptosis eventually. These findings provide a novel interpretation on the anti-neoplastic activity of epigenetic drugs as a new therapeutic approach in NSCLC.

关键词： Leukemia   Molt4   ER stress   Apoptosis   Gene expression  

摘要： In this study, we demonstrate that treatment of T lymphoblastic leukemic Molt4 cells with farnesol activates the apoptosome via the intrinsic pathway of apoptosis. This induction was associated with changes in the level of intracellular potassium and calcium, the dissipation of the mitochondria] and plasma membrane potential, release of cytochrome c, activation of several caspases, and PARP cleavage. The induction of apoptosis by farnesol was inhibited by the addition of the pan-caspase inhibitor Z-VAD-fmk and by the exogenous expression of the anti-apoptotic protein Bcl2. Analysis of the gene expression profiles by microarray analysis revealed that farnesol increased the expression of several genes related to the unfolded protein response (UPR), including CHOP and CHAC1. This induction was associated with the activation of the PERK-eIF2 alpha-ATF3/4 cascade, but not the XBP-1 branch of the UPR. Although farnesol induced activation of the ERK1/2, p38, and JNK pathways, inhibition of these MAPKs had little effect on farnesol-induced apoptosis or the induction of UPR-related genes. Our data indicate that the induction of apoptosis in leukemic cells by farnesol is mediated through a pathway that involves activation of the apoptosome via the intrinsic pathway and induction of the PERK-eIF2 alpha-ATF3/4 cascade in a manner that is independent of the farnesol-induced activation of MAPKs. Published by Elsevier Inc.

关键词： TRANSCRIPTION factors   PROSTATE cancer research   CELL proliferation   PROTEIN-protein interactions   MICE as laboratory animals   GENE expression  

摘要： Activating transcription factor 3 (ATF3) responds to diverse cellular stresses, and regulates oncogenic activities (for example, proliferation, survival and migration) through direct transcriptional regulation or protein-protein interactions. Although aberrant ATF3 expression is frequently found in human cancers, the role of ATF3 in tumorigenesis is poorly understood. Here, we demonstrate that ATF3 suppresses the development of prostate cancer induced by knockout of the tumor suppressor Pten in mouse prostates. Whereas the oncogenic stress elicited by Pten loss induced ATF3 expression in prostate epithelium, we found that ATF3 deficiency increased cell proliferation and promoted cell survival, leading to early onset of mouse prostatic intraepithelial neoplasia and the progression of prostate lesions to invasive adenocarcinoma. Importantly, the loss of ATF3 promoted activation of the oncogenic AKT signaling evidenced by high levels of phosphorylated AKT and S6 proteins in ATF3-null prostate lesions. In line with these in vivo results, knockdown of ATF3 expression in human prostate cancer cells by single guided RNA-mediated targeting activated AKT and increased matrix metalloproteinase-9 expression. Our results thus link ATF3 to the AKT signaling, and suggest that ATF3 is a tumor suppressor for the major subset of prostate cancers harboring dysfunctional Pten.