关键词： SGK1   Radiotherapy   Locally advanced rectal cancer   ATF3   Neoadjuvant chemoradiotherapy  

摘要： Radiotherapy (RT) is a key component of neoadjuvant chemoradiotherapy to treat locally advanced rectal cancer (LARC). However, the therapeutic effect is limited due to radioresistance. Investigating the biomarkers of radioresistance might assist in the development of more effective therapeutic strategies for LARC. In this study, we investigated the different gene expressions in tumor samples from 110 patients using transcriptome analysis and immunohistochemistry (IHC), and identified serum- and glucocorticoid-regulated kinase 1 (SGK1) as a modulator of LARC radioresistance. We evaluated the impact of genetic and pharmacologic inhibition of the gene associated with radioresistance in vitro and in vivo. We found that the expression of SGK1 was upregulated in non-pathological complete response (non-pCR) patients. A high SGK1 expression was associated with radioresistance, whereas the genetic or pharmacologic inhibition of SGK1 expression reduced the radioresistance. We found that activate transcription factor 3 (ATF3) is a regulator of SGK1 in radioresistance. In conclusion, our findings indicate that SGK1 is a key player in LARC radioresistance, and drives radioresistance in an ATF3 dependent manner, which provides insights for future radio-sensitizer design.

关键词： endometriosis   P2X3   pain   ATF3   ATP  

摘要： STUDY QUESTION: Does P2X ligand-gated ion channel 3 (P2X3) play a role in endometriosis pain? SUMMARY ANSWER: Upregulation of P2X3 in dorsal root ganglia (DRG) tissues via the activating transcription factor 3 (ATF3)/activator protein (AP)-1 pathway contributed to endometriosis-associated hyperalgesia, which could be attenuated by the chitosan oligosaccharide stearic acid (CSOSA)/liposomes (LPs)/SP600125 delivery system. WHAT IS KNOWN ALREADY: Infiltrating nerve fibers and elevated nociceptors in endometriotic lesions are associated with endometriosis pain. P2X3 has been demonstrated to play an important role in neuropathic pain. STUDY DESIGN, SIZE, DURATION: A rat model of endometriosis was used to investigate the signaling pathways involved in P2X3-induced pain. PARTICIPANTS/MATERIALS, SETTING, METHODS: Degrees of hyperalgesia, endogenous adenosine 5'-triphosphate (ATP) contents and P2X3 expression levels in endometriotic lesions and DRG tissues were detected in a rat model of endometriosis. The expression levels of ATF3 and P2X3 were measured using qRT-PCR, western blot analysis and immunofluorescence analysis after adenosine 5'-diphosphate (ADP) exposure in DRG cells. Plasmids encoding ATF3 and its siRNA were used to investigate the role of ATF3 on ADP-induced P2X3 upregulation. The activity of ATF binding to the P2X3 promoter was evaluated by using chromatin immunoprecipitation (CHIP) and luciferase assays. SP600125, an inhibitor of c-JUN N-terminal kinase, was wrapped in CSOSA/LPs delivery system and its inhibitory effects on ADP-induced upregulation of P2X3 in DRG cells and endometriosis-induced hyperalgesia in rats were tested. MAIN RESULTS AND THE ROLE OF CHANCE: The concentrations of endogenous ATP and expression levels of P2X3 were significantly increased in both endometriotic lesions and DRG tissues in endometriosis rat models and were found to be positively correlated with the severity of hyperalgesia. In DRG cells, P2X3 expression levels were elevated

关键词： ATF3   CCL2   IL-6   neuroinflammation   spared nerve injury  

摘要： Neuron-immune interaction in the dorsal root ganglia (DRG) plays a pivotal role in the neuropathic pain development after nerve injury. Sigma-1 receptor (Sig-1R) is expressed by DRG neurons but its role in neuropathic pain is not fully understood. We investigated the effect of peripheral Sig-1R on neuroinflammation in the DRG after spared (sciatic) nerve injury (SNI) in mice. Nerve injury induced a decrease in NeuN staining along with the nuclear eccentricity and ATF3 expression in the injured DRG. Sig-1R was present in all DRG neurons examined, and after SNI this receptor translocated to the periphery of the soma and the vicinity of the nucleus, especially in injured ATF3 + neurons. In WT mice, injured DRG produced the chemokine CCL2, and this was followed by massive infiltration of macrophages/monocytes, which clustered mainly around sensory neurons with translocated Sig-1R, accompanied by robust IL-6 increase and mechanical allodynia. In contrast, Sig-1R knockout (Sig-1R-KO) mice showed reduced levels of CCL2, decreased macrophage/monocyte infiltration into DRG, and less IL-6 and neuropathic mechanical allodynia after SNI. Our findings point to an important role of peripheral Sig-1R in sensory neuron-macrophage/monocyte communication in the DRG after peripheral nerve injury;thus, these receptors may contribute to the neuropathic pain phenotype.

关键词： adenosine A1 receptor   PD-L1/PD-1   cAMP-dependent transcription factor 3   melanoma   immunotherapy   non-small cell lung cancer   immune checkpoint   adenosine signaling   combination therapy   tumor microenvironment  

摘要： Here, we show that tumor ADORA1 deletion suppresses cell growth in human melanoma cell lines in vitro and tumor development in vivo in immune-deficient xenografts. However, this deletion induces the upregulation of PD-L1 levels, which inactivates cocultured T cells in vitro, compromises anti-tumor immunity in vivo, and reduces anti-tumor efficacy in an immune-competent mouse model. Functionally, PD-1 mAb treatment enhances the efficacy of ADORA1-deficient or ADORA1 antagonist-treated melanoma and NSCLC immune-competent mouse models. Mechanistically, we identify ATF3 as the factor transcriptionally upregulating PD-L1 expression. Tumor ATF3 deletion improves the effect of ADORA1 antagonist treatment of melanoma and NSCLC xenografts. We observe higher ADORA1, lower ATF3, and lower PD-L1 expression levels in tumor tissues from nonresponders among PD-1 mAb-treated NSCLC patients.

关键词： ATF3   动脉粥样硬化   心肌缺血再灌注损伤   心肌肥厚   心衰  

摘要： 心血管疾病患病率逐年升高,占中国居民死亡原因的首位。其中,心肌缺血、心肌肥厚及心衰是导致患者死亡的主要原因。研究发现,转录激活因子3(activating transcription factor 3, ATF3)同时在动脉粥样硬化(atherosclerosis, AS)、心肌缺血再灌注损伤(myocardial ischemia reperfusion injury,MIRI)、心肌肥厚及心衰(heart failure, HF)的发生发展中均有重要调控作用。本文对ATF3在这四者中发挥的作用进行了综述,旨在为ATF3作为一个新的心血管疾病治疗靶点提供理论依据。

关键词： 延边黄牛   ATF3基因   组织表达谱   多态性   肉质性状  

摘要： 本研究旨在分析转录激活因子3(activating transcription factor 3,ATF3)基因在延边黄牛各组织中的表达差异及其多态性与肉质性状的相关性。以70头30月龄的健康延边黄牛为研究对象,用实时荧光定量PCR比较ATF 3基因在延边黄牛心脏、肝脏、脾脏、肺脏、肾脏、后腿肌、眼肌、西冷、上脑和皮下脂肪10个部位的表达水平差异;进一步对ATF 3基因的第4外显子进行PCR扩增,通过Sanger直接测序筛选出SNPs位点,用PCR-RFLP对筛选出的SNPs进行酶切验证,并与肉质性状进行关联分析。结果发现,ATF 3基因在延边黄牛10个组织中均有表达,其中在皮下脂肪组织中表达量极显著高于其他组织(P<0.01);西冷中ATF 3基因相对表达量与肌内脂肪(IMF)含量呈极显著正相关(P<0.01),相关系数为0.996;眼肌中ATF 3基因表达量与IMF含量呈显著正相关(P<0.05),相关系数为0.999;上脑和后腿肌中ATF 3基因表达量与IMF含量无显著相关(P>0.05),相关系数分别为0.757和0.658。ATF 3基因1428 bp处存在G→C突变,存在3种基因型:GG、GC、CC,其中GC和CC基因型的脂肪含量、背膘厚均显著高于GG基因型(P<0.05);大理石花纹等级极显著优于GG基因型(P<0.01)。说明该突变位点可作为延边黄牛肉质性状潜在的分子标记,ATF 3基因可能是影响延边黄牛脂肪沉积的候选基因。

关键词： albuminuria   ATF3   CKD   ER stress   Klotho  

摘要： Proteinuria is associated with renal function decline and cardiovascular mortality. This association may be attributed in part to alterations of Klotho expression induced by albuminuria, yet the underlying mechanisms are unclear. The presence of albumin decreased Klotho expression in the POD-ATTAC mouse model of proteinuric kidney disease as well as in kidney epithelial cell lines. This downregulation was related to both decreased Klotho transcription and diminished protein half-life, whereas cleavage by ADAM proteases was not modified. The regulation was albumin specific since it was neither observed in the analbuminemic Col4 alpha 3(-/-) Alport mice nor induced by exposure of kidney epithelial cells to purified immunoglobulins. Albumin induced features of ER stress in renal tubular cells with ATF3/ATF4 activation. ATF3 and ATF4 induction downregulated Klotho through altered transcription mediated by their binding on the Klotho promoter. Inhibiting ER stress with 4-PBA decreased the effect of albumin on Klotho protein levels without altering mRNA levels, thus mainly abrogating the increased protein degradation. Taken together, albuminuria decreases Klotho expression through increased protein degradation and decreased transcription mediated by ER stress induction. This implies that modulating ER stress may improve proteinuria-induced alterations of Klotho expression, and hence renal and extrarenal complications associated with Klotho loss.

关键词： NR5A1   ATF3   interaction   transcriptional activity   SUMOylation   phosphorylation  

摘要： Steroidogenic Factor 1 (SF-1/NR5A1), an orphan nuclear receptor, is important for sexual differentiation and the development of multiple endocrine organs, as well as cell proliferation in cancer cells. Activating transcription factor 3 (ATF3) is a transcriptional repressor, and its expression is rapidly induced by DNA damage and oncogenic stimuli. Since both NR5A1 and ATF3 can regulate and cooperate with several transcription factors, we hypothesized that NR5A1 may interact with ATF3 and plays a functional role in cancer development. First, we found that NR5A1 physically interacts with ATF3. We further demonstrated that ATF3 expression is up-regulated by NR5A1. Moreover, the promoter activity of the ATF3 is activated by NR5A1 in a dose-dependent manner in several cell lines. By mapping the ATF3 promoter as well as the site-directed mutagenesis analysis, we provide evidence that NR5A1 response elements (-695 bp and -665 bp) are required for ATF3 expression by NR5A1. It is well known that the transcriptional activities of NR5A1 are modulated by post-translational modifications, such as small ubiquitin-related modifier (SUMO) modification and phosphorylation. Notably, we found that both SUMOylation and phosphorylation of NR5A1 play roles, at least in part, for NR5A1-mediated ATF3 expression. Overall, our results provide the first evidence of a novel relationship between NR5A1 and ATF3.

关键词： Cell biology   Molecular biology  

摘要： The amino acid antiporter system Xc(-) is important for the synthesis of glutathione (GSH) that functions to prevent lipid peroxidation and protect cells from nonapoptotic, iron-dependent death (i.e., ferroptosis). While the activity of system Xc(-) often positively correlates with the expression level of its light chain encoded by SLC7A11, inhibition of system Xc(-) activity by small molecules (e.g., erastin) causes a decrease in the intracellular GSH level, leading to ferroptotic cell death. How system Xc(-) is regulated during ferroptosis remains largely unknown. Here we report that activating transcription factor 3 (ATF3), a common stress sensor, can promote ferroptosis induced by erastin. ATF3 suppressed system Xc(-), depleted intracellular GSH, and thereby promoted lipid peroxidation induced by erastin. ATF3 achieved this activity through binding to the SLC7A11 promoter and repressing SLC7A11 expression in a p53-independent manner. These findings thus add ATF3 to a short list of proteins that can regulate system Xc(-) and promote ferroptosis repressed by this antiporter.

摘要： Cockayne syndrome (CS) is a rare genetic disorder caused by mutations (dysfunction) in CSA and CSB. CS patients exhibit mild photosensitivity and severe neurological problems. Currently, CS diagnosis is based on the inefficiency of CS cells to recover RNA synthesis upon genotoxic (UV) stress. Indeed, upon genotoxic stress, ATF3, an immediate early gene is activated to repress up to 5000 genes encompassing its responsive element for a short period of time. On the contrary in CS cells, CSA and CSB dysfunction impairs the degradation of the chromatin-bound ATF3, leading to a permanent transcriptional arrest as observed by immunofluorescence and ChIP followed by RT-PCR. We analysed ChIP-seq of Pol II and ATF3 promoter occupation analysis and RNA sequencing-based gene expression profiling in CS cells, as well as performed immunofluorescence study of ATF3 protein stability and quantitative RT-PCR screening in 64 patient cell lines. We show that the analysis of few amount (as for example CDK5RAP2, NIPBL and NRG1) of ATF3 dependent genes, could serve as prominent molecular markers to discriminate between CS and non-CS patient's cells. Such assay can significantly simplify the timing and the complexity of the CS diagnostic procedure in comparison to the currently available methods.