关键词： retinal ganglion cell   optic nerve   axon regeneration and neuronal degeneration   ATF3   CHOP   ATF4   C/EBPg  

摘要： Regulatory programs governing neuronal death and axon regeneration in neurodegenerative diseases remain poorly understood. In adult mice, optic nerve crush (ONC) injury by severing retinal ganglion cell (RGC) axons results in massive RGC death and regenerative failure. We performed an in vivo CRISPR-Cas9-based genome-wide screen of 1,893 transcription factors (TFs) to seek repressors of RGC survival and axon regeneration following ONC. In parallel, we profiled the epigenetic and transcriptional landscapes of injured RGCs by ATAC-seq and RNA-seq to identify injury-responsive TFs and their targets. These analyses converged on four TFs as critical survival regulators, of which ATF3/CHOP preferentially regulate pathways activated by cytokines and innate immunity and ATF4/C/EBP gamma regulate pathways engaged by intrinsic neuronal stressors. Manipulation of these TFs protects RGCs in a glaucoma model. Our results reveal core transcription programs that transform an initial axonal insult into a degenerative process and suggest novel strategies for treating neurodegenerative diseases.

关键词： Nonalcoholic steatohepatitis (NASH)   Metabolic dysfunction-associated steatohepatitis (MASH)   Overnutrition   Type-2 diabetes mellites   Steatosis   High-fat diet   Fructose   Inflammation   Mitochondria   Mitochondrial dysregulation   Oxidative stress   Reactive oxygen species   Redox signalling   Endoplasmic reticulum stress   Apoptosis   Iron overload   Insulin resistance   Lipotoxicity   Fatty acid beta-oxidation   Nrf2   Glutathione   Thioredoxin   Detoxification   Autophagy   Keap1   beta-TrCP   Hrd1/SYVN1   JNK   p38(MAPK)   GSK-3   ATF3   Bach1   FOSL1/Fra1   TGF-beta  

摘要： Non-alcoholic steatohepatitis (NASH) represents a global health concern. It is characterised by fatty liver, hepatocyte cell death and inflammation, which are associated with lipotoxicity, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, iron overload and oxidative stress. NF-E2 p45-related factor 2 (Nrf2) is a transcription factor that combats oxidative stress. Remarkably, Nrf2 is downregulated during the development of NASH, which probably accelerates disease, whereas in pre-clinical studies the upregulation of Nrf2 inhibits NASH. We now review the scientific literature that proposes Nrf2 downregulation during NASH involves its increased ubiquitylation and proteasomal degradation, mediated by Kelch-like ECH-associated protein 1 (Keap1) and/or beta-transducin repeat-containing protein (beta-TrCP) and/or HMG-CoA reductase degradation protein 1 (Hrd1, also called synoviolin (SYVN1)). Additionally, downregulation of Nrf2-mediated transcription during NASH may involve diminished recruitment of coactivators by Nrf2, due to increased levels of activating transcription factor 3 (ATF3) and nuclear factor-kappaB (NF-kappa B) p65, or competition for promoter binding due to upregulation of BTB and CNC homology 1 (Bach1). Many processes that downregulate Nrf2 are triggered by transforming growth factor-beta (TGF-beta), with oxidative stress amplifying its signalling. Oxidative stress may also increase suppression of Nrf2 by beta-TrCP through facilitating formation of the DSGIS-containing phosphodegron in Nrf2 by glycogen synthase kinase-3. In animal models, knockout of Nrf2 increases susceptibility to NASH, while pharmacological activation of Nrf2 by inducing agents that target Keap1 inhibits development of NASH. These inducing agents probably counter Nrf2 downregulation affected by beta-TrCP, Hrd1/SYVN1, ATF3, NF-kappa B p65 and Bach1, by suppressing oxidative stress. Activation of Nrf2 is also likely to inhibit NASH by ameliorating lipotoxicity, inflammation, ER

关键词： ATF3   山羊   肌内前体脂肪细胞   过表达   诱导分化  

摘要： 本研究旨在探究山羊转录激活因子3(activating transcription factor 3,ATF3)对肌内前体脂肪细胞分化的影响,并从分子水平阐明其可能作用途径。利用基因重组方法构建pEGFP-N1-ATF3过表达重组质粒,脂质体转染肌内前体脂肪细胞,通过油红O脂肪染色法从细胞形态学水平确定对分化的影响,利用实时荧光定量PCR(qRT-PCR)技术检测脂肪细胞分化标记基因相对表达水平,从分子水平确定对分化的影响。最终成功构建pEGFP-N1-ATF3过表达载体,转染山羊肌内前体脂肪细胞后发现脂滴积聚被抑制,qRT-PCR检测到脂肪细胞分化标志基因PPARγ、C/EBPα、SREBP1极显著下调(P<0.01),C/EBPβ、AP2显著下调(P<0.05),通过ALGGEN PROMO程序预测PPARγ、C/EBPα和AP2的启动子区域存在ATF3结合位点。研究表明,过表达山羊ATF3抑制肌内前体脂肪细胞脂滴积聚,这种作用通过下调PPARγ、C/EBPα和AP2来实现,研究结果为阐明山羊ATF3调控肌内前体脂肪细胞分化机制提供重要的基础数据。

关键词： brown adipose tissue   Adipocytes   Proteasome   Ubiquitin   Proteostasis   PSMB4   ATF3  

摘要： Objective: Regulation of proteasomal activity is an essential component of cellular proteostasis and function. This is evident in patients with mutations in proteasome subunits and associated regulators, who suffer from proteasome-associated autoinflammatory syndromes (PRAAS). These patients display lipodystrophy and fevers, which may be partly related to adipocyte malfunction and abnormal thermogenesis in adipose tissue. However, the cell-intrinsic pathways that could underlie these symptoms are unclear. Here, we investigate the impact of two proteasome subunits implicated in PRAAS, Psmb4 and Psmb8, on differentiation, function and proteostasis of brown adipocytes. Methods: In immortalized mouse brown pre-adipocytes, levels of Psmb4, Psmb8, and downstream effectors genes were downregulated through reverse transfection with siRNA. Adipocytes were differentiated and analyzed with various assays of adipogenesis, lipogenesis, lipolysis, inflammation, and respiration. Results: Loss of Psmb4, but not Psmb8, disrupted proteostasis and adipogenesis. Proteasome function was reduced upon Psmb4 loss, but partly recovered by the activation of Nuclear factor, erythroid-2, like-1 (Nfe2l1). In addition, cells displayed higher levels of surrogate inflammation and stress markers, including Activating transcription factor-3 (Atf3). Simultaneous silencing of Psmb4 and Atf3 lowered inflammation and restored adipogenesis. Conclusions: Our study shows that Psmb4 is required for adipocyte development and function in cultured adipocytes. These results imply that in humans with PSMB4 mutations, PRAAS-associated lipodystrophy is partly caused by disturbed adipogenesis. While we uncover a role for Nfe2l1 in the maintenance of proteostasis under these conditions, Atf3 is a key effector of inflammation and blocking adipogenesis. In conclusion, our work highlights how proteasome dysfunction is sensed and mitigated by the integrated stress response in adipocytes with potential relevance for PRAA

摘要： EP234

关键词： Cancer stem cells   Oncogenes  

摘要： Glioblastoma multiforme (GBM) is the most lethal type of craniocerebral gliomas. Glioma stem cells (GSCs) are fundamental reasons for the malignancy and recurrence of GBM. Revealing the critical mechanism within GSCs' self-renewal ability is essential. Our study found a novel circular RNA (circRPPH1) that was up-regulated in GSCs and correlated with poor survival. The effect of circRPPH1 on the malignant phenotype and self-renewal of GSCs was detected in vitro and in vivo. Mechanistically, UPF1 can bind to circRPPH1 and maintain its stability. Therefore, more existing circRPPH1 can interact with transcription factor ATF3 to further transcribe UPF1 and Nestin expression. It formed a feedback loop to keep a stable stream for stemness biomarker Nestin to strengthen tumorigenesis of GSCs continually. Besides, ATF3 can activate the TGF-beta signaling to drive GSCs for tumorigenesis. Knocking down the expression of circRPPH1 significantly inhibited the proliferation and clonogenicity of GSCs both in vitro and in vivo. The overexpression of circRPPH1 enhanced the self-renewal of GSCs. Our findings suggest that UPF1/circRPPH1/ATF3 maintains the potential self-renewal of GSCs through interacting with RNA-binding protein and activating the TGF-beta signal pathway. Breaking the feedback loop against self-renewing GSCs may represent a novel therapeutic target in GBM treatment.

关键词： Glioma   TFCP2   Serine synthesis   PHGDH   ATF3  

摘要： Glioma is one of the most common malignancies. De novo serine synthesis promotes glioma progression and therapeutic resistance. Therefore, clarifying the regulatory mechanism of serine synthesis is of great significance for glioma therapy. In this study, we found that the expression of TFCP2 was upregulated in glioma and that TFCP2 promoted glioma cell growth and sphere formation. Knockdown of TFCP2 expression inhibited glioma cell growth, sphere formation and tumorigenicity in nude mice. In terms of its molecular mechanism, TFCP2 was found to interact with ATF3 to cooperatively regulate the de novo synthesis of serine. Knockdown of TFCP2 expression significantly inhibited the binding of ATF3 to the promoter of PHGDH (a rate-limiting enzyme in the serine synthesis process). In conclusion, our studies proved that TFCP2 jointly regulates the de novo synthesis of serine through interaction with ATF3, thus promoting glioma progression. This study suggests that TFCP2 is a potential target for glioma therapy.

关键词： 三叉神经痛   眶下神经缩窄术   miR-30b   ATF3  

摘要： 目的探讨miR-30b在三叉神经痛(TN)模型大鼠三叉神经节(TG)中发挥的作用。方法采用眶下神经缩窄术(ION-CCI)构建大鼠TN模型。用Von Frey毛刷检测大鼠的机械痛阈。通过qRT-PCR及Western blot检测术侧TG内miR-30b和激活转录因子3(ATF3)表达变化。经眶下孔分别向ION-CCI大鼠的TG内定位注射miR-30b的类似物(agomir)和agomir的阴性对照(agomir NC),检测大鼠的机械痛阈及干预后ATF3表达的变化。结果ION-CCI组大鼠在术后第2~28天出现机械痛阈的降低(P<0.05)。ION-CCI组较假手术组(Sham组)术后TG中miR-30b表达降低,ATF3表达升高(P<0.05)。ION-CCI组过表达miR-30b后,大鼠机械痛阈升高,TG中ATF3表达降低(P<0.05)。结论miR-30b参与调控TN的发生、发展,miR-30b可能是TN潜在的治疗靶点。

关键词： Econazole   Autophagy   PDAC   ATF3   AKT   Organoid   Trametinib   Therapy  

摘要： Pancreatic ductal adenocarcinoma(PDAC)is characterized by the highest mortality among *** pathogenesis of PDAC requires elevated autophagy,inhibition of which using hydroxychloroquine has shown ***,current realization is impeded by its suboptimal use and unpredictable *** to identify novel autophagy-modulating agents from already approved drugs offer a rapid and accessible ***,using a patient-derived organoid model,we performed a comparative analysis of therapeutic responses among various antimalarial/fungal/parasitic/viral agents,through which econazole(ECON),an antifungal compound,emerged as the top *** testing in cell-line and xenograft models of PDAC validated this activity,which occurred as a direct consequence of dysfunctional *** specifically,ECON boosted autophagy initiation but blocked lysosome *** sequencing analysis revealed that this autophagic induction was largely attributed to the altered expression of activation transcription factor 3(ATF3).Increased nuclear import of ATF3 and its transcriptional repression of inhibitor of differentiation-1(ID-1)led to inactivation of the AKT/mammalian target of rapamycin(m TOR)pathway,thus giving rise to autophagosome accumulation in PDAC *** magnitude of the increase in autophagosomes was sufficient to elicit ER stress-mediated ***,ECON,as an autophagy inhibitor,exhibited synergistic effects with trametinib on *** study provides direct preclinical and experimental evidence for the therapeutic efficacy of ECON in PDAC treatment and reveals a mechanism whereby ECON inhibits PDAC growth.

关键词： E box   endoplasmic reticulum stress   gene silencing   microarray analysis   muscle regeneration   myoblast differentiation   promoter   skeletal muscle   transcription  

摘要： During skeletal myogenesis, the zinc-finger transcription factors SNAI1 and SNAI2, are expressed in proliferating myoblasts and regulate the transition to terminally differentiated myotubes while repressing pro-differentiation genes. Here, we demonstrate that SNAI1 is upregulated in vivo during the early phase of muscle regeneration induced by bupivacaine injury. Using shRNA-mediated gene silencing in C2C12 myoblasts and whole-transcriptome microarray analysis, we identified a collection of genes belonging to the endoplasmic reticulum (ER) stress pathway whose expression, induced by myogenic differentiation, was upregulated in absence of SNAI1. Among these, key ER stress genes, such as Atf3, Ddit3/Chop, Hspa5/Bip, and Fgf21, a myokine involved in muscle differentiation, were strongly upregulated. Furthermore, by promoter mutant analysis and Chromatin immune precipitation assay, we demonstrated that SNAI1 represses Fgf21 and Atf3 in proliferating myoblasts by directly binding to multiple E boxes in their respective promoter regions. Together, these data describe a new regulatory mechanism of myogenic differentiation involving the direct repressive action of SNAI1 on ER stress and Fgf21 expression, ultimately contributing to maintaining the proliferative and undifferentiated state of myoblasts.