关键词： neuron   neurite outgrowth   neurite growth   long noncoding RNA (long ncRNA   lncRNA)   regeneration   microRNA (miRNA)   Arrl1   axon regeneration   competing endogenous RNA (ceRNA)   long noncoding RNA   peripheral nerve injury   miR-761   cyclin-dependent kinase inhibitor 2B (Cdkn2b)   RNA sponge   transcriptomics   AXON REGENERATION   INTRINSIC CONTROL   NERVOUS-SYSTEM   OVEREXPRESSION   MECHANISMS   EVOLUTION   INJURY   STAT3   PTEN   ATF3  

摘要： The intrinsic regeneration ability of neurons is a pivotal factor in the repair of peripheral nerve injury. Therefore, identifying the key modulators of nerve regeneration may help improve axon regeneration and functional recovery after injury. Unlike for classical transcription factors and regeneration-associated genes, the function of long noncoding RNAs (lncRNAs) in the regulation of neuronal regeneration remains mostly unknown. In this study, we used RNA-Seq?based transcriptome profiling to analyze the expression patterns of lncRNAs and mRNAs in rat dorsal root ganglion (DRG) following sciatic nerve injury. Analyses using the lncRNA-mRNA co-expression network, gene ontology enrichment, and Kyoto Encyclopedia of Genes and Genomes pathway databases indicated that the lncRNA Arrl1 decreases neurite outgrowth after neuronal injury. shRNA-mediated Arrl1 silencing increased axon regeneration bothin vitroandin vivoand improved functional recovery of the sciatic nerve. Moreover, inhibiting an identified target gene of Arrl1, cyclin-dependent kinase inhibitor 2B (Cdkn2b), markedly promoted neurite outgrowth of DRG neurons. We also found that Arrl1 acts as a competing endogenous RNA that sponges a Cdkn2b repressor, microRNA-761 (miR-761), and thereby up-regulates Cdkn2b expression during neuron regeneration. We conclude that the lncRNA Arrl1 affects the intrinsic regeneration of DRG neurons by derepressing Cdkn2b expression. Our findings indicate a role for an lncRNA-microRNA-kinase pathway in the regulation of axon regeneration and functional recovery following peripheral nerve injury in rats.

关键词： Bioluminescence resonance energy transfer   Cancer progression   Extracellular signal-regulated kinase   Phospholipase   EPITHELIAL-MESENCHYMAL TRANSITION   TRANSCRIPTION FACTOR-3   DOWN-REGULATION   EXPRESSION   ATF3   GROWTH   PROLIFERATION   TRANSDUCTION   MIGRATION   APOPTOSIS  

摘要： Background Protease-activated receptor 4 (PAR4) is a seven transmembrane G-protein coupled receptor (GPCR) activated by endogenous proteases, such as thrombin. PAR4 is involved in various pathophysiologies including cancer, inflammation, pain, and thrombosis. Although regulators of G-protein signaling (RGS) are known to modulate GPCR/G alpha-mediated pathways, their specific effects on PAR4 are not fully understood at present. We previously reported that RGS proteins attenuate PAR1- and PAR2-mediated signaling through interactions with these receptors in conjunction with distinct G alpha subunits. Methods We employed a bioluminescence resonance energy transfer technique and confocal microscopy to examine potential interactions among PAR4, RGS, and G alpha subunits. The inhibitory effects of RGS proteins on PAR4-mediated downstream signaling and cancer progression were additionally investigated by using several assays including ERK phosphorylation, calcium mobilization, RhoA activity, cancer cell proliferation, and related gene expression. Results In live cells, RGS2 interacts with PAR4 in the presence of G alpha(q)while RGS4 binding to PAR4 occurs in the presence of G alpha(q)and G alpha(12/13). Co-expression of PAR4 and G alpha(q)induced a shift in the subcellular localization of RGS2 and RGS4 from the cytoplasm to plasma membrane. Combined PAR4 and G alpha(12/13)expression additionally promoted translocation of RGS4 from the cytoplasm to the membrane. Both RGS2 and RGS4 abolished PAR4-activated ERK phosphorylation, calcium mobilization and RhoA activity, as well as PAR4-mediated colon cancer cell proliferation and related gene expression. Conclusions RGS2 and RGS4 forms ternary complex with PAR4 in G alpha-dependent manner and inhibits its downstream signaling. Our findings support a novel physiological function of RGS2 and RGS4 as inhibitors of PAR4-mediated signaling through selective PAR4/RGS/G alpha coupling.

关键词： 乳腺癌   ATF3   侵袭转移   化疗敏感性   放疗敏感性   信号通路调节  

摘要： 转录激活因子3(activating transcription factor 3,ATF3)作为转录激活因子,可通过调控细胞增殖及凋亡机制的平衡在乳腺癌的形成、转移和治疗中发挥着重要作用,而乳腺癌作为女性最常见的恶性肿瘤一直是医学界广泛关注的热点。该文就ATF3在乳腺癌中调节增殖、侵袭和转移机制,化、放疗敏感性以及相关信号通路调节方面的研究进展进行介绍,阐述ATF3与乳腺癌之间的关系,为乳腺癌的临床治疗提供参考靶点和理论依据。

关键词： 肝细胞肝癌   LC3-Ⅱ   激活转录因子3   免疫组织化学   Western blot  

摘要： 目的分析微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)和激活转录因子3(ATF3)在肝细胞癌中的表达情况,探讨其蛋白表达与HCC患者预后的关系,并分析在HCC组织中,两者的表达是否具有相关性。方法应用免疫组织化学法检测HCC组织及相应癌旁组织蜡块标本中LC3-Ⅱ与ATF3蛋白的表达情况,并分析其与患者临床病理特征和生存期之间的关系。使用免疫蛋白印迹(Western blot)法检测新鲜HCC组织及相应癌旁组织中LC3-Ⅱ与ATF3蛋白的表达,分析两种蛋白表达的相关性。结果LC3-Ⅱ和ATF3蛋白在癌旁组织中的表达明显高于HCC组织,两者的表达水平与HCC组织病理分级和静脉癌栓情况相关(均P<0.05),但与年龄、性别、血清甲胎蛋白、肿瘤直径、HBsAg等的相关性无统计学意义(均P>0.05)。LC3-Ⅱ和ATF3的低表达与HCC患者的不良预后显著相关(均P<0.05)。结论LC3-Ⅱ和ATF3蛋白表达均与HCC的发生发展有关,两者的联合检测有助于HCC的恶性程度的评估,有望成为判断患者预后的重要指标。

关键词： ATF3   ChIP-seq   epigenetics   genomics   Kupffer cell   LXR   nonalcoholic steatohepatitis   scRNA-seq   tissue macrophage   TREM2  

摘要： Tissue-resident and recruited macrophages contribute to both host defense and pathology. Multiple macrophage phenotypes are represented in diseased tissues, but we lack deep understanding of mechanisms controlling diversification. Here, we investigate origins and epigenetic trajectories of hepatic macrophages during diet-induced non-alcoholic steatohepatitis (NASH). The NASH diet induced significant changes in Kupffer cell enhancers and gene expression, resulting in partial loss of Kupffer cell identity, induction of Trem2 and Cd9 expression, and cell death. Kupffer cell loss was compensated by gain of adjacent monocyte-derived macrophages that exhibited convergent epigenomes, transcriptomes, and functions. NASH-induced changes in Kupffer cell enhancers were driven by AP-1 and EGR that reprogrammed LXR functions required for Kupffer cell identity and survival to instead drive a scar-associated macrophage phenotype. These findings reveal mechanisms by which disease-associated environmental signals instruct resident and recruited macrophages to acquire distinct gene expression programs and corresponding functions. • Myeloid cell diversity in NASH is associated with distinct microanatomical niches • Reprogramming of LXR activity leads to impaired Kupffer cell identify and survival • ATF3 collaborates with LXRs to promote a scar-associated macrophage phenotype • Altered enhancer landscapes enable inference of disease mechanisms Kupffer cells and recruited myeloid cells contribute to the pathology of nonalcoholic steatohepatitis (NASH), but molecular mechanisms specifying their distinct identities and functions are not known. Seidman and colleagues address this problem by defining cell- and disease-specific enhancer landscapes that enable inference of key transcription factors that drive myeloid cell diversity in NASH. [ABSTRACT FROM AUTHOR]

关键词： DNA-DAMAGE   ATF3   MDM2   DEGRADATION   TRANSCRIPTION   RING   LIGASE   DOMAIN   CELLS   UBIQUITYLATION  

摘要： Blocking p53 ubiquitination through disrupting its interaction with MDM2 or inhibiting the MDM2 catalytic activity is the central mechanism by which the tumor suppressor p53 is activated in response to genotoxic challenges. Although MDM2 is first characterized as the major E3 ubiquitin ligase for p53, it can also catalyze the conjugation of ubiquitin moieties to other proteins (e.g., activating transcription factor 3, or ATF3). Here we report that ATF3 can act as an ubiquitin "trap" and competes with p53 for MDM2-mediated ubiquitination. While ATF3-mediated p53 stabilization required ATF3 binding to the MDM2 RING domain, we demonstrated that ATF3 ubiquitination catalyzed by MDM2 was indispensable for p53 activation in response to DNA damage. Moreover, a cancer-derived ATF3 mutant (R88G) devoid of ubiquitination failed to prevent p53 from MDM2-mediated degradation and thus was unable to activate the tumor suppressor. Therefore, we have identified a previously-unknown mechanism that can activate p53 in the genotoxic response.

关键词： Neddylation   MLN4924   NF-kappa B   catalase   ATF3   Autophagy   Apoptosis   Esophageal Cancer   NEDD8-ACTIVATING ENZYME-INHIBITOR   TRANSCRIPTION FACTOR-3   PROTEIN NEDDYLATION   INDUCED APOPTOSIS   UBIQUITIN LIGASE   MLN4924   PATHWAY   ATF3   DEATH   REREPLICATION  

摘要： Background Protein neddylation plays a tumor-promoting role in esophageal cancer. Our previous study demonstrated that neddylation inhibition induced the accumulation of ATF4 to promote apoptosis in esophageal cancer cells. However, it is completely unknown whether neddylation inhibition could induce autophagy in esophageal cancer cells and affect the expression of other members of ATF/CREB subfamily, such as ATF3. Methods The expression of relevant proteins of NF-kappa B/Catalase/ATF3 pathway after neddylation inhibition was determined by immunoblotting analysis and downregulated by siRNA silencing for mechanistic studies. ROS generation upon MLN4924 treatment was determined by H2-DCFDA staining. The proliferation inhibition induced by MLN4924 was evaluated by ATPLite assay and apoptosis was evaluated by Annexin V /PI double staining. Results For the first time, we reported that MLN4924, a specific inhibitor of Nedd8-activating enzyme, promoted the expression of ATF3 to induce autophagy in esophageal cancer. Mechanistically, MLN4924 inhibited the activity of CRLs and induced the accumulation of its substrate I kappa B alpha to block NF-kappa B activation and Catalase expression. As a result, MLN4924 activated ATF3-induced protective autophagy, thereby inhibiting MLN4924-induced apoptosis, which could be alleviated by ATF3 silencing. Conclusions In our study, we elucidates a novel mechanism of NF-kappa B/Catalase/ATF3 pathway in MLN4924-induced protective autophagy in esophageal cancer cells, which provides a sound rationale and molecular basis for combinational anti-ESCC therapy with knockdown ATF3 and neddylation inhibitor (e.g. MLN4924).

关键词： Heat shock factor protein 1 (HSF1)   gene regulation   obesity   lipid metabolism   uncoupling protein   uncoupling protein 1 (UCP1)   activating transcription factor 3 (ATF3)   beta-adrenergic stimuli   brown fat   beige fat   thermogenesis   ACTIVATED PROTEIN-KINASE   BEIGE FAT   BROWN   OBESITY   WHITE   DYSFUNCTION   ROLES   CELLS  

摘要： Heat shock factor 1 (HSF1) regulates cellular adaptation to challenges such as heat shock and oxidative and proteotoxic stresses. We have recently reported a previously unappreciated role for HSF1 in the regulation of energy metabolism in fat tissues; however, whether HSF1 is differentially expressed in adipose depots and how its levels are regulated in fat tissues remain unclear. Here, we show that HSF1 levels are higher in brown and subcutaneous fat tissues than in those in the visceral depot and that HSF1 is more abundant in differentiated, thermogenic adipocytes. Gene expression experiments indicated that HSF1 is transcriptionally regulated in fat by agents that modulate cAMP levels, by cold exposure, and by pharmacological stimulation of ?-adrenergic signaling. An in silico promoter analysis helped identify a putative response element for activating transcription factor 3 (ATF3) at ?258 to ?250 base pairs from the HSF1 transcriptional start site, and electrophoretic mobility shift and ChIP assays confirmed ATF3 binding to this sequence. Furthermore, functional assays disclosed that ATF3 is necessary and sufficient for HSF1 regulation. Detailed gene expression analysis revealed that ATF3 is one of the most highly induced ATFs in thermogenic tissues of mice exposed to cold temperatures or treated with the ?-adrenergic receptor agonist CL316,243 and that its expression is induced by modulators of cAMP levels in isolated adipocytes. To the best of our knowledge, our results show for the first time that HSF1 is transcriptionally controlled by ATF3 in response to classic stimuli that promote heat generation in thermogenic tissues.

关键词： endometriosis   P2X3   pain   ATF3   ATP   NANOSTRUCTURED LIPID CARRIERS   DORSAL-ROOT   RECEPTOR SUBTYPES   TRPV1 EXPRESSION   NEUROPATHIC PAIN   PROTEIN-KINASES   ATP RELEASE   ATF3   GANGLIA   NEURONS  

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： TRANSGENIC MICE   GENE   EXPRESSION   ATF3   HOMEOSTASIS   DELETION   GAMMA   FATE   HAEMANGIOBLAST   PROMOTER  

摘要： The cardiac and hematopoietic progenitors (CPs and HPs, respectively) in the mesoderm ultimately form a well-organized circulation system, but mechanisms that reconcile their development remain elusive. We found that activating transcription factor 3 (atf3) was highly expressed in the CPs, HPs, and mesoderm, in zebrafish. The atf3(-/-) mutants exhibited atrial dilated cardiomyopathy and a high ratio of immature myeloid cells. These manifestations were primarily caused by the blockade of differentiation of both CPs and HPs within the anterior lateral plate mesoderm. Mechanistically, Atf3 targets cebp gamma to repress slc2a1a-mediated glucose utilization. The high rate of glucose metabolism in atf3(-/-) mutants inhibited the differentiation of progenitors by changing the redox state. Therefore, atf3 could provide CPs and HPs with metabolic adaptive capacity to changes in glucose levels. Our study provides new insights into the role of atf3 in the coordination of differentiation of CPs and HPs by regulating glucose metabolism.