关键词： Sodium   Potassium   Calcium   Egrl   Atf3   Nr4a1   Ptgs2   Excitation-transcription coupling  

摘要： In rat vascular smooth muscle cells (RVSMC), 3-h Na+,K+-ATPase inhibition by ouabain or in K+-free medium resulted in the inversion of the [Na+](i)/[K+](i) ratio and elevation up to 7-fold the content of Egr1, Atf3, Nr4a1 and Ptgs2 mRNAs. Ouabain increased the rate of 45Ca(2+) influx by 2 -fold that was abolished by L-type voltage-gated Ca2+ channel blocker nicardipine, but it was resistant to Na+/Ca2+ exchanger inhibitor KB-R7943. To study the role of Ca2+-mediated signaling in the expression of Na-i(+)/K-i(+)-sensitive genes we used intracellular Ca2+ chelator BAPTA and incubated RVSMC in Ca2+-free medium. The elevation of Nr4a1 and Ptgs2 expression triggered by ouabain was diminished in Ca2+-depeleted cells as well as in the presence of nicardipine and calmodulin antagonists A-7 and W-7. Ptgs2 expression was also suppressed by inhibitor of Ca2+/calmodulin-dependent protein kinase (CaMKII) KN-93 whereas increment of Nr4a1 content triggered by ouabain was attenuated by inhibitor of Ca2+/calmodulin-dependent protein phosphatase (calcineurin, CaN) cyclosporin A. Neither Ca2+ depletion nor above listed compounds had any impact on the augmented expression of Egr1 and Atf3 in ouabain-treated RVSMC. Our results strongly suggest that dissipation of transmembrane gradient of monovalent cations increases Ptgs2 and Nr4a1 transcription via augment Ca2+ influx through L-type Ca2+ channels that, in turn, leads to CaMKII-mediated phosphorylation of CREB and calcineurin-mediated dephosphorylation of NFAT, respectively. Additional experiments should be performed to identify intermediates of Na-i(+),K-i(+)-mediated Ca2+-independent excitation-transcription coupling involved the regulation of Egr1 and Atf3 expression.

关键词： acute lung injury   ATF3   inflammation   RRID   TL1A  

摘要： Excessive inflammatory responses are critical in the pathogenesis of acute lung injury (ALI). Activating transcription factor 3 (ATF3) is a stress-induced transcriptional regulator that is a negative regulator of inflammatory responses. Therefore, we investigated the role and signaling pathways of ATF3 in lipopolysaccharide (LPS)-induced ALI in mice. The mouse macrophage RAW264.7 cells were cultured on HTS 24-Transwell filter plates in presence of ATF3 siRNA before exposure to LPS. ATF3 knock-out (KO) and wild type (WT) mice were challenged by intra-peritoneal injection of LPS (15mg/kg). Gene analysis was used to analyze differential gene expression between ATF3 KO and WT mice. LPS increased the expression of ATF3 in RAW264.7 cells and in lung tissues of mice, The concentration of TNF and IL-6 was significantly increased in ATF3 siRNA-treated RAW264.7 cells compared to control cells after LPS stimulation. The concentration of TNF, IL-6 and IL-1 in serum and lung tissue of ATF3 KO mice was significantly increased compared to ATF3 WT mice. In addition, the lung wet/dry weight and BALF protein were significantly increased in ATF3 KO mice after LPS injection at 6, 24, and 48hr. The survival of ATF3 KO mice significantly decreased. Differential gene analysis showed that TL1A was highly expressed in LPS-induced lung tissues of ATF3 KO ***, ATF3 down-regulated the expression of TL1A in RAW264.7 cells and in lung tissues. These findings suggest that ATF3 protects against LPS-induced ALI via inhibiting TL1A expression.

关键词： 转录激活因子3   消化系统肿瘤  

摘要： 转录激活因子3(activating transcription factor,ATF3)属于转录因子ATF/CREB家族的成员,是一种适应反应基因,参与多种细胞活动的调控以适应细胞内外环境的变化。近年来的研究表明,ATF3作为抑癌或致癌基因在消化道系统肿瘤的发生及演变过程中发挥重要的作用。现就ATF3在消化系统肿瘤方面的研究进展作一概述。

摘要： 342

关键词： DNA damage response   gene expression   mRNA decay   p38   senescence   ATF3   nonsense-mediated RNA decay   persistent DNA damage  

摘要： Persistent DNA damage induces profound alterations in gene expression that, in turn, influence tissue homeostasis, tumorigenesis, and cancer treatment outcome. However, the underlying mechanism for gene expression reprogramming induced by persistent DNA damage remains poorly understood. Here, using a highly effective bioluminescence-based reporter system and other tools, we report that persistent DNA damage inhibits nonsense-mediated RNA decay (NMD), an RNA surveillance and gene-regulatory pathway, in noncycling cells. NMD suppression by persistent DNA damage required the activity of the p38 alpha MAPK. Activating transcription factor 3 (ATF3), anNMD target and a key stress-inducible transcription factor, was stabilized in a p38 alpha-and NMD-dependent manner following persistent DNA damage. Our results reveal a novel p38 alpha-dependent pathway that regulates NMD activity in response to persistent DNA damage, which, in turn, controls ATF3 expression in affected cells.

关键词： Peripheral nerve injury   Minocycline   CNTF   Colchicine  

摘要： Microglia are essential in developmental processes and maintenance of neuronal homeostasis. Experimental axotomy of motor neurons results in neurodegeneration, and microglia in motor nuclei become activated and migrate towards injured neurons. However, whether these activated microglia are protective or destructive to neurons remains controversial. In the present study, we transected the hypo-glossal nerve in BALB/c mice, causing activating transcription factor 3 (ATF3) and growth associated protein 43 (GAP43) induction, and partial neuronal death. Inhibition of microglial accumulation by minocycline administration impaired microglial accumulation, decreased GAP43 mRNA expression, and reduced motor neuron survival. Expression of ATF3 contributed to nerve regeneration, and increased within 6 h after axotomy, prior to microglial migration. Further, microglial contact with neuronal cell bodies was associated with neuronal ATF3 expression. Colchicine administration blocked lesion-induced ATF3 transcription in axotomized neurons and microglial accumulation. In addition, perineuronal microglia-derived ciliary neurotrophic factor (CNTF) increased, indicating that perineuronal microglia in the hypoglossal nucleus protect axotomized motor neurons by releasing trophic factors. We also observed that microglia secrete CNTF and that neurons have CNTFR alpha and can respond to it in vitro. CNTF promote neurite elongation and neuronal survival of primary cultured neurons. Microglia make contact through unknown neuronal signals that are possibly regulated by ATF3 in hypoglossal nucleus. Moreover, they play important roles in regenerating motor neurons and are potential new therapeutic targets for motor neuron diseases. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： activating transcription factor 3   macrophage   M1/M2 polarization   tenascin-C  

摘要： There are different polarization states of macrophages, including the classically activated M1 phenotype and the alternatively activated M2 phenotype. These have different functions in the inflammation process. Activating transcription factor 3 (ATF3) is a key transcriptional regulator that inhibits the inflammatory response. However, the effects of ATF3 on migration and anti-inflammatory control mechanisms of macrophages have not been thoroughly investigated. The present study investigated the effect of ATF3 on macrophage migration and M1/M2 polarization. Results revealed that overexpression of ATF3 promoted macrophage migration and the expression of the M2 phenotype markers [cluster of differentiation (CD) 163, mannose receptor C type 1, arginase 1 and peroxisome proliferator-activated receptor gamma] and inhibited expression of the M1 phenotype markers (monocyte chemoattractant protein-1, inducible nitric oxide synthase, CD16 and tumor necrosis factor-alpha), whereas knockdown of ATF3 resulted in a contrary effect. In addition, the wingless-type MMTV integration site family member (Wnt)/beta-catenin signaling pathway was activated and the expression level of tenascin (TNC) was significantly upregulated by overexpression of ATF3. Additionally, inhibition of Wnt/beta-catenin signaling significantly attenuated the upregulatory effect of ATF3 on TNC. Finally, the effect of ATF3 on macrophage migration and markers of the M1 or M2 state was investigated using TNC-specific siRNA. In conclusion, the results of the present study suggested that ATF3 promotes macrophage migration and reverses M1-polarized macrophages to the M2 phenotype by upregulation of TNC via the Wnt/beta-catenin signaling pathway.

关键词： activating transcription factor-3 (ATF3)   inflammation   Mycoplasma pneumonia (MP)  

摘要： ObjectivesActivating transcription factor-3 (ATF3) is a key regulator of inflammatory responses. We aimed to investigate the effects and mechanisms of ATF3 on the inflammatory cytokines are induced by Mycoplasma pneumonia (MP). Study DesignRAW264.7 and mouse peritoneal macrophages were exposed to various time with or without MP infection (3, 6, 12, 24, and 48h), and detect the expression of ATF3. Adenovirus-expression of ATF3 (Ad/ATF3) or Ad/gal was transfected into cells which were exposed to MP for 48h, RT-PCR and ELISA was used to evaluate the expression and secretion of TNF-, IL-1, IL-6, and IL-18. In addition, intravenous administration Ad/ATF3 or Ad/gal into the mice, the secretion of inflammatory cytokines were detected using ELISA. ChIP assay was used to determine whether ATF3 can bind to the promoter of Early growth response protein 1 (Egr-1). Western blot was used to detect the expression of Egr-1 and Fyn. ResultsATF3 was increased at 3, 6, 12, and 24h and the highest expression levels occurs in 6h, there is no significant differences at 24 and 48h compared with 0h or CON group in RAW 264.7. Similar results were seen in mouse peritoneal macrophages. Overexpression of ATF3 resulted in the reduction of inflammatory cytokines. ChIP assay revealed that ATF3 can bind to the promoter of Egr-1. Overexpression of ATF3 inhibited the protein expression of Egr-1 and Fyn;conversely, ATF3-deficiency promoted the expression of Egr-1 and Fyn. Overexpression of Egr-1 reduced the anti-inflammatory action of ATF3. ConclusionsATF3 inhibit the expression and release of TNF-, IL-1, IL-6, and IL-18 induced by MP in vitro and in vivo, which is associated with its negative regulation of Egr-1/Fyn signaling pathway.

关键词： Ebselen   IL-6   IL-1   Cancer induced inflammation  

摘要： Background: Chronic inflammatory skin diseases are characterized by controlled proliferation of keratinocytes. Here, activating transcription factor 3 (ATF3) might play a fundamental role. In these inflammatory diseases, proliferation is controlled and only rarely leads to cancer development which can be supported by an inflammatory microenvironment. ATF3 is a dual function protein as it suppresses pro inflammatory IL-6 and IL-8, but also acts as a pro-oncogenic factor by the suppression of p53. We therefore analyzed ATF3 expression comparing myeloid cells with keratinocytes. Objective: To dissect the bi-modal role of ATF3 we pharmacologically induced ATF3 and analyzed its influence on cytokine expression and secretion in a cell type specific manner. Methods: Since inflammatory skin diseases can be treated systemically with Cyclosporin A or Dimethylfumarate we stimulated myeloid cells and primary human keratinocytes with these drugs and analyzed gene expression by quantitative real-time PCR. Cytokine secretion was measured by ELISA. Results: In the present study, we could show that ATF3 is induced in PBMCs by DMF and weakly by Ebselen, while CsA is the most prominent inducer of ATF3 in keratinocytes without enhancing HO-1 transcription. Further we could show that induction of stress by LPS treatment elevates IL-1 beta and IL-6 and weakly ATF3 transcription in PBMCs. While transcription of both cytokines is elevated, LPS treatment mediates IL-6 secretion with only little IL-1 beta secretion. Treatment with DMF dampens LPS-induced transcription. Conclusions: Taken together, our results shed light into the different carcinogenic potential of CsA and DMF, which both target ATF3. Collectively our data demonstrate that CsA strongly induces pro carcinogenic ATF3 in keratinocytes, whereas ATF3 induction by DMF in myeloid cells acts antiinflammatory. (C) 2017 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

关键词： PNS   Axon regeneration   Facial nerve   ATF3   Muscle  

摘要： Traumatic injuries to human peripheral nerves are frequently associated with damage to nerve surrounding tissues including muscles and blood vessels. Currently, most rodent models of peripheral nerve injuries (e.g., facial or sciatic nerve) employ surgical nerve transection with scissors or scalpels. However, such an isolated surgical nerve injury only mildly damages neighboring tissues and weakly activates an immune response. In order to provide a rodent nerve injury model accounting for such nerve-associated tissue damage and immune cell activation, we developed a drop tower-based facial nerve trauma model in mice. We compare nerve regeneration in this novel peripheral nerve trauma model with the established surgical nerve injury along several parameters. These include gene expression, histological and functional facial motoneuron (FMN) regeneration, facial nerve degeneration, immune cell activation and muscle damage. Regeneration-associated genes (RAGs;e.g., Atf3) were strongly induced in FMNs subjected to traumatic and surgical injury. Regeneration of FMNs and functional recovery of whisker movement were faster in traumatic versus complete surgical injury, thus cutting down experimentation time. Wallerian degeneration of distal nerve stumps was readily observed in this novel trauma injury model. Importantly, drop tower-inflicted facial nerve injury resulted in muscle damage, activation of muscle satellite cell markers (PAX7) and pronounced infiltration of immune cells to the injury site only in this model but not upon surgical nerve transection. Thus, we provide a novel rodent PNS trauma model that can be easily adopted to other PNS nerves such as the sciatic nerve. Since this nerve trauma model replicates multiple tissue damage frequently encountered in clinical routine, it will be well suited to identify molecular and cellular mechanisms of PNS nerve repair in wild-type and genetically modified rodents.