Association of MMP7 -181A→G Promoter Polymorphism with Gastric Cancer Risk: INFLUENCE OF NICOTINE IN DIFFERENTIAL ALLELE-SPECIFIC TRANSCRIPTION VIA INCREASED PHOSPHORYLATION OF cAMP-RESPONSE ELEMENT-BINDING PROTEIN (CREB).

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Kesh, Kousik; Subramanian, Lakshmi; Ghosh, Nillu; Gupta, Vinayak; Gupta, Arnab; Bhattacharya, Samir; Mahapatra, Nitish R; Swarnakar, Snehasikta

2015-06-05

Elevated expression of matrix metalloproteinase7 (MMP7) has been demonstrated to play a pivotal role in cancer invasion. The -181A→G (rs11568818) polymorphism in the MMP7 promoter modulates gene expression and possibly affects cancer progression. Here, we evaluated the impact of -181A→G polymorphism on MMP7 promoter activity and its association with gastric cancer risk in eastern Indian case-control cohorts (n = 520). The GG genotype as compared with the AA genotype was predisposed (p = 0.02; odds ratio = 1.9, 95% confidence interval = 1.1-3.3) to gastric cancer risk. Stratification analysis showed that tobacco addiction enhanced gastric cancer risk in GG subjects when compared with AA subjects (p = 0.03, odds ratio = 2.46, and 95% confidence interval = 1.07-5.68). Meta-analysis revealed that tobacco enhanced the risk for cancer more markedly in AG and GG carriers. Activity and expression of MMP7 were significantly higher in GG than in AA carriers. In support, MMP7 promoter-reporter assays showed greater transcriptional activity toward A to G transition under basal/nicotine-induced/cAMP-response element-binding protein (CREB) overexpressed conditions in gastric adenocarcinoma cells. Moreover, nicotine (a major component of tobacco) treatment significantly up-regulated MMP7 expression due to enhanced CREB phosphorylation followed by its nuclear translocation in gastric adenocarcinoma cells. Furthermore, chromatin immunoprecipitation experiments revealed higher binding of phosphorylated CREB with the -181G than the -181A allele. Altogether, specific binding of phosphorylated CREB to the G allele-carrying promoter enhances MMP7 gene expression that is further augmented by nicotine due to increased CREB phosphorylation and thereby increases the risk for gastric cancer. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

cAMP-response-element-binding protein positively regulates breast cancer metastasis and subsequent bone destruction

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Son, Jieun; Lee, Jong-Ho; Kim, Ha-Neui; Ha, Hyunil, E-mail: hyunil74@hotmail.com; Lee, Zang Hee, E-mail: zang1959@snu.ac.kr

2010-07-23

Research highlights: {yields} CREB is highly expressed in advanced breast cancer cells. {yields} Tumor-related factors such as TGF-{beta} further elevate CREB expression. {yields} CREB upregulation stimulates metastatic potential of breast cancer cells. {yields} CREB signaling is required for breast cancer-induced bone destruction. -- Abstract: cAMP-response-element-binding protein (CREB) signaling has been reported to be associated with cancer development and poor clinical outcome in various types of cancer. However, it remains to be elucidated whether CREB is involved in breast cancer development and osteotropism. Here, we found that metastatic MDA-MB-231 breast cancer cells exhibited higher CREB expression than did non-metastatic MCF-7 cells and that CREB expression was further increased by several soluble factors linked to cancer progression, such as IL-1, IGF-1, and TGF-{beta}. Using wild-type CREB and a dominant-negative form (K-CREB), we found that CREB signaling positively regulated the proliferation, migration, and invasion of MDA-MB-231 cells. In addition, K-CREB prevented MDA-MB-231 cell-induced osteolytic lesions in a mouse model of cancer metastasis. Furthermore, CREB signaling in cancer cells regulated the gene expression of PTHrP, MMPs, and OPG, which are closely involved in cancer metastasis and bone destruction. These results indicate that breast cancer cells acquire CREB overexpression during their development and that this CREB upregulation plays an important role in multiple steps of breast cancer bone metastasis.

Human T-cell leukemia virus type 1 Tax requires direct access to DNA for recruitment of CREB binding protein to the viral promoter.

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Lenzmeier, B A; Giebler, H A; Nyborg, J K

1998-02-01

Efficient human T-cell leukemia virus type 1 (HTLV-1) replication and viral gene expression are dependent upon the virally encoded oncoprotein Tax. To activate HTLV-1 transcription, Tax interacts with the cellular DNA binding protein cyclic AMP-responsive element binding protein (CREB) and recruits the coactivator CREB binding protein (CBP), forming a nucleoprotein complex on the three viral cyclic AMP-responsive elements (CREs) in the HTLV-1 promoter. Short stretches of dG-dC-rich (GC-rich) DNA, immediately flanking each of the viral CREs, are essential for Tax recruitment of CBP in vitro and Tax transactivation in vivo. Although the importance of the viral CRE-flanking sequences is well established, several studies have failed to identify an interaction between Tax and the DNA. The mechanistic role of the viral CRE-flanking sequences has therefore remained enigmatic. In this study, we used high resolution methidiumpropyl-EDTA iron(II) footprinting to show that Tax extended the CREB footprint into the GC-rich DNA flanking sequences of the viral CRE. The Tax-CREB footprint was enhanced but not extended by the KIX domain of CBP, suggesting that the coactivator increased the stability of the nucleoprotein complex. Conversely, the footprint pattern of CREB on a cellular CRE lacking GC-rich flanking sequences did not change in the presence of Tax or Tax plus KIX. The minor-groove DNA binding drug chromomycin A3 bound to the GC-rich flanking sequences and inhibited the association of Tax and the Tax-CBP complex without affecting CREB binding. Tax specifically cross-linked to the viral CRE in the 5'-flanking sequence, and this cross-link was blocked by chromomycin A3. Together, these data support a model where Tax interacts directly with both CREB and the minor-groove viral CRE-flanking sequences to form a high-affinity binding site for the recruitment of CBP to the HTLV-1 promoter.

Distinctive Roles for Amygdalar CREB in Reconsolidation and Extinction of Fear Memory

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Tronson, Natalie C.; Wiseman, Shari L.; Neve, Rachael L.; Nestler, Eric J.; Olausson, Peter; Taylor, Jane R.

2012-01-01

Cyclic AMP response element binding protein (CREB) plays a critical role in fear memory formation. Here we determined the role of CREB selectively within the amygdala in reconsolidation and extinction of auditory fear. Viral overexpression of the inducible cAMP early repressor (ICER) or the dominant-negative mCREB, specifically within the lateral…

GSK-3α Is a Novel Target of CREB and CREB-GSK-3α Signaling Participates in Cell Viability in Lung Cancer.

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Sin-Aye Park

Full Text Available Overexpression or activation of cyclic AMP-response element-binding protein (CREB has been known to be involved in several human malignancies, including lung cancer. Genes regulated by CREB have been reported to suppress apoptosis, induce cell proliferation, inflammation, and tumor metastasis. However, the critical target genes of CREB in lung cancer have not been well understood. Here, we identified GSK-3α as one of the CREB target genes which is critical for the viability of lung cancer cells. The CREB knockdown significantly reduced the expression of GSK-3α and the direct binding of CREB on the promoter of GSK3A was identified. Kaplan-Meier analysis with a public database showed a prognostic significance of aberrant GSK-3α expression in lung cancer. Inhibition of GSK-3α suppressed cell viability, colony formation, and tumor growth. For the first time, we demonstrated that GSK-3α is regulated by CREB in lung cancer and is required for the cell viability. These findings implicate CREB-GSK-3α axis as a novel therapeutic target for lung cancer treatment.

Enhanced phosphorylation of cyclic AMP response element binding protein in Brain of mice following repetitive hypoxic exposure

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Gao Yanan; Gao Ge; Long Caixia; Han Song; Zu Pengyu; Fang Li; Li Junfa

2006-01-01

Cerebral ischemic/hypoxic preconditioning (I/HPC) is a phenomenon of endogenous protection that renders Brain tolerant to sustained ischemia/hypoxia. This profound protection induced by I/HPC makes it an attractive target for developing potential clinical therapeutic approaches. However, the molecular mechanism of I/HPC is unclear. Cyclic AMP (cAMP) response element binding protein (CREB), a selective nuclear transcriptional factor, plays a key role in the neuronal functions. Phosphorylation of CREB on Ser-133 may facilitate its transcriptional activity in response to various stresses. In the current study, we observed the changes in CREB phosphorylation (Ser-133) and protein expression in Brain of auto-hypoxia-induced HPC mice by using Western blot analysis. We found that the levels of phosphorylated CREB (Ser-133), but not protein expression of CREB, increased significantly (p < 0.05) in the hippocampus and the frontal cortex of mice after repetitive hypoxic exposure (H2-H4, n = 6 for each group), when compared to that of the normoxic (H0, n = 6) or hypoxic exposure once group (H1, n = 6). In addition, a significant enhancement (p < 0.05) of CREB phosphorylation (Ser-133) could also be found in the nuclear extracts from the whole hippocampus of hypoxic preconditioned mice (H2-H4, n = 6 for each group). These results suggest that the phosphorylation of CREB might be involved in the development of cerebral hypoxic preconditioning

Regulation of Cox-2 by Cyclic AMP Response Element Binding Protein in Prostate Cancer: Potential Role for Nexrutine

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Rita Ghosh

2007-11-01

Full Text Available We recently showed that NexrutineR, a Phellodendron amurense bark extract, suppresses proliferation of prostate cancer cell lines and tumor development in the transgenic adenocarcinoma of mouse prostate (TRAMP model. Our data also indicate that the antiproliferative effects of NexrutineR are mediated in part by Akt and Cyclic AMP response element binding protein (CREB. Cyclooxygenase (Cox-2, a pro-inflammatory mediator, is a CREB target that induces prostaglandin E2 (PGE2 and suppresses apoptosis. Treatment of LNCaP cells with NexrutineR reduced tumor necrosis factor α-induced enzymatic as well as promoter activities of Cox-2. NexrutineR also reduced the expression and promoter activity of Cox-2 in PC-3 cells that express high constitutive levels of Cox-2. Deletion analysis coupled with mutational analysis of the Cox-2 promoter identified CRE as being sufficient for mediating NexrutineR response. Immunohistochemical analysis of human prostate tumors show increased expression of CREB and DNA binding activity in high-grade tumors (three-fold higher in human prostate tumors compared to normal prostate; P = .01. We have identified CREB-mediated activation of Cox-2 as a potential signaling pathway in prostate cancer which can be blocked with a nontoxic, cost-effective dietary supplement like NexrutineR, demonstrating a prospective for development of NexrutineR for prostate cancer management.

Protein domains involved in both in vivo and in vitro interactions between human T-cell leukemia virus type I tax and CREB.

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Yin, M J; Paulssen, E J; Seeler, J S; Gaynor, R B

1995-06-01

Gene expression from the human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR) is mediated by three cis-acting regulatory elements known as 21-bp repeats and the transactivator protein Tax. The 21-bp repeats can be subdivided into three motifs known as A, B, and C, each of which is important for maximal gene expression in response to Tax. The B motif contains nucleotide sequences known as a cyclic AMP response element (CRE) or tax-response element which binds members of the ATF/CREB family of transcription factors. Though mutations of this element in the HTLV-I LTR eliminate tax activation, Tax will not activate most other promoters containing these CRE sites. In this study, we investigated the mechanism by which Tax activates gene expression in conjunction with members of the ATF/CREB family. We found that Tax enhanced the binding of one member of the ATF/CREB family, CREB 1, to each of the three HTLV-I LTR 21-bp repeats but not another member designated CRE-BP1 or CREB2. Tax enhanced the binding of CREB1 to nonpalindromic CRE binding sites such as those found in the HTLV-I LTR, but Tax did not enhance the binding of CREB1 to palindromic CRE binding sites such as found in the somatostatin promoter. This finding may help explain the failure of Tax to activate promoters containing consensus CRE sites. These studies were extended by use of the mammalian two-hybrid system. Tax was demonstrated to interact directly with CREB1 but not with other bZIP proteins, including CREB2 and Jun. Site-directed mutagenesis of both Tax and CREB1 demonstrated that the amino terminus of Tax and both the basic and the leucine zipper regions of CREB1 were required for direct interactions between these proteins both in vivo and in vitro. This interaction occurred in vivo and thus did not require the presence of the HTLV-I 21-bp repeats, as previously suggested. These results define the domains required for interaction between Tax and CREB that are likely critical for the

Expression profile of CREB knockdown in myeloid leukemia cells

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Pellegrini, Matteo; Cheng, Jerry C; Voutila, Jon; Judelson, Dejah; Taylor, Julie; Nelson, Stanley F; Sakamoto, Kathleen M

2008-01-01

The cAMP Response Element Binding Protein, CREB, is a transcription factor that regulates cell proliferation, differentiation, and survival in several model systems, including neuronal and hematopoietic cells. We demonstrated that CREB is overexpressed in acute myeloid and leukemia cells compared to normal hematopoietic stem cells. CREB knockdown inhibits leukemic cell proliferation in vitro and in vivo, but does not affect long-term hematopoietic reconstitution. To understand downstream pathways regulating CREB, we performed expression profiling with RNA from the K562 myeloid leukemia cell line transduced with CREB shRNA. By combining our expression data from CREB knockdown cells with prior ChIP data on CREB binding we were able to identify a list of putative CREB regulated genes. We performed extensive analyses on the top genes in this list as high confidence CREB targets. We found that this list is enriched for genes involved in cancer, and unexpectedly, highly enriched for histone genes. Furthermore, histone genes regulated by CREB were more likely to be specifically expressed in hematopoietic lineages. Decreased expression of specific histone genes was validated in K562, TF-1, and primary AML cells transduced with CREB shRNA. We have identified a high confidence list of CREB targets in K562 cells. These genes allow us to begin to understand the mechanisms by which CREB contributes to acute leukemia. We speculate that regulation of histone genes may play an important role by possibly altering the regulation of DNA replication during the cell cycle

Dopamine modulates acetylcholine release via octopamine and CREB signaling in Caenorhabditis elegans.

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Satoshi Suo

Full Text Available Animals change their behavior and metabolism in response to external stimuli. cAMP response element binding protein (CREB is a signal-activated transcription factor that enables the coupling of extracellular signals and gene expression to induce adaptive changes. Biogenic amine neurotransmitters regulate CREB and such regulation is important for long-term changes in various nervous system functions, including learning and drug addiction. In Caenorhabditis elegans, the amine neurotransmitter octopamine activates a CREB homolog, CRH-1, in cholinergic SIA neurons, whereas dopamine suppresses CREB activation by inhibiting octopamine signaling in response to food stimuli. However, the physiological role of this activation is unknown. In this study, the effect of dopamine, octopamine, and CREB on acetylcholine signaling was analyzed using the acetylcholinesterase inhibitor aldicarb. Mutants with decreased dopamine signaling exhibited reduced acetylcholine signaling, and octopamine and CREB functioned downstream of dopamine in this regulation. This study demonstrates that the regulation of CREB by amine neurotransmitters modulates acetylcholine release from the neurons of C. elegans.

A CREB-Sirt1-Hes1 Circuitry Mediates Neural Stem Cell Response to Glucose Availability

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Salvatore Fusco

2016-02-01

Full Text Available Summary: Adult neurogenesis plays increasingly recognized roles in brain homeostasis and repair and is profoundly affected by energy balance and nutrients. We found that the expression of Hes-1 (hairy and enhancer of split 1 is modulated in neural stem and progenitor cells (NSCs by extracellular glucose through the coordinated action of CREB (cyclic AMP responsive element binding protein and Sirt-1 (Sirtuin 1, two cellular nutrient sensors. Excess glucose reduced CREB-activated Hes-1 expression and results in impaired cell proliferation. CREB-deficient NSCs expanded poorly in vitro and did not respond to glucose availability. Elevated glucose also promoted Sirt-1-dependent repression of the Hes-1 promoter. Conversely, in low glucose, CREB replaced Sirt-1 on the chromatin associated with the Hes-1 promoter enhancing Hes-1 expression and cell proliferation. Thus, the glucose-regulated antagonism between CREB and Sirt-1 for Hes-1 transcription participates in the metabolic regulation of neurogenesis. : Using a combination of in vitro and in vivo studies, Fusco et al. find that excess glucose impairs the self-renewal capacity of neural stem cells through a molecular circuit that involves the transcription factor CREB and Sirtuin 1. The authors suggest that this circuitry may link nutrient excess with neurodegeneration and brain aging. Keywords: neural stem cells, adult neurogenesis, CREB, Sirt-1, nutrients, metabolism, diabetes

In vitro selection of DNA elements highly responsive to the human T-cell lymphotropic virus type I transcriptional activator, Tax.

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Paca-Uccaralertkun, S; Zhao, L J; Adya, N; Cross, J V; Cullen, B R; Boros, I M; Giam, C Z

1994-01-01

The human T-cell lymphotropic virus type I (HTLV-I) transactivator, Tax, the ubiquitous transcriptional factor cyclic AMP (cAMP) response element-binding protein (CREB protein), and the 21-bp repeats in the HTLV-I transcriptional enhancer form a ternary nucleoprotein complex (L. J. Zhao and C. Z. Giam, Proc. Natl. Acad. Sci. USA 89:7070-7074, 1992). Using an antibody directed against the COOH-terminal region of Tax along with purified Tax and CREB proteins, we selected DNA elements bound specifically by the Tax-CREB complex in vitro. Two distinct but related groups of sequences containing the cAMP response element (CRE) flanked by long runs of G and C residues in the 5' and 3' regions, respectively, were preferentially recognized by Tax-CREB. In contrast, CREB alone binds only to CRE motifs (GNTGACG[T/C]) without neighboring G- or C-rich sequences. The Tax-CREB-selected sequences bear a striking resemblance to the 5' or 3' two-thirds of the HTLV-I 21-bp repeats and are highly inducible by Tax. Gel electrophoretic mobility shift assays, DNA transfection, and DNase I footprinting analyses indicated that the G- and C-rich sequences flanking the CRE motif are crucial for Tax-CREB-DNA ternary complex assembly and Tax transactivation but are not in direct contact with the Tax-CREB complex. These data show that Tax recruits CREB to form a multiprotein complex that specifically recognizes the viral 21-bp repeats. The expanded DNA binding specificity of Tax-CREB and the obligatory role the ternary Tax-CREB-DNA complex plays in transactivation reveal a novel mechanism for regulating the transcriptional activity of leucine zipper proteins like CREB.

Hydrogen-Deuterium Exchange Mass Spectrometry Reveals Calcium Binding Properties and Allosteric Regulation of Downstream Regulatory Element Antagonist Modulator (DREAM).

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Zhang, Jun; Li, Jing; Craig, Theodore A; Kumar, Rajiv; Gross, Michael L

2017-07-18

Downstream regulatory element antagonist modulator (DREAM) is an EF-hand Ca 2+ -binding protein that also binds to a specific DNA sequence, downstream regulatory elements (DRE), and thereby regulates transcription in a calcium-dependent fashion. DREAM binds to DRE in the absence of Ca 2+ but detaches from DRE under Ca 2+ stimulation, allowing gene expression. The Ca 2+ binding properties of DREAM and the consequences of the binding on protein structure are key to understanding the function of DREAM. Here we describe the application of hydrogen-deuterium exchange mass spectrometry (HDX-MS) and site-directed mutagenesis to investigate the Ca 2+ binding properties and the subsequent conformational changes of full-length DREAM. We demonstrate that all EF-hands undergo large conformation changes upon calcium binding even though the EF-1 hand is not capable of binding to Ca 2+ . Moreover, EF-2 is a lower-affinity site compared to EF-3 and -4 hands. Comparison of HDX profiles between wild-type DREAM and two EF-1 mutated constructs illustrates that the conformational changes in the EF-1 hand are induced by long-range structural interactions. HDX analyses also reveal a conformational change in an N-terminal leucine-charged residue-rich domain (LCD) remote from Ca 2+ -binding EF-hands. This LCD domain is responsible for the direct interaction between DREAM and cAMP response element-binding protein (CREB) and regulates the recruitment of the co-activator, CREB-binding protein. These long-range interactions strongly suggest how conformational changes transmit the Ca 2+ signal to CREB-mediated gene transcription.

IGF-1 protects cardiac myocytes from hyperosmotic stress-induced apoptosis via CREB

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Maldonado, Carola; Cea, Paola; Adasme, Tatiana; Collao, Andres; Diaz-Araya, Guillermo; Chiong, Mario; Lavandero, Sergio

2005-01-01

Hyperosmotic stress stimulates a rapid and pronounced apoptosis in cardiac myocytes which is attenuated by insulin-like growth factor-1 (IGF-1). Because in these cells IGF-1 induces intracellular Ca 2+ increase, we assessed whether the cyclic AMP response element-binding protein (CREB) is activated by IGF-1 through Ca 2+ -dependent signalling pathways. In cultured cardiac myocytes, IGF-1 induced phosphorylation (6.5 ± 1.0-fold at 5 min), nuclear translocation (30 min post-stimulus) and DNA binding activity of CREB. IGF-1-induced CREB phosphorylation was mediated by MEK1/ERK, PI3-K, p38-MAPK, as well as Ca 2+ /calmodulin kinase and calcineurin. Exposure of cardiac myocytes to hyperosmotic stress (sorbitol 600 mOsm) decreased IGF-1-induced CREB activation Moreover, overexpression of a dominant negative CREB abolished the anti-apoptotic effects of IGF-1. Our results suggest that IGF-1 activates CREB through a complex signalling pathway, and this transcription factor plays an important role in the anti-apoptotic action of IGF-1 in cultured cardiac myocytes

Active CREB1 promotes a malignant TGFβ2 autocrine loop in glioblastoma.

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Rodón, Laura; Gonzàlez-Juncà, Alba; Inda, María del Mar; Sala-Hojman, Ada; Martínez-Sáez, Elena; Seoane, Joan

2014-10-01

In advanced cancer, including glioblastoma, the TGFβ pathway acts as an oncogenic factor. Some tumors exhibit aberrantly high TGFβ activity, and the mechanisms underlying this phenomenon are not well understood. We have observed that TGFβ can induce TGFβ2, generating an autocrine loop leading to aberrantly high levels of TGFβ2. We identified cAMP-responsive element-binding protein 1 (CREB1) as the critical mediator of the induction of TGFβ2 by TGFβ. CREB1 binds to the TGFB2 gene promoter in cooperation with SMAD3 and is required for TGFβ to activate transcription. Moreover, the PI3K-AKT and RSK pathways regulate the TGFβ2 autocrine loop through CREB1. The levels of CREB1 and active phosphorylated CREB1 correlate with TGFβ2 in glioblastoma. In addition, using patient-derived in vivo models of glioblastoma, we found that CREB1 levels determine the expression of TGFβ2. Our results show that CREB1 can be considered a biomarker to stratify patients for anti-TGFβ treatments and a therapeutic target in glioblastoma. TGFβ is considered a promising therapeutic target, and several clinical trials using TGFβ inhibitors are generating encouraging results. Here, we discerned the molecular mechanisms responsible for the aberrantly high levels of TGFβ2 found in certain tumors, and we propose biomarkers to predict the clinical response to anti-TGFβ therapies. ©2014 American Association for Cancer Research.

CREB Selectively Controls Learning-Induced Structural Remodeling of Neurons

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Middei, Silvia; Spalloni, Alida; Longone, Patrizia; Pittenger, Christopher; O'Mara, Shane M.; Marie, Helene; Ammassari-Teule, Martine

2012-01-01

The modulation of synaptic strength associated with learning is post-synaptically regulated by changes in density and shape of dendritic spines. The transcription factor CREB (cAMP response element binding protein) is required for memory formation and in vitro dendritic spine rearrangements, but its role in learning-induced remodeling of neurons…

Viral Vector Induction of CREB Expression in the Periaqueductal Gray Induces a Predator Stress-Like Pattern of Changes in pCREB Expression, Neuroplasticity, and Anxiety in Rodents

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Robert Adamec

2009-01-01

Full Text Available Predator stress is lastingly anxiogenic. Phosphorylation of CREB to pCREB (phosphorylated cyclic AMP response element binding protein is increased after predator stress in fear circuitry, including in the right lateral column of the PAG (periaqueductal gray. Predator stress also potentiates right but not left CeA-PAG (central amygdala-PAG transmission up to 12 days after stress. The present study explored the functional significance of pCREB changes by increasing CREB expression in non-predator stressed rats through viral vectoring, and assessing the behavioral, electrophysiological and pCREB expression changes in comparison with handled and predator stressed controls. Increasing CREB expression in right PAG was anxiogenic in the elevated plus maze, had no effect on risk assessment, and increased acoustic startle response while delaying startle habituation. Potentiation of the right but not left CeA-PAG pathway was also observed. pCREB expression was slightly elevated in the right lateral column of the PAG, while the dorsal and ventral columns were not affected. The findings of this study suggest that by increasing CREB and pCREB in the right lateral PAG, it is possible to produce rats that exhibit behavioral, brain, and molecular changes that closely resemble those seen in predator stressed rats.

Up-regulation of Ca2+/CaMKII/CREB signaling in salicylate-induced tinnitus in rats.

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Zhao, Jiuhan; Wang, Biao; Wang, Xiaohong; Shang, Xiuli

2018-02-09

The purpose of the study was to investigate the changes of Ca 2+ /calmodulin-dependent protein kinases II (CaMKII)/cAMP response element-binding protein (CREB) signaling pathway in a rat tinnitus model. Eighteen Wistar rats were randomly divided into three groups: normal control (NC), normal saline (NS), and tinnitus model (TM) groups. Tinnitus model was induced by intraperitoneal injection of salicylate. The concentration of intracellular calcium level in auditory cortex cells was determined using Fura-2 acetoxymethyl ester (Fura-2 AM) method with fluorospectrophotometer. Expressions of calmodulin (CaM), N-methyl-D-aspartate receptor 2B subunit (NR2B), calcium-calmodulin kinase II (CaMKII), and cAMP response element-binding protein (CREB) were detected with Western blot. Tinnitus model was successfully established by the intraperitoneal administration of salicylate in rats. Compared with rats in NC and NS groups, salicylate administration significantly elevated CaM, NR2B, phospho-CaMKII and phospho-CREB expression in auditory cortex from tinnitus model group (p salicylate administration causes tinnitus symptoms and elevates Ca 2+ /CaMKII/CREB signaling pathway in auditory cortex cells. Our study likely provides a new understanding of the development of tinnitus.

Protein kinases mediate increment of the phosphorylation of cyclic AMP -responsive element binding protein in spinal cord of rats following capsaicin injection

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Li Junfa

2005-09-01

Full Text Available Abstract Background Strong noxious stimuli cause plastic changes in spinal nociceptive neurons. Intracellular signal transduction pathways from cellular membrane to nucleus, which may further regulate gene expression by critical transcription factors, convey peripheral stimulation. Cyclic AMP-responsive element binding protein (CREB is a well-characterized stimulus-induced transcription factor whose activation requires phosphorylation of the Serine-133 residue. Phospho-CREB can further induce gene transcription and strengthen synaptic transmission by the activation of the protein kinase cascades. However, little is known about the mechanisms by which CREB phosphorylation is regulated by protein kinases during nociception. This study was designed to use Western blot analysis to investigate the role of mitogen-activated protein (MAP/extracellular signal-regulated kinase (ERK kinase (MEK 1/2, PKA and PKC in regulating the phosphorylation of CREB in the spinal cord of rats following intraplantar capsaicin injection. Results We found that capsaicin injection significantly increased the phosphorylation level of CREB in the ipsilateral side of the spinal cord. Pharmacological manipulation of MEK 1/2, PKA and PKC with their inhibitors (U0126, H89 and NPC 15473, respectively significantly blocked this increment of CREB phosphorylation. However, the expression of CREB itself showed no change in any group. Conclusion These findings suggest that the activation of intracellular MAP kinase, PKA and PKC cascades may contribute to the regulation of phospho-CREB in central nociceptive neurons following peripheral painful stimuli.

Enrichment of conserved synaptic activity-responsive element in neuronal genes predicts a coordinated response of MEF2, CREB and SRF.

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Fernanda M Rodríguez-Tornos

Full Text Available A unique synaptic activity-responsive element (SARE sequence, composed of the consensus binding sites for SRF, MEF2 and CREB, is necessary for control of transcriptional upregulation of the Arc gene in response to synaptic activity. We hypothesize that this sequence is a broad mechanism that regulates gene expression in response to synaptic activation and during plasticity; and that analysis of SARE-containing genes could identify molecular mechanisms involved in brain disorders. To search for conserved SARE sequences in the mammalian genome, we used the SynoR in silico tool, and found the SARE cluster predominantly in the regulatory regions of genes expressed specifically in the nervous system; most were related to neural development and homeostatic maintenance. Two of these SARE sequences were tested in luciferase assays and proved to promote transcription in response to neuronal activation. Supporting the predictive capacity of our candidate list, up-regulation of several SARE containing genes in response to neuronal activity was validated using external data and also experimentally using primary cortical neurons and quantitative real time RT-PCR. The list of SARE-containing genes includes several linked to mental retardation and cognitive disorders, and is significantly enriched in genes that encode mRNA targeted by FMRP (fragile X mental retardation protein. Our study thus supports the idea that SARE sequences are relevant transcriptional regulatory elements that participate in plasticity. In addition, it offers a comprehensive view of how activity-responsive transcription factors coordinate their actions and increase the selectivity of their targets. Our data suggest that analysis of SARE-containing genes will reveal yet-undescribed pathways of synaptic plasticity and additional candidate genes disrupted in mental disease.

The cellular transcription factor CREB corresponds to activating transcription factor 47 (ATF-47) and forms complexes with a group of polypeptides related to ATF-43.

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Hurst, H C; Masson, N; Jones, N C; Lee, K A

1990-12-01

Promoter elements containing the sequence motif CGTCA are important for a variety of inducible responses at the transcriptional level. Multiple cellular factors specifically bind to these elements and are encoded by a multigene family. Among these factors, polypeptides termed activating transcription factor 43 (ATF-43) and ATF-47 have been purified from HeLa cells and a factor referred to as cyclic AMP response element-binding protein (CREB) has been isolated from PC12 cells and rat brain. We demonstrated that CREB and ATF-47 are identical and that CREB and ATF-43 form protein-protein complexes. We also found that the cis requirements for stable DNA binding by ATF-43 and CREB are different. Using antibodies to ATF-43 we have identified a group of polypeptides (ATF-43) in the size range from 40 to 43 kDa. ATF-43 polypeptides are related by their reactivity with anti-ATF-43, DNA-binding specificity, complex formation with CREB, heat stability, and phosphorylation by protein kinase A. Certain cell types vary in their ATF-43 complement, suggesting that CREB activity is modulated in a cell-type-specific manner through interaction with ATF-43. ATF-43 polypeptides do not appear simply to correspond to the gene products of the ATF multigene family, suggesting that the size of the ATF family at the protein level is even larger than predicted from cDNA-cloning studies.

Molecular interactions involved in the transactivation of the human T-cell leukemia virus type 1 promoter mediated by Tax and CREB-2 (ATF-4).

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Gachon, F; Thebault, S; Peleraux, A; Devaux, C; Mesnard, J M

2000-05-01

The human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates viral transcription through three 21-bp repeats located in the U3 region of the HTLV-1 long terminal repeat and called Tax-responsive elements (TxREs). Each TxRE contains nucleotide sequences corresponding to imperfect cyclic AMP response elements (CRE). In this study, we demonstrate that the bZIP transcriptional factor CREB-2 is able to bind in vitro to the TxREs and that CREB-2 binding to each of the 21-bp motifs is enhanced by Tax. We also demonstrate that Tax can weakly interact with CREB-2 bound to a cellular palindromic CRE motif such as that found in the somatostatin promoter. Mutagenesis of Tax and CREB-2 demonstrates that both N- and C-terminal domains of Tax and the C-terminal region of CREB-2 are required for direct interaction between the two proteins. In addition, the Tax mutant M47, defective for HTLV-1 activation, is unable to form in vitro a ternary complex with CREB-2 and TxRE. In agreement with recent results suggesting that Tax can recruit the coactivator CREB-binding protein (CBP) on the HTLV-1 promoter, we provide evidence that Tax, CREB-2, and CBP are capable of cooperating to stimulate viral transcription. Taken together, our data highlight the major role played by CREB-2 in Tax-mediated transactivation.

Suppressing cAMP response element-binding protein transcription shortens the duration of status epilepticus and decreases the number of spontaneous seizures in the pilocarpine model of epilepsy.

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Zhu, Xinjian; Dubey, Deepti; Bermudez, Camilo; Porter, Brenda E

2015-12-01

Current epilepsy therapies directed at altering the function of neurotransmitter receptors or ion channels, or release of synaptic vesicles fail to prevent seizures in approximately 30% of patients. A better understanding of the molecular mechanism underlying epilepsy is needed to provide new therapeutic targets. The activity of cyclic AMP (cAMP) response element-binding protein (CREB), a major transcription factor promoting CRE-mediated transcription, increases following a prolonged seizure called status epilepticus. It is also increased in the seizure focus of patients with medically intractable focal epilepsy. Herein we explored the effect of acute suppression of CREB activity on status epilepticus and spontaneous seizures in a chronic epilepsy model. Pilocarpine chemoconvulsant was used to induce status epilepticus. To suppress CREB activity, a transgenic mouse line expressing an inducible dominant negative mutant of CREB (CREB(IR) ) with a serine to alanine 133 substitution was used. Status epilepticus and spontaneous seizures of transgenic and wild-type mice were analyzed using video-electroencephalography (EEG) to assess the effect of CREB suppression on seizures. Our findings indicate that activation of CREB(IR) shortens the duration of status epilepticus. The frequency of spontaneous seizures decreased in mice with chronic epilepsy during CREB(IR) induction; however, the duration of the spontaneous seizures was unchanged. Of interest, we found significantly reduced levels of phospho-CREB Ser133 upon activation of CREB(IR) , supporting prior work suggesting that binding to the CRE site is important for CREB phosphorylation. Our results suggest that CRE transcription supports seizure activity both during status epilepticus and in spontaneous seizures. Thus, blocking of CRE transcription is a novel target for the treatment of epilepsy. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Regulatory motifs for CREB-binding protein and Nfe2l2 transcription factors in the upstream enhancer of the mitochondrial uncoupling protein 1 gene.

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Rim, Jong S; Kozak, Leslie P

2002-09-13

Thermogenesis against cold exposure in mammals occurs in brown adipose tissue (BAT) through mitochondrial uncoupling protein (UCP1). Expression of the Ucp1 gene is unique in brown adipocytes and is regulated tightly. The 5'-flanking region of the mouse Ucp1 gene contains cis-acting elements including PPRE, TRE, and four half-site cAMP-responsive elements (CRE) with BAT-specific enhancer elements. In the course of analyzing how these half-site CREs are involved in Ucp1 expression, we found that a DNA regulatory element for NF-E2 overlaps CRE2. Electrophoretic mobility shift assay and competition assays with the CRE2 element indicates that nuclear proteins from BAT, inguinal fat, and retroperitoneal fat tissue interact with the CRE2 motif (CGTCA) in a specific manner. A supershift assay using an antibody against the CRE-binding protein (CREB) shows specific affinity to the complex from CRE2 and nuclear extract of BAT. Additionally, Western blot analysis for phospho-CREB/ATF1 shows an increase in phosphorylation of CREB/ATF1 in HIB-1B cells after norepinephrine treatment. Transient transfection assay using luciferase reporter constructs also indicates that the two half-site CREs are involved in transcriptional regulation of Ucp1 in response to norepinephrine and cAMP. We also show that a second DNA regulatory element for NF-E2 is located upstream of the CRE2 region. This element, which is found in a similar location in the 5'-flanking region of the human and rodent Ucp1 genes, shows specific binding to rat and human NF-E2 by electrophoretic mobility shift assay with nuclear extracts from brown fat. Co-transfections with an Nfe2l2 expression vector and a luciferase reporter construct of the Ucp1 enhancer region provide additional evidence that Nfe2l2 is involved in the regulation of Ucp1 by cAMP-mediated signaling.

CREB Regulates Experience-Dependent Spine Formation and Enlargement in Mouse Barrel Cortex

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Annabella Pignataro

2015-01-01

Full Text Available Experience modifies synaptic connectivity through processes that involve dendritic spine rearrangements in neuronal circuits. Although cAMP response element binding protein (CREB has a key function in spines changes, its role in activity-dependent rearrangements in brain regions of rodents interacting with the surrounding environment has received little attention so far. Here we studied the effects of vibrissae trimming, a widely used model of sensory deprivation-induced cortical plasticity, on processes associated with dendritic spine rearrangements in the barrel cortex of a transgenic mouse model of CREB downregulation (mCREB mice. We found that sensory deprivation through prolonged whisker trimming leads to an increased number of thin spines in the layer V of related barrel cortex (Contra in wild type but not mCREB mice. In the barrel field controlling spared whiskers (Ipsi, the same trimming protocol results in a CREB-dependent enlargement of dendritic spines. Last, we demonstrated that CREB regulates structural rearrangements of synapses that associate with dynamic changes of dendritic spines. Our findings suggest that CREB plays a key role in dendritic spine dynamics and synaptic circuits rearrangements that account for new brain connectivity in response to changes in the environment.

Appetitive Pavlovian conditioned stimuli increase CREB phosphorylation in the nucleus accumbens.

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Shiflett, Michael W; Mauna, Jocelyn C; Chipman, Amanda M; Peet, Eloise; Thiels, Edda

2009-10-01

The transcription factor cAMP response element-binding protein (CREB) in the nucleus accumbens (NAc) has been shown to regulate an animal's behavioral responsiveness to emotionally salient stimuli, and an increase in CREB phosphorylation in the NAc has been observed during exposure to rewarding stimuli, such as drugs of abuse. Here we show that CREB phosphorylation increases in the NAc also during exposure to cues that an animal has associated with delivery of natural rewards. Adult male Sprague-Dawley rats (rattus norvegicus) were trained to associate an auditory stimulus with delivery of food pellets, and CREB phosphorylation was examined in the striatum following training. We found that repeated tone-food pairings resulted in an increase in CREB phosphorylation in the NAc but not in the adjacent dorsal striatum or in the NAc 3h after the final training session. We further found that the cue itself, as opposed to the food pellets, the training context, or tone-food pairings, was sufficient to increase CREB phosphorylation in the NAc. These results suggest that the processing of primary rewarding stimuli and of environmental cues that predict them triggers similar accumbal signaling mechanisms.

Hepatic CREB3L3 controls whole-body energy homeostasis and improves obesity and diabetes.

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Nakagawa, Yoshimi; Satoh, Aoi; Yabe, Sachiko; Furusawa, Mika; Tokushige, Naoko; Tezuka, Hitomi; Mikami, Motoki; Iwata, Wakiko; Shingyouchi, Akiko; Matsuzaka, Takashi; Kiwata, Shiori; Fujimoto, Yuri; Shimizu, Hidehisa; Danno, Hirosuke; Yamamoto, Takashi; Ishii, Kiyoaki; Karasawa, Tadayoshi; Takeuchi, Yoshinori; Iwasaki, Hitoshi; Shimada, Masako; Kawakami, Yasushi; Urayama, Osamu; Sone, Hirohito; Takekoshi, Kazuhiro; Kobayashi, Kazuto; Yatoh, Shigeru; Takahashi, Akimitsu; Yahagi, Naoya; Suzuki, Hiroaki; Yamada, Nobuhiro; Shimano, Hitoshi

2014-12-01

Transcriptional regulation of metabolic genes in the liver is the key to maintaining systemic energy homeostasis during starvation. The membrane-bound transcription factor cAMP-responsive element-binding protein 3-like 3 (CREB3L3) has been reported to be activated during fasting and to regulate triglyceride metabolism. Here, we show that CREB3L3 confers a wide spectrum of metabolic responses to starvation in vivo. Adenoviral and transgenic overexpression of nuclear CREB3L3 induced systemic lipolysis, hepatic ketogenesis, and insulin sensitivity with increased energy expenditure, leading to marked reduction in body weight, plasma lipid levels, and glucose levels. CREB3L3 overexpression activated gene expression levels and plasma levels of antidiabetic hormones, including fibroblast growth factor 21 and IGF-binding protein 2. Amelioration of diabetes by hepatic activation of CREB3L3 was also observed in several types of diabetic obese mice. Nuclear CREB3L3 mutually activates the peroxisome proliferator-activated receptor (PPAR) α promoter in an autoloop fashion and is crucial for the ligand transactivation of PPARα by interacting with its transcriptional regulator, peroxisome proliferator-activated receptor gamma coactivator-1α. CREB3L3 directly and indirectly controls fibroblast growth factor 21 expression and its plasma level, which contributes at least partially to the catabolic effects of CREB3L3 on systemic energy homeostasis in the entire body. Therefore, CREB3L3 is a therapeutic target for obesity and diabetes.

Knock-in Luciferase Reporter Mice for In Vivo Monitoring of CREB Activity.

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Dmitry Akhmedov

Full Text Available The cAMP response element binding protein (CREB is induced during fasting in the liver, where it stimulates transcription of rate-limiting gluconeogenic genes to maintain metabolic homeostasis. Adenoviral and transgenic CREB reporters have been used to monitor hepatic CREB activity non-invasively using bioluminescence reporter imaging. However, adenoviral vectors and randomly inserted transgenes have several limitations. To overcome disadvantages of the currently used strategies, we created a ROSA26 knock-in CREB reporter mouse line (ROSA26-CRE-luc. cAMP-inducing ligands stimulate the reporter in primary hepatocytes and myocytes from ROSA26-CRE-luc animals. In vivo, these animals exhibit little hepatic CREB activity in the ad libitum fed state but robust induction after fasting. Strikingly, CREB was markedly stimulated in liver, but not in skeletal muscle, after overnight voluntary wheel-running exercise, uncovering differential regulation of CREB in these tissues under catabolic states. The ROSA26-CRE-luc mouse line is a useful resource to study dynamics of CREB activity longitudinally in vivo and can be used as a source of primary cells for analysis of CREB regulatory pathways ex vivo.

Rescue of cAMP response element-binding protein signaling reversed spatial memory retention impairments induced by subanesthetic dose of propofol.

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Zhang, Hao; Zhang, Shao-Bo; Zhang, Qing-Qing; Liu, Meng; He, Xing-Ying; Zou, Zui; Sun, Hai-Jing; You, Zhen-Dong; Shi, Xue-Yin

2013-07-01

The intravenous anesthetic propofol caused episodic memory impairments in human. We hypothesized propofol caused episodic-like spatial memory retention but not acquisition impairments in rats and rescuing cAMP response element-binding protein (CREB) signaling using selective type IV phosphodiesterase (PDEIV) inhibitor rolipram reversed these effects. Male Sprague-Dawley rats were randomized into four groups: control; propofol (25 mg/kg, intraperitoneal); rolipram; and rolipram + propofol (pretreatment of rolipram 25 min before propofol, 0.3 mg/kg, intraperitoneal). Sedation and motor coordination were evaluated 5, 15, and 25 min after propofol injection. Invisible Morris water maze (MWM) acquisition and probe test (memory retention) were performed 5 min and 24 h after propofol injection. Visible MWM training was simultaneously performed to resist nonspatial effects. Hippocampal CREB signaling was detected 5 min, 50 min, and 24 h after propofol administration. Rolipram did not change propofol-induced anesthetic/sedative states or impair motor skills. No difference was found on the latency to the platform during the visible MWM. Propofol impaired spatial memory retention but not acquisition. Rolipram reversed propofol-induced spatial memory impairments and suppression on cAMP levels, CaMKIIα and CREB phosphorylation, brain-derived neurotropic factor (BDNF) and Arc protein expression. Propofol caused spatial memory retention impairments but not acquisition inability possibly by inhibiting CREB signaling. © 2013 John Wiley & Sons Ltd.

O-GlcNAcylation modulates PKA-CREB signaling in a manner specific to PKA catalytic subunit isoforms.

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Jin, Nana; Ma, Denglei; Gu, Jianlan; Shi, Jianhua; Xu, Xiaotao; Iqbal, Khalid; Gong, Cheng-Xin; Liu, Fei; Chu, Dandan

2018-02-26

O-GlcNAcylation is a post-translational modification of proteins. Protein kinase A (PKA)-cAMP response element binding protein (CREB) signaling plays critical roles in multiple biological processes. Isoforms α and β of PKA catalytic subunit (PKAc) and CREB are modified by O-GlcNAcylation. In the present study, we determined the role of O-GlcNAcylation in PKAc isoform-specific CREB signaling. We found that up-regulation of O-GlcNAcylation enhanced CREB phosphorylation, but suppressed CREB expression in exogenous PKAc isoform-unspecific manner. PKAc isoforms affected exogenous expression of OGT or OGA and protein O-GlcNAcylation differently. Up-regulation of O-GlcNAcylation did not significantly affect net PKAcα-CREB signaling, but enhanced PKAcβ-CREB signaling. The role of O-GlcNAcylation in PKA-CREB signaling was desensitized by insulin treatment. This study suggests a role of O-GlcNAcylation in PKA-CREB signaling by affecting phosphorylation of CREB in a PKAc isoform-specific manner. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

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Park, Serk In, E-mail: serkin@korea.edu [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); The BK21 Plus Program for Biomedical Sciences, Korea University College of Medicine, Seoul (Korea, Republic of); Department of Medicine and Center for Bone Biology, Vanderbilt University School of Medicine, Nashville, TN (United States); Park, Sung-Jun [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Laboratory of Obesity and Aging Research, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Park, Yun Gyu, E-mail: parkyg@korea.ac.kr [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

2016-01-15

The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

International Nuclear Information System (INIS)

Park, Serk In; Park, Sung-Jun; Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won; Park, Yun Gyu

2016-01-01

The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

Roles of p300 and cyclic adenosine monophosphate response element binding protein in high glucose-induced hypoxia-inducible factor 1α inactivation under hypoxic conditions.

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Ding, Lingtao; Yang, Minlie; Zhao, Tianlan; Lv, Guozhong

2017-05-01

Given the high prevalence of diabetes and burn injuries worldwide, it is essential to dissect the underlying mechanism of delayed burn wound healing in diabetes patients, especially the high glucose-induced hypoxia-inducible factor 1 (HIF-1)-mediated transcription defects. Human umbilical vein endothelial cells were cultured with low or high concentrations of glucose. HIF-1α-induced vascular endothelial growth factor (VEGF) transcription was measured by luciferase assay. Immunofluorescence staining was carried out to visualize cyclic adenosine monophosphate response element binding protein (CREB) localization. Immunoprecipitation was carried out to characterize the association between HIF-1α/p300/CREB. To test whether p300, CREB or p300+CREB co-overexpression was sufficient to rescue the HIF-1-mediated transcription defect after high glucose exposure, p300, CREB or p300+CREB co-overexpression were engineered, and VEGF expression was quantified. Finally, in vitro angiogenesis assay was carried out to test whether the high glucose-induced angiogenesis defect is rescuable by p300 and CREB co-overexpression. Chronic high glucose treatment resulted in impaired HIF-1-induced VEGF transcription and CREB exclusion from the nucleus. P300 or CREB overexpression alone cannot rescue high glucose-induced HIF-1α transcription defects. In contrast, co-overexpression of p300 and CREB dramatically ameliorated high glucose-induced impairment of HIF-1-mediated VEGF transcription, as well as in vitro angiogenesis. Finally, we showed that co-overexpression of p300 and CREB rectifies the dissociation of HIF-1α-p300-CREB protein complex in chronic high glucose-treated cells. Both p300 and CREB are required for the function integrity of HIF-1α transcription machinery and subsequent angiogenesis, suggesting future studies to improve burn wound healing might be directed to optimization of the interaction between p300, CREB and HIF-1α. © 2016 The Authors. Journal of Diabetes

cAMP response element binding protein1 is essential for activation of steroyl co-enzyme a desaturase 1 (Scd1 in mouse lung type II epithelial cells.

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Nisha Antony

Full Text Available Cyclic AMP Response Element-Binding Protein 1 (Creb1 is a transcription factor that mediates cyclic adenosine 3', 5'-monophosphate (cAMP signalling in many tissues. Creb1(-/- mice die at birth due to respiratory failure and previous genome-wide microarray analysis of E17.5 Creb1(-/- fetal mouse lung identified important Creb1-regulated gene targets during lung development. The lipogenic enzymes stearoyl-CoA desaturase 1 (Scd1 and fatty acid synthase (Fasn showed highly reduced gene expression in Creb1(-/- lungs. We therefore hypothesized that Creb1 plays a crucial role in the transcriptional regulation of genes involved in pulmonary lipid biosynthetic pathways during lung development. In this study we confirmed that Scd1 and Fasn mRNA levels were down regulated in the E17.5 Creb1(-/- mouse lung while the lipogenic-associated transcription factors SrebpF1, C/ebpα and Pparγ were increased. In vivo studies using germline (Creb1(-/- and lung epithelial-specific (Creb1(EpiΔ/Δ Creb1 knockout mice showed strongly reduced Scd1, but not Fasn gene expression and protein levels in lung epithelial cells. In vitro studies using mouse MLE-15 epithelial cells showed that forskolin-mediated activation of Creb1 increased both Scd1 gene expression and protein synthesis. Additionally, MLE15 cells transfected with a dominant-negative ACreb vector blocked forskolin-mediated stimulation of Scd1 gene expression. Lipid profiling in MLE15 cells showed that dominant-negative ACreb suppressed forskolin-induced desaturation of ether linked lipids to produce plasmalogens, as well as levels of phosphatidylethanolamine, ceramide and lysophosphatidylcholine. Taken together these results demonstrate that Creb1 is essential for the induction and maintenance of Scd1 in developing fetal mouse lung epithelial cells.

The transcription factor cyclic adenosine 3',5'-monophosphate response element-binding protein enhances the odonto/osteogenic differentiation of stem cells from the apical papilla.

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Su, S; Zhu, Y; Li, S; Liang, Y; Zhang, J

2017-09-01

To investigate the role of cAMP response element-binding protein (CREB) in the regulation of odonto/osteogenic differentiation of stem cells from the apical papilla (SCAPs). Stem cells from the apical papilla were obtained from human impacted third molars (n = 15). Isolated SCAPs were transfected with CREB overexpressing/silenced lentivirus. Transfected cells were stained with alizarin red to investigate mineralized nodule formation. The expression of the mineralization-related genes, alkaline phosphatase (ALP), collagen type I (Col I), runt-related transcription factor 2 (RUNX2), osterix (OSX) and osteocalcin (OCN), was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Protein expression of the odontogenic-related marker dentine sialoprotein (DSP) and the osteogenic-related marker RUNX2 was measured by Western blotting analysis. One-way analysis of variance (anova) and Student's t-test were used for statistical analysis (a = 0.05). The overexpression of CREB enhanced mineralized nodule formation and up-regulated (P odonto/osteogenic-related markers, including ALP, Col I, RUNX2, OSX and OCN, and also increased (P odonto/osteogenic-related markers. Up-regulation of CREB expression promoted odonto/osteogenic differentiation of SCAPs and provided a potential method for the regeneration of the dentine-pulp complex. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The cellular transcription factor CREB corresponds to activating transcription factor 47 (ATF-47) and forms complexes with a group of polypeptides related to ATF-43.

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Hurst, H C; Masson, N; Jones, N C; Lee, K A

1990-01-01

Promoter elements containing the sequence motif CGTCA are important for a variety of inducible responses at the transcriptional level. Multiple cellular factors specifically bind to these elements and are encoded by a multigene family. Among these factors, polypeptides termed activating transcription factor 43 (ATF-43) and ATF-47 have been purified from HeLa cells and a factor referred to as cyclic AMP response element-binding protein (CREB) has been isolated from PC12 cells and rat brain. We...

DPPC regulates COX-2 expression in monocytes via phosphorylation of CREB

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Morris, R.H.K.; Tonks, A.J.; Jones, K.P.; Ahluwalia, M.K.; Thomas, A.W.; Tonks, A.; Jackson, S.K.

2008-01-01

The major phospholipid in pulmonary surfactant dipalmitoyl phosphatidylcholine (DPPC) has been shown to modulate inflammatory responses. Using human monocytes, this study demonstrates that DPPC significantly increased PGE 2 (P < 0.05) production by 2.5-fold when compared to untreated monocyte controls. Mechanistically, this effect was concomitant with an increase in COX-2 expression which was abrogated in the presence of a COX-2 inhibitor. The regulation of COX-2 expression was independent of NF-κB activity. Further, DPPC increased the phosphorylation of the cyclic AMP response element binding protein (CREB; an important nuclear transcription factor important in regulating COX-2 expression). In addition, we also show that changing the fatty acid groups of PC (e.g. using L-α-phosphatidylcholine β-arachidonoyl-γ-palmitoyl (PAPC)) has a profound effect on the regulation of COX-2 expression and CREB activation. This study provides new evidence for the anti-inflammatory activity of DPPC and that this activity is at least in part mediated via CREB activation of COX-2

Learning-dependent gene expression of CREB1 isoforms in the molluscan brain

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Hisayo Sadamoto

2010-05-01

Full Text Available Cyclic AMP-responsive element binding protein1 (CREB1 has multiple functions in gene regulation. Various studies have reported that CREB1-dependent gene induction is necessary for memory formation and long-lasting behavioral changes in both vertebrates and invertebrates. In the present study, we characterized Lymnaea CREB1 (LymCREB1 mRNA isoforms of spliced variants in the central nervous system (CNS of the pond snail Lymnaea stagnalis. Among these spliced variants, the three isoforms that code a whole LymCREB1 protein are considered to be the activators for gene regulation. The other four isoforms, which code truncated LymCREB1 proteins with no kinase inducible domain, are the repressors. For a better understanding of the possible roles of different LymCREB1 isoforms, the expression level of these isoform mRNAs was investigated by a real-time quantitative RT-PCR method. Further, we examined the changes in gene expression for all the isoforms in the CNS after conditioned taste aversion (CTA learning or backward conditioning as a control. The results showed that CTA learning increased LymCREB1 gene expression, but it did not change the activator/repressor ratio. Our findings showed that the repressor isoforms, as well as the activator ones, are expressed in large amounts in the CNS, and the gene expression of CREB1 isoforms appeared to be specific for the given stimulus. This was the first quantitative analysis of the expression patterns of CREB1 isoforms at the mRNA level and their association with learning behavior.

The Inhibitory Effect of Somatostatin Receptor Activation on Bee Venom-Evoked Nociceptive Behavior and pCREB Expression in Rats

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Li Li

2014-01-01

Full Text Available The present study examined nociceptive behaviors and the expression of phosphorylated cAMP response element-binding protein (pCREB in the dorsal horn of the lumbar spinal cord and the dorsal root ganglion (DRG evoked by bee venom (BV. The effect of intraplantar preapplication of the somatostatin analog octreotide on nociceptive behaviors and pCREB expression was also examined. Subcutaneous injection of BV into the rat unilateral hindpaw pad induced significant spontaneous nociceptive behaviors, primary mechanical allodynia, primary thermal hyperalgesia, and mirror-thermal hyperalgesia, as well as an increase in pCREB expression in the lumbar spinal dorsal horn and DRG. Octreotide pretreatment significantly attenuated the BV-induced lifting/licking response and mechanical allodynia. Local injection of octreotide also significantly reduced pCREB expression in the lumbar spinal dorsal horn and DRG. Furthermore, pretreatment with cyclosomatostatin, a somatostatin receptor antagonist, reversed the octreotide-induced inhibition of the lifting/licking response, mechanical allodynia, and the expression of pCREB. These results suggest that BV can induce nociceptive responses and somatostatin receptors are involved in mediating the antinociception, which provides new evidence for peripheral analgesic action of somatostatin in an inflammatory pain state.

CREB expression in the brains of two closely related parasitic wasp species that differ in long-term memory formation

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Van den Berg, M.; Verbaarschot, P.; Hontelez, S.; Vet, L.E.M.; Dicke, M.; Smid, H.M.

2010-01-01

The cAMP/PKA signalling pathway and transcription factor cAMP response element-binding protein (CREB) play key roles in long-term memory (LTM) formation. We used two closely related parasitic wasp species, Cotesia glomerata and Cotesia rubecula, which were previously shown to be different in LTM

CREB Overexpression Ameliorates Age-related Behavioral and Biophysical Deficits

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Yu, Xiao-Wen

Age-related cognitive deficits are observed in both humans and animals. Yet, the molecular mechanisms underlying these deficits are not yet fully elucidated. In aged animals, a decrease in intrinsic excitability of pyramidal neurons from the CA1 sub-region of hippocampus is believed to contribute to age-related cognitive impairments, but the molecular mechanism(s) that modulate both these factors has yet to be identified. Increasing activity of the transcription factor cAMP response element-binding protein (CREB) in young adult rodents has been shown to facilitate cognition, and increase intrinsic excitability of their neurons. However, how CREB changes with age, and how that impacts cognition in aged animals, is not clear. Therefore, we first systematically characterized age- and training-related changes in CREB levels in dorsal hippocampus. At a remote time point after undergoing behavioral training, levels of total CREB and activated CREB (phosphorylated at S133, pCREB) were measured in both young and aged rats. We found that pCREB, but not total CREB was significantly reduced in dorsal CA1 of aged rats. Importantly, levels of pCREB were found to be positively correlated with short-term spatial memory in both young and aged rats i.e. higher pCREB in dorsal CA1 was associated with better spatial memory. These findings indicate that an age-related deficit in CREB activity may contribute to the development of age-related cognitive deficits. However, it was still unclear if increasing CREB activity would be sufficient to ameliorate age-related cognitive, and biophysical deficits. To address this question, we virally overexpressed CREB in CA1, where we found the age-related deficit. Young and aged rats received control or CREB virus, and underwent water maze training. While control aged animals exhibited deficits in long-term spatial memory, aged animals with CREB overexpression performed at levels comparable to young animals. Concurrently, aged neurons

cAMP response element-binding protein in the amygdala is required for long- but not short-term conditioned taste aversion memory.

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Lamprecht, R; Hazvi, S; Dudai, Y

1997-11-01

In conditioned taste aversion (CTA) organisms learn to avoid a taste if the first encounter with that taste is followed by transient poisoning. The neural mechanisms that subserve this robust and long-lasting association of taste and malaise have not yet been elucidated, but several brain areas have been implicated in the process, including the amygdala. In this study we investigated the role of amygdala in general, and the cAMP response element-binding protein (CREB) in the amygdala in particular, in CTA learning and memory. Toward that end, we combined antisense technology in vivo with behavioral, molecular, and histochemical analysis. Local microinjection of phosphorothioate-modified oligodeoxynucleotides (ODNs) antisense to CREB into the rat amygdala several hours before CTA training transiently reduced the level of CREB protein during training and impaired CTA memory when tested 3-5 d later. In comparison, sense ODNs had no effect on memory. The effect of antisense was not attributable to differential tissue damage and was site-specific. CREB antisense in the amygdala had no effect on retrieval of CTA memory once it had been formed, and did not affect short-term CTA memory. We propose that the amygdala, specifically the central nucleus, is required for the establishment of long-term CTA memory in the behaving rat; that the process involves long-term changes, subserved by CRE-regulated gene expression, in amygdala neurons; and that the amygdala may retain some CTA-relevant information over time rather than merely modulating the gustatory trace during acquisition of CTA.

Identification of CREB3L1 as a Biomarker Predicting Doxorubicin Treatment Outcome.

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Bray Denard

Full Text Available Doxorubicin has been shown to inhibit proliferation of cancer cells through proteolytic activation of CREB3L1 (cAMP response element binding protein 3-like 1, a transcription factor synthesized as a membrane-bound precursor. Upon doxorubicin treatment, CREB3L1 is cleaved so that the N-terminal domain of the protein can reach the nucleus where it activates transcription of genes that inhibit cell proliferation. These results suggest that the level of CREB3L1 in cancer cells may determine their sensitivity to doxorubicin.Mice transplanted with 6 lines of renal cell carcinoma (RCC were injected with doxorubicin to observe the effect of the chemotherapy on tumor growth. Immunohistochemistry and bioinformatics analyses were performed to compare CREB3L1 levels in types of cancer known to respond to doxorubicin versus those resistant to doxorubicin.Higher levels of CREB3L1 protein are correlated with increased doxorubicin sensitivity of xenograft RCC tumors (p = 0.017 by Pearson analysis. From patient tumor biopsies we analyzed, CREB3L1 was expressed in 19% of RCC, which is generally resistant to doxorubicin, but in 70% of diffuse large B-cell lymphoma that is sensitive to doxorubicin. Doxorubicin is used as the standard treatment for cancers that express the highest levels of CREB3L1 such as osteosarcoma and malignant fibrous histiocytoma but is not generally used to treat those that express the lowest levels of CREB3L1 such as RCC.Identification of CREB3L1 as the biomarker for doxorubicin sensitivity may markedly improve the doxorubicin response rate by applying doxorubicin only to patients with cancers expressing CREB3L1.

Two Alkaloids from Bulbs of Lycoris sanguinea MAXIM. Suppress PEPCK Expression by Inhibiting the Phosphorylation of CREB.

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Yun, Young Sook; Tajima, Miki; Takahashi, Shigeru; Takahashi, Yuji; Umemura, Mariko; Nakano, Haruo; Park, Hyun Sun; Inoue, Hideshi

2016-10-01

In the fasting state, gluconeogenesis is upregulated by glucagon. Glucagon stimulates cyclic adenosine monophosphate production, which induces the expression of key enzymes for gluconeogenesis, such as cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), which are involved in gluconeogenesis through the protein kinase A/cAMP response element-binding protein (CREB) pathway. Using a luciferase reporter gene assay, a methanol extract of the bulbs of Lycoris sanguinea M AXIM. var. kiushiana Makino was found to suppress cAMP-enhanced PEPCK-C promoter activity. In addition, two alkaloids, lycoricidine and lycoricidinol, in the extract were identified as active constituents. In forskolin-stimulated human hepatoma cells, these alkaloids suppressed the expression of a reporter gene under the control of cAMP response element and also prevented increases in the endogenous levels of phosphorylated CREB and PEPCK mRNA expression. These results suggest that lycoricidine and lycoricidinol suppress PEPCK-C expression by inhibiting the phosphorylation of CREB and may thus have the potential to prevent excessive gluconeogenesis in type 2 diabetes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Histone acetylation and CREB binding protein are required for neuronal resistance against ischemic injury.

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Ferah Yildirim

Full Text Available Epigenetic transcriptional regulation by histone acetylation depends on the balance between histone acetyltransferase (HAT and deacetylase activities (HDAC. Inhibition of HDAC activity provides neuroprotection, indicating that the outcome of cerebral ischemia depends crucially on the acetylation status of histones. In the present study, we characterized the changes in histone acetylation levels in ischemia models of focal cerebral ischemia and identified cAMP-response element binding protein (CREB-binding protein (CBP as a crucial factor in the susceptibility of neurons to ischemic stress. Both neuron-specific RNA interference and neurons derived from CBP heterozygous knockout mice showed increased damage after oxygen-glucose deprivation (OGD in vitro. Furthermore, we demonstrated that ischemic preconditioning by a short (5 min subthreshold occlusion of the middle cerebral artery (MCA, followed 24 h afterwards by a 30 min occlusion of the MCA, increased histone acetylation levels in vivo. Ischemic preconditioning enhanced CBP recruitment and histone acetylation at the promoter of the neuroprotective gene gelsolin leading to increased gelsolin expression in neurons. Inhibition of CBP's HAT activity attenuated neuronal ischemic preconditioning. Taken together, our findings suggest that the levels of CBP and histone acetylation determine stroke outcome and are crucially associated with the induction of an ischemia-resistant state in neurons.

Creb1 regulates late stage mammalian lung development via respiratory epithelial and mesenchymal-independent mechanisms

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Antony, N.; McDougall, A. R.; Mantamadiotis, T.; Cole, T. J.; Bird, A. D.

2016-01-01

During mammalian lung development, the morphological transition from respiratory tree branching morphogenesis to a predominantly saccular architecture, capable of air-breathing at birth, is dependent on physical forces as well as molecular signaling by a range of transcription factors including the cAMP response element binding protein 1 (Creb1). Creb1−/− mutant mice exhibit complete neonatal lethality consistent with a lack of lung maturation beyond the branching phase. To further define its role in the developing mouse lung, we deleted Creb1 separately in the respiratory epithelium and mesenchyme. Surprisingly, we found no evidence of a morphological lung defect nor compromised neonatal survival in either conditional Creb1 mutant. Interestingly however, loss of mesenchymal Creb1 on a genetic background lacking the related Crem protein showed normal lung development but poor neonatal survival. To investigate the underlying requirement for Creb1 for normal lung development, Creb1−/− mice were re-examined for defects in both respiratory muscles and glucocorticoid hormone signaling, which are also required for late stage lung maturation. However, these systems appeared normal in Creb1−/− mice. Together our results suggest that the requirement of Creb1 for normal mammalian lung morphogenesis is not dependent upon its expression in lung epithelium or mesenchyme, nor its role in musculoskeletal development. PMID:27150575

Adenovirus DNA binding protein inhibits SrCap-activated CBP and CREB-mediated transcription

International Nuclear Information System (INIS)

Xu Xiequn; Tarakanova, Vera; Chrivia, John; Yaciuk, Peter

2003-01-01

The SNF2-related CBP activator protein (SrCap) is a potent activator of transcription mediated by CBP and CREB. We have previously demonstrated that the Adenovirus 2 DNA Binding Protein (DBP) binds to SrCap and inhibits the transcription mediated by the carboxyl-terminal region of SrCap (amino acids 1275-2971). We report here that DBP inhibits the ability of full-length SrCap (1-2971) to activate transcription mediated by Gal-CREB and Gal-CBP. In addition, DBP also inhibits the ability of SrCap to enhance Protein Kinase A (PKA) activated transcription of the enkaphalin promoter. DBP was found to dramatically inhibit transcription of a mammalian two-hybrid system that was dependent on the interaction of SrCap and CBP binding domains. We also found that DBP has no effect on transcription mediated by a transcriptional activator that is not related to SrCap, indicating that our reported transcriptional inhibition is specific for SrCap and not due to nonspecific effects of DBP's DNA binding activity on the CAT reporter plasmid. Taken together, these results suggest a model in which DBP inhibits cellular transcription mediated by the interaction between SrCap and CBP

ABFs, a family of ABA-responsive element binding factors.

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Choi, H; Hong, J; Ha, J; Kang, J; Kim, S Y

2000-01-21

Abscisic acid (ABA) plays an important role in environmental stress responses of higher plants during vegetative growth. One of the ABA-mediated responses is the induced expression of a large number of genes, which is mediated by cis-regulatory elements known as abscisic acid-responsive elements (ABREs). Although a number of ABRE binding transcription factors have been known, they are not specifically from vegetative tissues under induced conditions. Considering the tissue specificity of ABA signaling pathways, factors mediating ABA-dependent stress responses during vegetative growth phase may thus have been unidentified so far. Here, we report a family of ABRE binding factors isolated from young Arabidopsis plants under stress conditions. The factors, isolated by a yeast one-hybrid system using a prototypical ABRE and named as ABFs (ABRE binding factors) belong to a distinct subfamily of bZIP proteins. Binding site selection assay performed with one ABF showed that its preferred binding site is the strong ABRE, CACGTGGC. ABFs can transactivate an ABRE-containing reporter gene in yeast. Expression of ABFs is induced by ABA and various stress treatments, whereas their induction patterns are different from one another. Thus, a new family of ABRE binding factors indeed exists that have the potential to activate a large number of ABA/stress-responsive genes in Arabidopsis.

Two CGTCA motifs and a GHF1/Pit1 binding site mediate cAMP-dependent protein kinase A regulation of human growth hormone gene expression in rat anterior pituitary GC cells.

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Shepard, A R; Zhang, W; Eberhardt, N L

1994-01-21

We established the cis-acting elements which mediate cAMP responsiveness of the human growth hormone (hGH) gene in transiently transfected rat anterior pituitary tumor GC cells. Analysis of the intact hGH gene or hGH 5'-flanking DNA (5'-FR) coupled to the hGh cDNA or chloramphenicol acetyltransferase or luciferase genes, indicated that cAMP primarily stimulated hGH promoter activity. Cotransfection of a protein kinase A inhibitory protein cDNA demonstrated that the cAMP response was mediated by protein kinase A. Mutational analysis of the hGH promoter identified two core cAMP response element motifs (CGTCA) located at nucleotides -187/-183 (distal cAMP response element; dCRE) and -99/-95 (proximal cAMP response element; pCRE) and a pituitary-specific transcription factor (GHF1/Pit1) binding site at nucleotides -123/-112 (dGHF1) which were required for cAMP responsiveness. GHF1 was not a limiting factor, since overexpression of GHF1 in cotransfections increased basal but not forskolin induction levels. Gel shift analyses indicated that similar, ubiquitous, thermostable protein(s) specifically bound the pCRE and dCRE motifs. The CGTCA motif-binding factors were cAMP response element binding protein (CREB)/activating transcription factor-1 (ATF-1)-related, since the DNA-protein complex was competed by unlabeled CREB consensus oligonucleotide, specifically supershifted by antisera to CREB and ATF-1 but not ATF-2, and was bound by purified CREB with the same relative binding affinity (pCRE < dCRE < CREB) and mobility as the GC nuclear extract. UV cross-linking and Southwestern blot analyses revealed multiple DNA-protein interactions of which approximately 100- and approximately 45-kDa proteins were predominant; the approximately 45-kDa protein may represent CREB. These results indicate that CREB/ATF-1-related factors act coordinately with the cell-specific factor GHF1 to mediate cAMP-dependent regulation of hGH-1 gene transcription in anterior pituitary somatotrophs.

CREB activity in dopamine D1 receptor expressing neurons regulates cocaine-induced behavioral effects

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Bilbao, Ainhoa; Rieker, Claus; Cannella, Nazzareno; Parlato, Rosanna; Golda, Slawomir; Piechota, Marcin; Korostynski, Michal; Engblom, David; Przewlocki, Ryszard; Schütz, Günther; Spanagel, Rainer; Parkitna, Jan R.

2014-01-01

It is suggested that striatal cAMP responsive element binding protein (CREB) regulates sensitivity to psychostimulants. To test the cell-specificity of this hypothesis we examined the effects of a dominant-negative CREB protein variant expressed in dopamine receptor D1 (D1R) neurons on cocaine-induced behaviors. A transgenic mouse strain was generated by pronuclear injection of a BAC-derived transgene harboring the A-CREB sequence under the control of the D1R gene promoter. Compared to wild-type, drug-naïve mutants showed moderate alterations in gene expression, especially a reduction in basal levels of activity-regulated transcripts such as Arc and Egr2. The behavioral responses to cocaine were elevated in mutant mice. Locomotor activity after acute treatment, psychomotor sensitization after intermittent drug injections and the conditioned locomotion after saline treatment were increased compared to wild-type littermates. Transgenic mice had significantly higher cocaine conditioned place preference, displayed normal extinction of the conditioned preference, but showed an augmented cocaine-seeking response following priming-induced reinstatement. This enhanced cocaine-seeking response was associated with increased levels of activity-regulated transcripts and prodynorphin. The primary reinforcing effects of cocaine were not altered in the mutant mice as they did not differ from wild-type in cocaine self-administration under a fixed ratio schedule at the training dose. Collectively, our data indicate that expression of a dominant-negative CREB variant exclusively in neurons expressing D1R is sufficient to recapitulate the previously reported behavioral phenotypes associated with virally expressed dominant-negative CREB. PMID:24966820

Glycogen Synthase Kinase 3α Is the Main Isoform That Regulates the Transcription Factors Nuclear Factor-Kappa B and cAMP Response Element Binding in Bovine Endothelial Cells Infected with Staphylococcus aureus

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Octavio Silva-García

2018-01-01

Full Text Available Glycogen synthase kinase 3 (GSK3 is a constitutive enzyme implicated in the regulation of cytokine expression and the inflammatory response during bacterial infections. Mammals have two GSK3 isoforms named GSK3α and GSK3β that plays different but often overlapping functions. Although the role of GSK3β in cytokine regulation during the inflammatory response caused by bacteria is well described, GSK3α has not been found to participate in this process. Therefore, we tested if GSK3α may act as a regulatory isoform in the cytokine expression by bovine endothelial cells infected with Staphylococcus aureus because this bacterium is one of the major pathogens that cause tissue damage associated with inflammatory dysfunction. Interestingly, although both isoforms were phosphorylated–inactivated, we consistently observed a higher phosphorylation of GSK3α at Ser21 than that of GSK3β at Ser9 after bacterial challenge. During a temporal course of infection, we characterized a molecular switch from pro-inflammatory cytokine expression (IL-8, promoted by nuclear factor-kappa B (NF-κB, at an early stage (2 h to an anti-inflammatory cytokine expression (IL-10, promoted by cAMP response element binding (CREB, at a later stage (6 h. We observed an indirect effect of GSK3α activity on NF-κB activation that resulted in a low phosphorylation of CREB at Ser133, a decreased interaction between CREB and the co-activator CREB-binding protein (CBP, and a lower expression level of IL-10. Gene silencing of GSK3α and GSK3β with siRNA indicated that GSK3α knockout promoted the interaction between CREB and CBP that, in turn, increased the expression of IL-10, reduced the interaction of NF-κB with CBP, and reduced the expression of IL-8. These results indicate that GSK3α functions as the primary isoform that regulates the expression of IL-10 in endothelial cells infected with S. aureus.

Fluoxetine increases the activity of the ERK-CREB signal system and alleviates the depressive-like behavior in rats exposed to chronic forced swim stress.

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Qi, Xiaoli; Lin, Wenjuan; Li, Junfa; Li, Huanhuan; Wang, Weiwen; Wang, Donglin; Sun, Meng

2008-08-01

Our previous research indicates that the extracellular signal-regulated kinase (ERK)-cyclic AMP-responsive-element-binding protein (CREB) signal system may be involved in the molecular mechanism of depression. The present study further investigated the effect of antidepressant fluoxetine on the ERK-CREB signal system and the depressive-like behaviors in rats. Fluoxetine was administrated to either naive rats or stressed rats for 21 days. The results showed that chronic forced swim stress induced depressive-like behaviors and decreased the levels of P-ERK2, P-CREB, ERK1/2 and CREB in hippocampus and prefrontal cortex. Fluoxetine alleviated the depressive-like behaviors and reversed the disruptions of the P-ERK2 and P-CREB in stressed rats. Fluoxetine also exerted mood-elevating effect and increased the levels of the P-ERK2 and P-CREB in naive rats. These results suggest that the ERK-CREB signal system may be the targets of the antidepressant action of fluoxetine and participate in the neuronal mechanism of depression.

The Role of CREB, SRF, and MEF2 in Activity-Dependent Neuronal Plasticity in the Visual Cortex.

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Pulimood, Nisha S; Rodrigues, Wandilson Dos Santos; Atkinson, Devon A; Mooney, Sandra M; Medina, Alexandre E

2017-07-12

The transcription factors CREB (cAMP response element binding factor), SRF (serum response factor), and MEF2 (myocyte enhancer factor 2) play critical roles in the mechanisms underlying neuronal plasticity. However, the role of the activation of these transcription factors in the different components of plasticity in vivo is not well known. In this study, we tested the role of CREB, SRF, and MEF2 in ocular dominance plasticity (ODP), a paradigm of activity-dependent neuronal plasticity in the visual cortex. These three proteins bind to the synaptic activity response element (SARE), an enhancer sequence found upstream of many plasticity-related genes (Kawashima et al., 2009; Rodríguez-Tornos et al., 2013), and can act cooperatively to express Arc , a gene required for ODP (McCurry et al., 2010). We used viral-mediated gene transfer to block the transcription function of CREB, SRF, and MEF2 in the visual cortex, and measured visually evoked potentials in awake male and female mice before and after a 7 d monocular deprivation, which allowed us to examine both the depression component (Dc-ODP) and potentiation component (Pc-ODP) of plasticity independently. We found that CREB, SRF, and MEF2 are all required for ODP, but have differential effects on Dc-ODP and Pc-ODP. CREB is necessary for both Dc-ODP and Pc-ODP, whereas SRF and MEF2 are only needed for Dc-ODP. This finding supports previous reports implicating SRF and MEF2 in long-term depression (required for Dc-ODP), and CREB in long-term potentiation (required for Pc-ODP). SIGNIFICANCE STATEMENT Activity-dependent neuronal plasticity is the cellular basis for learning and memory, and it is crucial for the refinement of neuronal circuits during development. Identifying the mechanisms of activity-dependent neuronal plasticity is crucial to finding therapeutic interventions in the myriad of disorders where it is disrupted, such as Fragile X syndrome, Rett syndrome, epilepsy, major depressive disorder, and autism

The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

International Nuclear Information System (INIS)

Zuloaga, R.; Fuentes, E.N.; Molina, A.; Valdés, J.A.

2013-01-01

Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP 3 /calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation

The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

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Zuloaga, R. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Fuentes, E.N.; Molina, A. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile); Valdés, J.A., E-mail: jvaldes@unab.cl [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile)

2013-10-18

Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP{sub 3}/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.

A CREB1 Gene Polymorphism (rs2253206) Is Associated with Prospective Memory in a Healthy Cohort.

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Avgan, Nesli; Sutherland, Heidi G; Lea, Rodney A; Spriggens, Lauren K; Haupt, Larisa M; Shum, David H K; Griffiths, Lyn R

2017-01-01

Prospective memory (PM) is generally defined as remembering to perform intended actions in the future and is important for functioning in daily life. Cyclic adenosine monophosphate (cAMP) responsive element binding protein 1 (CREB1) plays an important role in cognitive functions. In this study, we hypothesized that genetic variation in the CREB1 gene is associated with PM. We genotyped a CREB1 promoter polymorphism rs2253206 and tested it for association with PM in 619 healthy subjects. PM performance was measured using the Prospective and Retrospective Memory Questionnaire (PRMQ), the Comprehensive Assessment of Prospective Memory (CAPM), and the Memory for Intentions Screening Test (MIST). Generalized linear model analysis was conducted for each PM test independently using different inheritance models to identify any associations ( p CAPM instrumental activities of daily living measure ( p = 0.016). These results suggest that the rs2253206 polymorphism in the CREB1 gene locus is associated with PM in healthy individuals and contributes to knowledge on the genetics of this particular type of memory.

CREB binding protein is required for both short-term and long-term memory formation.

NARCIS (Netherlands)

Chen, G.; Zou, X.; Watanabe, H.; Deursen, J.M.A. van; Shen, J.

2010-01-01

CREB binding protein (CBP) is a transcriptional coactivator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated

In mpkCCD cells, long-term regulation of aquaporin-2 by vasopressin occurs independent of protein kinase A and CREB but may involve Epac

DEFF Research Database (Denmark)

Kortenoeven, Marleen; Trimpert, Christiane; van den Brand, Michiel

2012-01-01

kinase A (PKA) inhibitor H89. Moreover, phosphorylation of the cAMP-responsive element binding protein (CREB) and CRE-dependent transcription was observed after short-term dDAVP stimulation. With 4 days of dDAVP, AQP2 transcription remained elevated, but this was not blocked by H89, and CRE...

The transcription factors CREB and c-Fos play key roles in NCAM-mediated neuritogenesis in PC12-E2 cells

DEFF Research Database (Denmark)

Jessen, U; Novitskaya, V; Pedersen, N

2001-01-01

The neural cell adhesion molecule (NCAM) stimulates axonal outgrowth by activation of the Ras-mitogen activated protein kinase (MAPK) pathway and by generation of arachidonic acid. We investigated whether the transcription factors, cyclic-AMP response-element binding protein (CREB) and c-Fos play...... roles in this process by estimating NCAM-dependent neurite outgrowth from PC12-E2 cells grown in co-culture with NCAM-negative or NCAM-positive fibroblasts. PC12-E2 cells were transiently transfected with expression plasmids encoding wild-type or dominant negative forms of CREB and c-Fos or an activated...... form of the MAPK kinase, MEK2. Alternatively, PC12-E2 cells were treated with arachidonic acid, the cAMP analogue dBcAMP, or protein kinase A (PKA) inhibitors. The negative forms of CREB and c-Fos inhibited neurite outgrowth mediated by NCAM, arachidonic acid, dBcAMP, or MEK2. Neither CREB nor c...

Monosialotetrahexosylganglioside Inhibits the Expression of p-CREB and NR2B in the Auditory Cortex in Rats with Salicylate-Induced Tinnitus.

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Song, Rui-Biao; Lou, Wei-Hua

2015-01-01

This study investigated the effects of monosialotetrahexosylganglioside (GM1) on the expression of N-methyl-D-aspartate receptor subunit 2B (NR2B) and phosphorylated (p)-cyclic AMP response element-binding protein (CREB) in the auditory cortex of rats with tinnitus. Tinnitus-like behavior in rats was tested with the gap prepulse inhibition of acoustic startle paradigm. We then investigated the NR2B mRNA and protein and p-CREB protein levels in the auditory cortex of tinnitus rats compared with normal rats. Rats treated for 4 days with salicylate exhibited tinnitus. NR2B mRNA and protein and p-CREB protein levels were upregulated in these animals, with expression returning to normal levels 14 days after cessation of treatment; baseline levels of NR2B and p-CREB were also restored by GM1 administration. These data suggest that chronic salicylate administration induces tinnitus via upregulation of p-CREB and NR2B expression, and that GM1 can potentially be used to treat tinnitus.

Inhibition of Cyclic Adenosine Monophosphate (cAMP-response Element-binding Protein (CREB-binding Protein (CBP/β-Catenin Reduces Liver Fibrosis in Mice

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Yosuke Osawa

2015-11-01

Full Text Available Wnt/β-catenin is involved in every aspect of embryonic development and in the pathogenesis of many human diseases, and is also implicated in organ fibrosis. However, the role of β-catenin-mediated signaling on liver fibrosis remains unclear. To explore this issue, the effects of PRI-724, a selective inhibitor of the cAMP-response element-binding protein-binding protein (CBP/β-catenin interaction, on liver fibrosis were examined using carbon tetrachloride (CCl4- or bile duct ligation (BDL-induced mouse liver fibrosis models. Following repetitive CCl4 administrations, the nuclear translocation of β-catenin was observed only in the non-parenchymal cells in the liver. PRI-724 treatment reduced the fibrosis induced by CCl4 or BDL. C-82, an active form of PRI-724, inhibited the activation of isolated primary mouse quiescent hepatic stellate cells (HSCs and promoted cell death in culture-activated HSCs. During the fibrosis resolution period, an increase in F4/80+ CD11b+ and Ly6Clow CD11b+ macrophages was induced by CCl4 and was sustained for two weeks thereafter, even after having stopped CCl4 treatment. PRI-724 accelerated the resolution of CCl4-induced liver fibrosis, and this was accompanied by increased matrix metalloproteinase (MMP-9, MMP-2, and MMP-8 expression in intrahepatic leukocytes. In conclusion, targeting the CBP/β-catenin interaction may become a new therapeutic strategy in treating liver fibrosis.

Novel CREB3L3 Nonsense Mutation in a Family With Dominant Hypertriglyceridemia.

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Cefalù, Angelo B; Spina, Rossella; Noto, Davide; Valenti, Vincenza; Ingrassia, Valeria; Giammanco, Antonina; Panno, Maria D; Ganci, Antonina; Barbagallo, Carlo M; Averna, Maurizio R

2015-12-01

Cyclic AMP responsive element-binding protein 3-like 3 (CREB3L3) is a novel candidate gene for dominant hypertriglyceridemia. To date, only 4 kindred with dominant hypertriglyceridemia have been found to be carriers of 2 nonsense mutations in CREB3L3 gene (245fs and W46X). We investigated a family in which hypertriglyceridemia displayed an autosomal dominant pattern of inheritance. The proband was a 49-year-old woman with high plasma triglycerides (≤1300 mg/dL; 14.68 mmol/L). Her father had a history of moderate hypertriglyceridemia, and her 51-year-old brother had triglycerides levels as high as 1600 mg/dL (18.06 mmol/L). To identify the causal mutation in this family, we analyzed the candidate genes of recessive and dominant forms of primary hypertriglyceridemia by direct sequencing. The sequencing of CREB3L3 gene led to the discovery of a novel minute frame shift mutation in exon 3 of CREB3L3 gene, predicted to result in the formation of a truncated protein devoid of function (c.359delG-p.K120fsX20). Heterozygosity for the c.359delG mutation resulted in a severe phenotype occurring later in life in the proband and her brother and a good response to diet and a hypotriglyceridemic treatment. The same mutation was detected in a 13-year-old daughter who to date is normotriglyceridemic. We have identified a novel pathogenic mutation in CREB3L3 gene in a family with dominant hypertriglyceridemia with a variable pattern of penetrance. © 2015 American Heart Association, Inc.

DNA cytosine methylation in the bovine leukemia virus promoter is associated with latency in a lymphoma-derived B-cell line: potential involvement of direct inhibition of cAMP-responsive element (CRE)-binding protein/CRE modulator/activation transcription factor binding.

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Pierard, Valérie; Guiguen, Allan; Colin, Laurence; Wijmeersch, Gaëlle; Vanhulle, Caroline; Van Driessche, Benoît; Dekoninck, Ann; Blazkova, Jana; Cardona, Christelle; Merimi, Makram; Vierendeel, Valérie; Calomme, Claire; Nguyên, Thi Liên-Anh; Nuttinck, Michèle; Twizere, Jean-Claude; Kettmann, Richard; Portetelle, Daniel; Burny, Arsène; Hirsch, Ivan; Rohr, Olivier; Van Lint, Carine

2010-06-18

Bovine leukemia virus (BLV) proviral latency represents a viral strategy to escape the host immune system and allow tumor development. Besides the previously demonstrated role of histone deacetylation in the epigenetic repression of BLV expression, we showed here that BLV promoter activity was induced by several DNA methylation inhibitors (such as 5-aza-2'-deoxycytidine) and that overexpressed DNMT1 and DNMT3A, but not DNMT3B, down-regulated BLV promoter activity. Importantly, cytosine hypermethylation in the 5'-long terminal repeat (LTR) U3 and R regions was associated with true latency in the lymphoma-derived B-cell line L267 but not with defective latency in YR2 cells. Moreover, the virus-encoded transactivator Tax(BLV) decreased DNA methyltransferase expression levels, which could explain the lower level of cytosine methylation observed in the L267(LTaxSN) 5'-LTR compared with the L267 5'-LTR. Interestingly, DNA methylation inhibitors and Tax(BLV) synergistically activated BLV promoter transcriptional activity in a cAMP-responsive element (CRE)-dependent manner. Mechanistically, methylation at the -154 or -129 CpG position (relative to the transcription start site) impaired in vitro binding of CRE-binding protein (CREB) transcription factors to their respective CRE sites. Methylation at -129 CpG alone was sufficient to decrease BLV promoter-driven reporter gene expression by 2-fold. We demonstrated in vivo the recruitment of CREB/CRE modulator (CREM) and to a lesser extent activating transcription factor-1 (ATF-1) to the hypomethylated CRE region of the YR2 5'-LTR, whereas we detected no CREB/CREM/ATF recruitment to the hypermethylated corresponding region in the L267 cells. Altogether, these findings suggest that site-specific DNA methylation of the BLV promoter represses viral transcription by directly inhibiting transcription factor binding, thereby contributing to true proviral latency.

CRTC2 Is a Coactivator of GR and Couples GR and CREB in the Regulation of Hepatic Gluconeogenesis.

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Hill, Micah J; Suzuki, Shigeru; Segars, James H; Kino, Tomoshige

2016-01-01

Glucocorticoid hormones play essential roles in the regulation of gluconeogenesis in the liver, an adaptive response that is required for the maintenance of circulating glucose levels during fasting. Glucocorticoids do this by cooperating with glucagon, which is secreted from pancreatic islets to activate the cAMP-signaling pathway in hepatocytes. The cAMP-response element-binding protein (CREB)-regulated transcription coactivator 2 (CRTC2) is a coactivator known to be specific to CREB and plays a central role in the glucagon-mediated activation of gluconeogenesis in the early phase of fasting. We show here that CRTC2 also functions as a coactivator for the glucocorticoid receptor (GR). CRTC2 strongly enhances GR-induced transcriptional activity of glucocorticoid-responsive genes. CRTC2 physically interacts with the ligand-binding domain of the GR through a region spanning amino acids 561-693. Further, CRTC2 is required for the glucocorticoid-associated cooperative mRNA expression of the glucose-6-phosphatase, a rate-limiting enzyme for hepatic gluconeogenesis, by facilitating the attraction of GR and itself to its promoter region already occupied by CREB. CRTC2 is required for the maintenance of blood glucose levels during fasting in mice by enhancing the GR transcriptional activity on both the G6p and phosphoenolpyruvate carboxykinase (Pepck) genes. Finally, CRTC2 modulates the transcriptional activity of the progesterone receptor, indicating that it may influence the transcriptional activity of other steroid/nuclear receptors. Taken together, these results reveal that CRTC2 plays an essential role in the regulation of hepatic gluconeogenesis through coordinated regulation of the glucocorticoid/GR- and glucagon/CREB-signaling pathways on the key genes G6P and PEPCK.

Inducible forebrain-specific ablation of the transcription factor Creb during adulthood induces anxiety but no spatial/contextual learning deficits

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Miriam Annika Vogt

2014-11-01

Full Text Available The cyclic AMP (cAMP-response element binding protein (CREB is an activity-dependent transcription factor playing a role in synaptic plasticity, learning and memory, and emotional behavior. However, the impact of Creb ablation on rodent behavior is vague as e.g. memory performance of different Creb mutant mice depends on the specific type of mutation per se but additionally on the background and learning protocol differences. Here we present the first targeted ablation of CREB induced during adulthood selectively in principal forebrain neurons in a pure background strain of C57BL/6 mice. All hippocampal principal neurons exhibited lack of CREB expression. Mutant mice showed a severe anxiety phenotype in the openfield and novel object exploration test as well as in the Dark-Light Box Test, but unaltered hippocampus-dependent long-term memory in the Morris water maze and in context dependent fear conditioning. On the molecular level, CREB ablation led to CREM up regulation in the hippocampus and frontal cortex which may at least in part compensate for the loss of CREB. BDNF, a postulated CREB target gene, was down regulated in the frontal lobe but not in the hippocampus; neurogenesis remained unaltered. Our data indicate that in the adult mouse forebrain the late onset of CREB ablation can, in case of memory functionality, be compensated for and is not essential for memory consolidation and retrieval during adulthood. In contrast, the presence of CREB protein during adulthood seems to be pivotal for the regulation of emotional behavior.

Distinct changes in CREB phosphorylation in frontal cortex and striatum during contingent and non-contingent performance of a visual attention task

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Mirjana eCarli

2011-10-01

Full Text Available The cyclic-AMP response element binding protein (CREB family of transcription factors has been implicated in numerous forms of behavioural plasticity. We investigated CREB phosphorylation along some nodes of corticostriatal circuitry such as frontal cortex (FC and dorsal (caudate putamen, CPu and ventral (nucleus accumbens, NAC striatum in response to the contingent or non-contingent performance of the five-choice serial reaction time task (5-CSRTT used to assess visuospatial attention. Three experimental manipulations were used; an attentional performance group (contingent, master, a group trained previously on the task but for whom the instrumental contingency coupling responding with stimulus detection and reward was abolished (non-contingent, yoked and a control group matched for food deprivation and exposure to the test apparatus (untrained. Rats trained on the 5-CSRTT (both master and yoked had higher levels of CREB protein in the FC, CPu and NAC compared to untrained controls. Despite the divergent behaviour of master and yoked rats CREB activity in the FC was not substantially different. In rats performing the 5-CSRTT (master, CREB activity was completely abolished in the CPu whereas in the NAC it remained unchanged. In contrast, CREB phosphorylation in CPu and NAC increased only when the contingency changed from goal-dependent to goal-independent reinforcement (yoked. The present results indicate that up-regulation of CREB protein expression across cortical and striatal regions possibly reflects the extensive instrumental learning and performance whereas increased CREB activity in striatal regions may signal the unexpected change in the relationship between instrumental action and reinforcement.

Activation of the CREB/c-Fos Pathway during Long-Term Synaptic Plasticity in the Cerebellum Granular Layer

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Daniela Gandolfi

2017-06-01

Full Text Available The induction of long-term potentiation and depression (LTP and LTD is thought to trigger gene expression and protein synthesis, leading to consolidation of synaptic and neuronal changes. However, while LTP and LTD have been proposed to play important roles for sensori-motor learning in the cerebellum granular layer, their association with these mechanisms remained unclear. Here, we have investigated phosphorylation of the cAMP-responsive element binding protein (CREB and activation of the immediate early gene c-Fos pathway following the induction of synaptic plasticity by theta-burst stimulation (TBS in acute cerebellar slices. LTP and LTD were localized using voltage-sensitive dye imaging (VSDi. At two time points following TBS (15 min and 120 min, corresponding to the early and late phases of plasticity, slices were fixed and processed to evaluate CREB phosphorylation (P-CREB and c-FOS protein levels, as well as Creb and c-Fos mRNA expression. High levels of P-CREB and Creb/c-Fos were detected before those of c-FOS, as expected if CREB phosphorylation triggered gene expression followed by protein synthesis. No differences between control slices and slices stimulated with TBS were observed in the presence of an N-methyl-D-aspartate receptor (NMDAR antagonist. Interestingly, activation of the CREB/c-Fos system showed a relevant degree of colocalization with long-term synaptic plasticity. These results show that NMDAR-dependent plasticity at the cerebellum input stage bears about transcriptional and post-transcriptional processes potentially contributing to cerebellar learning and memory consolidation.

Dexamethasone-induced and estradiol-induced CREB activation and annexin 1 expression in CCRF-CEM lymphoblastic cells: evidence for the involvement of cAMP and p38 MAPK

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M. Castro-caldas

2003-01-01

Full Text Available Aims: Annexin 1 (ANXA1, a member of the annexin family of calcium-binding and phospholipid-binding proteins, is a key mediator of the anti-inflammatory actions of steroid hormones. We have previously demonstrated that, in the human lymphoblastic CCRF-CEM cell line, both the synthetic glucocorticoid hormone, dexamethasone (Dex, and the estrogen hormone, 17β-estradiol (E2β, induce the synthesis of ANXA1, by a mechanism independent of the activation of their nuclear receptors. Recently, it was reported that the gene coding for ANXA1 contains a cAMP-responsive element (CRE. In this work, we investigated whether Dex and E2β were able to induce the activation of CRE binding proteins (CREB in the CCRF-CEM cells. Moreover, we studied the intracellular signalling pathways involved in CREB activation and ANXA1 synthesis in response to Dex and E2β; namely, the role of cAMP and the p38 mitogen-activated protein kinase (MAPK.

Bicarbonate-responsive “soluble” adenylyl cyclase defines a nuclear cAMP microdomain

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Zippin, Jonathan H.; Farrell, Jeanne; Huron, David; Kamenetsky, Margarita; Hess, Kenneth C.; Fischman, Donald A.; Levin, Lonny R.; Buck, Jochen

2004-01-01

Bicarbonate-responsive “soluble” adenylyl cyclase resides, in part, inside the mammalian cell nucleus where it stimulates the activity of nuclear protein kinase A to phosphorylate the cAMP response element binding protein (CREB). The existence of this complete and functional, nuclear-localized cAMP pathway establishes that cAMP signals in intracellular microdomains and identifies an alternate pathway leading to CREB activation. PMID:14769862

Regulation of anxiety and initiation of sexual behavior by CREB in the nucleus accumbens

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Barrot, Michel; Wallace, Deanna L.; Bolaños, Carlos A.; Graham, Danielle L.; Perrotti, Linda I.; Neve, Rachael L.; Chambliss, Heather; Yin, Jerry C.; Nestler, Eric J.

2005-01-01

Sexual deficits and other behavioral disturbances such as anxiety-like behaviors can be observed in animals that have undergone social isolation, especially in species having important social interactions. Using a model of protracted social isolation in adult rats, we observed increased anxiety-like behavior and deficits in both the latency to initiate sexual behavior and the latency to ejaculate. We show, using transgenic cAMP response element (CRE)-LacZ reporter mice, that protracted social isolation also reduces CRE-dependent transcription within the nucleus accumbens. This decrease in CRE-dependent transcription can be mimicked in nonisolated animals by local viral gene transfer of a dominant negative mutant of CRE-binding protein (CREB). We previously showed that this manipulation increases anxiety-like behavior. We show here that it also impairs initiation of sexual behavior in nonisolated animals, a deficit that can be corrected by anxiolytic drug treatment. This local reduction in CREB activity, however, has no influence on ejaculation parameters. Reciprocally, we used the viral transgenic approach to overexpress CREB in the nucleus accumbens of isolated animals. We show that this local increase in CREB activity completely rescued the anxiety phenotype of the isolated animals, as well as their deficit in initiating sexual behavior, but failed to rescue the deficit in ejaculation. Our data suggest a role for the nucleus accumbens in anxiety responses and in specific aspects of sexual behavior. The results also provide insight into the molecular mechanisms by which social interactions affect brain plasticity and behavior. PMID:15923261

Transcription factor assisted loading and enhancer dynamics dictate the hepatic fasting response

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Goldstein, Ido; Baek, Songjoon; Presman, Diego M.; Paakinaho, Ville; Swinstead, Erin E.; Hager, Gordon L.

2017-01-01

Fasting elicits transcriptional programs in hepatocytes leading to glucose and ketone production. This transcriptional program is regulated by many transcription factors (TFs). To understand how this complex network regulates the metabolic response to fasting, we aimed at isolating the enhancers and TFs dictating it. Measuring chromatin accessibility revealed that fasting massively reorganizes liver chromatin, exposing numerous fasting-induced enhancers. By utilizing computational methods in combination with dissecting enhancer features and TF cistromes, we implicated four key TFs regulating the fasting response: glucocorticoid receptor (GR), cAMP responsive element binding protein 1 (CREB1), peroxisome proliferator activated receptor alpha (PPARA), and CCAAT/enhancer binding protein beta (CEBPB). These TFs regulate fuel production by two distinctly operating modules, each controlling a separate metabolic pathway. The gluconeogenic module operates through assisted loading, whereby GR doubles the number of sites occupied by CREB1 as well as enhances CREB1 binding intensity and increases accessibility of CREB1 binding sites. Importantly, this GR-assisted CREB1 binding was enhancer-selective and did not affect all CREB1-bound enhancers. Single-molecule tracking revealed that GR increases the number and DNA residence time of a portion of chromatin-bound CREB1 molecules. These events collectively result in rapid synergistic gene expression and higher hepatic glucose production. Conversely, the ketogenic module operates via a GR-induced TF cascade, whereby PPARA levels are increased following GR activation, facilitating gradual enhancer maturation next to PPARA target genes and delayed ketogenic gene expression. Our findings reveal a complex network of enhancers and TFs that dynamically cooperate to restore homeostasis upon fasting. PMID:28031249

Pharmacological Activators of the NR4A Nuclear Receptors Enhance LTP in a CREB/CBP-Dependent Manner.

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Bridi, Morgan S; Hawk, Joshua D; Chatterjee, Snehajyoti; Safe, Stephen; Abel, Ted

2017-05-01

Nr4a nuclear receptors contribute to long-term memory formation and are required for long-term memory enhancement by a class of broad-acting drugs known as histone deacetylase (HDAC) inhibitors. Understanding the molecular mechanisms that regulate these genes and identifying ways to increase their activity may provide novel therapeutic approaches for ameliorating cognitive dysfunction. In the present study, we find that Nr4a gene expression after learning requires the cAMP-response element binding (CREB) interaction domain of the histone acetyltransferase CREB-binding protein (CBP). These gene expression deficits emerge at a time after learning marked by promoter histone acetylation in wild-type mice. Further, mutation of the CREB-CBP interaction domain reduces Nr4a promoter acetylation after learning. As memory enhancement by HDAC inhibitors requires CREB-CBP interaction and Nr4a gene function, these data support the notion that the balance of histone acetylation at the Nr4a promoters is critical for memory formation. NR4A ligands have recently been described, but the effect of these drugs on synaptic plasticity or memory has not been investigated. We find that the 'C-DIM' NR4A ligands, para-phenyl substituted di-indolylmethane compounds, enhance long-term contextual fear memory and increase the duration of long-term potentiation (LTP), a form of hippocampal synaptic plasticity. LTP enhancement by these drugs is eliminated in mice expressing a dominant negative form of NR4A and attenuated in mice with mutation of the CREB-CBP interaction domain. These data define the molecular connection between histone acetylation and Nr4a gene expression after learning. In addition, they suggest that NR4A-activating C-DIM compounds may serve as a potent and selective means to enhance memory and synaptic plasticity.

Connexin31.1 deficiency in the mouse impairs object memory and modulates open-field exploration, acetylcholine esterase levels in the striatum, and cAMP response element-binding protein levels in the striatum and piriform cortex.

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Dere, E; Zheng-Fischhöfer, Q; Viggiano, D; Gironi Carnevale, U A; Ruocco, L A; Zlomuzica, A; Schnichels, M; Willecke, K; Huston, J P; Sadile, A G

2008-05-02

Neuronal gap junctions in the brain, providing intercellular electrotonic signal transfer, have been implicated in physiological and behavioral correlates of learning and memory. In connexin31.1 (Cx31.1) knockout (KO) mice the coding region of the Cx31.1 gene was replaced by a LacZ reporter gene. We investigated the impact of Cx31.1 deficiency on open-field exploration, the behavioral response to an odor, non-selective attention, learning and memory performance, and the levels of memory-related proteins in the hippocampus, striatum and the piriform cortex. In terms of behavior, the deletion of the Cx31.1 coding DNA in the mouse led to increased exploratory behaviors in a novel environment, and impaired one-trial object recognition at all delays tested. Despite strong Cx31.1 expression in the peripheral and central olfactory system, Cx31.1 KO mice exhibited normal behavioral responses to an odor. We found increased levels of acetylcholine esterase (AChE) and cAMP response element-binding protein (CREB) in the striatum of Cx31.1 KO mice. In the piriform cortex the Cx31.1 KO mice had an increased heterogeneity of CREB expression among neurons. In conclusion, gap-junctions featuring the Cx31.1 protein might be involved in open-field exploration as well as object memory and modulate levels of AChE and CREB in the striatum and piriform cortex.

Morphine Reward Promotes Cue-Sensitive Learning: Implication of Dorsal Striatal CREB Activity

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Mathieu Baudonnat

2017-05-01

Full Text Available Different parallel neural circuits interact and may even compete to process and store information: whereas stimulus–response (S–R learning critically depends on the dorsal striatum (DS, spatial memory relies on the hippocampus (HPC. Strikingly, despite its potential importance for our understanding of addictive behaviors, the impact of drug rewards on memory systems dynamics has not been extensively studied. Here, we assessed long-term effects of drug- vs food reinforcement on the subsequent use of S–R vs spatial learning strategies and their neural substrates. Mice were trained in a Y-maze cue-guided task, during which either food or morphine injections into the ventral tegmental area (VTA were used as rewards. Although drug- and food-reinforced mice learned the Y-maze task equally well, drug-reinforced mice exhibited a preferential use of an S–R learning strategy when tested in a water-maze competition task designed to dissociate cue-based and spatial learning. This cognitive bias was associated with a persistent increase in the phosphorylated form of cAMP response element-binding protein phosphorylation (pCREB within the DS, and a decrease of pCREB expression in the HPC. Pharmacological inhibition of striatal PKA pathway in drug-rewarded mice limited the morphine-induced increase in levels of pCREB in DS and restored a balanced use of spatial vs cue-based learning. Our findings suggest that drug (opiate reward biases the engagement of separate memory systems toward a predominant use of the cue-dependent system via an increase in learning-related striatal pCREB activity. Persistent functional imbalance between striatal and hippocampal activity could contribute to the persistence of addictive behaviors, or counteract the efficiency of pharmacological or psychotherapeutic treatments.

Aripiprazole Increases the PKA Signalling and Expression of the GABAA Receptor and CREB1 in the Nucleus Accumbens of Rats.

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Pan, Bo; Lian, Jiamei; Huang, Xu-Feng; Deng, Chao

2016-05-01

The GABAA receptor is implicated in the pathophysiology of schizophrenia and regulated by PKA signalling. Current antipsychotics bind with D2-like receptors, but not the GABAA receptor. The cAMP-responsive element-binding protein 1 (CREB1) is also associated with PKA signalling and may be related to the positive symptoms of schizophrenia. This study investigated the effects of antipsychotics in modulating D2-mediated PKA signalling and its downstream GABAA receptors and CREB1. Rats were treated orally with aripiprazole (0.75 mg/kg, ter in die (t.i.d.)), bifeprunox (0.8 mg/kg, t.i.d.), haloperidol (0.1 mg/kg, t.i.d.) or vehicle for 1 week. The levels of PKA-Cα and p-PKA in the prefrontal cortex (PFC), nucleus accumbens (NAc) and caudate putamen (CPu) were detected by Western blots. The mRNA levels of Gabrb1, Gabrb2, Gabrb3 and Creb1, and their protein expression were measured by qRT-PCR and Western blots, respectively. Aripiprazole elevated the levels of p-PKA and the ratio of p-PKA/PKA in the NAc, but not the PFC and CPu. Correlated with this elevated PKA signalling, aripiprazole elevated the mRNA and protein expression of the GABAA (β-1) receptor and CREB1 in the NAc. While haloperidol elevated the levels of p-PKA and the ratio of p-PKA/PKA in both NAc and CPu, it only tended to increase the expression of the GABAA (β-1) receptor and CREB1 in the NAc, but not the CPu. Bifeprunox had no effects on PKA signalling in these brain regions. These results suggest that aripiprazole has selective effects on upregulating the GABAA (β-1) receptor and CREB1 in the NAc, probably via activating PKA signalling.

CREB, NF-Y and MEIS1 conserved binding sites are essential to balance Myostatin promoter/enhancer activity during early myogenesis.

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Grade, Carla Vermeulen Carvalho; Mantovani, Carolina Stefano; Fontoura, Marina Alves; Yusuf, Faisal; Brand-Saberi, Beate; Alvares, Lúcia Elvira

2017-10-01

Myostatin (MSTN) is a strong inhibitor of skeletal muscle growth in human and other vertebrates. Its transcription is controlled by a proximal promoter/enhancer (Mstn P/E) containing a TATA box besides CREB, NF-Y, MEIS1 and FXR transcription factor binding sites (TFBSs), which are conserved throughout evolution. The aim of this work was to investigate the role of these TFBSs on Mstn P/E activity and evaluate the potential of their putative ligands as Mstn trans regulators. Mstn P/E mutant constructs were used to establish the role of conserved TFBSs using dual-luciferase assays. Expression analyses were performed by RT-PCR and in situ hybridization in C2C12 myoblasts and E10.5 mouse embryos, respectively. Our results revealed that CREB, NF-Y and MEIS1 sites are required to balance Mstn P/E activity, keeping Mstn transcription within basal levels during myoblast proliferation. Furthermore, our data showed that NF-Y site is essential, although not sufficient, to mediate Mstn P/E transcriptional activity. In turn, CREB and MEIS1 binding sites seem to depend on the presence of NF-Y site to induce Mstn P/E. FXR appears not to confer any effect on Mstn P/E activity, except in the absence of all other conserved TFBS. Accordingly, expression studies pointed to CREB, NF-Y and MEIS1 but not to FXR factors as possible regulators of Mstn transcription in the myogenic context. Altogether, our findings indicated that CREB, NF-Y and MEIS1 conserved sites are essential to control basal Mstn transcription during early myogenesis, possibly by interacting with these or other related factors.

Lactoferricin B Inhibits the Phosphorylation of the Two-Component System Response Regulators BasR and CreB*

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Ho, Yu-Hsuan; Sung, Tzu-Cheng; Chen, Chien-Sheng

2012-01-01

Natural antimicrobial peptides provide fundamental protection for multicellular organisms from microbes, such as Lactoferricin B (Lfcin B). Many studies have shown that Lfcin B penetrates the cell membrane and has intracellular activities. To elucidate the intracellular behavior of Lfcin B, we first used Escherichia coli K12 proteome chips to identify the intracellular targets of Lfcin B. The results showed that Lfcin B binds to two response regulators, BasR and CreB, of the two-component system. For further analysis, we conducted several in vitro and in vivo experiments and utilized bioinformatics methods. The electrophoretic mobility shift assays and kinase assays indicate that Lfcin B inhibits the phosphorylation of the response regulators (BasR and CreB) and their cognate sensor kinases (BasS and CreC). Antibacterial assays showed that Lfcin B reduced E. coli's tolerance to environmental stimuli, such as excessive ferric ions and minimal medium conditions. This is the first study to show that an antimicrobial peptide inhibits the growth of bacteria by influencing the phosphorylation of a two-component system directly. PMID:22138548

Lactoferricin B inhibits the phosphorylation of the two-component system response regulators BasR and CreB.

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Ho, Yu-Hsuan; Sung, Tzu-Cheng; Chen, Chien-Sheng

2012-04-01

Natural antimicrobial peptides provide fundamental protection for multicellular organisms from microbes, such as Lactoferricin B (Lfcin B). Many studies have shown that Lfcin B penetrates the cell membrane and has intracellular activities. To elucidate the intracellular behavior of Lfcin B, we first used Escherichia coli K12 proteome chips to identify the intracellular targets of Lfcin B. The results showed that Lfcin B binds to two response regulators, BasR and CreB, of the two-component system. For further analysis, we conducted several in vitro and in vivo experiments and utilized bioinformatics methods. The electrophoretic mobility shift assays and kinase assays indicate that Lfcin B inhibits the phosphorylation of the response regulators (BasR and CreB) and their cognate sensor kinases (BasS and CreC). Antibacterial assays showed that Lfcin B reduced E. coli's tolerance to environmental stimuli, such as excessive ferric ions and minimal medium conditions. This is the first study to show that an antimicrobial peptide inhibits the growth of bacteria by influencing the phosphorylation of a two-component system directly.

Curcumin confers neuroprotection against alcohol-induced hippocampal neurodegeneration via CREB-BDNF pathway in rats.

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Motaghinejad, Majid; Motevalian, Manijeh; Fatima, Sulail; Hashemi, Hajar; Gholami, Mina

2017-03-01

Alcohol abuse causes severe damage to the brain neurons. Studies have reported the neuroprotective effects of curcumin against alcohol-induced neurodegeneration. However, the precise mechanism of action remains unclear. Seventy rats were equally divided into 7 groups (10 rats per group). Group 1 received normal saline (0.7ml/rat) and group 2 received alcohol (2g/kg/day) for 21days. Groups 3, 4, 5 and 6 concurrently received alcohol (2g/kg/day) and curcumin (10, 20, 40 and 60mg/kg, respectively) for 21days. Animals in group 7 self- administered alcohol for 21days. Group 8 treated with curcumin (60mg/kg, i.p.) alone for 21days. Open Field Test (OFT) was used to investigate motor activity in rats. Hippocampal oxidative, antioxidative and inflammatory factors were evaluated. Furthermore, brain cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) and brain derived neurotrophic factor (BDNF) levels were studied at gene level by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, protein expression for BDNF, CREB, phosphorylated CREB (CREB-P), Bax and Bcl-2 was determined by western blotting. Voluntary and involuntary administration of alcohol altered motor activity in OFT, and curcumin treatment inhibited this alcohol-induced motor disturbance. Also, alcohol administration augmented lipid peroxidation, mitochondrial oxidized glutathione (GSSG), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and Bax levels in isolated hippocampal tissues. Furthermore, alcohol-induced significant reduction were observed in reduced form of glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) activities and CREB, BDNF and Bcl-2 levels. Also curcumin alone did not change the behavior and biochemical and molecular parameters. Curcumin can act as a neuroprotective agent against neurodegenerative effects of alcohol abuse, probably via activation of CREB-BDNF signaling pathway

Specific rescue by ortho-hydroxy atorvastatin of cortical GABAergic neurons from previous oxygen/glucose deprivation: role of pCREB.

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Guirao, Verónica; Martí-Sistac, Octavi; DeGregorio-Rocasolano, Núria; Ponce, Jovita; Dávalos, Antoni; Gasull, Teresa

2017-11-01

The statin atorvastatin (ATV) given as a post-treatment has been reported beneficial in stroke, although the mechanisms involved are not well understood so far. Here, we investigated in vitro the effect of post-treatment with ATV and its main bioactive metabolite ortho-hydroxy ATV (o-ATV) on neuroprotection after oxygen and glucose deprivation (OGD), and the role of the pro-survival cAMP response element-binding protein (CREB). Post-OGD treatment of primary cultures of rat cortical neurons with o-ATV, but not ATV, provided neuroprotection to a specific subset of cortical neurons that were large and positive for glutamic acid decarboxylase (large-GAD (+) neurons, GABAergic). Significantly, only these GABAergic neurons showed an increase in phosphorylated CREB (pCREB) early after neuronal cultures were treated post-OGD with o-ATV. We found that o-ATV, but not ATV, increased the neuronal uptake of glutamate from the medium; this provides a rationale for the specific effect of o-ATV on pCREB in large-GABAergic neurons, which have a higher ratio of synaptic (pCREB-promoting) vs extrasynaptic (pCREB-reducing) N-methyl-D-aspartate (NMDA) receptors (NMDAR) than that of small-non-GABAergic neurons. When we pharmacologically increased pCREB levels post-OGD in non-GABAergic neurons, through the selective activation of synaptic NMDAR, we observed as well long-lasting neuronal survival. We propose that the statin metabolite o-ATV given post-OGD boosts the intrinsic pro-survival factor pCREB in large-GABAergic cortical neurons in vitro, this contributing to protect them from OGD. © 2017 International Society for Neurochemistry.

Sleep deprivation prevents stimulation-induced increases of levels of P-CREB and BDNF: protection by caffeine.

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Alhaider, Ibrahim A; Aleisa, Abdulaziz M; Tran, Trinh T; Alkadhi, Karim A

2011-04-01

It is well known that caffeine and sleep deprivation have opposing effects on learning and memory; therefore, this study was undertaken to determine the effects of chronic (4wks) caffeine treatment (0.3g/l in drinking water) on long-term memory deficit associated with 24h sleep deprivation. Animals were sleep deprived using the modified multiple platform method. The results showed that chronic caffeine treatment prevented the impairment of long-term memory as measured by performance in the radial arm water maze task and normalized L-LTP in area CA1 of the hippocampi of sleep-deprived anesthetized rats. Sleep deprivation prevents the high frequency stimulation-induced increases in the levels of phosphorylated-cAMP response element binding protein (P-CREB) and brain-derived neurotrophic factor (BDNF) seen during the expression of late phase long-term potentiation (L-LTP). However, chronic caffeine treatment prevented the effect of sleep-deprivation on the stimulated levels of P-CREB and BDNF. The results suggest that chronic caffeine treatment may protect the sleep-deprived brain probably by preserving the levels of P-CREB and BDNF. Copyright © 2011 Elsevier Inc. All rights reserved.

Extracellular visfatin activates gluconeogenesis in HepG2 cells through the classical PKA/CREB-dependent pathway.

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Choi, Y J; Choi, S-E; Ha, E S; Kang, Y; Han, S J; Kim, D J; Lee, K W; Kim, H J

2014-04-01

Adipokines reportedly affect hepatic gluconeogenesis, and the adipokine visfatin is known to be related to insulin resistance and type 2 diabetes. However, whether visfatin contributes to hepatic gluconeogenesis remains unclear. Visfatin, also known as nicotinamide phosphoribosyltransferase (NAMPT), modulates sirtuin1 (SIRT1) through the regulation of nicotinamide adenine dinucleotide (NAD). Therefore, we investigated the effect of extracellular visfatin on glucose production in HepG2 cells, and evaluated whether extracellular visfatin affects hepatic gluconeogenesis via an NAD+-SIRT1-dependent pathway. Treatment with visfatin significantly increased glucose production and the mRNA expression and protein levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in HepG2 cells in a time- and concentration-dependent manner. Knockdown of SIRT1 had no remarkable effect on the induction of gluconeogenesis by visfatin. Subsequently, we evaluated if extracellular visfatin stimulates the production of gluconeogenic enzymes through the classical protein kinase A (PKA)/cyclic AMP-responsive element (CRE)-binding protein (CREB)-dependent process. The phosphorylation of CREB and PKA increased significantly in HepG2 cells treated with visfatin. Additionally, knockdown of CREB and PKA inhibited visfatin-induced gluconeogenesis in HepG2 cells. In summary, extracellular visfatin modulates glucose production in HepG2 cells through the PKA/CREB pathway, rather than via SIRT1 signaling. © Georg Thieme Verlag KG Stuttgart · New York.

Electroacupuncture Ameliorates Learning and Memory via Activation of the CREB Signaling Pathway in the Hippocampus to Attenuate Apoptosis after Cerebral Hypoperfusion

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Han, Xiaohua; Zhao, Xiuxiu; Lu, Min; Liu, Fang; Guo, Feng; Zhang, Jinghui; Huang, Xiaolin

2013-01-01

Studies have shown that electroacupuncture (EA) ameliorates learning and memory after ischemic injury. However, there have been few studies elucidating the mechanisms of EA on learning and memory in cerebral hypoperfusion. In this study, we explored the cAMP response element-binding protein (CREB) signaling pathway-mediated antiapoptotic action involved in EA-induced improvement of learning and memory. EA at GV20 and GV14 acupoints was applied in cerebral hypoperfusion rats. A Morris water ma...

Atorvastatin inhibits insulin synthesis by inhibiting the Ras/Raf/ERK/CREB pathway in INS-1 cells

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Sun, Hongxi; Li, Yu; Sun, Bei; Hou, Ningning; Yang, Juhong; Zheng, Miaoyan; Xu, Jie; Wang, Jingyu; Zhang, Yi; Zeng, Xianwei; Shan, Chunyan; Chang, Bai; Chen, Liming; Chang, Baocheng

2016-01-01

Abstract Backround: Type 2 diabetes has become a global epidemic disease. Atorvastatin has become a cornerstone in the prevention and treatment of atherosclerosis. However, increasing evidence showed that statins can dose-dependently increase the risk of diabetes mellitus. The mechanism is not clear. Objective: The Ras complex pathway (Ras/Raf/extracellular signal-regulated kinase [ERK]/cAMP response element-binding protein [CREB]) is the major pathway that regulates the gene transcription. Except for the inhibition of cholesterol synthesis by inhibiting the 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-COA) reductase, statins can also downregulate the phosphorylation of a series of downstream substrates including the key proteins of the Ras complex pathway, therefore may inhibit the insulin syntheses in pancreatic beta cells. In our study, we investigated the inhibitory effect and the underlying mechanism of atorvastatin on insulin synthesis in rat islets. Methods: Islets were isolated from Wistar rats and cultured in Roswell Park Memorial Institute (RPMI)-1640 medium. The insulin content in the medium was measured by radioimmunoassay before and after the treatment of 50 μM atorvastatin. Effect of atorvastatin on the expression of insulin message Ribonucleic acid (mRNA) in pancreatic islet beta cells was also detected using quantitative real-time polymerase chain reaction. Western blotting was used to explore the possible role of the Ras complex pathway (Ras/Raf/ERK/CREB) in atorvastatin-inhibited insulin synthesis. The effects of atorvastatin on the binding of nuclear transcription factor p-CREB with CRE in INS-1 cells were examined via chromatin immunoprecipitation assay. Results: Compared with the control group, the insulin level decreased by 27.1% at 24 hours after atorvastatin treatment. Atorvastatin inhibited insulin synthesis by decreasing insulin mRNA expression of pancreatic islet beta cells. The activities of Ras, Raf-1, and p-CREB in the Ras complex

Complex regulation of CREB-binding protein by homeodomain-interacting protein kinase 2

KAUST Repository

Ková cs, Krisztiá n A.; Steinmann, Myriam; Halfon, Olivier; Magistretti, Pierre J.; Cardinaux, Jean René

2015-01-01

CREB-binding protein (CBP) and p300 are transcriptional coactivators involved in numerous biological processes that affect cell growth, transformation, differentiation, and development. In this study, we provide evidence of the involvement of homeodomain-interacting protein kinase 2 (HIPK2) in the regulation of CBP activity. We show that HIPK2 interacts with and phosphorylates several regions of CBP. We demonstrate that serines 2361, 2363, 2371, 2376, and 2381 are responsible for the HIPK2-induced mobility shift of CBP C-terminal activation domain. Moreover, we show that HIPK2 strongly potentiates the transcriptional activity of CBP. However, our data suggest that HIPK2 activates CBP mainly by counteracting the repressive action of cell cycle regulatory domain 1 (CRD1), located between amino acids 977 and 1076, independently of CBP phosphorylation. Our findings thus highlight a complex regulation of CBP activity by HIPK2, which might be relevant for the control of specific sets of target genes involved in cellular proliferation, differentiation and apoptosis. © 2015 Elsevier Inc.

Complex regulation of CREB-binding protein by homeodomain-interacting protein kinase 2

KAUST Repository

Kovács, Krisztián A.

2015-11-01

CREB-binding protein (CBP) and p300 are transcriptional coactivators involved in numerous biological processes that affect cell growth, transformation, differentiation, and development. In this study, we provide evidence of the involvement of homeodomain-interacting protein kinase 2 (HIPK2) in the regulation of CBP activity. We show that HIPK2 interacts with and phosphorylates several regions of CBP. We demonstrate that serines 2361, 2363, 2371, 2376, and 2381 are responsible for the HIPK2-induced mobility shift of CBP C-terminal activation domain. Moreover, we show that HIPK2 strongly potentiates the transcriptional activity of CBP. However, our data suggest that HIPK2 activates CBP mainly by counteracting the repressive action of cell cycle regulatory domain 1 (CRD1), located between amino acids 977 and 1076, independently of CBP phosphorylation. Our findings thus highlight a complex regulation of CBP activity by HIPK2, which might be relevant for the control of specific sets of target genes involved in cellular proliferation, differentiation and apoptosis. © 2015 Elsevier Inc.

Suppression of type I interferon production by porcine epidemic diarrhea virus and degradation of CREB-binding protein by nsp1

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qingzhan; Shi, Kaichuang; Yoo, Dongwan, E-mail: dyoo@illinois.edu

2016-02-15

Type I interferons (IFN-α/β) are the major components of the innate immune response of hosts, and in turn many viruses have evolved to modulate the host response during infection. We found that the IFN-β production was significantly suppressed during PEDV infection in cells. To identify viral IFN antagonists and to study their suppressive function, viral coding sequences for the entire structural and nonstructural proteins were cloned and expressed. Of 16 PEDV nonstructural proteins (nsps), nsp1, nsp3, nsp7, nsp14, nsp15 and nsp16 were found to inhibit the IFN-β and IRF3 promoter activities. The sole accessory protein ORF3, structure protein envelope (E), membrane (M), and nucleocapsid (N) protein were also shown to inhibit such activities. PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP) by degrading CBP. A further study showed that the CBP degradation by nsp1 was proteasome-dependent. Our data demonstrate that PEDV modulates the host innate immune responses by degrading CBP and suppressing ISGs expression. - Highlights: • PEDV modulates the host innate immune system by suppressing the type I interferon production and ISGs expression. • Ten viral proteins were identified as IFN antagonists, and nsp1 was the most potent viral IFN antagonist. • PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP). • PEDV nsp1 caused the CBP degradation in the nucleus, which may be the key mechanism for PEDV-mediated IFN downregulation.

Hormone response element binding proteins: novel regulators of vitamin D and estrogen signaling.

Science.gov (United States)

Lisse, Thomas S; Hewison, Martin; Adams, John S

2011-03-01

Insights from vitamin D-resistant New World primates and their human homologues as models of natural and pathological insensitivity to sterol/steroid action have uncovered a family of novel intracellular vitamin D and estrogen regulatory proteins involved in hormone action. The proteins, known as "vitamin D or estrogen response element-binding proteins", behave as potent cis-acting, transdominant regulators to inhibit steroid receptor binding to DNA response elements and is responsible for vitamin D and estrogen resistances. This set of interactors belongs to the heterogeneous nuclear ribonucleoprotein (hnRNP) family of previously known pre-mRNA-interacting proteins. This review provides new insights into the mechanism by which these novel regulators of signaling and metabolism can act to regulate responses to vitamin D and estrogen. In addition the review also describes other molecules that are known to influence nuclear receptor signaling through interaction with hormone response elements. Copyright © 2011 Elsevier Inc. All rights reserved.

Ginsenosides Rb1 and Rg1 Stimulate Melanogenesis in Human Epidermal Melanocytes via PKA/CREB/MITF Signaling

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Mao Lin

2014-01-01

Full Text Available Reduced or defective melanin skin pigmentation may cause many hypopigmentation disorders and increase the risk of damage to the skin triggered by UV irradiation. Ginsenosides Rb1 and Rg1 have many molecular targets including the cAMP-response element-binding protein (CREB, which is involved in melanogenesis. This study aimed to investigate the effects of ginsenosides Rb1 and Rg1 on melanogenesis in human melanocytes and their related mechanisms. The effects of Rb1 and Rg1 on cell viability, tyrosinase activity, cellular melanin content and protein levels of tyrosinase, microphthalmia-associated transcription factor (MITF, and activation of CREB in melanocytes were assessed. Results showed that Rb1 or Rg1 significantly increased cellular melanin content and tyrosinase activity in a dose-dependent manner. By contrast, the cell viability of melanocytes remained unchanged. After exposure to Rb1 or Rg1, the protein levels of tyrosinase, MITF, and phosphorylated CREB were significantly increased. Furthermore, pretreatment with the selective PKA inhibitor H-89 significantly blocked the Rb1- or Rg1-induced increase of melanin content. These findings indicated that Rb1 and Rg1 increased melanogenesis and tyrosinase activity in human melanocytes, which was associated with activation of PKA/CREB/MITF signaling. The effects and mechanisms of Rb1 or Rg1 on skin pigmentation deserve further study.

v-src induction of the TIS10/PGS2 prostaglandin synthase gene is mediated by an ATF/CRE transcription response element.

Science.gov (United States)

Xie, W; Fletcher, B S; Andersen, R D; Herschman, H R

1994-10-01

We recently reported the cloning of a mitogen-inducible prostaglandin synthase gene, TIS10/PGS2. In addition to growth factors and tumor promoters, the v-src oncogene induces TIS10/PGS2 expression in 3T3 cells. Deletion analysis, using luciferase reporters, identifies a region between -80 and -40 nucleotides 5' of the TIS10/PGS2 transcription start site that mediates pp60v-src induction in 3T3 cells. This region contains the sequence CGTCACGTG, which includes overlapping ATF/CRE (CGTCA) and E-box (CACGTG) sequences. Gel shift-oligonucleotide competition experiments with nuclear extracts from cells stably transfected with a temperature-sensitive v-src gene demonstrate that the CGTCACGTG sequence can bind proteins at both the ATF/CRE and E-box sequences. Dominant-negative CREB and Myc proteins that bind DNA, but do not transactivate, block v-src induction of a luciferase reporter driven by the first 80 nucleotides of the TIS10/PGS2 promoter. Mutational analysis distinguishes which TIS10/PGS2 cis-acting element mediates pp60v-src induction. E-box mutation has no effect on the fold induction in response to pp60v-src. In contrast, ATF/CRE mutation attenuates the pp60v-src response. Antibody supershift and methylation interference experiments demonstrate that CREB and at least one other ATF transcription factor in these extracts bind to the TIS10/PGS2 ATF/CRE element. Expression of a dominant-negative ras gene also blocks TIS10/PGS2 induction by v-src. Our data suggest that Ras mediates pp60v-src activation of an ATF transcription factor, leading to induced TIS10/PGS2 expression via the ATF/CRE element of the TIS10/PGS2 promoter. This is the first description of v-src activation of gene expression via an ATF/CRE element.

Regulation of T cell activation by HIV-1 accessory proteins: Vpr acts via distinct mechanisms to cooperate with Nef in NFAT-directed gene expression and to promote transactivation by CREB

International Nuclear Information System (INIS)

Lahti, Anna L.; Manninen, Aki; Saksela, Kalle

2003-01-01

Nef and Vpr are lentiviral accessory proteins that have been implicated in regulation of cellular gene expression. We noticed that Vpr can potentiate Nef-induced activation of nuclear factor of activated T cells (NFAT)-dependent transcription. Unlike Nef, which stimulated calcium signaling to activate NFAT, Vpr functioned farther downstream. Similar to the positive effects of Vpr on most of the transcriptional test systems that we used, potentiation of NFAT-directed gene expression was relatively modest in magnitude (two- to threefold) and depended on the cell cycle-arresting capacity of Vpr. By contrast, we found that Vpr could cause more than fivefold upregulation of cyclic AMP response element (CRE)-directed transcription via a mechanism that did not require Vpr-induced G2/M arrest. This effect, however, was only evident under suboptimal conditions known to lead to serine phosphorylation of the CRE binding factor (CREB) but not to CREB-dependent gene expression. This suggested that Vpr may act by stabilizing interactions with CREB and its transcriptional cofactor CREB binding protein (CBP). Indeed, this effect could be blocked by cotransfection of the adenoviral CBP inhibitor E1A. These results provide additional evidence for cell cycle-independent regulation of gene expression by Vpr and implicate CREB as a potentially important target for Vpr action in HIV-infected host cells

TLR4 induces CREB-mediated IL-6 production via upregulation of F-spondin to promote vascular smooth muscle cell migration

Energy Technology Data Exchange (ETDEWEB)

Lee, Guan-Lin [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Wu, Jing-Yiing [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Yeh, Chang-Ching [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Kuo, Cheng-Chin, E-mail: kuocc@nhri.org.tw [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

2016-05-13

Toll-like receptor 4 (TLR4) is important in promoting inflammation and vascular smooth muscle cell (VSMC) migration, both of which contribute to atherosclerosis development and progression. But the mechanism underlying the regulation of TLR4 in VSMC migration remains unclear. Stimulation of VSMCs with LPS increased the cellular level of F-spondin which is associated with the regulation of proinflammatory cytokine production. The LPS-induced F-spondin expression depended on TLR4-mediated PI3K/Akt pathway. Suppression of F-spondin level by siRNA inhibited not only F-spondin expression but also LPS-induced phosphorylation of cAMP response element binding protein (CREB) and IL-6 expression, VSMC migration and proliferation as well as MMP9 expression. Moreover, suppression of CREB level by siRNA inhibited TLR4-induced IL-6 production and VSMC migration. Inhibition of F-spondin siRNA on LPS-induced migration was restored by addition of exogenous recombinant mouse IL-6. We conclude that upon ligand binding, TLR4 activates PI3K/Akt signaling to induce F-spondin expression, subsequently control CREB-mediated IL-6 production to promote VSMC migration. These findings provide vital insights into the essential role of F-spondin in VSMC function and will be valuable for developing new therapeutic strategies against atherosclerosis. -- Highlights: •LPS-induced F-spondin expression of VSMCs is via a TLR4/PI3K/Akt signaling. •F-spondin is pivotal for LPS-induced CREB-mediated IL-6 production. •F-spondin is required for LPS-induced VSMC migration and proliferation.

TLR4 induces CREB-mediated IL-6 production via upregulation of F-spondin to promote vascular smooth muscle cell migration

International Nuclear Information System (INIS)

Lee, Guan-Lin; Wu, Jing-Yiing; Yeh, Chang-Ching; Kuo, Cheng-Chin

2016-01-01

Toll-like receptor 4 (TLR4) is important in promoting inflammation and vascular smooth muscle cell (VSMC) migration, both of which contribute to atherosclerosis development and progression. But the mechanism underlying the regulation of TLR4 in VSMC migration remains unclear. Stimulation of VSMCs with LPS increased the cellular level of F-spondin which is associated with the regulation of proinflammatory cytokine production. The LPS-induced F-spondin expression depended on TLR4-mediated PI3K/Akt pathway. Suppression of F-spondin level by siRNA inhibited not only F-spondin expression but also LPS-induced phosphorylation of cAMP response element binding protein (CREB) and IL-6 expression, VSMC migration and proliferation as well as MMP9 expression. Moreover, suppression of CREB level by siRNA inhibited TLR4-induced IL-6 production and VSMC migration. Inhibition of F-spondin siRNA on LPS-induced migration was restored by addition of exogenous recombinant mouse IL-6. We conclude that upon ligand binding, TLR4 activates PI3K/Akt signaling to induce F-spondin expression, subsequently control CREB-mediated IL-6 production to promote VSMC migration. These findings provide vital insights into the essential role of F-spondin in VSMC function and will be valuable for developing new therapeutic strategies against atherosclerosis. -- Highlights: •LPS-induced F-spondin expression of VSMCs is via a TLR4/PI3K/Akt signaling. •F-spondin is pivotal for LPS-induced CREB-mediated IL-6 production. •F-spondin is required for LPS-induced VSMC migration and proliferation.

Cyclophilin D deficiency rescues Aβ-impaired PKA/CREB signaling and alleviates synaptic degeneration.

Science.gov (United States)

Du, Heng; Guo, Lan; Wu, Xiaoping; Sosunov, Alexander A; McKhann, Guy M; Chen, John Xi; Yan, Shirley ShiDu

2014-12-01

The coexistence of neuronal mitochondrial pathology and synaptic dysfunction is an early pathological feature of Alzheimer's disease (AD). Cyclophilin D (CypD), an integral part of mitochondrial permeability transition pore (mPTP), is involved in amyloid beta (Aβ)-instigated mitochondrial dysfunction. Blockade of CypD prevents Aβ-induced mitochondrial malfunction and the consequent cognitive impairments. Here, we showed the elimination of reactive oxygen species (ROS) by antioxidants probucol or superoxide dismutase (SOD)/catalase blocks Aβ-mediated inactivation of protein kinase A (PKA)/cAMP regulatory-element-binding (CREB) signal transduction pathway and loss of synapse, suggesting the detrimental effects of oxidative stress on neuronal PKA/CREB activity. Notably, neurons lacking CypD significantly attenuate Aβ-induced ROS. Consequently, CypD-deficient neurons are resistant to Aβ-disrupted PKA/CREB signaling by increased PKA activity, phosphorylation of PKA catalytic subunit (PKA C), and CREB. In parallel, lack of CypD protects neurons from Aβ-induced loss of synapses and synaptic dysfunction. Furthermore, compared to the mAPP mice, CypD-deficient mAPP mice reveal less inactivation of PKA-CREB activity and increased synaptic density, attenuate abnormalities in dendritic spine maturation, and improve spontaneous synaptic activity. These findings provide new insights into a mechanism in the crosstalk between the CypD-dependent mitochondrial oxidative stress and signaling cascade, leading to synaptic injury, functioning through the PKA/CREB signal transduction pathway. Copyright © 2013 Elsevier B.V. All rights reserved.

Alcohol exposure decreases CREB binding protein expression and histone acetylation in the developing cerebellum.

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Weixiang Guo

Full Text Available Fetal alcohol exposure affects 1 in 100 children making it the leading cause of mental retardation in the US. It has long been known that alcohol affects cerebellum development and function. However, the underlying molecular mechanism is unclear.We demonstrate that CREB binding protein (CBP is widely expressed in granule and Purkinje neurons of the developing cerebellar cortex of naïve rats. We also show that exposure to ethanol during the 3(rd trimester-equivalent of human pregnancy reduces CBP levels. CBP is a histone acetyltransferase, a component of the epigenetic mechanism controlling neuronal gene expression. We further demonstrate that the acetylation of both histone H3 and H4 is reduced in the cerebellum of ethanol-treated rats.These findings indicate that ethanol exposure decreases the expression and function of CBP in the developing cerebellum. This effect of ethanol may be responsible for the motor coordination deficits that characterize fetal alcohol spectrum disorders.

CREB1 is a strong genetic predictor of the variation in exercise heart rate response to regular exercise: the HERITAGE Family Study.

Science.gov (United States)

Rankinen, Tuomo; Argyropoulos, George; Rice, Treva; Rao, D C; Bouchard, Claude

2010-06-01

A genome-wide linkage scan identified a quantitative trait locus for exercise training-induced changes in submaximal exercise (50 W) heart rate (DeltaHR50) on chromosome 2q33.3-q34 in the HERITAGE Family Study (n=472). To fine-map the region, 1450 tag SNPs were genotyped between 205 and 215 Mb on chromosome 2. The strongest evidence of association with DeltaHR50 was observed with 2 single-nucleotide polymorphisms (SNPs) located in the 5' region of the cAMP-responsive element-binding protein 1 (CREB1) gene (rs2253206: P=1.6x10(-5) and rs2360969: P=4.3x10(-5)). The associations remained significant (P=0.01 and P=0.023, respectively) after accounting for multiple testing. Regression modeling of the 39 most significant SNPs in the single-SNP analysis identified 9 SNPs that collectively explained 20% of the DeltaHR50 variance. CREB1 SNP rs2253206 had the strongest effect (5.45% of variance), followed by SNPs in the FASTKD2 (3.1%), MAP2 (2.6%), SPAG16 (2.1%), ERBB4 (3 SNPs approximately 1.4% each), IKZF2 (1.4%), and PARD3B (1.0%) loci. In conditional linkage analysis, 6 SNPs from the final regression model (CREB1, FASTKD2, MAP2, ERBB4, IKZF2, and PARD3B) accounted for the original linkage signal: The log of the odds score dropped from 2.10 to 0.41 after adjusting for all 6 SNPs. Functional studies revealed that the common allele of rs2253206 exhibits significantly (P<0.05) lower promoter activity than the minor allele. Our data suggest that functional DNA sequence variation in the CREB1 locus is strongly associated with DeltaHR50 and explains a considerable proportion of the quantitative trait locus variance. However, at least 5 additional SNPs seem to be required to fully account for the original linkage signal.

Period1 gates the circadian modulation of memory-relevant signaling in mouse hippocampus by regulating the nuclear shuttling of the CREB kinase pP90RSK.

Science.gov (United States)

Rawashdeh, Oliver; Jilg, Antje; Maronde, Erik; Fahrenkrug, Jan; Stehle, Jörg H

2016-09-01

Memory performance varies over a 24-h day/night cycle. While the detailed underlying mechanisms are yet unknown, recent evidence suggests that in the mouse hippocampus, rhythmic phosphorylation of mitogen-activated protein kinase (MAPK) and cyclic adenosine monophosphate response element-binding protein (CREB) are central to the circadian (~ 24 h) regulation of learning and memory. We recently identified the clock protein PERIOD1 (PER1) as a vehicle that translates information encoding time of day to hippocampal plasticity. We here elaborate how PER1 may gate the sensitivity of memory-relevant hippocampal signaling pathways. We found that in wild-type mice (WT), spatial learning triggers CREB phosphorylation only during the daytime, and that this effect depends on the presence of PER1. The time-of-day-dependent induction of CREB phosphorylation can be reproduced pharmacologically in acute hippocampal slices prepared from WT mice, but is absent in preparations made from Per1-knockout (Per1(-/-) ) mice. We showed that the PER1-dependent CREB phosphorylation is regulated downstream of MAPK. Stimulation of WT hippocampal neurons triggered the co-translocation of PER1 and the CREB kinase pP90RSK (pMAPK-activated ribosomal S6 kinase) into the nucleus. In hippocampal neurons from Per1(-/-) mice, however, pP90RSK remained perinuclear. A co-immunoprecipitation assay confirmed a high-affinity interaction between PER1 and pP90RSK. Knocking down endogenous PER1 in hippocampal cells inhibited adenylyl cyclase-dependent CREB activation. Taken together, the PER1-dependent modulation of cytoplasmic-to-nuclear signaling in the murine hippocampus provides a molecular explanation for how the circadian system potentially shapes a temporal framework for daytime-dependent memory performance, and adds a novel facet to the versatility of the clock gene protein PER1. We provide evidence that the circadian clock gene Period1 (Per1) regulates CREB phosphorylation in the mouse hippocampus

The Neuroprotective Effect of Curcumin Against Nicotine-Induced Neurotoxicity is Mediated by CREB-BDNF Signaling Pathway.

Science.gov (United States)

Motaghinejad, Majid; Motevalian, Manijeh; Fatima, Sulail; Faraji, Fahimeh; Mozaffari, Shiva

2017-10-01

Nicotine abuse adversely affects brain and causes apoptotic neurodegeneration. Curcumin- a bright yellow chemical compound found in turmeric is associated with neuroprotective properties. The current study was designed to evaluate the role of CREB-BDNF signaling in mediating the neuroprotective effects of curcumin against nicotine-induced apoptosis, oxidative stress and inflammation in rats. Sixty adult male rats were divided randomly into six groups. Group 1 received 0.7 ml/rat normal saline, group 2 received 6 mg/kg nicotine. Groups 3, 4, 5 and 6 were treated concurrently with nicotine (6 mg/kg) and curcumin (10, 20, 40 and 60 mg/kg i.p. respectively) for 21 days. Open Field Test (OFT) was used to evaluate the motor activity. Hippocampal oxidative, anti-oxidant, inflammatory and apoptotic factors were evaluated. Furthermore, phosphorylated brain cyclic adenosine monophosphate (cAMP) response element binding protein (P-CREB) and brain derived neurotrophic factor (BDNF) levels were studied at gene and protein levels. We found that nicotine disturbed the motor activity in OFT and simultaneous treatment with curcumin (40 and 60 mg/kg) reduced the nicotine-induced motor activity disturbances. In addition, nicotine treatment increased lipid peroxidation and the levels of GSH, IL-1β, TNF-α and Bax, while reducing Bcl-2, P-CREB and BDNF levels in the hippocampus. Nicotine also reduced the activity of superoxide dismutase, glutathione peroxidase and glutathione reductase in hippocampus. In contrast, various doses of curcumin attenuated nicotine-induced apoptosis, oxidative stress and inflammation; while elevating P-CREB and BDNF levels. Thus, curcumin via activation of P-CREB/BDNF signaling pathway, confers neuroprotection against nicotine-induced inflammation, apoptosis and oxidative stress.

An essential GT motif in the lamin A promoter mediates activation by CREB-binding protein

International Nuclear Information System (INIS)

Janaki Ramaiah, M.; Parnaik, Veena K.

2006-01-01

Lamin A is an important component of nuclear architecture in mammalian cells. Mutations in the human lamin A gene lead to highly degenerative disorders that affect specific tissues. In studies directed towards understanding the mode of regulation of the lamin A promoter, we have identified an essential GT motif at -55 position by reporter gene assays and mutational analysis. Binding of this sequence to Sp transcription factors has been observed in electrophoretic mobility shift assays and by chromatin immunoprecipitation studies. Further functional analysis by co-expression of recombinant proteins and ChIP assays has shown an important regulatory role for CREB-binding protein in promoter activation, which is mediated by the GT motif

Period1 gates the circadian modulation of memory-relevant signaling in mouse hippocampus by regulating the nuclear shuttling of the CREB kinase pP90RSK

DEFF Research Database (Denmark)

Rawashdeh, Oliver; Jilg, Antje; Maronde, Erik

2016-01-01

, the presence of PER1 in hippocampal neurons is a prerequisite for the time-of-day-dependent phosphorylation of CREB, as it regulates the shuttling of pP90RSK into the nucleus. Representative immunofluorescence images show a temporal difference in phosphorylated cAMP response element-binding protein (p...... activation. Taken together, the PER1-dependent modulation of cytoplasmic-to-nuclear signaling in the murine hippocampus provides a molecular explanation for how the circadian system potentially shapes a temporal framework for daytime-dependent memory performance, and adds a novel facet to the versatility......CREB; green color) levels in all regions of the dorsal hippocampus between a wild-type C3H mouse (WT; left) and a Period1-knockout (Per1−/−; right) mouse. Images were taken 2 h after lights on, thus, when fluctuating levels of pCREB peak in WT mouse hippocampus. Insets show a representative hippocampal neuron...

Inhibition of the cAMP/PKA/CREB Pathway Contributes to the Analgesic Effects of Electroacupuncture in the Anterior Cingulate Cortex in a Rat Pain Memory Model.

Science.gov (United States)

Shao, Xiao-Mei; Sun, Jing; Jiang, Yong-Liang; Liu, Bo-Yi; Shen, Zui; Fang, Fang; Du, Jun-Ying; Wu, Yuan-Yuan; Wang, Jia-Ling; Fang, Jian-Qiao

2016-01-01

Pain memory is considered as endopathic factor underlying stubborn chronic pain. Our previous study demonstrated that electroacupuncture (EA) can alleviate retrieval of pain memory. This study was designed to observe the different effects between EA and indomethacin (a kind of nonsteroid anti-inflammatory drugs, NSAIDs) in a rat pain memory model. To explore the critical role of protein kinase A (PKA) in pain memory, a PKA inhibitor was microinjected into anterior cingulate cortex (ACC) in model rats. We further investigated the roles of the cyclic adenosine monophosphate (cAMP), PKA, cAMP response element-binding protein (CREB), and cAMP/PKA/CREB pathway in pain memory to explore the potential molecular mechanism. The results showed that EA alleviates the retrieval of pain memory while indomethacin failed. Intra-ACC microinjection of a PKA inhibitor blocked the occurrence of pain memory. EA reduced the activation of cAMP, PKA, and CREB and the coexpression levels of cAMP/PKA and PKA/CREB in the ACC of pain memory model rats, but indomethacin failed. The present findings identified a critical role of PKA in ACC in retrieval of pain memory. We propose that the proper mechanism of EA on pain memory is possibly due to the partial inhibition of cAMP/PKA/CREB signaling pathway by EA.

Curcumin reverses the effects of chronic stress on behavior, the HPA axis, BDNF expression and phosphorylation of CREB.

Science.gov (United States)

Xu, Ying; Ku, Baoshan; Tie, Lu; Yao, Haiyan; Jiang, Wengao; Ma, Xing; Li, Xuejun

2006-11-29

Curcuma longa is a major constituent of the traditional Chinese medicine Xiaoyao-san, which has been used to effectively manage stress and depression-related disorders in China. Curcumin is the active component of curcuma longa, and its antidepressant effects were described in our prior studies in mouse models of behavioral despair. We hypothesized that curcumin may also alleviate stress-induced depressive-like behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Thus in present study we assessed whether curcumin treatment (2.5, 5 and 10 mg/kg, p.o.) affects behavior in a chronic unpredictable stress model of depression in rats and examined what its molecular targets may be. We found that subjecting animals to the chronic stress protocol for 20days resulted in performance deficits in the shuttle-box task and several physiological effects, such as an abnormal adrenal gland weight to body weight (AG/B) ratio and increased thickness of the adrenal cortex as well as elevated serum corticosterone levels and reduced glucocorticoid receptor (GR) mRNA expression. These changes were reversed by chronic curcumin administration (5 or 10 mg/kg, p.o.). In addition, we also found that the chronic stress procedure induced a down-regulation of brain-derived neurotrophic factor (BDNF) protein levels and reduced the ratio of phosphorylated cAMP response element-binding protein (pCREB) to CREB levels (pCREB/CREB) in the hippocampus and frontal cortex of stressed rats. Furthermore, these stress-induced decreases in BDNF and pCREB/CREB were also blocked by chronic curcumin administration (5 or 10 mg/kg, p.o.). These results provide compelling evidence that the behavioral effects of curcumin in chronically stressed animals, and by extension humans, may be related to their modulating effects on the HPA axis and neurotrophin factor expressions.

Osthole Enhances Osteogenesis in Osteoblasts by Elevating Transcription Factor Osterix via cAMP/CREB Signaling In Vitro and In Vivo

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Zhong-Rong Zhang

2017-06-01

Full Text Available Anabolic anti-osteoporotic agents are desirable for treatment and prevention of osteoporosis and fragility fractures. Osthole is a coumarin derivative extracted from the medicinal herbs Cnidium monnieri (L. Cusson and Angelica pubescens Maxim.f. Osthole has been reported with osteogenic and anti-osteoporotic properties, whereas the underlying mechanism of its benefit still remains unclear. The objective of the present study was to investigate the osteopromotive action of osthole on mouse osteoblastic MC3T3-E1 cells and on mouse femoral fracture repair, and to explore the interaction between osthole-induced osteopromotive effect and cyclic adenosine monophosphate (cAMP elevating effect. Osthole treatment promoted osteogenesis in osteoblasts by enhancing alkaline phosphatase (ALP activity and mineralization. Oral gavage of osthole enhanced fracture repair and increased bone strength. Mechanistic study showed osthole triggered the cAMP/CREB pathway through the elevation of the intracellular cAMP level and activation of the phosphorylation of the cAMP response element-binding protein (CREB. Blockage of cAMP/CREB downstream signals with protein kinase A (PKA inhibitor KT5720 partially suppressed osthole-mediated osteogenesis by inhibiting the elevation of transcription factor, osterix. In conclusion, osthole shows osteopromotive effect on osteoblasts in vitro and in vivo. Osthole-mediated osteogenesis is related to activation of the cAMP/CREB signaling pathway and downstream osterix expression.

Cross-Sectional and Longitudinal Effects of CREB1 Genotypes on Individual Differences in Memory and Executive Function: Findings from the BLSA

Directory of Open Access Journals (Sweden)

Claudia Wolf

2017-05-01

Full Text Available Purpose: Previously, we have shown that the SNP rs10932201 genotype of the cyclic AMP responsive element binding protein 1 gene (CREB1 contributes to individual differences in executive and memory function at the neural system and behavioral levels in healthy, young adults. However, longitudinal effects of CREB1 genotypes on cognition have not yet been addressed. Furthermore we were interested in replicating associations between CREB1 genotypes and human cognition in previous cross-sectional studies and explore whether APOE4 status might modify these relations.Materials and Methods: We investigated whether common, independent tag SNPs within CREB1 (rs2253206, rs10932201, rs6785 influence individual differences in age-related longitudinal change and level of executive function and memory performance independent of baseline age, sex, APOE4 status, and education. Our analysis included data from cognitively unimpaired older adults participating in the Baltimore Longitudinal Study of Aging. Eleven measures from six cognitive tests (sample sizes range 617–786 were analyzed using linear mixed effects and generalized estimating equations models. Mean baseline age ranged from 50 to 69 years and mean time of follow-up (interval ranged from 8 to 22 years.Results: We found significant effects of all three CREB1 SNPs on performance level and/or longitudinal change in performance based on eight measures assessing semantic memory, episodic memory, or both executive function and semantic memory. SNP rs10932201 showed the most significant and largest effect (Cohen’s d = -0.70, p < 0.01 on age-related longitudinal decline of semantic memory. Additionally, we show interactions between all three CREB1 SNPs and APOE4 status on age-related longitudinal declines and levels of memory and executive function.Conclusion: Our results suggest that CREB1 genotypes independently and by interactions with APOE4 status contribute to individual differences in cognitive aging.

v-src Induction of the TIS10/PGS2 prostaglandin synthase gene is mediated by an ATF/CRE transcription response element

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Xie, W.; Fletcher, B.S.; Andersen, R.D.; Herschman, H.R. [Univ. of California, Los Angeles, CA (United States)

1994-10-01

The authors recently reported the cloning of a mitogen-inducible prostaglandin synthase gene, TIS10/PGS2. In addition to growth factor and tumor promoters, the v-src oncogene induces TIS10/PGS2 expression in 3T3 cells. Deletion analysis, using luciferase reporters, identifies a region between -80 and -40 nucleotides 5{prime} of the TIS10/PGS2 transcription start site that mediates pp60{sup v-src} induction in 3T3 cells. This region contains the sequence CGTCACGTG, which includes overlapping ATF/CRE (CGTCA) and E-box (CACGTG) sequences. Gel shift-oligonucleotide competition experiments with nuclear extracts from cells stably transfected with a temperature-sensitive v-src gene demonstrate that the CGTCACGTG sequence can bind proteins at both the AFT/CRE and E-box sequences. Dominant-negative CREB and Myc proteins that bind DNA, but do not transactivate, block v-src induction of a luciferase reporter driven by the first 80 nucleotides of the TIS10/PGS2 promoter. Mutational analysis distinguishes which TIS10/PGS2 cis-acting element mediates pp60{sup v-src} induction. E-box mutation has no effect on the fold induction in response to pp60{sup v-src}. In contrast, ATF/CRE mutation attenuates the pp{sup v-src} response. Antibody supershift and methylation interference experiments demonstrate that CREB and at least one other ATF transcription factor in these extracts bind to the TIS10/PGS2 ATF/CRE element. Expression of a dominant-negative ras gene also blocks TIS10/PGS2 induction by v-src. The data suggest that Ras mediates pp60{sup v-src} activation of an ATF transcription factor, leading to induced TIS10/PGS2 expression via the ATF/CRE element of the TIS10/PGS2 promoter. This is the first description of v-src activation of gene expression via an ATF/CRE element. 64 refs., 8 figs.

Tau hyperphosphorylation and P-CREB reduction are involved in acrylamide-induced spatial memory impairment: Suppression by curcumin.

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Yan, Dandan; Yao, Jianling; Liu, Ying; Zhang, Xing; Wang, Yiqi; Chen, Xiaoyi; Liu, Liegang; Shi, Nian; Yan, Hong

2018-04-26

Acrylamide (ACR) is an axonal toxicant that produces peripheral neuropathy in laboratory animals and humans. Epidemiological study found that diet ACR exposure was associated with a mild cognitive decline in men. However, limited information is available as regards its potential and underlying mechanism to cause memory alterations. Curcumin is a polyphenol with neuroprotective and cognitive-enhancing properties. In this study, we aimed to investigate the mechanism of ACR-induced spatial memory impairment and the beneficial effect of curcumin. ACR exposure at 10 mg/kg/d for 7 weeks caused slight gait abnormality and spatial memory deficits, which was associated with an activation of glial cells, a reduction of phosphorylated cAMP response elements binding protein (P-CREB) and an aggregation of hyperphosphorylated tau including p-tau (Ser 262 ), AT8 (p-tau Ser 202 /Thr 205 ) and PHF1 (p-tau Ser 396/404 ) in the hippocampus and cortex. ACR markedly regulate the expression of glycogen synthase kinase-3β (GSK-3β) and cyclin-dependent kinase-5 (cdk5) to accelerate tau hyperphosphorylation. ACR inhibited the protein phosphatase 2A (PP2A) and lysosomal protease cathepsin D to decrease the p-tau dephosphorylation and degradation. The P-CREB and brain derived neurotrophic factor (BDNF) were significantly decreased by ACR. The upstream signalings of P-CREB, extracellular signal-related kinase (ERK) and Akt were markedly inhibited. The protein kinase RNA-like endoplasmic reticulum kinase (PERK) -eukaryotic initiation factor-2α (eIF2α) - activating transcription factor 4 (ATF4) signaling which negatively regulate memory processes by suppressing CREB was activated by ACR. Curcumin alleviated ACR-induced spatial memory impairment through reversing tau abnormalities and P-CREB reduction in the hippocampus. These results offered deeper insight into the mechanisms of and presented a potential new treatment for ACR-induced neurotoxicity. Copyright © 2018 Elsevier Inc. All

Exercise Prevents Memory Impairment Induced by Arsenic Exposure in Mice: Implication of Hippocampal BDNF and CREB.

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Bao-Fei Sun

Full Text Available High concentrations of arsenic, which can be occasionally found in drinking water, have been recognized as a global health problem. Exposure to arsenic can disrupt spatial memory; however, the underlying mechanism remains unclear. In the present study, we tested whether exercise could interfere with the effect of arsenic exposure on the long-term memory (LTM of object recognition in mice. Arsenic (0, 1, 3, and 10 mg/ kg, i.g. was administered daily for 12 weeks. We found that arsenic at dosages of 1, 3, and 10 mg/kg decreased body weight and increased the arsenic content in the brain. The object recognition LTM (tested 24 h after training was disrupted by 3 mg/ kg and 10 mg/ kg, but not 1 mg/ kg arsenic exposure. Swimming exercise also prevented LTM impairment induced by 3 mg/ kg, but not with 10 mg/ kg, of arsenic exposure. The expression of brain-derived neurotrophic factor (BDNF and phosphorylated cAMP-response element binding protein (pCREB in the CA1 and dentate gyrus areas (DG of the dorsal hippocampus were decreased by 3 mg/ kg and 10 mg/ kg, but not by 1 mg/ kg, of arsenic exposure. The decrease in BDNF and pCREB in the CA1 and DG induced by 3 mg/ kg, but not 10 mg/ kg, of arsenic exposure were prevented by swimming exercise. Arsenic exposure did not affect the total CREB expression in the CA1 or DG. Taken together, these results indicated that swimming exercise prevented the impairment of object recognition LTM induced by arsenic exposure, which may be mediated by BDNF and CREB in the dorsal hippocampus.

Tongqiao Huoxue Decoction ameliorates learning and memory defects in rats with vascular dementia by up-regulating the Ca(2+)-CaMKII-CREB pathway.

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Ge, Chao-Liang; Wang, Xin-Ming; Huang, Zhao-Gang; Xia, Quan; Wang, Ning; Xu, Du-Juan

2015-11-01

The present study was aimed at determining the effects of Tongqiao Huoxue Decoction (TQHXD) on the Ca(2+)-CaMKII-CREB pathway and the memory and learning capacities of rats with vascular dementia (VD). The rat VD model was established by using an improved bilateral carotid artery ligation method. The Morris water maze experiment was used to evaluate the ethology of the VD rats following treatments with TQHXD at 3.01, 6.02, and 12.04 g·kg(-1) per day for 31 days. At the end of experiment, the hippocampus were harvested and analyzed. Western blotting and RT-PCR were used to measure the expression levels of calmodulin-binding protein kinase II(CaMKII), protein kinase A(PKA), cAMP-response element binding protein(CREB), and three N-methyl-D-aspartic acid receptor subunits (NR1, NR2A, and NR2B). Our results revealed that TQHXD could alleviate the loss of learning abilities and increase the memory capacity (P < 0.05 and P < 0.01 vs the model group, respectively). The treatment with 6.02 and 12.04 g·kg(-1) of TQHXD significantly up-regulated the Ca(2+)-CaMKII-CREB pathway in the hippocampus. In conclusion, TQHXD showed therapeutic effects on a bilateral carotid artery ligation-induced vascular dementia model, through the up-regulation of calcium signalling pathways. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

DA-9801 promotes neurite outgrowth via ERK1/2-CREB pathway in PC12 cells.

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Won, Jong Hoon; Ahn, Kyong Hoon; Back, Moon Jung; Ha, Hae Chan; Jang, Ji Min; Kim, Ha Hyung; Choi, Sang-Zin; Son, Miwon; Kim, Dae Kyong

2015-01-01

In the present study, we examined the mechanisms underlying the effect of DA-9801 on neurite outgrowth. We found that DA-9801 elicits its effects via the mitogen-activated protein kinase (MEK) extracellular signal-regulated kinase (ERK)1/2-cAMP response element-binding protein (CREB) pathway. DA-9801, an extract from a mixture of Dioscorea japonica and Dioscorea nipponica, was reported to promote neurite outgrowth in PC12 cells. The effects of DA-9801 on cell viability and expression of neuronal markers were evaluated in PC12 cells. To investigate DA-9801 action, specific inhibitors targeting the ERK signaling cascade were used. No cytotoxicity was observed in PC12 cells at DA-9801 concentrations of less than 30 µg/mL. In the presence of nerve growth factor (NGF, 2 ng/mL), DA-9801 promoted neurite outgrowth and increased the relative mRNA levels of neurofilament-L (NF-L), a marker of neuronal differentiation. The Raf-1 inhibitor GW5074 and MEK inhibitor PD98059 significantly attenuated DA-9801-induced neurite outgrowth. Additionally, the MEK1 and MEK2 inhibitor SL327 significantly attenuated the increase in the percentage of neurite-bearing PC12 cells induced by DA-9801 treatment. Conversely, the selective p38 mitogen-activated protein kinase inhibitor SB203580 did not attenuate the DA-9801 treatment-induced increase in the percentage of neurite-bearing PC12 cells. DA-9801 enhanced the phosphorylation of ERK1/2 and CREB in PC12 cells incubated with and without NGF. Pretreatment with PD98059 blocked the DA-9801-induced phosphorylation of ERK1/2 and CREB. In conclusion, DA-9801 induces neurite outgrowth by affecting the ERK1/2-CREB signaling pathway. Insights into the mechanism underlying this effect of DA-9801 may suggest novel potential strategies for the treatment of peripheral neuropathy.

Overlapping ETS and CRE Motifs (G/CCGGAAGTGACGTCA) Preferentially Bound by GABPα and CREB Proteins

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Chatterjee, Raghunath; Zhao, Jianfei; He, Ximiao; Shlyakhtenko, Andrey; Mann, Ishminder; Waterfall, Joshua J.; Meltzer, Paul; Sathyanarayana, B. K.; FitzGerald, Peter C.; Vinson, Charles

2012-01-01

Previously, we identified 8-bps long DNA sequences (8-mers) that localize in human proximal promoters and grouped them into known transcription factor binding sites (TFBS). We now examine split 8-mers consisting of two 4-mers separated by 1-bp to 30-bps (X4-N1-30-X4) to identify pairs of TFBS that localize in proximal promoters at a precise distance. These include two overlapping TFBS: the ETS⇔ETS motif (C/GCCGGAAGCGGAA) and the ETS⇔CRE motif (C/GCGGAAGTGACGTCAC). The nucleotides in bold are part of both TFBS. Molecular modeling shows that the ETS⇔CRE motif can be bound simultaneously by both the ETS and the B-ZIP domains without protein-protein clashes. The electrophoretic mobility shift assay (EMSA) shows that the ETS protein GABPα and the B-ZIP protein CREB preferentially bind to the ETS⇔CRE motif only when the two TFBS overlap precisely. In contrast, the ETS domain of ETV5 and CREB interfere with each other for binding the ETS⇔CRE. The 11-mer (CGGAAGTGACG), the conserved part of the ETS⇔CRE motif, occurs 226 times in the human genome and 83% are in known regulatory regions. In vivo GABPα and CREB ChIP-seq peaks identified the ETS⇔CRE as the most enriched motif occurring in promoters of genes involved in mRNA processing, cellular catabolic processes, and stress response, suggesting that a specific class of genes is regulated by this composite motif. PMID:23050235

SCM-198 Ameliorates Cognitive Deficits, Promotes Neuronal Survival and Enhances CREB/BDNF/TrkB Signaling without Affecting Aβ Burden in AβPP/PS1 Mice.

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Hong, Zhen-Yi; Yu, Shuang-Shuang; Wang, Zhi-Jun; Zhu, Yi-Zhun

2015-08-07

SCM-198 is an alkaloid found only in Herba leonuri and it has been reported to possess considerable neuroprotective effects in animal models of ischemic stroke, Parkinson's disease and Alzheimer's disease (AD). In this study, we demonstrated for the first time that 3-month oral SCM-198 treatment could significantly improve both recognition and spatial memory, inhibit microgliosis and promote neuronal survival in amyloid-β protein precursor and presenilin-1(AβPP/PS1) double-transgenic mice without affecting amyloid-β (Aβ) burden. In addition, decreases in cAMP-response element-binding protein (CREB) phosphorylation, brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) phosphorylation were attenuated by SCM-198 both in vivo and in primary cortical neurons, which could be blocked by protein kinase A (PKA) inhibitors, suggesting the involvement of upstream PKA in enhancing the BDNF/TrkB/CREB signaling by SCM-198. Our results indicate that SCM-198, a drug that could promote neuronal survival and enhance BDNF/TrkB/CREB signaling, has beneficial effects on behavioral and biochemical alterations without affecting Aβ burden in AβPP/PS1 mice and might become a potential drug candidate for AD treatment in the future.

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus.

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Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

2016-09-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. Copyright © 2016. Published by Elsevier Inc.

IL-1β Upregulates StAR and Progesterone Production Through the ERK1/2- and p38-Mediated CREB Signaling Pathways in Human Granulosa-Lutein Cells.

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Dang, Xuan; Zhu, Qinling; He, Yaqiong; Wang, Yuan; Lu, Yao; Li, Xiaoxue; Qi, Jia; Wu, Hasiximuke; Sun, Yun

2017-10-01

The proinflammatory cytokine interleukin-1β (IL-1β) may be involved in several ovulation-associated events, such as protease synthesis, prostaglandin production, and steroidogenesis in granulosa cells. However, the exact effect of IL-1β on progesterone synthesis in granulosa cells and the underlying mechanism remain unclear. By using cultured granulosa-lutein cells collected from women undergoing in vitro fertilization or intracytoplasmic sperm injection, we found that IL-1β upregulated steroidogenic acute regulatory protein (StAR) expression and progesterone synthesis in granulosa-lutein cells, which was comparable with luteinizing hormone effect and could be abolished by an IL-1 receptor antagonist. Moreover, IL-1β activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB), and knockdown of CREB attenuated the induction of StAR expression and progesterone synthesis by IL-1β in granulosa-lutein cells. Furthermore, IL-1β activated the extracellular signal-regulated kinase (ERK)1/2 and p38 pathways and inhibition of the ERK1/2 and p38 pathways attenuated the IL-1β-induced phosphorylation of CREB, StAR expression, and progesterone synthesis in granulosa-lutein cells. In conclusion, IL-1β could upregulate StAR expression and stimulate progesterone biosynthesis through increase in CREB phosphorylation via activating the ERK1/2 and p38 pathways in human granulosa-lutein cells. Copyright © 2017 Endocrine Society.

Sp1 and CREB regulate basal transcription of the human SNF2L gene

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Xia Yu; Jiang Baichun; Zou Yongxin; Gao Guimin; Shang Linshan; Chen Bingxi; Liu Qiji; Gong Yaoqin

2008-01-01

Imitation Switch (ISWI) is a member of the SWI2/SNF2 superfamily of ATP-dependent chromatin remodelers, which are involved in multiple nuclear functions, including transcriptional regulation, replication, and chromatin assembly. Mammalian genomes encode two ISWI orthologs, SNF2H and SNF2L. In order to clarify the molecular mechanisms governing the expression of human SNF2L gene, we functionally examined the transcriptional regulation of human SNF2L promoter. Reporter gene assays demonstrated that the minimal SNF2L promoter was located between positions -152 to -86 relative to the transcription start site. In this region we have identified a cAMP-response element (CRE) located at -99 to -92 and a Sp1-binding site at -145 to -135 that play a critical role in regulating basal activity of human SNF2L gene, which were proven by deletion and mutation of specific binding sites, EMSA, and down-regulating Sp1 and CREB via RNAi. This study provides the first insight into the mechanisms that control basal expression of human SNF2L gene

Antidepressant-like activity of red wine phenolic extracts in repeated corticosterone-induced depression mice via BDNF/TrkB/CREB signaling pathway

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Jia Ying

2016-01-01

Full Text Available The aim of this study was to investigate the antidepressant-like effect of red wine phenolic extracts in mouse model exposed to exogenous corticosterone. The results showed that 3-week corticosterone injections caused depression-like behavior in mice, as indicated by the significant decrease in sucrose consumption and increase immobility time in the forced swim test. Red wine phenolic extracts treatment significantly reduced serum corticosterone levels. Moreover, it was found that red wine phenolic extract increased the brain-derived neurotrophic factor protein (BNDF and Tropomyosin-related kinase B (TrkB phosphorylation and cAMP-responsive element binding protein (CREB phosphorylation levels in the hippocampus and prefrontal cortex. However, K252a, an inhibitor of TrkB, completely abolished those antidepressant-like effects. These results suggested that the red wine phenolic extracts produce an antidepressant-like effect in corticosterone-treated mice, at least in part, which is possibly mediated by modulating hypothalamic-pituitary-adrenal (HPA axis, BDNF, TrkB and CREB phosphorylation levels in the brain region of mice.

Dorsal hippocampal NMDA receptor blockade impairs extinction of naloxone-precipitated conditioned place aversion in acute morphine-treated rats by suppressing ERK and CREB phosphorylation in the basolateral amygdala.

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Wang, Wei-Sheng; Chen, Zhong-Guo; Liu, Wen-Tao; Chi, Zhi-Qiang; He, Ling; Liu, Jing-Gen

2015-01-01

Substantial evidence shows that negative reinforcement resulting from the aversive affective consequences of opiate withdrawal may play a crucial role in drug relapse. Understanding the mechanisms underlying the loss (extinction) of conditioned aversion of drug withdrawal could facilitate the treatment of drug addiction. Naloxone-induced conditioned place aversion (CPA) of Sprague-Dawley rats was used to measure conditioned aversion. An NMDA receptor antagonist and MAPK kinase inhibitor were applied through intracranial injections. The phosphorylation of ERK and cAMP response element-binding protein (CREB) was detected using Western blot. The extinction of CPA behaviour increased the phosphorylation of ERK and CREB in the dorsal hippocampus (DH) and basolateral amygdala (BLA), but not in the central amygdala (CeA). Intra-DH injection of AP5 or intra-BLA injection of AP-5 or U0126 before extinction training significantly attenuated ERK and CREB phosphorylation in the BLA and impaired the extinction of CPA behaviour. Although intra-DH injections of AP-5 attenuated extinction training-induced activation of the ERK-CREB pathway in the BLA, intra-BLA injection of AP5 had no effect on extinction training-induced activation of the ERK-CREB pathway in the DH. These results suggest that activation of ERK and CREB in the BLA and DH is involved in the extinction of CPA behaviour and that the DH, via a direct or indirect pathway, modulates the activity of ERK and CREB in the BLA through activation of NMDA receptors after extinction training. Understanding the mechanisms underlying the extinction of conditioned aversion could facilitate the treatment of drug addiction. This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2. © 2014 The British Pharmacological Society.

YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

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Hwang, Tsong-Long, E-mail: htl@mail.cgu.edu.tw [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan, Taiwan (China); Tang, Ming-Chi [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Kuo, Liang-Mou [Department of General Surgery, Chang Gung Memorial Hospital at Chia-Yi, Taiwan (China); Chang, Wen-De; Chung, Pei-Jen; Chang, Ya-Wen; Fang, Yao-Ching [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China)

2012-04-15

Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E{sub 1} (a stable PGE{sub 2} analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE{sub 1}- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE{sub 1} significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE{sub 1}-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE{sub 1} also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE{sub 1}-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway. Highlights: ► YC-1 potentiated PGE1-induced iNOS expression in alveolar macrophages. ► The combination of YC-1 and PGE1 increased CREB but not NFκB activation. �

cAMP/PKA-CREB-BDNF signaling pathway in hippocampus mediates cyclooxygenase 2-induced learning/memory deficits of rats subjected to chronic unpredictable mild stress.

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Luo, Ying; Kuang, Shengnan; Li, Huan; Ran, Dongzhi; Yang, Junqing

2017-05-30

To investigate the mechanism of cyclooxygenase 2 (COX2) in learning and memory impairments in rats subjected to chronic unpredictable mild stress (CUMS), meloxicam was used intragastrically to inhibit the activity of cyclooxygenase 2. Moreover, cyclooxygenase 2 over-expressing or RNA interfere lentivirus was injected intraventricularly to increase or decrease the enzyme's expression, respectively. The body weights and sucrose consumption were used to analyze depressive behaviors, while the Morris water maze and step-down-type passive avoidance tests were carried out to evaluate the learning-memory functions. The levels of inflammatory cytokines were measured to estimate inflammation and the contents of cyclic adenosine monophosphate (cAMP) were used to measure the levels of the second messenger. Changes in cyclooxygenase 2 mRNA levels were analyzed using reverse transcription polymerase chain reaction. Moreover, the expression of cyclooxygenase 2, brain-derived neurotrophic factor (BDNF), prostaglandins receptor 3 (EP3), protein kinase A (PKA), cAMP response element binding protein (CREB), and phosphorylated CREB were estimated using immunohistochemical staining or western blotting. The results showed that CUMS led to significant depressive-like behaviors and learning and memory dysfunctions. Also, the cAMP levels decreased significantly, while levels of inflammatory cytokines and prostaglandins E2 increased significantly. The expressions of PKA, BDNF, phosphorylated CREB/CREB declined and cyclooxygenase 2 was increased. Meloxicam and cyclooxygenase 2 RNA interfere lentivirus reversed the changes caused by CUMS while cyclooxygenase 2-overexpressing lentivirus worsened these abnormalities. The findings also showed that CUMS increased cyclooxygenase 2 expression, which can cause learning and memory impairments, mainly through activating the hippocampal neuronal cAMP/PKA-CREB-BDNF signaling pathways.

SCM-198 Ameliorates Cognitive Deficits, Promotes Neuronal Survival and Enhances CREB/BDNF/TrkB Signaling without Affecting Aβ Burden in AβPP/PS1 Mice

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Zhen-Yi Hong

2015-08-01

Full Text Available SCM-198 is an alkaloid found only in Herba leonuri and it has been reported to possess considerable neuroprotective effects in animal models of ischemic stroke, Parkinson’s disease and Alzheimer’s disease (AD. In this study, we demonstrated for the first time that 3-month oral SCM-198 treatment could significantly improve both recognition and spatial memory, inhibit microgliosis and promote neuronal survival in amyloid-β protein precursor and presenilin-1(AβPP/PS1 double-transgenic mice without affecting amyloid-β (Aβ burden. In addition, decreases in cAMP-response element-binding protein (CREB phosphorylation, brain-derived neurotrophic factor (BDNF and tropomyosin-related kinase B (TrkB phosphorylation were attenuated by SCM-198 both in vivo and in primary cortical neurons, which could be blocked by protein kinase A (PKA inhibitors, suggesting the involvement of upstream PKA in enhancing the BDNF/TrkB/CREB signaling by SCM-198. Our results indicate that SCM-198, a drug that could promote neuronal survival and enhance BDNF/TrkB/CREB signaling, has beneficial effects on behavioral and biochemical alterations without affecting Aβ burden in AβPP/PS1 mice and might become a potential drug candidate for AD treatment in the future.

Attenuation of pCREB and Egr1 expression in the insular and anterior cingulate cortices associated with enhancement of CFA-evoked mechanical hypersensitivity after repeated forced swim stress.

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Imbe, Hiroki; Kimura, Akihisa

2017-09-01

The perception and response to pain are severely impacted by exposure to stressors. In some animal models, stress increases pain sensitivity, which is termed stress-induced hyperalgesia (SIH). The insular cortex (IC) and anterior cingulate cortex (ACC), which are typically activated by noxious stimuli, affect pain perception through the descending pain modulatory system. In the present study, we examined the expression of phospho-cAMP response element-binding protein (pCREB) and early growth response 1 (Egr1) in the IC and ACC at 3h (the acute phase of peripheral tissue inflammation) after complete Freund's adjuvant (CFA) injection in naïve rats and rats preconditioned with forced swim stress (FS) to clarify the effect of FS, a stressor, on cortical cell activities in the rats showing SIH induced by FS. The CFA injection into the hindpaw induced mechanical hypersensitivity and increased the expression of the pCREB and Egr1 in the IC and ACC at 3h after the injection. FS (day 1, 10min; days 2-3, 20min) prior to the CFA injection enhanced the CFA-induced mechanical hypersensitivity and attenuated the increase in the expression of pCREB and Egr1 in the IC and ACC. These findings suggested that FS modulates the CFA injection-induced neuroplasticity in the IC and ACC to enhance the mechanical hypersensitivity. These findings are thought to signify stressor-induced dysfunction of the descending pain modulatory system. Copyright © 2017 Elsevier Inc. All rights reserved.

Glutamatergic induction of CREB phosphorylation and Fos expression in primary cultures of the suprachiasmatic hypothalamus in vitro is mediated by co-ordinate activity of NMDA and non-NMDA receptors.

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Schurov, I L; McNulty, S; Best, J D; Sloper, P J; Hastings, M H

1999-01-01

Exposure of Syrian hamsters to light 1 h after lights-off rapidly (10 min) induced nuclear immunoreactivity (-ir) to the phospho-Ser133 form of the Ca2+/cAMP response element (CRE) binding protein (pCREB) in the retinorecipient zone of the suprachiasmatic nuclei (SCN). Light also induced nuclear Fos-ir in the same region of the SCN after 1 h. The glutamatergic N-methyl-D-aspartate (NMDA) receptor blocker MK801 attenuated the photic induction of both factors. To investigate glutamatergic regulation of pCREB and Fos further, tissue blocks and primary cultures of neonatal hamster SCN were examined by Western blotting and immunocytochemistry in vitro. On Western blots of SCN tissue, the pCREB-ir signal at 45 kDa was enhanced by glutamate or a mixture of glutamatergic agonists (NMDA, amino-methyl proprionic acid (AMPA), and Kainate (KA)), whereas total CREB did not change. Glutamate or the mixture of agonists also induced a 56 kDa band identified as Fos protein in SCN tissue. In dissociated cultures of SCN, glutamate caused a rapid (15 min) induction of nuclear pCREB-ir and Fos-ir (after 60 min) exclusively in neurones, both GABA-ir and others. Treatment with NMDA alone had no effect on pCREB-ir. AMPA alone caused a slight increase in pCREB-ir. However, kainate alone or in combination with NMDA and AMPA induced nuclear pCREB-ir equal to that induced by glutamate. The effects of glutamate on pCREB-ir and Fos-ir were blocked by antagonists of both NMDA (MK801) and AMPA/KA (NBQX) receptors. In the absence of extracellular Mg2+, MK801 blocked glutamatergic induction of Fos-ir. However, the AMPA/KA receptor antagonist was no longer effective at blocking glutamatergic induction of either Fos-ir or pCREB-ir, consistent with the model that glutamate regulates gene expression in the SCN by a co-ordinate action through both NMDA and AMPA/KA receptors. Glutamatergic induction of nuclear pCREB-ir in GABA-ir neurones was blocked by KN-62 an inhibitor of Ca2+/Calmodulin (Ca

Effects of rare earth elements and REE-binding proteins on physiological responses in plants.

Science.gov (United States)

Liu, Dongwu; Wang, Xue; Chen, Zhiwei

2012-02-01

Rare earth elements (REEs), which include 17 elements in the periodic table, share chemical properties related to a similar external electronic configuration. REEs enriched fertilizers have been used in China since the 1980s. REEs could enter the cell and cell organelles, influence plant growth, and mainly be bound with the biological macromolecules. REE-binding proteins have been found in some plants. In addition, the chlorophyll activities and photosynthetic rate can be regulated by REEs. REEs could promote the protective function of cell membrane and enhance the plant resistance capability to stress produced by environmental factors, and affect the plant physiological mechanism by regulating the Ca²⁺ level in the plant cells. The focus of present review is to describe how REEs and REE-binding proteins participate in the physiological responses in plants.

Ginger improves cognitive function via NGF-induced ERK/CREB activation in the hippocampus of the mouse.

Science.gov (United States)

Lim, Soonmin; Moon, Minho; Oh, Hyein; Kim, Hyo Geun; Kim, Sun Yeou; Oh, Myung Sook

2014-10-01

Ginger (the rhizome of Zingiber officinale Roscoe) has been used worldwide for many centuries in cooking and for treatment of several diseases. The main pharmacological properties of ginger include anti-inflammatory, antihyperglycemic, antiarthritic, antiemetic and neuroprotective actions. Recent studies demonstrated that ginger significantly enhances cognitive function in various cognitive disorders as well as in healthy brain. However, the biochemical mechanisms underlying the ginger-mediated enhancement of cognition have not yet been studied in normal or diseased brain. In the present study, we assessed the memory-enhancing effects of dried ginger extract (GE) in a model of scopolamine-induced memory deficits and in normal animals by performing a novel object recognition test. We found that GE administration significantly improved the ability of mice to recognize novel objects, indicating improvements in learning and memory. Furthermore, to elucidate the mechanisms of GE-mediated cognitive enhancement, we focused on nerve growth factor (NGF)-induced signaling pathways. NGF enzyme-linked immunosorbent assay analysis revealed that GE administration led to elevated NGF levels in both the mouse hippocampus and rat glioma C6 cells. GE administration also resulted in phosphorylation of extracellular-signal-regulated kinase (ERK) and cyclic AMP response element-binding protein (CREB), as revealed by Western blotting analysis. Neutralization of NGF with a specific NGF antibody inhibited GE-triggered activation of ERK and CREB in the hippocampus. Also, GE treatment significantly increased pre- and postsynaptic markers, synaptophysin and PSD-95, which are related to synapse formation in the brain. These data suggest that GE has a synaptogenic effect via NGF-induced ERK/CREB activation, resulting in memory enhancement. Copyright © 2014 Elsevier Inc. All rights reserved.

GPR39 (zinc receptor) knockout mice exhibit depression-like behavior and CREB/BDNF down-regulation in the hippocampus.

Science.gov (United States)

Młyniec, Katarzyna; Budziszewska, Bogusława; Holst, Birgitte; Ostachowicz, Beata; Nowak, Gabriel

2014-10-31

Zinc may act as a neurotransmitter in the central nervous system by activation of the GPR39 metabotropic receptors. In the present study, we investigated whether GPR39 knockout would cause depressive-like and/or anxiety-like behavior, as measured by the forced swim test, tail suspension test, and light/dark test. We also investigated whether lack of GPR39 would change levels of cAMP response element-binding protein (CREB),brain-derived neurotrophic factor (BDNF) and tropomyosin related kinase B (TrkB) protein in the hippocampus and frontal cortex of GPR39 knockout mice subjected to the forced swim test, as measured by Western-blot analysis. In this study, GPR39 knockout mice showed an increased immobility time in both the forced swim test and tail suspension test, indicating depressive-like behavior and displayed anxiety-like phenotype. GPR39 knockout mice had lower CREB and BDNF levels in the hippocampus, but not in the frontal cortex, which indicates region specificity for the impaired CREB/BDNF pathway (which is important in antidepressant response) in the absence of GPR39. There were no changes in TrkB protein in either structure. In the present study, we also investigated activity in the hypothalamus-pituitary-adrenal axis under both zinc- and GPR39-deficient conditions. Zinc-deficient mice had higher serum corticosterone levels and lower glucocorticoid receptor levels in the hippocampus and frontal cortex. There were no changes in the GPR39 knockout mice in comparison with the wild-type control mice, which does not support a role of GPR39 in hypothalamus-pituitary-adrenal axis regulation. The results of this study indicate the involvement of the GPR39 Zn(2+)-sensing receptor in the pathophysiology of depression with component of anxiety. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Sweet Dream Liquid Chinese Medicine Ameliorates Learning and Memory Deficit in a Rat Model of Paradoxical Sleep Deprivation through the ERK/CREB Signaling Pathway.

Science.gov (United States)

Su, Xinyun; Wang, Chunhua; Wang, Xiuhua; Han, Fang; Lv, Changjun; Zhang, Xiuli

2016-05-01

Sweet dream oral liquid (SDOL), a traditional Chinese herbal compound contains 17 traditional Chinese medicines. It has various pharmacological effects, such as improving brain dysfunction and increasing sleeping quality. This study investigated the neuroprotective effect and the underlying mechanisms of SDOL-impaired hippocampus learning and memory-induced paradoxical sleep deprivation (PSD) in rats. Sixty Male Wistar rats were randomly divided into six groups. Before PSD, SDOL treatment group rats were intragastrically administered SDOL for 25 days at dose of 2.1, 4.2, and 8.4 mL/kg body weight per day. Normal control group, large platform control group, and PSD groups were treated with normal saline instead of SDOL. After 25 days treatment, PSD and SDOL groups were deprived of paradoxical sleep for 72 h. Then two behavioral studies were conducted to test the spatial learning and memory ability using the open field test and Morris water maze test. Expression of the c-fos, c-jun, cyclic AMP response element binding protein (CREB), extracellular signal-regulated protein kinase (ERK), mitogen-activated protein kinases (MAPK)/ERK kinase (MEK), and p-CREB, p-ERK, and p-MEK in the hippocampus were also assayed by western blot. In this study, PSD decreased the levels of p-CREB, p-ERK, p-MEK, c-fos, and c-jun. However, SDOL treatment increased expressions of these proteins. Our results showed that SDOL improved 72-h PSD-induced cognitive impairment. These affects may be mediated by increasing the contents of c-fos, c-jun, and p-CREB/ERK signaling.

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus

Energy Technology Data Exchange (ETDEWEB)

Shan, Qun, E-mail: shanp@jsnu.edu.cn; Zheng, Guihong, E-mail: ghzhengsd@jsnu.edu.cn; Zhu, Aihua, E-mail: ahzhu@jsnu.edu.cn; Cao, Li, E-mail: 948113717@qq.com; Lu, Jun, E-mail: lu-jun75@163.com; Wu, Dongmei, E-mail: wdm8610@jsnu.edu.cn; Zhang, ZiFeng, E-mail: zhangzifengsuper@jsnu.edu.cn; Fan, Shaohua, E-mail: fshfly@126.com; Sun, Chunhui, E-mail: 306484866@qq.com; Hu, Bin, E-mail: hubin@jsnu.edu.cn; Zheng, Yuanlin, E-mail: ylzheng@jsnu.edu.cn

2016-09-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35 mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. - Highlights: • Diabetes induces the decrease of miR-10a level in the kidney. • MiR-10a overexpression improves kidney damage of diabetes. • MiR-10a targeting CREB1/FN

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus

International Nuclear Information System (INIS)

Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

2016-01-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35 mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. - Highlights: • Diabetes induces the decrease of miR-10a level in the kidney. • MiR-10a overexpression improves kidney damage of diabetes. • MiR-10a targeting CREB1/FN

Angelica sinensis polysaccharides promotes apoptosis in human breast cancer cells via CREB-regulated caspase-3 activation

International Nuclear Information System (INIS)

Zhou, Wei-Jie; Wang, Sheng; Hu, Zhuang; Zhou, Zhen-Yu; Song, Cai-Juan

2015-01-01

Angelica sinensis polysaccharide (ASP) is purified from the fresh roots of Angelica sinensis (AS). This traditional Chinese medicine has been used for thousands of years for treating gynecological diseases and used in functional foods for the prevention and treatment of various diseases, such as inflammation and cancer. The antitumor activity of ASP is related to its biological activities, because it suppresses a variety of pro-proliferative or anti-apoptotic factors that are dramatically expressed in cancer cells of given types. In this study, we show that angelica sinensis polysaccharide induced apoptosis in breast cancer cells of T47D over-expressing the Cyclic AMP response element binding protein (CREB), inducing apoptosis-related signaling pathway activity. The result also found that ASP caused cell death was linked to caspase activity, accompanied by the loss of mitochondrial membrane potential, cytochrome c release, and Bax translocation from the cytosol to the mitochondria. We found that ASP significantly affected the poly-ADP-ribose polymerase (PARP), Bcl-2 Associated X Protein (Bax), Bcl-2, Bcl-xL and apoptotic protease activating facter-1 (Apaf1) protein expression in a dose- and time-dependent manner. DAPI staining and Flow cytometry were used to analyze apoptosis. The nude mice xenograft model was used to evaluate the antitumor effect of ASP in vivo. ASP has profound antitumor effect on T47D cells, probably by inducing apoptosis through CREB signaling pathway. Thus, these results suggest that ASP would be a promising therapeutic agent for breast cancer. - Highlights: • CREB and Caspase-3 signaling pathways are involved in the ASP induced breast cancer cells apoptosis. • ROCK1/Mlc signaling pathway plays a critical role in this ASP-mediated apoptosis. • Angelica sinensis polysaccharide (ASP) affected the PARP, Bax, Bcl-2, Bcl-xL and Apaf1 protein expression. • The activation of CREB and ROCK1 promotes caspase-3 activation and apoptosis induced

Angelica sinensis polysaccharides promotes apoptosis in human breast cancer cells via CREB-regulated caspase-3 activation

Energy Technology Data Exchange (ETDEWEB)

Zhou, Wei-Jie; Wang, Sheng [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Hu, Zhuang, E-mail: zhuanghu475000@sina.com [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Zhengzhou Center for Disease Control and Prevention, Zhengzhou 475000 (China); Zhou, Zhen-Yu; Song, Cai-Juan [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Zhengzhou Center for Disease Control and Prevention, Zhengzhou 475000 (China)

2015-11-20

Angelica sinensis polysaccharide (ASP) is purified from the fresh roots of Angelica sinensis (AS). This traditional Chinese medicine has been used for thousands of years for treating gynecological diseases and used in functional foods for the prevention and treatment of various diseases, such as inflammation and cancer. The antitumor activity of ASP is related to its biological activities, because it suppresses a variety of pro-proliferative or anti-apoptotic factors that are dramatically expressed in cancer cells of given types. In this study, we show that angelica sinensis polysaccharide induced apoptosis in breast cancer cells of T47D over-expressing the Cyclic AMP response element binding protein (CREB), inducing apoptosis-related signaling pathway activity. The result also found that ASP caused cell death was linked to caspase activity, accompanied by the loss of mitochondrial membrane potential, cytochrome c release, and Bax translocation from the cytosol to the mitochondria. We found that ASP significantly affected the poly-ADP-ribose polymerase (PARP), Bcl-2 Associated X Protein (Bax), Bcl-2, Bcl-xL and apoptotic protease activating facter-1 (Apaf1) protein expression in a dose- and time-dependent manner. DAPI staining and Flow cytometry were used to analyze apoptosis. The nude mice xenograft model was used to evaluate the antitumor effect of ASP in vivo. ASP has profound antitumor effect on T47D cells, probably by inducing apoptosis through CREB signaling pathway. Thus, these results suggest that ASP would be a promising therapeutic agent for breast cancer. - Highlights: • CREB and Caspase-3 signaling pathways are involved in the ASP induced breast cancer cells apoptosis. • ROCK1/Mlc signaling pathway plays a critical role in this ASP-mediated apoptosis. • Angelica sinensis polysaccharide (ASP) affected the PARP, Bax, Bcl-2, Bcl-xL and Apaf1 protein expression. • The activation of CREB and ROCK1 promotes caspase-3 activation and apoptosis induced

Capacity for cooperative binding of thyroid hormone (T3) receptor dimers defines wild type T3 response elements.

Science.gov (United States)

Brent, G A; Williams, G R; Harney, J W; Forman, B M; Samuels, H H; Moore, D D; Larsen, P R

1992-04-01

Thyroid hormone response elements (T3REs) have been identified in a variety of promoters including those directing expression of rat GH (rGH), alpha-myosin heavy chain (rMHC), and malic enzyme (rME). A detailed biochemical and genetic analysis of the rGH element has shown that it consists of three hexamers related to the consensus [(A/G)GGT(C/A)A]. We have extended this analysis to the rMHC and rME elements. Binding of highly purified thyroid hormone receptor (T3R) to T3REs was determined using the gel shift assay, and thyroid hormone (T3) induction was measured in transient tranfections. We show that the wild type version of each of the three elements binds T3R dimers cooperatively. Mutational analysis of the rMHC and rME elements identified domains important for binding T3R dimers and allowed a direct determination of the relationship between T3R binding and function. In each element two hexamers are required for dimer binding, and mutations that interfere with dimer formation significantly reduce T3 induction. Similar to the rGH element, the rMHC T3RE contains three hexameric domains arranged as a direct repeat followed by an inverted copy, although the third domain is weaker than in rGH. All three are required for full function and T3R binding. The rME T3RE is a two-hexamer direct repeat T3RE, which also binds T3R monomer and dimer. Across a series of mutant elements, there was a strong correlation between dimer binding in vitro and function in vivo for rMHC (r = 0.99, P less than 0.01) and rME (r = 0.67, P less than 0.05) T3REs. Our results demonstrate a similar pattern of T3R dimer binding to a diverse array of hexameric sequences and arrangements in three wild type T3REs. Addition of nuclear protein enhanced T3R binding but did not alter the specificity of binding to wild type or mutant elements. Binding of purified T3R to T3REs was highly correlated with function, both with and without the addition of nuclear protein. T3R dimer formation is the common

Development of a pluripotent stem cell derived neuronal model to identify chemically induced pathway perturbations in relation to neurotoxicity: Effects of CREB pathway inhibition

Energy Technology Data Exchange (ETDEWEB)

Pistollato, Francesca; Louisse, Jochem; Scelfo, Bibiana; Mennecozzi, Milena [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy); Accordi, Benedetta; Basso, Giuseppe [Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova (Italy); Gaspar, John Antonydas [Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, Cologne (Germany); Zagoura, Dimitra; Barilari, Manuela; Palosaari, Taina [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy); Sachinidis, Agapios [Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, Cologne (Germany); Bremer-Hoffmann, Susanne, E-mail: susanne.bremer@jrc.ec.europa.eu [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy)

2014-10-15

According to the advocated paradigm shift in toxicology, acquisition of knowledge on the mechanisms underlying the toxicity of chemicals, such as perturbations of biological pathways, is of primary interest. Pluripotent stem cells (PSCs), such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), offer a unique opportunity to derive physiologically relevant human cell types to measure molecular and cellular effects of such pathway modulations. Here we compared the neuronal differentiation propensity of hESCs and hiPSCs with the aim to develop novel hiPSC-based tools for measuring pathway perturbation in relation to molecular and cellular effects in vitro. Among other fundamental pathways, also, the cAMP responsive element binding protein (CREB) pathway was activated in our neuronal models and gave us the opportunity to study time-dependent effects elicited by chemical perturbations of the CREB pathway in relation to cellular effects. We show that the inhibition of the CREB pathway, using 2-naphthol-AS-E-phosphate (KG-501), induced an inhibition of neurite outgrowth and synaptogenesis, as well as a decrease of MAP2{sup +} neuronal cells. These data indicate that a CREB pathway inhibition can be related to molecular and cellular effects that may be relevant for neurotoxicity testing, and, thus, qualify the use of our hiPSC-derived neuronal model for studying chemical-induced neurotoxicity resulting from pathway perturbations. - Highlights: • HESCs derived neuronal cells serve as benchmark for iPSC based neuronal toxicity test development. • Comparisons between hESCs and hiPSCs demonstrated variability of the epigenetic state • CREB pathway modulation have been explored in relation to the neurotoxicant exposure KG-501 • hiPSC might be promising tools to translate theoretical AoPs into toxicological in vitro tests.

Γ-Ionizing radiation activated EGFR-p38/ERK-STAT3/CREB-1-EMT pathway for promotion of the migration/invasion of lung cancer cell and its inhibition by podophyllotoxin acetate

Energy Technology Data Exchange (ETDEWEB)

Cho, Jeong Hyun; Um, Hong Duck; Park, Jong Kuk [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2016-05-15

In this study, we sought to identify the intracellular machinery responsible for IR induced cancer invasion/migration. We report that IR activates the EGFR - p38/ERK - CREB-1/STAT3 pathway, which triggers EMT and increases invasion/migration of lung cancer. Moreover, we show that podophyllotoxin acetate (PA) inhibits IR-induced invasion/migration at least partly by blocking EGFR - p38/ERK - STAT3/ CREB-1signaling and thereby suppressing EMT. Our results revealed that IR increased the invasion/migration of A549 cells, and this effect was decreased by 10 nM PA treatment. PA also inhibited the expressions/activities of matrix metalloprotase (MMP) -2, MMP-9, and vimentin, suggesting that PA could block the IR-induced epithelial-mesenchymal transition (EMT). The IR induced increases in invasion/migration were associated with the activation of EGFR-AKT, and PA inhibited this effect. P38 and p44/42 ERK were also involved in IR induced invasion/migration, and combined treatments with PA plus inhibitors of each MAPK synergistically blocked this invasion/migration. In terms of transcription factors (TFs), IR-induced increases in cyclic AMP response element-binding protein-1 (CREB-1) and signal transducer and activator of transcription 3 (STAT3) increased invasion/migration and EMT. PA also inhibited these transcription factors and then blocked IR-induced invasion/migration.

Γ-Ionizing radiation activated EGFR-p38/ERK-STAT3/CREB-1-EMT pathway for promotion of the migration/invasion of lung cancer cell and its inhibition by podophyllotoxin acetate

International Nuclear Information System (INIS)

Cho, Jeong Hyun; Um, Hong Duck; Park, Jong Kuk

2016-01-01

In this study, we sought to identify the intracellular machinery responsible for IR induced cancer invasion/migration. We report that IR activates the EGFR - p38/ERK - CREB-1/STAT3 pathway, which triggers EMT and increases invasion/migration of lung cancer. Moreover, we show that podophyllotoxin acetate (PA) inhibits IR-induced invasion/migration at least partly by blocking EGFR - p38/ERK - STAT3/ CREB-1signaling and thereby suppressing EMT. Our results revealed that IR increased the invasion/migration of A549 cells, and this effect was decreased by 10 nM PA treatment. PA also inhibited the expressions/activities of matrix metalloprotase (MMP) -2, MMP-9, and vimentin, suggesting that PA could block the IR-induced epithelial-mesenchymal transition (EMT). The IR induced increases in invasion/migration were associated with the activation of EGFR-AKT, and PA inhibited this effect. P38 and p44/42 ERK were also involved in IR induced invasion/migration, and combined treatments with PA plus inhibitors of each MAPK synergistically blocked this invasion/migration. In terms of transcription factors (TFs), IR-induced increases in cyclic AMP response element-binding protein-1 (CREB-1) and signal transducer and activator of transcription 3 (STAT3) increased invasion/migration and EMT. PA also inhibited these transcription factors and then blocked IR-induced invasion/migration

The Traditional Japanese Herbal Medicine Hachimijiogan Elicits Neurite Outgrowth Effects in PC12 Cells and Improves Cognitive in AD Model Rats via Phosphorylation of CREB

Directory of Open Access Journals (Sweden)

Kaori Kubota

2017-11-01

Full Text Available Hachimijiogan (HJG is a traditional herbal medicine that improves anxiety disorders in patients with dementia. In this study, we tested the hypothesis that HJG exerts neurotrophic factor-like effects to ameliorate memory impairment in Alzheimer disease (AD model rats. First, we describe that HJG acts to induce neurite outgrowth in PC12 cells (a rat pheochromocytoma cell line like nerve growth factor (NGF in a concentration-dependent manner (3 μg/ml HJG, p < 0.05; 10–500 μg/ml HJG, p < 0.001. While six herbal constituents of HJG, Rehmannia root, Dioscorea rhizome, Rhizoma Alismatis, Poria sclerotium, Moutan bark, and Cinnamon bark, could induce neurite outgrowth effects, the effect was strongest with HJG (500 μg/ml. Second, we demonstrated that HJG-induced neurite outgrowth was blocked by an inhibitor of cAMP response element binding protein (CREB, KG-501 (10 μM, p < 0.001. Moreover, HJG was observed to induce CREB phosphorylation 20–90 min after treatment (20 min, 2.50 ± 0.58-fold and CRE-mediated transcription in cultured PC12 cells (500 μg/ml, p < 0.01; 1000 μg/ml, p < 0.001. These results suggest a CREB-dependent mechanism underlies the neurotrophic effects of HJG. Finally, we examined improvements of memory impairment following HJG treatment using a Morris water maze in AD model animals (CI + Aβ rats. Repeated oral administration of HJG improved memory impairment (300 mg/kg, p < 0.05; 1000 mg/kg, p < 0.001 and induced CREB phosphorylation within the hippocampus (1000 mg/kg, p < 0.01. Together, our results suggest that HJG possesses neurotrophic effects similar to those of NGF, and can ameliorate cognitive dysfunction in a rat dementia model via CREB activation. Thus, HJG could potentially be a substitute for neurotrophic factors as a treatment for dementia.

Participation of Water in the Binding of Estrogen Receptor with Estrogen Responsive Element in vitro.

Science.gov (United States)

Zhu, Guo-Zhang; Tang, Guo-Qing; Ruan, Kang-Cheng; Gong, Yue-Ting; Zhang, Yong-Lian

1998-01-01

Many reports have showed that bound water was involved in the interaction between/among the macromolecules. However, it has not been reported whether bound water is also involved in the binding of trans-factors and cis-elements in the regulation of the eukaryotic gene trans-cription or not. Preliminary studies have been made on the effect of bound water on the binding of estrogen receptor with estrogen responsive element in vitro. In the gel retardation assay using the cytosol extract of rat uterus as the supplier of estrogen receptor and 32 bp oligonucleotide containing a concensus vitellogenin A(2) ERE as the probe, various cosolvents, such as glycerol, sucrose, N-dimethylformamide and dimethylsulfoxide, were added respectively to the reaction mixture in varying concentrations to regulate the osmotic pressure. The results indicated that the binding of ER-ERE was enhanced with the increase in the final concentration of these individual cosolvents. On the other hand, when the reaction was carried out under an increasing hydrostatic pressure, the ER-ERE binding was decreased sharply. After decompression the binding of ER-ERE was gradually restored to the normal level with the lapse of time. These results suggested that bound water was directly involved in the binding of ER-ERE and may play an important role in the regulation of the eukaryotic gene transcription.

Meta-analysis of the effect of overexpression of C-repeat/dehydration-responsive element binding family genes on temperature stress tolerance and related responses

Science.gov (United States)

C-repeat/dehydration-responsive element binding proteins are transcription factors that play a critical role in plant response to temperature stress. Over-expression of CBF/DREB genes has been demonstrated to enhance temperature stress tolerance. A series of physiological and biochemical modificat...

The α and Δ isoforms of CREB1 are required to maintain normal pulmonary vascular resistance.

Directory of Open Access Journals (Sweden)

Lili Li

Full Text Available Chronic hypoxia causes pulmonary hypertension associated with structural alterations in pulmonary vessels and sustained vasoconstriction. The transcriptional mechanisms responsible for these distinctive changes are unclear. We have previously reported that CREB1 is activated in the lung in response to alveolar hypoxia but not in other organs. To directly investigate the role of α and Δ isoforms of CREB1 in the regulation of pulmonary vascular resistance we examined the responses of mice in which these isoforms of CREB1 had been inactivated by gene mutation, leaving only the β isoform intact (CREB(αΔ mice. Here we report that expression of CREB regulated genes was altered in the lungs of CREB(αΔ mice. CREB(αΔ mice had greater pulmonary vascular resistance than wild types, both basally in normoxia and following exposure to hypoxic conditions for three weeks. There was no difference in rho kinase mediated vasoconstriction between CREB(αΔ and wild type mice. Stereological analysis of pulmonary vascular structure showed characteristic wall thickening and lumen reduction in hypoxic wild-type mice, with similar changes observed in CREB(αΔ. CREB(αΔ mice had larger lungs with reduced epithelial surface density suggesting increased pulmonary compliance. These findings show that α and Δ isoforms of CREB1 regulate homeostatic gene expression in the lung and that normal activity of these isoforms is essential to maintain low pulmonary vascular resistance in both normoxic and hypoxic conditions and to maintain the normal alveolar structure. Interventions that enhance the actions of α and Δ isoforms of CREB1 warrant further investigation in hypoxic lung diseases.

Neural Plasticity Associated with Hippocampal PKA-CREB and NMDA Signaling Is Involved in the Antidepressant Effect of Repeated Low Dose of Yueju Pill on Chronic Mouse Model of Learned Helplessness.

Science.gov (United States)

Zou, Zhilu; Chen, Yin; Shen, Qinqin; Guo, Xiaoyan; Zhang, Yuxuan; Chen, Gang

2017-01-01

Yueju pill is a traditional Chinese medicine formulated to treat syndromes of mood disorders. Here, we investigated the therapeutic effect of repeated low dose of Yueju in the animal model mimicking clinical long-term depression condition and the role of neural plasticity associated with PKA- (protein kinase A-) CREB (cAMP response element binding protein) and NMDA (N-methyl-D-aspartate) signaling. We showed that a single low dose of Yueju demonstrated antidepressant effects in tests of tail suspension, forced swim, and novelty-suppressed feeding. A chronic learned helplessness (LH) protocol resulted in a long-term depressive-like condition. Repeated administration of Yueju following chronic LH remarkably alleviated all of depressive-like symptoms measured, whereas conventional antidepressant fluoxetine only showed a minor improvement. In the hippocampus, Yueju and fluoxetine both normalized brain-derived neurotrophic factor (BDNF) and PKA level. Only Yueju, not fluoxetine, rescued the deficits in CREB signaling. The chronic LH upregulated the expression of NMDA receptor subunits NR1, NR2A, and NR2B, which were all attenuated by Yueju. Furthermore, intracerebraventricular administration of NMDA blunted the antidepressant effect of Yueju. These findings supported the antidepressant efficacy of repeated routine low dose of Yueju in a long-term depression model and the critical role of CREB and NMDA signaling.

Taurine promotes cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1α pathway.

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Jia, Ning; Sun, Qinru; Su, Qian; Dang, Shaokang; Chen, Guomin

2016-12-01

Substantial evidence has shown that the oxidative damage to hippocampal neurons is associated with the cognitive impairment induced by adverse stimuli during gestation named prenatal stress (PS). Taurine, a conditionally essential amino acid, possesses multiple roles in the brain as a neuromodulator or antioxidant. In this study, to explore the roles of taurine in PS-induced learning and memory impairment, prenatal restraint stress was set up and Morris water maze (MWM) was employed for testing the cognitive function in the one-month-old rat offspring. The mitochondrial reactive oxygen species (ROS) level，mitochondrial membrane potential (MMP), ATP and cytochrome c oxidase (CcO) activity and apoptosis-related proteins in the hippocampus were detected. The activity of the Akt-cyclic AMP response element-binding protein (CREB)-peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) pathway in the hippocampus was measured. The results showed that high dosage of taurine administration in the early postnatal period attenuated impairment of spatial learning and memory induced by PS. Meanwhile, taurine administration diminished the increase in mitochondrial ROS, and recovered the reduction of MMP, ATP level and the activities of CcO, superoxide dismutase 2 (SOD2) and catalase induced by PS in the hippocampus. In addition, taurine administration recovered PS-suppressed SOD2 expression level. Taurine administration blocked PS-induced decrease in the ratio of Bcl-2/Bax and increase in the ratio of cleaved caspase-3/full-length caspase-3. Notably, taurine inhibited PS-decreased phosphorylation of Akt (pAkt) and phosphorylation of CREB (pCREB), which consequently enhanced the mRNA and protein levels of PGC1α. Taken together, these results suggest that high dosage of taurine administration during the early postnatal period can significantly improve the cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1α pathway. Therefore

Taurine promotes cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1α pathway

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Ning Jia

2016-12-01

Full Text Available Substantial evidence has shown that the oxidative damage to hippocampal neurons is associated with the cognitive impairment induced by adverse stimuli during gestation named prenatal stress (PS. Taurine, a conditionally essential amino acid, possesses multiple roles in the brain as a neuromodulator or antioxidant. In this study, to explore the roles of taurine in PS-induced learning and memory impairment, prenatal restraint stress was set up and Morris water maze (MWM was employed for testing the cognitive function in the one-month-old rat offspring. The mitochondrial reactive oxygen species (ROS level，mitochondrial membrane potential (MMP, ATP and cytochrome c oxidase (CcO activity and apoptosis-related proteins in the hippocampus were detected. The activity of the Akt-cyclic AMP response element-binding protein (CREB-peroxisome proliferator-activated receptor–γ coactivator-1α (PGC1α pathway in the hippocampus was measured. The results showed that high dosage of taurine administration in the early postnatal period attenuated impairment of spatial learning and memory induced by PS. Meanwhile, taurine administration diminished the increase in mitochondrial ROS, and recovered the reduction of MMP, ATP level and the activities of CcO, superoxide dismutase 2 (SOD2 and catalase induced by PS in the hippocampus. In addition, taurine administration recovered PS-suppressed SOD2 expression level. Taurine administration blocked PS-induced decrease in the ratio of Bcl-2/Bax and increase in the ratio of cleaved caspase-3/full-length caspase-3. Notably, taurine inhibited PS-decreased phosphorylation of Akt (pAkt and phosphorylation of CREB (pCREB, which consequently enhanced the mRNA and protein levels of PGC1α. Taken together, these results suggest that high dosage of taurine administration during the early postnatal period can significantly improve the cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1�

Ethanol sensitivity: a central role for CREB transcription regulation in the cerebellum

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Biswal Shyam

2006-12-01

Full Text Available Abstract Background Lowered sensitivity to the effects of ethanol increases the risk of developing alcoholism. Inbred mouse strains have been useful for the study of the genetic basis of various drug addiction-related phenotypes. Inbred Long-Sleep (ILS and Inbred Short-Sleep (ISS mice differentially express a number of genes thought to be implicated in sensitivity to the effects of ethanol. Concomitantly, there is evidence for a mediating role of cAMP/PKA/CREB signalling in aspects of alcoholism modelled in animals. In this report, the extent to which CREB signalling impacts the differential expression of genes in ILS and ISS mouse cerebella is examined. Results A training dataset for Machine Learning (ML and Exploratory Data Analyses (EDA was generated from promoter region sequences of a set of genes known to be targets of CREB transcription regulation and a set of genes whose transcription regulations are potentially CREB-independent. For each promoter sequence, a vector of size 132, with elements characterizing nucleotide composition features was generated. Genes whose expressions have been previously determined to be increased in ILS or ISS cerebella were identified, and their CREB regulation status predicted using the ML scheme C4.5. The C4.5 learning scheme was used because, of four ML schemes evaluated, it had the lowest predicted error rate. On an independent evaluation set of 21 genes of known CREB regulation status, C4.5 correctly classified 81% of instances with F-measures of 0.87 and 0.67 respectively for the CREB-regulated and CREB-independent classes. Additionally, six out of eight genes previously determined by two independent microarray platforms to be up-regulated in the ILS or ISS cerebellum were predicted by C4.5 to be transcriptionally regulated by CREB. Furthermore, 64% and 52% of a cross-section of other up-regulated cerebellar genes in ILS and ISS mice, respectively, were deemed to be CREB-regulated. Conclusion These

Analysis list: CREB1 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available CREB1 Blood,Digestive tract,Liver,Pluripotent stem cell,Prostate,Uterus + hg19 http...://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/CREB1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/CRE...B1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/CREB1.10.tsv http://dbarchive.b...iosciencedbc.jp/kyushu-u/hg19/colo/CREB1.Blood.tsv,http://dbarchive.biosciencedbc....jp/kyushu-u/hg19/colo/CREB1.Digestive_tract.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/CREB1.

Regulation of CYP3A4 by pregnane X receptor: The role of nuclear receptors competing for response element binding

Energy Technology Data Exchange (ETDEWEB)

Istrate, Monica A., E-mail: monicai@scripps.edu [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany); Nussler, Andreas K., E-mail: nuessler@uchir.me.tum.de [Department of Traumatology, Technical University Munich, Ismaningerstr. 22, 81675 Munich (Germany); Eichelbaum, Michel, E-mail: michel.eichelbaum@ikp-stuttgart.de [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany); Burk, Oliver, E-mail: oliver.burk@ikp-stuttgart.de [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany)

2010-03-19

Induction of the major drug metabolizing enzyme CYP3A4 by xenobiotics contributes to the pronounced interindividual variability of its expression and often results in clinically relevant drug-drug interactions. It is mainly mediated by PXR, which regulates CYP3A4 expression by binding to several specific elements in the 5' upstream regulatory region of the gene. Induction itself shows a marked interindividual variability, whose underlying determinants are only partly understood. In this study, we investigated the role of nuclear receptor binding to PXR response elements in CYP3A4, as a potential non-genetic mechanism contributing to interindividual variability of induction. By in vitro DNA binding experiments, we showed that several nuclear receptors bind efficiently to the proximal promoter ER6 and distal xenobiotic-responsive enhancer module DR3 motifs. TR{alpha}1, TR{beta}1, COUP-TFI, and COUP-TFII further demonstrated dose-dependent repression of PXR-mediated CYP3A4 enhancer/promoter reporter activity in transient transfection in the presence and absence of the PXR inducer rifampin, while VDR showed this effect only in the absence of treatment. By combining functional in vitro characterization with hepatic expression analysis, we predict that TR{alpha}1, TR{beta}1, COUP-TFI, and COUP-TFII show a strong potential for the repression of PXR-mediated activation of CYP3A4 in vivo. In summary, our results demonstrate that nuclear receptor binding to PXR response elements interferes with PXR-mediated expression and induction of CYP3A4 and thereby contributes to the interindividual variability of induction.

Neural Plasticity Associated with Hippocampal PKA-CREB and NMDA Signaling Is Involved in the Antidepressant Effect of Repeated Low Dose of Yueju Pill on Chronic Mouse Model of Learned Helplessness

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Zhilu Zou

2017-01-01

Full Text Available Yueju pill is a traditional Chinese medicine formulated to treat syndromes of mood disorders. Here, we investigated the therapeutic effect of repeated low dose of Yueju in the animal model mimicking clinical long-term depression condition and the role of neural plasticity associated with PKA- (protein kinase A- CREB (cAMP response element binding protein and NMDA (N-methyl-D-aspartate signaling. We showed that a single low dose of Yueju demonstrated antidepressant effects in tests of tail suspension, forced swim, and novelty-suppressed feeding. A chronic learned helplessness (LH protocol resulted in a long-term depressive-like condition. Repeated administration of Yueju following chronic LH remarkably alleviated all of depressive-like symptoms measured, whereas conventional antidepressant fluoxetine only showed a minor improvement. In the hippocampus, Yueju and fluoxetine both normalized brain-derived neurotrophic factor (BDNF and PKA level. Only Yueju, not fluoxetine, rescued the deficits in CREB signaling. The chronic LH upregulated the expression of NMDA receptor subunits NR1, NR2A, and NR2B, which were all attenuated by Yueju. Furthermore, intracerebraventricular administration of NMDA blunted the antidepressant effect of Yueju. These findings supported the antidepressant efficacy of repeated routine low dose of Yueju in a long-term depression model and the critical role of CREB and NMDA signaling.

Low-functional programming of the CREB/BDNF/TrkB pathway mediates cognitive impairment in male offspring after prenatal dexamethasone exposure.

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Dong, Wanting; Xu, Dan; Hu, Zewen; He, Xia; Guo, Zijing; Jiao, Zhexiao; Yu, Ying; Wang, Hui

2018-02-01

Adverse intrauterine environments can increase susceptibility to neuropsychiatric diseases that are related to cognitive impairment. In this study, we observed the cognitive impairment of male offspring rats after prenatal dexamethasone exposure (PDE) and explored the associated intrauterine programming mechanism. Pregnant Wistar rats were subcutaneously injected with 0.2mg/kgd dexamethasone from gestational day 9 (GD9) to GD20. A cohort of the pregnant rat group was sacrificed on GD20, and the male fetal rats were collected. Another group of pregnant rats delivered their offspring naturally, and the male adult offspring rats were subjected to behavioural tests postnatally at 26 weeks and then sacrificed. The adult PDE male offspring rats exhibited cognitive impairment, decreased cell proliferation and increased cell apoptosis in the hippocampus, along with damaged synaptic plasticity and disrupted protein synthesis. Meanwhile, activation of GR and downregulation of the cAMP responsive element binding protein (CREB)/brain-derived neurotrophic factor (BDNF)/tropomyosin receptor tyrosine B (TrkB) signalling pathway were found in the adult PDE offspring rats. Further examinations indicated consistent alterations to the fetal hippocampus by PDE. We concluded that PDE can cause cognitive impairment in adult male offspring rats. The mechanism may be associated with low-functional programming of the hippocampal CREB/BDNF/TrkB signalling pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

Resveratrol stimulates c-Fos gene transcription via activation of ERK1/2 involving multiple genetic elements.

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Thiel, Gerald; Rössler, Oliver G

2018-06-05

The polyphenol resveratrol is found in many plant and fruits and is a constituent of our diet. Resveratrol has been proposed to have chemopreventive and anti-inflammatory activities. On the cellular level, resveratrol activates stimulus-regulated transcription factors. To identify resveratrol-responsive elements within a natural gene promoter, the molecular pathway leading to c-Fos gene expression by resveratrol was dissected. The c-Fos gene encodes a basic region leucine zipper transcription factor and is a prototype of an immediate-early gene that is regulated by a wide range of signaling molecules. We analyzed chromatin-integrated c-Fos promoter-luciferase reporter genes where transcription factor binding sites were destroyed by point mutations or deletion mutagenesis. The results show that mutation of the binding sites for serum response factor (SRF), activator protein-1 (AP-1) and cAMP response element binding protein (CREB) significantly reduced reporter gene transcription following stimulation of the cells with resveratrol. Inactivation of the binding sites for signal transducer and activator of transcription (STAT) or ternary complex factors did not influence resveratrol-regulated c-Fos promoter activity. Thus, the c-Fos promoter contains three resveratrol-responsive elements, the cAMP response element (CRE), and the binding sites for SRF and AP-1. Moreover, we show that the transcriptional activation potential of the c-Fos protein is increased in resveratrol-stimulated cells, indicating that the biological activity of c-Fos is elevated by resveratrol stimulation. Pharmacological and genetic experiments revealed that the protein kinase ERK1/2 is the signal transducer that connects resveratrol treatment with the c-Fos gene. Copyright © 2018 Elsevier B.V. All rights reserved.

Regulation of Energy Stores and Feeding by Neuronal and Peripheral CREB Activity in Drosophila

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Iijima, Koichi; Zhao, LiJuan; Shenton, Christopher; Iijima-Ando, Kanae

2009-01-01

The cAMP-responsive transcription factor CREB functions in adipose tissue and liver to regulate glycogen and lipid metabolism in mammals. While Drosophila has a homolog of mammalian CREB, dCREB2, its role in energy metabolism is not fully understood. Using tissue-specific expression of a dominant-negative form of CREB (DN-CREB), we have examined the effect of blocking CREB activity in neurons and in the fat body, the primary energy storage depot with functions of adipose tissue and the liver in flies, on energy balance, stress resistance and feeding behavior. We found that disruption of CREB function in neurons reduced glycogen and lipid stores and increased sensitivity to starvation. Expression of DN-CREB in the fat body also reduced glycogen levels, while it did not affect starvation sensitivity, presumably due to increased lipid levels in these flies. Interestingly, blocking CREB activity in the fat body increased food intake. These flies did not show a significant change in overall body size, suggesting that disruption of CREB activity in the fat body caused an obese-like phenotype. Using a transgenic CRE-luciferase reporter, we further demonstrated that disruption of the adipokinetic hormone receptor, which is functionally related to mammalian glucagon and β-adrenergic signaling, in the fat body reduced CRE-mediated transcription in flies. This study demonstrates that CREB activity in either neuronal or peripheral tissues regulates energy balance in Drosophila, and that the key signaling pathway regulating CREB activity in peripheral tissue is evolutionarily conserved. PMID:20041126

Dopamine receptors modulate cytotoxicity of natural killer cells via cAMP-PKA-CREB signaling pathway.

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Wei Zhao

Full Text Available Dopamine (DA, a neurotransmitter in the nervous system, has been shown to modulate immune function. We have previously reported that five subtypes of DA receptors, including D1R, D2R, D3R, D4R and D5R, are expressed in T lymphocytes and they are involved in regulation of T cells. However, roles of these DA receptor subtypes and their coupled signal-transduction pathway in modulation of natural killer (NK cells still remain to be clarified. The spleen of mice was harvested and NK cells were isolated and purified by negative selection using magnetic activated cell sorting. After NK cells were incubated with various drugs for 4 h, flow cytometry measured cytotoxicity of NK cells against YAC-1 lymphoma cells. NK cells expressed the five subtypes of DA receptors at mRNA and protein levels. Activation of D1-like receptors (including D1R and D5R with agonist SKF38393 enhanced NK cell cytotoxicity, but activation of D2-like receptors (including D2R, D3R and D4R with agonist quinpirole attenuated NK cells. Simultaneously, SKF38393 elevated D1R and D5R expression, cAMP content, and phosphorylated cAMP-response element-binding (CREB level in NK cells, while quinpirole reduced D3R and D4R expression, cAMP content, and phosphorylated CREB level in NK cells. These effects of SKF38393 were blocked by SCH23390, an antagonist of D1-like receptors, and quinpirole effects were abolished by haloperidol, an antagonist of D2-like receptors. In support these results, H89, an inhibitor of phosphokinase A (PKA, prevented the SKF38393-dependent enhancement of NK cells and forskolin, an activator of adenylyl cyclase (AC, counteracted the quinpirole-dependent suppression of NK cells. These findings show that DA receptor subtypes are involved in modulation of NK cells and suggest that D1-like receptors facilitate NK cells by stimulating D1R/D5R-cAMP-PKA-CREB signaling pathway and D2-like receptors suppress NK cells by inhibiting D3R/D4R-cAMP-PKA-CREB signaling pathway. The

Modulation of type I interferon induction by porcine reproductive and respiratory syndrome virus and degradation of CREB-binding protein by non-structural protein 1 in MARC-145 and HeLa cells

International Nuclear Information System (INIS)

Kim, Oekyung; Sun Yan; Lai, Frances W.; Song Cheng; Yoo, Dongwan

2010-01-01

Porcine reproductive and respiratory syndrome (PRRS) is an emerged disease of swine characterized by negligible response of type I IFNs and viral persistence. We show that the PRRSV non-structural protein 1 (Nsp1) is the viral component responsible for modulation of IFN response. Nsp1 blocked dsRNA-induced IRF3 and IFN promoter activities. Nsp1 did not block phosphorylation and nuclear translocation of IRF3 but inhibited IRF3 association with CREB-binding protein (CBP) in the nucleus. While IRF3 was stable, CBP was degraded, and CBP degradation was proteasome-dependent, suggesting that CBP degradation is not due to the protease activity of Nsp1 but an intermediary is involved. Our data suggest that the Nsp1-mediated CBP degradation inhibits the recruitment of CBP for enhanceosome assembly, leading to the block of IFN response. CBP degradation is a novel strategy for viral evasion from the host response, and Nsp1 may form a new class of viral antagonists for IFN modulation.

Activation of the carbohydrate response element binding protein (ChREBP) in response to anoxia in the turtle Trachemys scripta elegans.

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Krivoruchko, Anastasia; Storey, Kenneth B

2014-10-01

ChREBP (carbohydrate response element binding protein) is a glucose-responsive transcription factor that is known to be an important regulator of glycolytic and lipogenic genes in response to glucose. We hypothesized that activation of ChREBP could be relevant to anoxia survival by the anoxia-tolerant turtle, Trachemys scripta elegans. Expression of ChREBP in response to 5 and 20h of anoxia was examined using RT-PCR and Western immunoblotting. In addition, subcellular localization and DNA-binding activity of ChREBP protein were assessed and transcript levels of liver pyruvate kinase (LPK), a downstream gene under ChREBP control were quantified using RT-PCR. ChREBP was anoxia-responsive in kidney and liver, with transcript levels increasing by 1.2-1.8 fold in response to anoxia and protein levels increasing by 1.8-1.9 fold. Enhanced nuclear presence under anoxia was also observed in both tissues by 2.2-2.8 fold. A 4.2 fold increase in DNA binding activity of ChREBP was also observed in liver in response to 5h of anoxia. In addition, transcript levels of LPK increased by 2.1 fold in response to 5h of anoxia in the liver. The results suggest that activation of ChREBP in response to anoxia might be a crucial factor for anoxia survival in turtle liver by contributing to elevated glycolytic flux in the initial phases of oxygen limitation. This study provides the first demonstration of activation of ChREBP in response to anoxia in a natural model of anoxia tolerance, further improving our understanding of the molecular nature of anoxia tolerance. Copyright © 2014 Elsevier B.V. All rights reserved.

NMDA receptor adjusted co-administration of ecstasy and cannabinoid receptor-1 agonist in the amygdala via stimulation of BDNF/Trk-B/CREB pathway in adult male rats.

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Ashabi, Ghorbangol; Sadat-Shirazi, Mitra-Sadat; Khalifeh, Solmaz; Elhampour, Laleh; Zarrindast, Mohammad-Reza

2017-04-01

Consumption of cannabinoid receptor-1 (CB-1) agonist such as cannabis is widely taken in 3,4- methylenedioxymethamphetamine (MDMA) or ecstasy users; it has been hypothesized that co-consumption of CB-1 agonist might protect neurons against MDMA toxicity. N-methyl-d-aspartate (NMDA) receptors regulate neuronal plasticity and firing rate in the brain through Tyrosine-kinase B (Trk-B) activation. The molecular and electrophysiological association among NMDA and MDMA/Arachidonylcyclopropylamide (ACPA, a selective CB-1 receptor agonist) co-consumption was not well-known. Here, neuronal spontaneous activity, Brain-derived neurotrophic factor (BDNF), Trk-B and cAMP response element binding protein (CREB) phosphorylation levels were recognized in ACPA and MDMA co-injected rats. Besides, we proved the role of NMDA receptor on MDMA and ACPA combination on neuronal spontaneous activity and Trk-B/BDNF pathway in the central amygdala (CeA). Male rats were anesthetized with intra-peritoneal injections of urethane; MDMA, D-2-amino-5-phosphonopentanoate (D-AP5, NMDA receptor antagonist) were injected into CeA. ACPA was administrated by intra-cerebroventricular injection. Thirty minutes following injections, neuronal firing rate was recorded from CeA. Two hours after drug injection, amygdala was collected from brain for molecular evaluations. Single administration of MDMA and/or ACPA reduced firing rates compared with sham group in the CeA dose-dependently. Injection of D-AP5, ACPA and MDMA reduced firing rate compared with sham group (P<0.001). Interestingly, injection of ACPA+MDMA enhanced BDNF, Trk-B and CREB phosphorylation compared with MDMA groups. D-AP5, ACPA and MDMA co-injection decreased BDNF, Trk-B and CREB phosphorylation levels compared with ACPA+MDMA in the amygdala (P<0.01). Probably, NMDA receptors are involved in the protective role of acute MDMA+ACPA co-injection via BDNF/Trk-B/CREB pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

Preventive role of social interaction for cocaine conditioned place preference: correlation with FosB/DeltaFosB and pCREB expression in rat mesocorticolimbic areas.

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El Rawas, Rana; Klement, Sabine; Salti, Ahmad; Fritz, Michael; Dechant, Georg; Saria, Alois; Zernig, Gerald

2012-01-01

The worsening of drug abuse by drug-associated social interaction is a well-studied phenomenon. In contrast, the molecular mechanisms of the beneficial effect of social interaction, if offered as a mutually exclusive choice to drugs of abuse, are under-investigated. In a rat place preference conditioning (CPP) paradigm, four 15 min episodes of social interaction with a gender- and weight-matched male early-adult conspecific inhibited cocaine-induced reinstatement of cocaine CPP, a model of relapse. These protective effects of social interaction were paralleled by a reduced activation, as assessed by Zif268 expression, in brain areas known to play pivotal roles in drug-seeking behavior. Here we show that social interaction during extinction of cocaine CPP also reduced cocaine-CPP-stimulated FosB expression in the nucleus accumbens shell and core. In addition, social interaction during cocaine CPP extinction increased pCREB (cAMP response element binding protein) expression in the nucleus accumbens shell and the cingulate cortex area 1 (Cg1). Our results show that FosB and pCREB may be implicated in the protective effect of social interaction against cocaine-induced reinstatement of CPP. Thus, social interaction, if offered in a context that is clearly distinct from the previously drug-associated one, may profoundly inhibit relapse to cocaine addiction.

CREB mediates the insulinotropic and anti-apoptotic effects of GLP-1 signaling in adult mouse β-cells

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Soona Shin

2014-11-01

Conclusions: In sum, our studies using conditional gene deletion put into question current notions about the importance of CREB in regulating β-cell function and mass. However, we reveal an important role for CREB in the β-cell response to GLP-1 receptor signaling, further validating CREB as a therapeutic target for diabetes.

Effect of XingPiJieYu decoction on spatial learning and memory and cAMP-PKA-CREB-BDNF pathway in rat model of depression through chronic unpredictable stress.

Science.gov (United States)

Wang, Chunye; Guo, Jianyou; Guo, Rongjuan

2017-01-24

Depression is a mental disorder characterized by a pervasive low mood and loss of pleasure or interest in usual activities, and often results in cognitive dysfunction. The disturbance of cognitive processes associated with depression, especially the impairment of learning and memory, exacerbates illness and increases recurrence of depression. XingPiJieYu (XPJY) is one of the most widely clinical formulas of traditional Chinese medicine (TCM) and can improve the symptoms of depression, including learning and memory. However, its regulatory effects haven't been comprehensively studied so far. Recently, some animal tests have indicated that the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element-binding protein (CREB)-brain derived neurotrophic factor (BDNF) signaling pathway in hippocampus is closely related to depression and the pathogenesis of cognitive function impairments. The present study was performed to investigate the effect and mechanism of XPJY on depression and learning and memory in animal model. The rat model of depression was established by chronic unpredictable stress (CUS) for 21 days. The rats were randomly divided into six groups: control group, CUS group, CUS + XPJY (1.4 g/kg, 0.7 g/kg and 0.35 g/kg) groups, and CUS + sertraline (10 mg/kg) group. The sucrose preference, open field exploration and Morris water maze (MWM) were tested. The expression of cAMP, CREB, PKA and BDNF protein in hippocampus was examined with Elisa and Western Blot. The mRNA level of CREB and BDNF in hippocampus was measured with PCR. The results demonstrated that rats subjected to CUS exhibited decreases in sucrose preference, total ambulation, percentage of central ambulation, rearing in the open field test and spatial performance in the MWM. CUS reduced the expression of cAMP, PKA, CREB and BDNF in hippocampus of model rats. These effects could be reversed by XPJY. The results indicated that XPJY can improve depression and

Gene network inference and biochemical assessment delineates GPCR pathways and CREB targets in small intestinal neuroendocrine neoplasia.

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Ignat Drozdov

Full Text Available Small intestinal (SI neuroendocrine tumors (NET are increasing in incidence, however little is known about their biology. High throughput techniques such as inference of gene regulatory networks from microarray experiments can objectively define signaling machinery in this disease. Genome-wide co-expression analysis was used to infer gene relevance network in SI-NETs. The network was confirmed to be non-random, scale-free, and highly modular. Functional analysis of gene co-expression modules revealed processes including 'Nervous system development', 'Immune response', and 'Cell-cycle'. Importantly, gene network topology and differential expression analysis identified over-expression of the GPCR signaling regulators, the cAMP synthetase, ADCY2, and the protein kinase A, PRKAR1A. Seven CREB response element (CRE transcripts associated with proliferation and secretion: BEX1, BICD1, CHGB, CPE, GABRB3, SCG2 and SCG3 as well as ADCY2 and PRKAR1A were measured in an independent SI dataset (n = 10 NETs; n = 8 normal preparations. All were up-regulated (p<0.035 with the exception of SCG3 which was not differently expressed. Forskolin (a direct cAMP activator, 10(-5 M significantly stimulated transcription of pCREB and 3/7 CREB targets, isoproterenol (a selective ß-adrenergic receptor agonist and cAMP activator, 10(-5 M stimulated pCREB and 4/7 targets while BIM-53061 (a dopamine D(2 and Serotonin [5-HT(2] receptor agonist, 10(-6 M stimulated 100% of targets as well as pCREB; CRE transcription correlated with the levels of cAMP accumulation and PKA activity; BIM-53061 stimulated the highest levels of cAMP and PKA (2.8-fold and 2.5-fold vs. 1.8-2-fold for isoproterenol and forskolin. Gene network inference and graph topology analysis in SI NETs suggests that SI NETs express neural GPCRs that activate different CRE targets associated with proliferation and secretion. In vitro studies, in a model NET cell system, confirmed that transcriptional

Specificity determinants for the abscisic acid response element ?

OpenAIRE

Sarkar, Aditya Kumar; Lahiri, Ansuman

2013-01-01

Abscisic acid (ABA) response elements (ABREs) are a group of cis-acting DNA elements that have been identified from promoter analysis of many ABA-regulated genes in plants. We are interested in understanding the mechanism of binding specificity between ABREs and a class of bZIP transcription factors known as ABRE binding factors (ABFs). In this work, we have modeled the homodimeric structure of the bZIP domain of ABRE binding factor 1 from Arabidopsis thaliana (AtABF1) and studied its interac...

HDAC Inhibition Modulates Hippocampus-Dependent Long-Term Memory for Object Location in a CBP-Dependent Manner

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Haettig, Jakob; Stefanko, Daniel P.; Multani, Monica L.; Figueroa, Dario X.; McQuown, Susan C.; Wood, Marcelo A.

2011-01-01

Transcription of genes required for long-term memory not only involves transcription factors, but also enzymatic protein complexes that modify chromatin structure. Chromatin-modifying enzymes, such as the histone acetyltransferase (HAT) CREB (cyclic-AMP response element binding) binding protein (CBP), are pivotal for the transcriptional regulation…

The role of the glucose-sensing transcription factor carbohydrate-responsive element-binding protein pathway in termite queen fertility

Czech Academy of Sciences Publication Activity Database

Sillam-Dusses, D.; Hanus, Robert; Poulsen, M.; Roy, V.; Favier, M.; Vasseur-Cognet, M.

2016-01-01

Roč. 6, č. 5 (2016), č. článku 160080. ISSN 2046-2441 R&D Projects: GA ČR(CZ) GA14-12774S Institutional support: RVO:61388963 Keywords : reproduction * phenotypic plasticity * carbohydrate-responsive element-binding protein * transcription factor * social insects * lipogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.481, year: 2016 http://rsob.royalsocietypublishing.org/content/6/5/160080

Preventive role of social interaction for cocaine conditioned place preference: correlation with FosB/DeltaFosB and pCREB expression in rat mesocorticolimbic areas

Science.gov (United States)

El Rawas, Rana; Klement, Sabine; Salti, Ahmad; Fritz, Michael; Dechant, Georg; Saria, Alois; Zernig, Gerald

2012-01-01

The worsening of drug abuse by drug-associated social interaction is a well-studied phenomenon. In contrast, the molecular mechanisms of the beneficial effect of social interaction, if offered as a mutually exclusive choice to drugs of abuse, are under-investigated. In a rat place preference conditioning (CPP) paradigm, four 15 min episodes of social interaction with a gender- and weight-matched male early-adult conspecific inhibited cocaine-induced reinstatement of cocaine CPP, a model of relapse. These protective effects of social interaction were paralleled by a reduced activation, as assessed by Zif268 expression, in brain areas known to play pivotal roles in drug-seeking behavior. Here we show that social interaction during extinction of cocaine CPP also reduced cocaine-CPP-stimulated FosB expression in the nucleus accumbens shell and core. In addition, social interaction during cocaine CPP extinction increased pCREB (cAMP response element binding protein) expression in the nucleus accumbens shell and the cingulate cortex area 1 (Cg1). Our results show that FosB and pCREB may be implicated in the protective effect of social interaction against cocaine-induced reinstatement of CPP. Thus, social interaction, if offered in a context that is clearly distinct from the previously drug-associated one, may profoundly inhibit relapse to cocaine addiction. PMID:22403532

Preventive role of social interaction for cocaine conditioned place preference: correlation with FosB/DeltaFosB and pCREB expression in rat mesocorticolimbic areas

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Rana eEl Rawas

2012-03-01

Full Text Available The worsening of drug abuse by drug-associated social interaction is a well-studied phenomenon. In contrast, the molecular mechanisms of the beneficial effect of social interaction, if offered as a mutually exclusive choice to drugs of abuse, are under-investigated. In a rat place preference conditioning (CPP paradigm, four 15 min episodes of social interaction with a gender- and weight matched male early-adult conspecific inhibited cocaine-induced reinstatement of cocaine CPP, a model of relapse. These protective effects of social interaction were paralleled by a reduced activation, as assessed by Zif268 expression in brain areas known to play pivotal roles in drug-seeking behavior. Here we show that social interaction during extinction of cocaine CPP also reduced cocaine-CPP-stimulated FosB expression in the nucleus accumbens shell and core. In addition, social interaction during cocaine CPP extinction increased pCREB (cAMP response element binding protein expression in the nucleus accumbens shell and the cingulate cortex area 1 (Cg1. Our results show that FosB and pCREB may be implicated in the protective effect of social interaction against cocaine-induced reinstatement of CPP. Thus, social interaction, if offered in a context that is clearly distinct from the previously drug-associated one, may profoundly inhibit relapse to cocaine addiction.

ETHYLENE RESPONSE FACTOR 96 positively regulates Arabidopsis resistance to necrotrophic pathogens by direct binding to GCC elements of jasmonate - and ethylene-responsive defence genes.

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Catinot, Jérémy; Huang, Jing-Bo; Huang, Pin-Yao; Tseng, Min-Yuan; Chen, Ying-Lan; Gu, Shin-Yuan; Lo, Wan-Sheng; Wang, Long-Chi; Chen, Yet-Ran; Zimmerli, Laurent

2015-12-01

The ERF (ethylene responsive factor) family is composed of transcription factors (TFs) that are critical for appropriate Arabidopsis thaliana responses to biotic and abiotic stresses. Here we identified and characterized a member of the ERF TF group IX, namely ERF96, that when overexpressed enhances Arabidopsis resistance to necrotrophic pathogens such as the fungus Botrytis cinerea and the bacterium Pectobacterium carotovorum. ERF96 is jasmonate (JA) and ethylene (ET) responsive and ERF96 transcripts accumulation was abolished in JA-insensitive coi1-16 and in ET-insensitive ein2-1 mutants. Protoplast transactivation and electrophoresis mobility shift analyses revealed that ERF96 is an activator of transcription that binds to GCC elements. In addition, ERF96 mainly localized to the nucleus. Microarray analysis coupled to chromatin immunoprecipitation-PCR of Arabidopsis overexpressing ERF96 revealed that ERF96 enhances the expression of the JA/ET defence genes PDF1.2a, PR-3 and PR-4 as well as the TF ORA59 by direct binding to GCC elements present in their promoters. While ERF96-RNAi plants demonstrated wild-type resistance to necrotrophic pathogens, basal PDF1.2 expression levels were reduced in ERF96-silenced plants. This work revealed ERF96 as a key player of the ERF network that positively regulates the Arabidopsis resistance response to necrotrophic pathogens. © 2015 John Wiley & Sons Ltd.

Inositol polyphosphate multikinase is a coactivator for serum response factor-dependent induction of immediate early genes

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Kim, Eunha; Tyagi, Richa; Lee, Joo-Young; Park, Jina; Kim, Young-ran; Beon, Jiyoon; Chen, Po Yu; Cha, Jiyoung Y.; Snyder, Solomon H.; Kim, Seyun

2013-01-01

Inositol polyphosphate multikinase (IPMK) is a notably pleiotropic protein. It displays both inositol phosphate kinase and phosphatidylinositol kinase catalytic activities. Noncatalytically, IPMK stabilizes the mammalian target of rapamycin complex 1 and acts as a transcriptional coactivator for CREB-binding protein/E1A binding protein p300 and tumor suppressor protein p53. Serum response factor (SRF) is a major transcription factor for a wide range of immediate early genes. We report that IPMK, in a noncatalytic role, is a transcriptional coactivator for SRF mediating the transcription of immediate early genes. Stimulation by serum of many immediate early genes is greatly reduced by IPMK deletion. IPMK stimulates expression of these genes, an influence also displayed by catalytically inactive IPMK. IPMK acts by binding directly to SRF and thereby enhancing interactions of SRF with the serum response element of diverse genes. PMID:24248338

The Antidepressant Agomelatine Improves Memory Deterioration and Upregulates CREB and BDNF Gene Expression Levels in Unpredictable Chronic Mild Stress (UCMS-Exposed Mice

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Esen Gumuslu

2014-01-01

Full Text Available Agomelatine, a novel antidepressant with established clinical efficacy, acts as an agonist of melatonergic MT 1 and MT 2 receptors and as an antagonist of 5-HT 2C receptors. The present study was undertaken to investigate whether chronic treatment with agomelatine would block unpredictable chronic mild stress (UCMS-induced cognitive deterioration in mice in passive avoidance (PA, modified elevated plus maze (mEPM, novel object recognition (NOR, and Morris water maze (MWM tests. Moreover, the effects of stress and agomelatine on brain-derived neurotrophic factor (BDNF and cyclic adenosine monophosphate (cAMP response element binding protein (CREB messenger ribonucleic acid (mRNA levels in the hippocampus was also determined using quantitative real-time polymerase chain reaction (RT-PCR. Male inbred BALB/c mice were treated with agomelatine (10 mg/kg, i.p., melatonin (10 mg/kg, or vehicle daily for five weeks. The results of this study revealed that UCMS-exposed animals exhibited memory deterioration in the PA, mEPM, NOR, and MWM tests. The chronic administration of melatonin had a positive effect in the PA and +mEPM tests, whereas agomelatine had a partial effect. Both agomelatine and melatonin blocked stress-induced impairment in visual memory in the NOR test and reversed spatial learning and memory impairment in the stressed group in the MWM test. Quantitative RT-PCR revealed that CREB and BDNF gene expression levels were downregulated in UCMS-exposed mice, and these alterations were reversed by chronic agomelatine or melatonin treatment. Thus, agomelatine plays an important role in blocking stress-induced hippocampal memory deterioration and activates molecular mechanisms of memory storage in response to a learning experience.

Azadirachtin interacts with retinoic acid receptors and inhibits retinoic acid-mediated biological responses.

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Thoh, Maikho; Babajan, Banaganapalli; Raghavendra, Pongali B; Sureshkumar, Chitta; Manna, Sunil K

2011-02-11

Considering the role of retinoids in regulation of more than 500 genes involved in cell cycle and growth arrest, a detailed understanding of the mechanism and its regulation is useful for therapy. The extract of the medicinal plant Neem (Azadirachta indica) is used against several ailments especially for anti-inflammatory, anti-itching, spermicidal, anticancer, and insecticidal activities. In this report we prove the detailed mechanism on the regulation of retinoic acid-mediated cell signaling by azadirachtin, active components of neem extract. Azadirachtin repressed all trans-retinoic acid (ATRA)-mediated nuclear transcription factor κB (NF-κB) activation, not the DNA binding but the NF-κB-dependent gene expression. It did not inhibit IκBα degradation, IκBα kinase activity, or p65 phosphorylation and its nuclear translocation but inhibited NF-κB-dependent reporter gene expression. Azadirachtin inhibited TRAF6-mediated, but not TRAF2-mediated NF-κB activation. It inhibited ATRA-induced Sp1 and CREB (cAMP-response element-binding protein) DNA binding. Azadirachtin inhibited ATRA binding with retinoid receptors, which is supported by biochemical and in silico evidences. Azadirachtin showed strong interaction with retinoid receptors. It suppressed ATRA-mediated removal of retinoid receptors, bound with DNA by inhibiting ATRA binding to its receptors. Overall, our data suggest that azadirachtin interacts with retinoic acid receptors and suppresses ATRA binding, inhibits falling off the receptors, and activates transcription factors like CREB, Sp1, NF-κB, etc. Thus, azadirachtin exerts anti-inflammatory and anti-metastatic responses by a novel pathway that would be beneficial for further anti-inflammatory and anti-cancer therapies.

Azadirachtin Interacts with Retinoic Acid Receptors and Inhibits Retinoic Acid-mediated Biological Responses*

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Thoh, Maikho; Babajan, Banaganapalli; Raghavendra, Pongali B.; Sureshkumar, Chitta; Manna, Sunil K.

2011-01-01

Considering the role of retinoids in regulation of more than 500 genes involved in cell cycle and growth arrest, a detailed understanding of the mechanism and its regulation is useful for therapy. The extract of the medicinal plant Neem (Azadirachta indica) is used against several ailments especially for anti-inflammatory, anti-itching, spermicidal, anticancer, and insecticidal activities. In this report we prove the detailed mechanism on the regulation of retinoic acid-mediated cell signaling by azadirachtin, active components of neem extract. Azadirachtin repressed all trans-retinoic acid (ATRA)-mediated nuclear transcription factor κB (NF-κB) activation, not the DNA binding but the NF-κB-dependent gene expression. It did not inhibit IκBα degradation, IκBα kinase activity, or p65 phosphorylation and its nuclear translocation but inhibited NF-κB-dependent reporter gene expression. Azadirachtin inhibited TRAF6-mediated, but not TRAF2-mediated NF-κB activation. It inhibited ATRA-induced Sp1 and CREB (cAMP-response element-binding protein) DNA binding. Azadirachtin inhibited ATRA binding with retinoid receptors, which is supported by biochemical and in silico evidences. Azadirachtin showed strong interaction with retinoid receptors. It suppressed ATRA-mediated removal of retinoid receptors, bound with DNA by inhibiting ATRA binding to its receptors. Overall, our data suggest that azadirachtin interacts with retinoic acid receptors and suppresses ATRA binding, inhibits falling off the receptors, and activates transcription factors like CREB, Sp1, NF-κB, etc. Thus, azadirachtin exerts anti-inflammatory and anti-metastatic responses by a novel pathway that would be beneficial for further anti-inflammatory and anti-cancer therapies. PMID:21127062

Up-regulation of Ciliary Neurotrophic Factor in Astrocytes by Aspirin

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Modi, Khushbu K.; Sendtner, Michael; Pahan, Kalipada

2013-01-01

Ciliary neurotrophic factor (CNTF) is a promyelinating trophic factor, and the mechanisms by which CNTF expression could be increased in the brain are poorly understood. Acetylsalicylic acid (aspirin) is one of the most widely used analgesics. Interestingly, aspirin increased mRNA and protein expression of CNTF in primary mouse and human astrocytes in a dose- and time-dependent manner. Aspirin induced the activation of protein kinase A (PKA) but not protein kinase C (PKC). H-89, an inhibitor of PKA, abrogated aspirin-induced expression of CNTF. The activation of cAMP-response element-binding protein (CREB), but not NF-κB, by aspirin, the abrogation of aspirin-induced expression of CNTF by siRNA knockdown of CREB, the presence of a consensus cAMP-response element in the promoter of CNTF, and the recruitment of CREB and CREB-binding protein to the CNTF promoter by aspirin suggest that aspirin increases the expression of the Cntf gene via the activation of CREB. Furthermore, we demonstrate that aspirin-induced astroglial CNTF was also functionally active and that supernatants of aspirin-treated astrocytes of wild type, but not Cntf null, mice increased myelin-associated proteins in oligodendrocytes and protected oligodendrocytes from TNF-α insult. These results highlight a new and novel myelinogenic property of aspirin, which may be of benefit for multiple sclerosis and other demyelinating disorders. PMID:23653362

Impact of transient down-regulation of DREAM in human embryonic stem cell pluripotency

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A. Fontán-Lozano

2016-05-01

Full Text Available Little is known about the functions of downstream regulatory element antagonist modulator (DREAM in embryonic stem cells (ESCs. However, DREAM interacts with cAMP response element-binding protein (CREB in a Ca2+-dependent manner, preventing CREB binding protein (CBP recruitment. Furthermore, CREB and CBP are involved in maintaining ESC self-renewal and pluripotency. However, a previous knockout study revealed the protective function of DREAM depletion in brain aging degeneration and that aging is accompanied by a progressive decline in stem cells (SCs function. Interestingly, we found that DREAM is expressed in different cell types, including human ESCs (hESCs, human adipose-derived stromal cells (hASCs, human bone marrow-derived stromal cells (hBMSCs, and human newborn foreskin fibroblasts (hFFs, and that transitory inhibition of DREAM in hESCs reduces their pluripotency, increasing differentiation. We stipulate that these changes are partly mediated by increased CREB transcriptional activity. Overall, our data indicates that DREAM acts in the regulation of hESC pluripotency and could be a target to promote or prevent differentiation in embryonic cells.

CREB binding protein is required for both short-term and long-term memory formation.

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Chen, Guiquan; Zou, Xiaoyan; Watanabe, Hirotaka; van Deursen, Jan M; Shen, Jie

2010-09-29

CREB binding protein (CBP) is a transcriptional coactivator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated conditional knock-out (cKO) mice in which CBP is completely inactivated in excitatory neurons of the postnatal forebrain. Histological analysis revealed normal neuronal morphology and absence of age-dependent neuronal degeneration in the CBP cKO cerebral cortex. CBP cKO mice exhibited robust impairment in the formation of spatial, associative, and object-recognition memory. In addition to impaired long-term memory, CBP cKO mice also displayed deficits in short-term associative and object-recognition memory. Administration of a histone deacetylase inhibitor, trichostatin A, rescued the reduction of acetylated histones in the CBP cKO cortex but failed to rescue either short- or long-term memory deficits, suggesting that the memory impairment may not be caused by general reduction of histone acetyltransferase activity in CBP cKO mice. Further microarray and Western analysis showed decreased expression of calcium-calmodulin-dependent kinase isoforms and NMDA and AMPA receptor subunits in the cerebral cortex of CBP cKO mice. Collectively, these findings suggest a crucial role for CBP in the formation of both short- and long-term memory.

A Bifunctional Intronic Element Regulates the Expression of the Arginine/Lysine Transporter Cat-1 via Mechanisms Involving the Purine-rich Element Binding Protein A (Purα)*

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Huang, Charlie C.; Chiribau, Calin-Bogdan; Majumder, Mithu; Chiang, Cheng-Ming; Wek, Ronald C.; Kelm, Robert J.; Khalili, Kamel; Snider, Martin D.; Hatzoglou, Maria

2009-01-01

Expression of the arginine/lysine transporter Cat-1 is highly induced in proliferating and stressed cells via mechanisms that include transcriptional activation. A bifunctional INE (intronic element) within the first intron of the Cat-1 gene was identified and characterized in this study. The INE had high sequence homology to an amino acid response element and was shown to act as a transcriptional enhancer in unstressed cells by binding the transcription factor, purine-rich element binding protein A (Purα). During endoplasmic reticulum stress, binding of Purα to the INE decreased; the element acted as a positive regulator in early stress by binding of the transcription factor ATF4 and as a negative regulator in prolonged stress by binding the stress-induced C/EBP family member, CHOP. We conclude that transcriptional control of the Cat-1 gene is tightly controlled by multiple cis-DNA elements, contributing to regulation of cationic amino acid transport for cell growth and proliferation. In addition, we propose that genes may use stress-response elements such as the INE to support basal expression in the absence of stress. PMID:19720825

Repeated forced swim stress enhances CFA-evoked thermal hyperalgesia and affects the expressions of pCREB and c-Fos in the insular cortex.

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Imbe, H; Kimura, A; Donishi, T; Kaneoke, Y

2014-02-14

Stress affects brain activity and promotes long-term changes in multiple neural systems. Exposure to stressors causes substantial effects on the perception and response to pain. In several animal models, chronic stress produces lasting hyperalgesia. The insular (IC) and anterior cingulate cortices (ACC) are the regions exhibiting most reliable pain-related activity. And the IC and ACC play an important role in pain modulation via the descending pain modulatory system. In the present study we examined the expression of phospho-cAMP response element-binding protein (pCREB) and c-Fos in the IC and ACC after forced swim stress (FS) and complete Freund's adjuvant (CFA) injection to clarify changes in the cerebral cortices that affect the activity of the descending pain modulatory system in the rats with stress-induced hyperalgesia. FS (day 1, 10min; days 2-3, 20min) induced an increase in the expression of pCREB and c-Fos in the anterior IC (AIC). CFA injection into the hindpaw after the FS shows significantly enhanced thermal hyperalgesia and induced a decrease in the expression of c-Fos in the AIC and the posterior IC (PIC). Quantitative image analysis showed that the numbers of c-Fos-immunoreactive neurons in the left AIC and PIC were significantly lower in the FS+CFA group (L AIC, 95.9±6.8; L PIC, 181.9±23.1) than those in the naive group (L AIC, 151.1±19.3, pCFA-induced thermal hyperalgesia through dysfunction of the descending pain modulatory system. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Serum brain-derived neurotrophic factor and glucocorticoid receptor levels in lymphocytes as markers of antidepressant response in major depressive patients: a pilot study.

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Rojas, Paulina Soledad; Fritsch, Rosemarie; Rojas, Romina Andrea; Jara, Pablo; Fiedler, Jenny Lucy

2011-09-30

Depressive patients often have altered cortisol secretion, an effect that likely derives from impaired activity of the glucocorticoid receptor (GR), the main regulator of the hypothalamus-pituitary-adrenal (HPA) axis. Glucocorticoids reduce the levels of brain-derived neurotrophic factor (BDNF), a downstream target of antidepressants. Antidepressants promote the transcriptional activity of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), a regulator of BDNF expression. To identify potential biomarkers for the onset of antidepressant action in depressive patients, GR and phospho-CREB (pCREB) levels in lymphocytes and serum BDNF levels were repeatedly measured during the course of antidepressant treatment. Thirty-four depressed outpatients (10 male and 24 female) were treated with venlafaxine (75mg/day), and individuals exhibiting a 50% reduction in their baseline 17-Item Hamilton Depression Rating Scale score by the 6th week of treatment were considered responders. Responders showed an early improvement in parallel with a rise in BDNF levels during the first two weeks of treatment. Non-responders showed increased GR levels by the third week and reduced serum BDNF by the sixth week of treatment. In contrast, venlafaxine did not affect levels of pCREB. We conclude that levels of BDNF in serum and GR levels in lymphocytes may represent biomarkers that could be used to predict responses to venlafaxine treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Curcumin modulates dopaminergic receptor, CREB and phospholipase c gene expression in the cerebral cortex and cerebellum of streptozotocin induced diabetic rats

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George Naijil

2010-05-01

Full Text Available Abstract Curcumin, an active principle component in rhizome of Curcuma longa, has proved its merit for diabetes through its anti-oxidative and anti-inflammatory properties. This study aims at evaluating the effect of curcumin in modulating the altered dopaminergic receptors, CREB and phospholipase C in the cerebral cortex and cerebellum of STZ induced diabetic rats. Radioreceptor binding assays and gene expression was done in the cerebral cortex and cerebellum of male Wistar rats using specific ligands and probes. Total dopaminergic receptor binding parameter, Bmax showed an increase in cerebral cortex and decrease in the cerebellum of diabetic rats. Gene expression studies using real time PCR showed an increased expression of dopamine D1 and D2 receptor in the cerebral cortex of diabetic rats. In cerebellum dopamine D1 receptor was down regulated and D2 receptor showed an up regulation. Transcription factor CREB and phospholipase C showed a significant down regulation in cerebral cortex and cerebellum of diabetic rats. We report that curcumin supplementation reduces diabetes induced alteration of dopamine D1, D2 receptors, transcription factor CREB and phospholipase C to near control. Our results indicate that curcumin has a potential to regulate diabetes induced malfunctions of dopaminergic signalling, CREB and Phospholipase C expression in cerebral cortex and cerebellum and thereby improving the cognitive and emotional functions associated with these regions. Furthermore, in line with these studies an interaction between curcumin and dopaminergic receptors, CREB and phospholipase C is suggested, which attenuates the cortical and cerebellar dysfunction in diabetes. These results suggest that curcumin holds promise as an agent to prevent or treat CNS complications in diabetes.

Curcumin modulates dopaminergic receptor, CREB and phospholipase C gene expression in the cerebral cortex and cerebellum of streptozotocin induced diabetic rats.

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Kumar, T Peeyush; Antony, Sherin; Gireesh, G; George, Naijil; Paulose, C S

2010-05-31

Curcumin, an active principle component in rhizome of Curcuma longa, has proved its merit for diabetes through its anti-oxidative and anti-inflammatory properties. This study aims at evaluating the effect of curcumin in modulating the altered dopaminergic receptors, CREB and phospholipase C in the cerebral cortex and cerebellum of STZ induced diabetic rats. Radioreceptor binding assays and gene expression was done in the cerebral cortex and cerebellum of male Wistar rats using specific ligands and probes. Total dopaminergic receptor binding parameter, B(max) showed an increase in cerebral cortex and decrease in the cerebellum of diabetic rats. Gene expression studies using real time PCR showed an increased expression of dopamine D1 and D2 receptor in the cerebral cortex of diabetic rats. In cerebellum dopamine D1 receptor was down regulated and D2 receptor showed an up regulation. Transcription factor CREB and phospholipase C showed a significant down regulation in cerebral cortex and cerebellum of diabetic rats. We report that curcumin supplementation reduces diabetes induced alteration of dopamine D1, D2 receptors, transcription factor CREB and phospholipase C to near control. Our results indicate that curcumin has a potential to regulate diabetes induced malfunctions of dopaminergic signalling, CREB and Phospholipase C expression in cerebral cortex and cerebellum and thereby improving the cognitive and emotional functions associated with these regions. Furthermore, in line with these studies an interaction between curcumin and dopaminergic receptors, CREB and phospholipase C is suggested, which attenuates the cortical and cerebellar dysfunction in diabetes. These results suggest that curcumin holds promise as an agent to prevent or treat CNS complications in diabetes.

The integral membrane protein ITM2A, a transcriptional target of PKA-CREB, regulates autophagic flux via interaction with the vacuolar ATPase.

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Namkoong, Sim; Lee, Kang Il; Lee, Jin I; Park, Rackhyun; Lee, Eun-Ju; Jang, Ik-Soon; Park, Junsoo

2015-01-01

The PKA-CREB signaling pathway is involved in many cellular processes including autophagy. Recent studies demonstrated that PKA-CREB inhibits autophagy in yeast; however, the role of PKA-CREB signaling in mammalian cell autophagy has not been fully characterized. Here, we report that the integral membrane protein ITM2A expression is positively regulated by PKA-CREB signaling and ITM2A expression interferes with autophagic flux by interacting with vacuolar ATPase (v-ATPase). The ITM2A promoter contains a CRE element, and mutation at the CRE consensus site decreases the promoter activity. Forskolin treatment and PKA expression activate the ITM2A promoter confirming that ITM2A expression is dependent on the PKA-CREB pathway. ITM2A expression results in the accumulation of autophagosomes and interferes with autolysosome formation by blocking autophagic flux. We demonstrated that ITM2A physically interacts with v-ATPase and inhibits lysosomal function. These results support the notion that PKA-CREB signaling pathway regulates ITM2A expression, which negatively regulates autophagic flux by interfering with the function of v-ATPase.

The requirement for enhanced CREB1 expression in consolidation of long-term synaptic facilitation and long-term excitability in sensory neurons of Aplysia

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Liu, Rong-Yu; Cleary, Leonard J.; Byrne, John H.

2011-01-01

Accumulating evidence suggests that the transcriptional activator CREB1 is important for serotonin (5-HT)-induced long-term facilitation (LTF) of the sensorimotor synapse in Aplysia. Moreover, creb1 is among the genes activated by CREB1, suggesting a role for this protein beyond the induction phase of LTF. The time course of the requirement for CREB1 synthesis in the consolidation of long-term facilitation was examined using RNA interference (RNAi) techniques in sensorimotor co-cultures. Injection of CREB1 small-interfering RNA (siRNA) immediately or 10 h after 5-HT treatment blocked LTF when measured at 24 h and 48 h after treatment. In contrast, CREB1 siRNA did not block LTF when injected 16 h after 5-HT treatment. These results demonstrate that creb1 expression must be sustained for a relatively long time in order to support the consolidation of LTF. In addition, LTF is also accompanied by a long-term increase in the excitability (LTE) of sensory neurons (SNs). Because LTE was observed in the isolated SN after 5-HT treatment, this long-term change was intrinsic to that element of the circuit. LTE was blocked when CREB1 siRNA was injected into isolated SNs immediately after 5-HT treatment. These data suggest that 5-HT-induced CREB1 synthesis is required for consolidation of both LTF and LTE. PMID:21543617

Protective effects of a green tea polyphenol, epigallocatechin-3-gallate, against sevoflurane-induced neuronal apoptosis involve regulation of CREB/BDNF/TrkB and PI3K/Akt/mTOR signalling pathways in neonatal mice.

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Ding, Mei-Li; Ma, Hui; Man, Yi-Gang; Lv, Hong-Yan

2017-12-01

Epigallocatechin-3-gallate (EGCG), a polyphenol in green tea, is an effective antioxidant and possesses neuroprotective effects. Brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are crucial for neurogenesis and synaptic plasticity. In this study, we aimed to assess the protective effects of EGCG against sevoflurane-induced neurotoxicity in neonatal mice. Distinct groups of C57BL/6 mice were given EGCG (25, 50, or 75 mg/kg body weight) from postnatal day 3 (P3) to P21 and were subjected to sevoflurane (3%; 6 h) exposure on P7. EGCG significantly inhibited sevoflurane-induced neuroapoptosis as determined by Fluoro-Jade B staining and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Increased levels of cleaved caspase-3, downregulated Bad and Bax, and significantly enhanced Bcl-2, Bcl-xL, xIAP, c-IAP-1, and survivin expression were observed. EGCG induced activation of the PI3K/Akt pathway as evidenced by increased Akt, phospho-Akt, GSK-3β, phospho-GSK-3β, and mTORc1 levels. Sevoflurane-mediated downregulation of cAMP/CREB and BDNF/TrkB signalling was inhibited by EGCG. Reverse transcription PCR analysis revealed enhanced BDNF and TrkB mRNA levels upon EGCG administration. Improved performance of mice in Morris water maze tests suggested enhanced learning and memory. The study indicates that EGCG was able to effectively inhibit sevoflurane-induced neurodegeneration and improve learning and memory retention of mice via activation of CREB/BDNF/TrkB-PI3K/Akt signalling.

A novel fluid resuscitation strategy modulates pulmonary transcription factor activation in a murine model of hemorrhagic shock

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Todd W. Costantini

2010-01-01

Full Text Available INTRODUCTION: Combining the hemodynamic and immune benefits of hypertonic saline with the anti-inflammatory effects of the phosphodiesterase inhibitor pentoxifylline (HSPTX as a hemorrhagic shock resuscitation strategy reduces lung injury when compared with the effects of Ringer's lactate (RL. We hypothesized that HSPTX exerts its anti-inflammatory effects by interfering with nuclear factor kappa B/cAMP response element-binding protein (NF-κB-CREB competition for the coactivator CREB-binding protein (CBP in lung tissue, thus affecting pro-inflammatory mediator production. METHODS: Male Sprague-Dawley rats underwent 60 minutes of hemorrhagic shock to reach a mean arterial blood pressure of 35 mmHg followed by resuscitation with either RL or HSPTX (7.5% HS + 25 mg/kg PTX. After four hours, lung samples were collected. NF-κB activation was assessed by measuring the levels of phosphorylated cytoplasmic inhibitor of kappa B (I-κB and nuclear NF-κB p65 by western blot. NF-κB and CREB DNA-binding activity were measured by electrophoretic mobility shift assay (EMSA. Competition between NF-κB and CREB for the coactivator CBP was determined by immunoprecipitation. Interleukin-8 (IL-8 levels in the lung were measured by ELISA. RESULTS: RL resuscitation produced significantly higher levels of lung IL-8 levels, I-κB phosphorylation, p65 phosphorylation, and NF-κB DNA binding compared with HSPTX. NF-κB-CBP-binding activity was similar in both groups, whereas CREB-CBP-binding activity was significantly increased with HSPTX. CREB-DNA binding-activity increased to a greater level with HSPTX compared with RL. DISCUSSION: HSPTX decreases lung inflammation following hemorrhagic shock compared with conventional resuscitation using RL through attenuation of NF-κB signaling and increased CREB-DNA binding activity. HSPTX may have therapeutic potential in the attenuation of ischemia-reperfusion injury observed after severe hemorrhagic shock.

Involvement of HTLV-I Tax and CREB in aneuploidy: a bioinformatics approach

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Pumfery Anne

2006-07-01

Full Text Available Abstract Background Adult T-cell leukemia (ATL is a complex and multifaceted disease associated with human T-cell leukemia virus type 1 (HTLV-I infection. Tax, the viral oncoprotein, is considered a major contributor to cell cycle deregulation in HTLV-I transformed cells by either directly disrupting cellular factors (protein-protein interactions or altering their transcription profile. Tax transactivates these cellular promoters by interacting with transcription factors such as CREB/ATF, NF-κB, and SRF. Therefore by examining which factors upregulate a particular set of promoters we may begin to understand how Tax orchestrates leukemia development. Results We observed that CTLL cells stably expressing wild-type Tax (CTLL/WT exhibited aneuploidy as compared to a Tax clone deficient for CREB transactivation (CTLL/703. To better understand the contribution of Tax transactivation through the CREB/ATF pathway to the aneuploid phenotype, we performed microarray analysis comparing CTLL/WT to CTLL/703 cells. Promoter analysis of altered genes revealed that a subset of these genes contain CREB/ATF consensus sequences. While these genes had diverse functions, smaller subsets of genes were found to be involved in G2/M phase regulation, in particular kinetochore assembly. Furthermore, we confirmed the presence of CREB, Tax and RNA Polymerase II at the p97Vcp and Sgt1 promoters in vivo through chromatin immunoprecipitation in CTLL/WT cells. Conclusion These results indicate that the development of aneuploidy in Tax-expressing cells may occur in response to an alteration in the transcription profile, in addition to direct protein interactions.

Therapeutic potential of fluoxetine in neurological disorders

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Mostert, Jop P.; Koch, Marcus W.; Heerings, Marco; Heersema, Dorothea J.; De Keyser, Jacques

2008-01-01

The selective serotonin reuptake inhibitor (SSRI) fluoxetine, which is registered for a variety of psychiatric disorders, has been found to stimulate the cAMP-responsive element binding protein (CREB), increase the production of brain-derived neurotrophic factor (BNDF) and the neurotrophic peptide

CREB regulates spine density of lateral amygdala neurons: implications for memory allocation

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Derya eSargin

2013-12-01

Full Text Available Neurons may compete against one another for integration into a memory trace. Specifically, neurons in the lateral nucleus of the amygdala with relatively higher levels of CREB seem to be preferentially allocated to a fear memory trace, while neurons with relatively decreased CREB function seem to be excluded from a fear memory trace. CREB is a ubiquitous transcription factor that modulates many diverse cellular processes, raising the question as to which of these CREB-mediated processes underlie memory allocation. CREB is implicated in modulating dendritic spine number and morphology. As dendritic spines are intimately involved in memory formation, we investigated whether manipulations of CREB function alter spine number or morphology of neurons at the time of fear conditioning. We used viral vectors to manipulate CREB function in the lateral amygdala principal neurons in mice maintained in their homecages. At the time that fear conditioning normally occurs, we observed that neurons with high levels of CREB had more dendritic spines, while neurons with low CREB function had relatively fewer spines compared to control neurons. These results suggest that the modulation of spine density provides a potential mechanism for preferential allocation of a subset of neurons to the memory trace.

Isoproterenol Increases RANKL Expression in a ATF4/NFATc1-Dependent Manner in Mouse Osteoblastic Cells

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Kyunghwa Baek

2017-10-01

Full Text Available Sympathetic nervous system stimulation-induced β-adrenergic signal transduction is known to induce bone loss and increase of osteoclast activity. Although isoproterenol, a nonspecific β-adrenergic receptor agonist, has been shown to increase receptor activator of NF-κB ligand (RANKL, the details of the regulatory mechanisms remain unclear. In the present study, we investigated the role of the nuclear factor of activated T-cells (NFAT in isoproterenol-induced RANKL expression in C2C12 and in primary cultured mouse calvarial cells. Isoproterenol increased nuclear factor of activated T-cells cytoplasmic 1 (NFATc1 and RANKL expressions at both mRNA and protein levels and increased NFAT reporter activity. NFATc1 knockdown blocked isoproterenol-mediated RANKL expression. Isoproterenol also promoted cAMP response element-binding protein 1 (CREB1 and activating transcription factor 4 (ATF4 phosphorylation. Isoproterenol-mediated transcriptional activation of NFAT was blocked by protein kinase A (PKA inhibitor H89. Isoproterenol-induced CREB1, ATF4, NFATc1, and RANKL expressions were suppressed by H89. Mutations in cAMP response element-like or NFAT-binding element suppressed isoproterenol-induced RANKL promoter activity. Chromatin immunoprecipitation analysis demonstrated that isoproterenol increased NFAT-binding and ATF4-binding activities on the mouse RANKL promoter, but did not increase CREB1-binding activity. Association of NFATc1 and ATF4 was not observed in a co-immunoprecipitation study. ATF4 knockdown suppressed isoproterenol-induced NFAT binding to the RANKL promoter, whereas NFATc1 knockdown did not suppress isoproterenol-induced ATF4 binding to the RANKL promoter. ATF4 knockdown suppressed isoproterenol-induced expressions of NFATc1 and RANKL. These results suggest that isoproterenol increases RANKL expression in an ATF4/NFATc1-dependent manner.

Rufinamide, an antiepileptic drug, improves cognition and increases neurogenesis in the aged gerbil hippocampal dentate gyrus via increasing expressions of IGF-1, IGF-1R and p-CREB.

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Chen, Bai Hui; Ahn, Ji Hyeon; Park, Joon Ha; Song, Minah; Kim, Hyunjung; Lee, Tae-Kyeong; Lee, Jae Chul; Kim, Young-Myeong; Hwang, In Koo; Kim, Dae Won; Lee, Choong-Hyun; Yan, Bing Chun; Kang, Il Jun; Won, Moo-Ho

2018-04-25

Rufinamide is a novel antiepileptic drug and commonly used in the treatment of Lennox-Gastaut syndrome. In the present study, we investigated effects of rufinamide on cognitive function using passive avoidance test and neurogenesis in the hippocampal dentate gyrus using Ki-67 (a marker for cell proliferation), doublecortin (DCX, a marker for neuroblast) and BrdU/NeuN (markers for newly generated mature neurons) immunohistochemistry in aged gerbils. Aged gerbils (24-month old) were treated with 1 mg/kg and 3 mg/kg rufinamide for 4 weeks. Treatment with 3 mg/kg rufinamide, not 1 mg/kg rufinamide, significantly improved cognitive function and increased neurogenesis, showing that proliferating cells (Ki-67-immunoreactive cells), differentiating neuroblasts (DCX-immunoreactive neuroblasts) and mature neurons (BrdU/NeuN-immunoreactive cells) in the aged dentate gyrus compared with those in the control group. When we examined its mechanisms, rufinamide significantly increased immunoreactivities of insulin-like growth factor-1 (IGF-1), its receptor (IGF-1R), and phosphorylated cAMP response element binding protein (p-CREB). However, rufinamide did not show any increase in immunoreactivities of brain-derived neurotrophic factor and its receptor. Therefore, our results indicate that rufinamide can improve cognitive function and increase neurogenesis in the hippocampus of the aged gerbil via increasing expressions of IGF-1, IGF-1R and p-CREB. Copyright © 2018 Elsevier B.V. All rights reserved.

Upregulation of CREB-mediated transcription enhances both short- and long-term memory.

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Suzuki, Akinobu; Fukushima, Hotaka; Mukawa, Takuya; Toyoda, Hiroki; Wu, Long-Jun; Zhao, Ming-Gao; Xu, Hui; Shang, Yuze; Endoh, Kengo; Iwamoto, Taku; Mamiya, Nori; Okano, Emiko; Hasegawa, Shunsuke; Mercaldo, Valentina; Zhang, Yue; Maeda, Ryouta; Ohta, Miho; Josselyn, Sheena A; Zhuo, Min; Kida, Satoshi

2011-06-15

Unraveling the mechanisms by which the molecular manipulation of genes of interest enhances cognitive function is important to establish genetic therapies for cognitive disorders. Although CREB is thought to positively regulate formation of long-term memory (LTM), gain-of-function effects of CREB remain poorly understood, especially at the behavioral level. To address this, we generated four lines of transgenic mice expressing dominant active CREB mutants (CREB-Y134F or CREB-DIEDML) in the forebrain that exhibited moderate upregulation of CREB activity. These transgenic lines improved not only LTM but also long-lasting long-term potentiation in the CA1 area in the hippocampus. However, we also observed enhanced short-term memory (STM) in contextual fear-conditioning and social recognition tasks. Enhanced LTM and STM could be dissociated behaviorally in these four lines of transgenic mice, suggesting that the underlying mechanism for enhanced STM and LTM are distinct. LTM enhancement seems to be attributable to the improvement of memory consolidation by the upregulation of CREB transcriptional activity, whereas higher basal levels of BDNF, a CREB target gene, predicted enhanced shorter-term memory. The importance of BDNF in STM was verified by microinfusing BDNF or BDNF inhibitors into the hippocampus of wild-type or transgenic mice. Additionally, increasing BDNF further enhanced LTM in one of the lines of transgenic mice that displayed a normal BDNF level but enhanced LTM, suggesting that upregulation of BDNF and CREB activity cooperatively enhances LTM formation. Our findings suggest that CREB positively regulates memory consolidation and affects memory performance by regulating BDNF expression.

SUMOylation regulates the nuclear mobility of CREB binding protein and its association with nuclear bodies in live cells

International Nuclear Information System (INIS)

Ryan, Colm M.; Kindle, Karin B.; Collins, Hilary M.; Heery, David M.

2010-01-01

The lysine acetyltransferase CREB binding protein (CBP) is required for chromatin modification and transcription at many gene promoters. In fixed cells, a large proportion of CBP colocalises to PML or nuclear bodies. Using live cell imaging, we show here that YFP-tagged CBP expressed in HEK293 cells undergoes gradual accumulation in nuclear bodies, some of which are mobile and migrate towards the nuclear envelope. Deletion of a short lysine-rich domain that contains the major SUMO acceptor sites of CBP abrogated its ability to be SUMO modified, and prevented its association with endogenous SUMO-1/PML speckles in vivo. This SUMO-defective CBP showed enhanced ability to co-activate AML1-mediated transcription. Deletion mapping revealed that the SUMO-modified region was not sufficient for targeting CBP to PML bodies, as C-terminally truncated mutants containing this domain showed a strong reduction in accumulation at PML bodies. Fluorescence recovery after photo-bleaching (FRAP) experiments revealed that YFP-CBPΔ998-1087 had a retarded recovery time in the nucleus, as compared to YFP-CBP. These results indicate that SUMOylation regulates CBP function by influencing its shuttling between nuclear bodies and chromatin microenvironments.

SUMOylation regulates the nuclear mobility of CREB binding protein and its association with nuclear bodies in live cells

Energy Technology Data Exchange (ETDEWEB)

Ryan, Colm M.; Kindle, Karin B.; Collins, Hilary M. [Gene Regulation Group, Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Heery, David M., E-mail: david.heery@nottingham.ac.uk [Gene Regulation Group, Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

2010-01-01

The lysine acetyltransferase CREB binding protein (CBP) is required for chromatin modification and transcription at many gene promoters. In fixed cells, a large proportion of CBP colocalises to PML or nuclear bodies. Using live cell imaging, we show here that YFP-tagged CBP expressed in HEK293 cells undergoes gradual accumulation in nuclear bodies, some of which are mobile and migrate towards the nuclear envelope. Deletion of a short lysine-rich domain that contains the major SUMO acceptor sites of CBP abrogated its ability to be SUMO modified, and prevented its association with endogenous SUMO-1/PML speckles in vivo. This SUMO-defective CBP showed enhanced ability to co-activate AML1-mediated transcription. Deletion mapping revealed that the SUMO-modified region was not sufficient for targeting CBP to PML bodies, as C-terminally truncated mutants containing this domain showed a strong reduction in accumulation at PML bodies. Fluorescence recovery after photo-bleaching (FRAP) experiments revealed that YFP-CBP{Delta}998-1087 had a retarded recovery time in the nucleus, as compared to YFP-CBP. These results indicate that SUMOylation regulates CBP function by influencing its shuttling between nuclear bodies and chromatin microenvironments.

Sex Differences in the Effects of Acute and Chronic Stress and Recovery after Long-Term Stress on Stress-Related Brain Regions of Rats

NARCIS (Netherlands)

Lin, Yanhua; Ter Horst, Gert J.; Wichmann, Romy; Bakker, Petra; Liu, Aihua; Li, Xuejun; Westenbroek, Christel

Studies show that sex plays a role in stress-related depression, with women experiencing a higher vulnerability to its effect. Two major targets of antidepressants are brain-derived neurotrophic factor (BDNF) and cyclic adenosine monophosphate response element-binding protein (CREB). The aim of this

Dichlorvos Exposure Results in Large Scale Disruption of Energy Metabolism in the Liver of the Zebra Fish, Danio Rerio

Science.gov (United States)

2015-10-24

see Methods). With phenotypes resembling human diseases, similar- ities in anatomy, biochemistry , and genetics [20], the zebrafish is an attractive...transcription factor 4), and Creb1(cyclic amp responsive element binding protein 1) (not shown). These changes are consistent with results showing that DDVP

Endogenous Parathyroid Hormone Promotes Fracture Healing by Increasing Expression of BMPR2 through cAMP/PKA/CREB Pathway in Mice

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Wei Zhou

2017-06-01

Full Text Available Background/Aims: Endogenous parathyroid hormone (PTH plays an important role in fracture healing. This study investigated whether endogenous PTH regulates fracture healing by bone morphogenetic protein (BMP and/or the transforming growth factor-β (TGF-β signaling pathway. Methods: Eight-week-old wild-type (WT and PTH-knockout (PTH KO male mice were selected, and models of open right-femoral fracture were constructed. Fracture healing and callus characteristics of mice in the two groups were compared by X-ray, micro-computed tomography, histological, and immunohistochemical examinations. Bone marrow mesenchymal stem cells (BMMSCs of 8-week-old WT and PTHKO male mice were obtained and induced into osteoblasts and chondrocytes. Results: We found that expression levels of Runt-related transcription factor (RUNX2, bone morphogenetic protein-receptor-type Ⅱ (BMPR2, phosphorylated Smad 1/5/8, and phosphorylated cyclic adenosine monophosphate-responsive element binding protein (CREB in the callus of PTHKO mice were significantly decreased, whereas no significant difference in expression of SOX9, TGF-βR2,or pSMAD2/3 was observed between PTHKO and WT mice. Additionally, the activity of osteoblast alkaline phosphatase was low at 7 days post-induction, and was upregulated by addition of PTH or dibutyryl cyclic adenosine monophosphate (dbcAMP to the cell culture. Furthermore, H89 (protein kinase A inhibitoreliminated the simulating effects of PTH and dbcAMP, and a low concentration of cyclic adenosine monophosphate (cAMP was observed in PTHKO mouse BMMSCs. Conclusion: These results suggested that endogenous PTH enhanced BMPR2 expression by a cAMP/PKA/CREB pathway in osteoblasts, and increased RUNX2 expression through transduction of the BMP/pSMAD1/5/8 signaling pathway.

Specificity determinants for the abscisic acid response element.

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Sarkar, Aditya Kumar; Lahiri, Ansuman

2013-01-01

Abscisic acid (ABA) response elements (ABREs) are a group of cis-acting DNA elements that have been identified from promoter analysis of many ABA-regulated genes in plants. We are interested in understanding the mechanism of binding specificity between ABREs and a class of bZIP transcription factors known as ABRE binding factors (ABFs). In this work, we have modeled the homodimeric structure of the bZIP domain of ABRE binding factor 1 from Arabidopsis thaliana (AtABF1) and studied its interaction with ACGT core motif-containing ABRE sequences. We have also examined the variation in the stability of the protein-DNA complex upon mutating ABRE sequences using the protein design algorithm FoldX. The high throughput free energy calculations successfully predicted the ability of ABF1 to bind to alternative core motifs like GCGT or AAGT and also rationalized the role of the flanking sequences in determining the specificity of the protein-DNA interaction.

Ankaferd Blood Stopper induces apoptosis and regulates PAR1 and ...

African Journals Online (AJOL)

Mine Mumcuoglu

2014-12-16

Dec 16, 2014 ... investigated for its properties. However there are no ... types of proteins and factors acting on cellular functions such as protein-2 (AP2), ... ATF1), cyclic AMP response element binding protein (CREB),. E2F1–5, E2F6, EGR, ...

High constitutive activity of a virus-encoded seven transmembrane receptor in the absence of the conserved DRY motif (Asp-Arg-Tyr) in transmembrane helix 3

DEFF Research Database (Denmark)

Rosenkilde, Mette M; Kledal, Thomas N; Schwartz, Thue W

2005-01-01

-driven transcriptional activity through a pertussis toxin-sensitive manner. Gs and Gq were not activated constitutively as determined by the lack of inositol phosphate turnover and activities of the three transcription factors: cAMP response element-binding protein (CREB), nuclear factor-kappaB, and nuclear factor...

Drosophila TDP-43 RNA-Binding Protein Facilitates Association of Sister Chromatid Cohesion Proteins with Genes, Enhancers and Polycomb Response Elements.

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Amanda Swain

2016-09-01

Full Text Available The cohesin protein complex mediates sister chromatid cohesion and participates in transcriptional control of genes that regulate growth and development. Substantial reduction of cohesin activity alters transcription of many genes without disrupting chromosome segregation. Drosophila Nipped-B protein loads cohesin onto chromosomes, and together Nipped-B and cohesin occupy essentially all active transcriptional enhancers and a large fraction of active genes. It is unknown why some active genes bind high levels of cohesin and some do not. Here we show that the TBPH and Lark RNA-binding proteins influence association of Nipped-B and cohesin with genes and gene regulatory sequences. In vitro, TBPH and Lark proteins specifically bind RNAs produced by genes occupied by Nipped-B and cohesin. By genomic chromatin immunoprecipitation these RNA-binding proteins also bind to chromosomes at cohesin-binding genes, enhancers, and Polycomb response elements (PREs. RNAi depletion reveals that TBPH facilitates association of Nipped-B and cohesin with genes and regulatory sequences. Lark reduces binding of Nipped-B and cohesin at many promoters and aids their association with several large enhancers. Conversely, Nipped-B facilitates TBPH and Lark association with genes and regulatory sequences, and interacts with TBPH and Lark in affinity chromatography and immunoprecipitation experiments. Blocking transcription does not ablate binding of Nipped-B and the RNA-binding proteins to chromosomes, indicating transcription is not required to maintain binding once established. These findings demonstrate that RNA-binding proteins help govern association of sister chromatid cohesion proteins with genes and enhancers.

Identification of the G13 (cAMP-response-element-binding protein-related protein) gene product related to activating transcription factor 6 as a transcriptional activator of the mammalian unfolded protein response.

Science.gov (United States)

Haze, K; Okada, T; Yoshida, H; Yanagi, H; Yura, T; Negishi, M; Mori, K

2001-04-01

Eukaryotic cells control the levels of molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) by a transcriptional induction process termed the unfolded protein response (UPR). The mammalian UPR is mediated by the cis-acting ER stress response element consisting of 19 nt (CCAATN(9)CCACG), the CCACG part of which is considered to provide specificity. We recently identified the basic leucine zipper (bZIP) protein ATF6 as a mammalian UPR-specific transcription factor; ATF6 is activated by ER stress-induced proteolysis and binds directly to CCACG. Here we report that eukaryotic cells express another bZIP protein closely related to ATF6 in both structure and function. This protein encoded by the G13 (cAMP response element binding protein-related protein) gene is constitutively synthesized as a type II transmembrane glycoprotein anchored in the ER membrane and processed into a soluble form upon ER stress as occurs with ATF6. The proteolytic processing of ATF6 and the G13 gene product is accompanied by their relocation from the ER to the nucleus; their basic regions seem to function as a nuclear localization signal. Overexpression of the soluble form of the G13 product constitutively activates the UPR, whereas overexpression of a mutant lacking the activation domain exhibits a strong dominant-negative effect. Furthermore, the soluble forms of ATF6 and the G13 gene product are unable to bind to several point mutants of the cis-acting ER stress response element in vitro that hardly respond to ER stress in vivo. We thus concluded that the two related bZIP proteins are crucial transcriptional regulators of the mammalian UPR, and propose calling the ATF6 gene product ATF6alpha and the G13 gene product ATF6beta.

Molecular analysis of UAS(E), a cis element containing stress response elements responsible for ethanol induction of the KlADH4 gene of Kluyveromyces lactis.

Science.gov (United States)

Mazzoni, C; Santori, F; Saliola, M; Falcone, C

2000-01-01

KlADH4 is a gene of Kluyveromyces lactis encoding a mitochondrial alcohol dehydrogenase activity, which is specifically induced by ethanol and insensitive to glucose repression. In this work, we report the molecular analysis of UAS(E), an element of the KlADH4 promoter which is essential for the induction of KlADH4 in the presence of ethanol. UAS(E) contains five stress response elements (STREs), which have been found in many genes of Saccharomyces cerevisiae involved in the response of cells to conditions of stress. Whereas KlADH4 is not responsive to stress conditions, the STREs present in UAS(E) seem to play a key role in the induction of the gene by ethanol, a situation that has not been observed in the related yeast S. cerevisiae. Gel retardation experiments showed that STREs in the KlADH4 promoter can bind factor(s) under non-inducing conditions. Moreover, we observed that the RAP1 binding site present in UAS(E) binds KlRap1p.

Low-temperature-induced expression of rice ureidoglycolate amidohydrolase is mediated by a C-repeat/dehydration-responsive element that specifically interacts with rice C-repeat-binding factor 3

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Juan eLi

2015-11-01

Full Text Available Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH, which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT but not abscisic acid- (ABA regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH. Series deletions revealed that a minimal region between -522 and -420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE element localized at position -434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily.

A CREB-MPP7-AMOT Regulatory Axis Controls Muscle Stem Cell Expansion and Self-Renewal Competence

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Lydia Li

2017-10-01

Full Text Available Summary: Skeletal muscle regeneration requires resident muscle stem cells, termed satellite cells (SCs. SCs are largely quiescent during homeostasis yet become activated upon injury to supply myonuclei and self-renewed SCs. Molecular mechanisms underlying the competence of SCs to proliferate and self-renew in response to injury remain unclear. Here, we show that CREB activity establishes proliferative potential during SC quiescence. SCs with inhibited CREB activity remain quiescent and positioned in their niche, but upon injury, they cannot enter or maintain a proliferative state for expansion and self-renewal. We demonstrate mechanistically that Mpp7 is a CREB target and its functional mediator. MPP7 loss affects the level and sub-cellular localization of AMOT and YAP1 in quiescent SCs. Furthermore, MPP7 and AMOT are required for YAP1 nuclear accumulation, and the three are individually required for a proliferative state in myoblasts. We propose that the CREB-MPP7-AMOT-YAP1 axis establishes the competence of quiescent SCs to expand and self-renew, thereby preserving stem cell function. : Satellite cells are quiescent muscle stem cells that have the ability to regenerate muscles after injury. Li and Fan reveal an MPP7-AMOT-YAP1 regulatory axis that acts downstream of CREB to instill satellite cell competence. They also show how this regulatory axis prepares satellite cells for robust muscle regeneration after injury.

Linderane Suppresses Hepatic Gluconeogenesis by Inhibiting the cAMP/PKA/CREB Pathway Through Indirect Activation of PDE 3 via ERK/STAT3

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Wei Xie

2018-05-01

Full Text Available The role of phosphodiesterase 3 (PDE3, a cyclic AMP (cAMP-degrading enzyme, in modulating gluconeogenesis remains unknown. Here, linderane, a natural compound, was found to inhibit gluconeogenesis by activating hepatic PDE3 in rat primary hepatocytes. The underlying molecular mechanism and its effects on whole-body glucose and lipid metabolism were investigated. The effect of linderane on gluconeogenesis, cAMP content, phosphorylation of cAMP-response element-binding protein (CREB and PDE activity were examined in cultured primary hepatocytes and C57BL/6J mice. The precise mechanism by which linderane activates PDE3 and inhibits the cAMP pathway was explored using pharmacological inhibitors. The amelioration of metabolic disorders was observed in ob/ob mice. Linderane inhibited gluconeogenesis, reduced phosphoenolpyruvate carboxykinase (Pck1 and glucose-6-phosphatase (G6pc gene expression, and decreased intracellular cAMP concentration and CREB phosphorylation in rat primary hepatocytes under both basal and forskolin-stimulated conditions. In rat primary hepatocytes, it also increased total PDE and PDE3 activity but not PDE4 activity. The suppressive effect of linderane on the cAMP pathway and gluconeogenesis was abolished by the non-specific PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX and the specific PDE3 inhibitor cilostazol. Linderane indirectly activated PDE3 through extracellular regulated protein kinase 1/2 (ERK1/2 and signal transducer and activator of transcription 3 (STAT3 activation. Linderane improved glucose and lipid metabolism after chronic oral administration in ob/ob mice. Our findings revealed linderane as an indirect PDE3 activator that suppresses gluconeogenesis through cAMP pathway inhibition and has beneficial effects on metabolic syndromes in ob/ob mice. This investigation highlighted the potential for PDE3 activation in the treatment of type 2 diabetes.

Functional interaction between Smad, CREB binding protein, and p68 RNA helicase

International Nuclear Information System (INIS)

Warner, Dennis R.; Bhattacherjee, Vasker; Yin, Xiaolong; Singh, Saurabh; Mukhopadhyay, Partha; Pisano, M. Michele; Greene, Robert M.

2004-01-01

The transforming growth factors β control a diversity of biological processes including cellular proliferation, differentiation, apoptosis, and extracellular matrix production, and are critical effectors of embryonic patterning and development, including that of the orofacial region. TGFβ superfamily members signal through specific cell surface receptors that phosphorylate the cytoplasmic Smad proteins, resulting in their translocation to the nucleus and interaction with promoters of TGFβ-responsive genes. Subsequent alterations in transcription are cell type-specific and dependent on recruitment to the Smad/transcription factor complex of coactivators, such as CBP and p300, or corepressors, such as c-ski and SnoN. Since the affinity of Smads for DNA is generally low, additional accessory proteins that facilitate Smad/DNA binding are required, and are often cell- and tissue-specific. In order to identify novel Smad 3 binding proteins in developing orofacial tissue, a yeast two hybrid assay was employed in which the MH2 domain of Smad 3 was used to screen an expression library derived from mouse embryonic orofacial tissue. The RNA helicase, p68, was identified as a unique Smad binding protein, and the specificity of the interaction was confirmed through various in vitro and in vivo assays. Co-expression of Smad 3 and a CBP-Gal4 DNA binding domain fusion protein in a Gal4-luciferase reporter assay resulted in increased TGFβ-stimulated reporter gene transcription. Moreover, co-expression of p68 RNA helicase along with Smad 3 and CBP-Gal4 resulted in synergistic activation of Gal4-luciferase reporter expression. Collectively, these data indicate that the RNA helicase, p68, can directly interact with Smad 3 resulting in formation of a transcriptionally active ternary complex containing Smad 3, p68, and CBP. This offers a means of enhancing TGFβ-mediated cellular responses in developing orofacial tissue

Antioxidative and Anti-Melanogenic Activities of Bamboo Stems (Phyllostachys nigra variety henosis) via PKA/CREB-Mediated MITF Downregulation in B16F10 Melanoma Cells.

Science.gov (United States)

Choi, Moon-Hee; Jo, Han-Gyo; Yang, Ji Hye; Ki, Sung Hwan; Shin, Hyun-Jae

2018-01-30

Phyllostachys nigra var. henosis, a domestic bamboo species, has been attracting much attention; its bioactive compounds (especially in the leaf) show antioxidant, anti-inflammatory, and anti-obesity activities. Little information is available on the antioxidative and anti-melanogenetic activities of the bioactive compounds in bamboo stems. The anti-melanogenic and antioxidative activities of the EtOAc fraction (PN3) of a P. nigra stem extract were investigated in a cell-free system and in B16F10 melanoma cells. PN3 consisted of a mixture of flavonoids, such as catechin, chlorogenic acid, caffeic acid, and p -coumaric acid. The antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS)), and hydroxyl radical scavenging) was evaluated, as well as the inhibition of reactive oxygen species (ROS) produced by the Fenton reaction. PN3 showed in vitro tyrosinase inhibition activity with the half maximal inbihitory concentration (IC 50 ) values of 240 μg/mL, and in vivo cytotoxic concentration ranges > 100 μg/mL. The protein expression levels and mRNA transcription levels of TYR , TRP-1 , and MITF were decreased in a dose-dependent manner by the treatment with PN3. PN3 interfered with the phosphorylation of intracellular protein kinase A (PKA)/cAMP response element-binding protein (CREB), demonstrating potent anti-melanogenic effects. PN3 could inhibit PKA/CREB and the subsequent degradation of microphthalmia-associated transcription factor (MITF), resulting in the suppression of melanogenic enzymes and melanin production, probably because of the presence of flavonoid compounds. These properties make it a candidate as an additive to whitening cosmetics.

H-2RIIBP, a member of the nuclear hormone receptor superfamily that binds to both the regulatory element of major histocompatibility class I genes and the estrogen response element.

Science.gov (United States)

Hamada, K; Gleason, S L; Levi, B Z; Hirschfeld, S; Appella, E; Ozato, K

1989-11-01

Transcription of major histocompatibility complex (MHC) class I genes is regulated by the conserved MHC class I regulatory element (CRE). The CRE has two factor-binding sites, region I and region II, both of which elicit enhancer function. By screening a mouse lambda gt 11 library with the CRE as a probe, we isolated a cDNA clone that encodes a protein capable of binding to region II of the CRE. This protein, H-2RIIBP (H-2 region II binding protein), bound to the native region II sequence, but not to other MHC cis-acting sequences or to mutant region II sequences, similar to the naturally occurring region II factor in mouse cells. The deduced amino acid sequence of H-2RIIBP revealed two putative zinc fingers homologous to the DNA-binding domain of steroid/thyroid hormone receptors. Although sequence similarity in other regions was minimal, H-2RIIBP has apparent modular domains characteristic of the nuclear hormone receptors. Further analyses showed that both H-2RIIBP and the natural region II factor bind to the estrogen response element (ERE) of the vitellogenin A2 gene. The ERE is composed of a palindrome, and half of this palindrome resembles the region II binding site of the MHC CRE. These results indicate that H-2RIIBP (i) is a member of the superfamily of nuclear hormone receptors and (ii) may regulate not only MHC class I genes but also genes containing the ERE and related sequences. Sequences homologous to the H-2RIIBP gene are widely conserved in the animal kingdom. H-2RIIBP mRNA is expressed in many mouse tissues, in agreement with the distribution of the natural region II factor.

Early-onset sleep defects in Drosophila models of Huntington's disease reflect alterations of PKA/CREB signaling

Science.gov (United States)

Gonzales, Erin D.; Tanenhaus, Anne K.; Zhang, Jiabin; Chaffee, Ryan P.; Yin, Jerry C.P.

2016-01-01

Huntington's disease (HD) is a progressive neurological disorder whose non-motor symptoms include sleep disturbances. Whether sleep and activity abnormalities are primary molecular disruptions of mutant Huntingtin (mutHtt) expression or result from neurodegeneration is unclear. Here, we report Drosophila models of HD exhibit sleep and activity disruptions very early in adulthood, as soon as sleep patterns have developed. Pan-neuronal expression of full-length or N-terminally truncated mutHtt recapitulates sleep phenotypes of HD patients: impaired sleep initiation, fragmented and diminished sleep, and nighttime hyperactivity. Sleep deprivation of HD model flies results in exacerbated sleep deficits, indicating that homeostatic regulation of sleep is impaired. Elevated PKA/CREB activity in healthy flies produces patterns of sleep and activity similar to those in our HD models. We were curious whether aberrations in PKA/CREB signaling were responsible for our early-onset sleep/activity phenotypes. Decreasing signaling through the cAMP/PKA pathway suppresses mutHtt-induced developmental lethality. Genetically reducing PKA abolishes sleep/activity deficits in HD model flies, restores the homeostatic response and extends median lifespan. In vivo reporters, however, show dCREB2 activity is unchanged, or decreased when sleep/activity patterns are abnormal, suggesting dissociation of PKA and dCREB2 occurs early in pathogenesis. Collectively, our data suggest that sleep defects may reflect a primary pathological process in HD, and that measurements of sleep and cAMP/PKA could be prodromal indicators of disease, and serve as therapeutic targets for intervention. PMID:26604145

Conformational selection in the molten globule state of the nuclear coactivator binding domain of CBP

DEFF Research Database (Denmark)

Kjærgaard, Magnus; Teilum, Kaare; Poulsen, Flemming M

2010-01-01

Native molten globules are the most folded kind of intrinsically disordered proteins. Little is known about the mechanism by which native molten globules bind to their cognate ligands to form fully folded complexes. The nuclear coactivator binding domain (NCBD) of CREB binding protein is particul......Native molten globules are the most folded kind of intrinsically disordered proteins. Little is known about the mechanism by which native molten globules bind to their cognate ligands to form fully folded complexes. The nuclear coactivator binding domain (NCBD) of CREB binding protein....... Biophysical studies show that despite the molten globule nature of the domain, it contains a small cooperatively folded core. By NMR spectroscopy, we have demonstrated that the folded core of NCBD has a well ordered conformer with specific side chain packing. This conformer resembles the structure of the NCBD...

Fasting launches CRTC to facilitate long-term memory formation in Drosophila.

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Hirano, Yukinori; Masuda, Tomoko; Naganos, Shintaro; Matsuno, Motomi; Ueno, Kohei; Miyashita, Tomoyuki; Horiuchi, Junjiro; Saitoe, Minoru

2013-01-25

Canonical aversive long-term memory (LTM) formation in Drosophila requires multiple spaced trainings, whereas appetitive LTM can be formed after a single training. Appetitive LTM requires fasting prior to training, which increases motivation for food intake. However, we found that fasting facilitated LTM formation in general; aversive LTM formation also occurred after single-cycle training when mild fasting was applied before training. Both fasting-dependent LTM (fLTM) and spaced training-dependent LTM (spLTM) required protein synthesis and cyclic adenosine monophosphate response element-binding protein (CREB) activity. However, spLTM required CREB activity in two neural populations--mushroom body and DAL neurons--whereas fLTM required CREB activity only in mushroom body neurons. fLTM uses the CREB coactivator CRTC, whereas spLTM uses the coactivator CBP. Thus, flies use distinct LTM machinery depending on their hunger state.

Metabolite Regulation of Nuclear Localization of Carbohydrate-response Element-binding Protein (ChREBP): ROLE OF AMP AS AN ALLOSTERIC INHIBITOR.

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Sato, Shogo; Jung, Hunmin; Nakagawa, Tsutomu; Pawlosky, Robert; Takeshima, Tomomi; Lee, Wan-Ru; Sakiyama, Haruhiko; Laxman, Sunil; Wynn, R Max; Tu, Benjamin P; MacMillan, John B; De Brabander, Jef K; Veech, Richard L; Uyeda, Kosaku

2016-05-13

The carbohydrate-response element-binding protein (ChREBP) is a glucose-responsive transcription factor that plays an essential role in converting excess carbohydrate to fat storage in the liver. In response to glucose levels, ChREBP is regulated by nuclear/cytosol trafficking via interaction with 14-3-3 proteins, CRM-1 (exportin-1 or XPO-1), or importins. Nuclear localization of ChREBP was rapidly inhibited when incubated in branched-chain α-ketoacids, saturated and unsaturated fatty acids, or 5-aminoimidazole-4-carboxamide ribonucleotide. Here, we discovered that protein-free extracts of high fat-fed livers contained, in addition to ketone bodies, a new metabolite, identified as AMP, which specifically activates the interaction between ChREBP and 14-3-3. The crystal structure showed that AMP binds directly to the N terminus of ChREBP-α2 helix. Our results suggest that AMP inhibits the nuclear localization of ChREBP through an allosteric activation of ChREBP/14-3-3 interactions and not by activation of AMPK. AMP and ketone bodies together can therefore inhibit lipogenesis by restricting localization of ChREBP to the cytoplasm during periods of ketosis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Cooperative interactions between CBP and TORC2 confer selectivity to CREB target gene expression

DEFF Research Database (Denmark)

Ravnskjær, Kim; Kester, Henri; Liu, Yi

2007-01-01

A number of hormones and growth factors stimulate gene expression by promoting the phosphorylation of CREB (P-CREB), thereby enhancing its association with the histone acetylase paralogs p300 and CBP (CBP/p300). Relative to cAMP, stress signals trigger comparable amounts of CREB phosphorylation...... to stress signals, however; and in its absence, P-CREB is unable to stimulate CRE-dependent transcription, due to a block in CBP recruitment. The effect of TORC2 on CBP/p300 promoter occupancy appears pivotal because a gain of function mutant CREB polypeptide with increased affinity for CBP restored CRE......-mediated transcription in cells exposed to stress signals. Taken together, these results indicate that TORC2 is one of the long sought after cofactors that mediates the differential effects of cAMP and stress pathways on CREB target gene expression....

Identification of a growth hormone-responsive STAT5-binding element in the rat insulin 1 gene

DEFF Research Database (Denmark)

Galsgaard, E D; Gouilleux, F; Groner, B

1996-01-01

promoter activity 2-fold, and this stimulation was abolished by introduction of a block mutation in a gamma-interferon-activated sequence (GAS)-like element (GLE) with the sequence 5'-TTCTGGGAA-3' located in the rat insulin 1 enhancer at position -330 to -322. This element, termed Ins-GLE, was able...... transfected with STAT5 and GH receptor cDNAs, it was found that expression of STAT5 was necessary for GH induction of these two DNA-binding complexes. These results suggest that GH stimulates insulin 1 promoter activity by inducing the binding of STAT5 to Ins-GLE.......GH and PRL stimulate both proliferation and insulin production in pancreatic beta-cells as well as in the rat insulinoma cell line RIN-5AH, We report here that human GH increases insulin mRNA levels in RIN-5AH cells via both somatogenic and lactogenic receptors. GH stimulated the rat insulin 1...

Response of brain oxygenation and metabolism to deep hypothermic circulatory arrest in newborn piglets: comparison of pH-stat and alpha-stat strategies.

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Markowitz, Scott D; Mendoza-Paredes, Alberto; Liu, Huiping; Pastuszko, Peter; Schultz, Steven P; Schears, Gregory J; Greeley, William J; Wilson, David F; Pastuszko, Anna

2007-07-01

To determine the effect of pH-stat as compared with alpha-stat management on brain oxygenation, level of striatal extracellular dopamine, phosphorylation, and levels of protein kinase B (Akt) and cyclic adenosine 3', 5'-monophosphate response element-binding protein (CREB), and levels of extracellular signal-regulated kinase (ERK)1/2, Bcl-2, and Bax in a piglet model of deep hypothermic circulatory arrest (DHCA). The piglets were placed on cardiopulmonary bypass (CPB), cooled with pH-stat or alpha-stat to 18 degrees C, subjected to 90 minutes of DHCA, rewarmed, weaned from CPB, and maintained for two hours recovery. The cortical oxygen was measured by: quenching of phosphorescence; dopamine by microdialysis; phosphorylation of CREB (p-CREB), ERK (p-ERK) 1/2, Akt (p-Akt), and level of Bcl-2, Bax by Western blots. Oxygen pressure histograms for the microvasculature of the cortex show substantially higher oxygen levels during cooling and during the oxygen depletion period after cardiac arrest (up to 15 minutes) when using pH-stat compared with alpha-stat management. Significant increases in dopamine occurred at 45 minutes and 60 minutes of DHCA in the alpha-stat and pH-stat groups, respectively. The p-CREB and p-Akt in the pH-stat group were significantly higher than in the alpha-stat group (140 +/- 9%, p model, prolongs "safe" time of DHCA and provides some brain protection against ischemic injury.

Dynamic SPR monitoring of yeast nuclear protein binding to a cis-regulatory element

International Nuclear Information System (INIS)

Mao, Grace; Brody, James P.

2007-01-01

Gene expression is controlled by protein complexes binding to short specific sequences of DNA, called cis-regulatory elements. Expression of most eukaryotic genes is controlled by dozens of these elements. Comprehensive identification and monitoring of these elements is a major goal of genomics. In pursuit of this goal, we are developing a surface plasmon resonance (SPR) based assay to identify and monitor cis-regulatory elements. To test whether we could reliably monitor protein binding to a regulatory element, we immobilized a 16 bp region of Saccharomyces cerevisiae chromosome 5 onto a gold surface. This 16 bp region of DNA is known to bind several proteins and thought to control expression of the gene RNR1, which varies through the cell cycle. We synchronized yeast cell cultures, and then sampled these cultures at a regular interval. These samples were processed to purify nuclear lysate, which was then exposed to the sensor. We found that nuclear protein binds this particular element of DNA at a significantly higher rate (as compared to unsynchronized cells) during G1 phase. Other time points show levels of DNA-nuclear protein binding similar to the unsynchronized control. We also measured the apparent association complex of the binding to be 0.014 s -1 . We conclude that (1) SPR-based assays can monitor DNA-nuclear protein binding and that (2) for this particular cis-regulatory element, maximum DNA-nuclear protein binding occurs during G1 phase

The transcriptional regulatory network mediated by banana (Musa acuminata) dehydration-responsive element binding (MaDREB) transcription factors in fruit ripening.

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Kuang, Jian-Fei; Chen, Jian-Ye; Liu, Xun-Cheng; Han, Yan-Chao; Xiao, Yun-Yi; Shan, Wei; Tang, Yang; Wu, Ke-Qiang; He, Jun-Xian; Lu, Wang-Jin

2017-04-01

Fruit ripening is a complex, genetically programmed process involving the action of critical transcription factors (TFs). Despite the established significance of dehydration-responsive element binding (DREB) TFs in plant abiotic stress responses, the involvement of DREBs in fruit ripening is yet to be determined. Here, we identified four genes encoding ripening-regulated DREB TFs in banana (Musa acuminata), MaDREB1, MaDREB2, MaDREB3, and MaDREB4, and demonstrated that they play regulatory roles in fruit ripening. We showed that MaDREB1-MaDREB4 are nucleus-localized, induced by ethylene and encompass transcriptional activation activities. We performed a genome-wide chromatin immunoprecipitation and high-throughput sequencing (ChIP-Seq) experiment for MaDREB2 and identified 697 genomic regions as potential targets of MaDREB2. MaDREB2 binds to hundreds of loci with diverse functions and its binding sites are distributed in the promoter regions proximal to the transcriptional start site (TSS). Most of the MaDREB2-binding targets contain the conserved (A/G)CC(G/C)AC motif and MaDREB2 appears to directly regulate the expression of a number of genes involved in fruit ripening. In combination with transcriptome profiling (RNA sequencing) data, our results indicate that MaDREB2 may serve as both transcriptional activator and repressor during banana fruit ripening. In conclusion, our study suggests a hierarchical regulatory model of fruit ripening in banana and that the MaDREB TFs may act as transcriptional regulators in the regulatory network. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Activation of PKA/CREB Signaling is Involved in BMP9-Induced Osteogenic Differentiation of Mesenchymal Stem Cells

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Hongyu Zhang

2015-09-01

Full Text Available Background/Aims: BMP9 is highly capable of promoting osteogenic differentiation of mesenchymal stem cells (MSCs although the molecular mechanism involved is largely unknown. Here, we explored the detail role of PKA/CREB signaling in BMP9-induced osteogenic differentiation. Methods: Activation status of PKA/CREB signaling is assessed by nonradioactive assay and Western blot. Using PKA inhibitors and a dominant negative protein of CREB (A-CREB, we investigated the effect of PKA/CREB signaling on BMP9-induced osteogenic differentiation. Results: We found that BMP9 promotes PKA activity and enhances CREB phosphorylation in MSCs. BMP9 is shown to down-regulate protein kinase A inhibitor γ (PKIγ expression. We demonstrated that PKA inhibitors suppress BMP9-induced early osteogenic marker alkaline phosphatase (ALP activity in MSCs as well as late osteogenic markers osteopontin (OPN, osteocalcin (OCN and matrix mineralization. We found that PKA inhibitor reduces BMP9-induced Runx2 activation and p38 phosphorylation in MSCs. Lastly, interference of CREB function by A-CREB decreased BMP9-induced osteogenic differentiation as well. Conclusion: Our results revealed that BMP9 may activate PKA/CREB signaling in MSCs through suppression of PKIγ expression. It is noteworthy that inhibition of PKA/CREB signaling may impair BMP9-induced osteogenic differentiation of MSCs, implying that activation of PKA/CREB signaling is required for BMP9 osteoinductive activity.

Epinephrine and glucose modulate training-related CREB phosphorylation in old rats: relationships to age-related memory impairments.

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Morris, Ken A; Gold, Paul E

2013-02-01

Epinephrine enhances memory in young adult rats, in part, by increasing blood glucose levels needed to modulate memory. In old rats, epinephrine is deficient at raising blood glucose levels and thus is only moderately effective at enhancing memory. In contrast, systemic glucose injections improve memory in old rats, with resulting memory performance equal to that of young rats. The diminished response of glucose to training in old rats may blunt downstream neurochemical and molecular mechanisms needed to upregulate memory processes. In the first experiment, young adult and old rats were trained on an inhibitory avoidance task with immediate post-training injections of aCSF or glucose into the dorsal hippocampus. Old rats had significant memory impairments compared to young rats 7 days after training. Intrahippocampal injections of glucose reversed age-related deficits, improving memory scores in old rats to values seen in young rats. A second experiment examined age-related changes in activation of the transcription factor CREB, which is widely implicated in memory formation and may act downstream of hormonal and metabolic signals. Activation was assessed in response to training with systemic injections of epinephrine and glucose at doses known to enhance memory. Young adult and old rats were trained on inhibitory avoidance with immediate post-training systemic injections of saline, epinephrine, or glucose. After training, old rats had significant impairments in CREB phosphorylation in area CA1 and the dentate gyrus region of the hippocampus, and in the basolateral and lateral amygdala. Epinephrine and glucose attenuated age-related deficits in CREB phosphorylation, but were more effective in the amygdala and hippocampus, respectively. Together, these results support the view that age-related changes in blood glucose responses to epinephrine contribute to memory impairments, which may be related to alterations in regional patterns of CREB phosphorylation. Copyright

Epigenetic regulation of the NR4A orphan nuclear receptor NOR1 by histone acetylation.

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Zhao, Yue; Nomiyama, Takashi; Findeisen, Hannes M; Qing, Hua; Aono, Jun; Jones, Karrie L; Heywood, Elizabeth B; Bruemmer, Dennis

2014-12-20

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Regulatory elements in vivo in the promoter of the abscisic acid responsive gene rab17 from maize.

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Busk, P K; Jensen, A B; Pagès, M

1997-06-01

The rab17 gene from maize is transcribed in late embryonic development and is responsive to abscisic acid and water stress in embryo and vegetative tissues. In vivo footprinting and transient transformation of rab17 were performed in embryos and vegetative tissues to characterize the cis-elements involved in regulation of the gene. By in vivo footprinting, protein binding was observed to nine elements in the promoter, which correspond to five putative ABREs (abscisic acid responsive elements) and four other sequences. The footprints indicated that distinct proteins interact with these elements in the two developmental stages. In transient transformation, six of the elements were important for high level expression of the rab17 promoter in embryos, whereas only three elements were important in leaves. The cis-acting sequences can be divided in embryo-specific, ABA-specific and leaf-specific elements on the basis of protein binding and the ability to confer expression of rab17. We found one positive, new element, called GRA, with the sequence CACTGGCCGCCC. This element was important for transcription in leaves but not in embryos. Two other non-ABRE elements that stimulated transcription from the rab17 promoter resemble previously described abscisic acid and drought-inducible elements. There were differences in protein binding and function of the five ABREs in the rab17 promoter. The possible reasons for these differences are discussed. The in vivo data obtained suggest that an embryo-specific pathway regulates transcription of the rab genes during development, whereas another pathway is responsible for induction in response to ABA and drought in vegetative tissues.

Characterization and localization of metal-responsive-element-binding transcription factors from tilapia

Energy Technology Data Exchange (ETDEWEB)

Cheung, Andrew Pok-Lap; Au, Candy Yee-Man; Chan, William Wai-Lun [Department of Biochemistry, Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong (Hong Kong); Chan, King Ming, E-mail: kingchan@cuhk.edu.hk [Department of Biochemistry, Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong (Hong Kong)

2010-08-01

Two isoforms of MTF-1, MTF-1L (long form) and MTF-1S (short form), were cloned in tilapia (Ti) and characterized in a tilapia liver cell line, Hepa-T1. The cloned tiMTF-1L has the characteristics of all of the tiMTF-1S identified so far with the zinc finger domain having six fingers, the acidic-rich, proline-rich, and serine/threonine-rich domains; however, the short form encodes for the zinc finger domain with five zinc fingers only and no other domains. The transient transfection of tiMTF-1L into human HepG2 cells showed both constitutive and zinc-induced metal-responsive-element (MRE)-driven reporter gene expression. However, the transfection of tiMTF-1S (which lacks all three transactivation domains) into a human cell line showed reduced transcriptional activities compared with an endogenous control in both basal- and Zn{sup 2+}-induced conditions. The tiMTF-1 isoforms were tagged with GFP and transfected into Hepa-T1 cells (tilapia hepatocytes). The nuclear translocation of tiMTF-1L was observed when the cells were exposed to a sufficient concentration of metals for 6 h. However, tiMTF-1S, was localized in the nucleus with or without metal treatment. Electrophoretic mobility shift assay (EMSA) confirmed that both of the isoforms were able to bind to the MRE specifically in vitro. Tissue distribution studies showed that tiMTF-1L was more abundant than tiMTF-1S in all of the tissues tested.

Characterization and localization of metal-responsive-element-binding transcription factors from tilapia

International Nuclear Information System (INIS)

Cheung, Andrew Pok-Lap; Au, Candy Yee-Man; Chan, William Wai-Lun; Chan, King Ming

2010-01-01

Two isoforms of MTF-1, MTF-1L (long form) and MTF-1S (short form), were cloned in tilapia (Ti) and characterized in a tilapia liver cell line, Hepa-T1. The cloned tiMTF-1L has the characteristics of all of the tiMTF-1S identified so far with the zinc finger domain having six fingers, the acidic-rich, proline-rich, and serine/threonine-rich domains; however, the short form encodes for the zinc finger domain with five zinc fingers only and no other domains. The transient transfection of tiMTF-1L into human HepG2 cells showed both constitutive and zinc-induced metal-responsive-element (MRE)-driven reporter gene expression. However, the transfection of tiMTF-1S (which lacks all three transactivation domains) into a human cell line showed reduced transcriptional activities compared with an endogenous control in both basal- and Zn 2+ -induced conditions. The tiMTF-1 isoforms were tagged with GFP and transfected into Hepa-T1 cells (tilapia hepatocytes). The nuclear translocation of tiMTF-1L was observed when the cells were exposed to a sufficient concentration of metals for 6 h. However, tiMTF-1S, was localized in the nucleus with or without metal treatment. Electrophoretic mobility shift assay (EMSA) confirmed that both of the isoforms were able to bind to the MRE specifically in vitro. Tissue distribution studies showed that tiMTF-1L was more abundant than tiMTF-1S in all of the tissues tested.

The neuroprotective effects of α-iso-cubebene on dopaminergic cell death: involvement of CREB/Nrf2 signaling.

Science.gov (United States)

Park, Sun Young; Son, Beung Gu; Park, Young Hoon; Kim, Cheol-Min; Park, Geuntae; Choi, Young-Whan

2014-09-01

As a part of ongoing studies to elucidate pharmacologically active components of Schisandra chinensis, we isolated and studied α-iso-cubebene. The neuroprotective mechanisms of α-iso-cubebene in human neuroblastoma SH-SY5Y cells were investigated. α-Iso-cubebene significantly inhibited cytotoxicity and apoptosis due to 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in dopaminergic SH-SY5Y cells. Pretreatment of cells with α-iso-cubebene reduced intracellular accumulation of ROS and calcium in response to 6-OHDA. The neuroprotective effects of α-iso-cubebene were found to result from protecting the mitochondrial membrane potential. Notably, α-iso-cubebene inhibited the release of apoptosis-inducing factor from the mitochondria into the cytosol and nucleus after 6-OHDA treatment. α-Iso-cubebene also induced the activation of PKA/PKB/CREB/Nrf2 and suppressed 6-OHDA-induced neurotoxicity. α-Iso-cubebene was found to induce phosphorylation of PKA and PKB and activate Nrf2 and CREB signaling pathways in a dose-dependent manner. Additionally, α-iso-cubebene stimulated the expression of the antioxidant response genes NQO1 and HO-1. Finally, α-iso-cubebene-mediated neuroprotective effects were found to be reversible after transfection with CREB and Nrf2 small interfering RNAs.

Estradiol up-regulates L-type Ca2+ channels via membrane-bound estrogen receptor/phosphoinositide-3-kinase/Akt/cAMP response element-binding protein signaling pathway.

Science.gov (United States)

Yang, Xiaoyan; Mao, Xiaofang; Xu, Gao; Xing, Shasha; Chattopadhyay, Ansuman; Jin, Si; Salama, Guy

2018-05-01

In long QT syndrome type 2, women are more prone than men to the lethal arrhythmia torsades de pointes. We previously reported that 17β-estradiol (E2) up-regulates L-type Ca 2+ channels and current (I Ca,L ) (∼30%) in rabbit ventricular myocytes by a classic genomic mechanism mediated by estrogen receptor-α (ERα). In long QT syndrome type 2 (I Kr blockade or bradycardia), the higher Ca 2+ influx via I Ca,L causes Ca 2+ overload, spontaneous sarcoplasmic reticulum Ca 2+ release, and reactivation of I Ca,L that triggers early afterdepolarizations and torsades de pointes. The purpose of this study was to investigate the molecular mechanisms whereby E2 up-regulates I Ca,L , which are poorly understood. H9C2 and rat myocytes were incubated with E2 ± ER antagonist, or inhibitors of downstream transcription factors, for 24 hours, followed by western blots of Cav1.2α1C and voltage-clamp measurements of I Ca,L . Incubation of H9C2 cells with E2 (10-100 nM) increased I Ca,L density and Cav1.2α1C expression, which were suppressed by the ER antagonist ICI182,780 (1 μM). Enhanced I Ca,L and Cav1.2α1C expression by E2 was suppressed by inhibitors of phosphoinositide-3-kinase (Pi3K) (30 μM LY294002; P L via plasma membrane ER and by activating Pi3K, Akt, and CREB signaling. The promoter regions of the CACNA1C gene (human-rabbit-rat) contain adjacent/overlapping binding sites for p-CREB and ERα, which suggests a synergistic regulation by these pathways. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

The Role of Carbohydrate Response Element Binding Protein in Intestinal and Hepatic Fructose Metabolism

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Katsumi Iizuka

2017-02-01

Full Text Available Many articles have discussed the relationship between fructose consumption and the incidence of obesity and related diseases. Fructose is absorbed in the intestine and metabolized in the liver to glucose, lactate, glycogen, and, to a lesser extent, lipids. Unabsorbed fructose causes bacterial fermentation, resulting in irritable bowl syndrome. Therefore, understanding the mechanisms underlying intestinal and hepatic fructose metabolism is important for the treatment of metabolic syndrome and fructose malabsorption. Carbohydrate response element binding protein (ChREBP is a glucose-activated transcription factor that controls approximately 50% of de novo lipogenesis in the liver. ChREBP target genes are involved in glycolysis (Glut2, liver pyruvate kinase, fructolysis (Glut5, ketohexokinase, and lipogenesis (acetyl CoA carboxylase, fatty acid synthase. ChREBP gene deletion protects against high sucrose diet-induced and leptin-deficient obesity, because Chrebp−/− mice cannot consume fructose or sucrose. Moreover, ChREBP contributes to some of the physiological effects of fructose on sweet taste preference and glucose production through regulation of ChREBP target genes, such as fibroblast growth factor-21 and glucose-6-phosphatase catalytic subunits. Thus, ChREBP might play roles in fructose metabolism. Restriction of excess fructose intake will be beneficial for preventing not only metabolic syndrome but also irritable bowl syndrome.

Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

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Tan Wenbin

2011-11-01

Full Text Available Abstract Background Insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control, which creates a major public health concern. Two-dimensional electrophoresis identified one protein segment with high sequence homology to part of Aedes aegypti iron-responsive element binding protein (IRE-BP. Method RT-PCR and RACE (rapid amplification of cDNA end were used to clone a cDNA encoding full length IRE-BP 1. Real-time quantitative RT-PCR was used to evaluate the transcriptional level changes in the Cr-IRE strain Aedes aegypti compared to the susceptible strain of Cx. pipiens pallens. The expression profile of the gene was established in the mosquito life cycle. Methyl tritiated thymidine (3H-TdR was used to observe the cypermethrin resistance changes in C6/36 cells containing the stably transfected IRE-BP 1 gene of Cx. pipiens pallens. Results The complete sequence of iron responsive element binding protein 1 (IRE-BP 1 has been cloned from the cypermethrin-resistant strain of Culex pipiens pallens (Cr-IRE strain. Quantitative RT-PCR analysis indicated that the IRE-BP 1 transcription level was 6.7 times higher in the Cr-IRE strain than in the susceptible strain of 4th instar larvae. The IRE-BP 1 expression was also found to be consistently higher throughout the life cycle of the Cr-IRE strain. A protein of predicted size 109.4 kDa has been detected by Western blotting in IRE-BP 1-transfected mosquito C6/36 cells. These IRE-BP 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by 3H-TdR incorporation. Conclusion IRE-BP 1 is expressed at higher levels in the Cr-IRE strain, and may confer some insecticide resistance in Cx. pipiens pallens.

Interaction between C/EBPβ and Tax down-regulates human T-cell leukemia virus type I transcription

International Nuclear Information System (INIS)

Hivin, P.; Gaudray, G.; Devaux, C.; Mesnard, J.-M.

2004-01-01

The human T-cell leukemia virus type I (HTLV-I) Tax protein trans-activates viral transcription through three imperfect tandem repeats of a 21-bp sequence called Tax-responsive element (TxRE). Tax regulates transcription via direct interaction with some members of the activating transcription factor/CRE-binding protein (ATF/CREB) family including CREM, CREB, and CREB-2. By interacting with their ZIP domain, Tax stimulates the binding of these cellular factors to the CRE-like sequence present in the TxREs. Recent observations have shown that CCAAT/enhancer binding protein β (C/EBPβ) forms stable complexes on the CRE site in the presence of CREB-2. Given that C/EBPβ has also been found to interact with Tax, we analyzed the effects of C/EBPβ on viral Tax-dependent transcription. We show here that C/EBPβ represses viral transcription and that Tax is no more able to form a stable complex with CREB-2 on the TxRE site in the presence of C/EBPβ. We also analyzed the physical interactions between Tax and C/EBPβ and found that the central region of C/EBPβ, excluding its ZIP domain, is required for direct interaction with Tax. It is the first time that Tax is described to interact with a basic leucine-zipper (bZIP) factor without recognizing its ZIP domain. Although unexpected, this result explains why C/EBPβ would be unable to form a stable complex with Tax on the TxRE site and could then down-regulate viral transcription. Lastly, we found that C/EBPβ was able to inhibit Tax expression in vivo from an infectious HTLV-I molecular clone. In conclusion, we propose that during cell activation events, which stimulate the Tax synthesis, C/EBPβ may down-regulate the level of HTLV-I expression to escape the cytotoxic-T-lymphocyte response

Overlearned responses hinder S-R binding.

Science.gov (United States)

Moeller, Birte; Frings, Christian

2017-01-01

Two mechanisms that are important for human action control are the integration of individual action plans (see Hommel, Müsseler, Aschersleben, & Prinz, 2001) and the automatization of overlearned actions to familiar stimuli (see Logan, 1988). In the present study, we analyzed the influence of automatization on action plan integration. Integration with pronunciation responses were compared for response incompatible word and nonword stimuli. Stimulus-response binding effects were observed for nonwords. In contrast, words that automatically triggered an overlearned pronunciation response were not integrated with pronunciation of a different word. That is, automatized response retrieval hindered binding effects regarding the retrieving stimulus and a new response. The results are a first indication of the way that binding and learning processes interact, and might also be a first step to understanding the more complex interdependency of the processes responsible for stimulus-response binding in action control and stimulus-response associations in learning research. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Reward or its denial during the neonatal period affects adult spatial memory and hippocampal phosphorylated cAMP response element-binding protein levels of both the neonatal and adult rat.

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Diamantopoulou, A; Stamatakis, A; Panagiotaropoulos, T; Stylianopoulou, F

2011-05-05

Early life experiences, particularly mother-infant interactions, have been shown to influence adult coping and learning abilities via gene-environment interactions. We have developed a paradigm, in which mother contact is used as either a positive or a negative reinforcer in a T-maze, during postnatal days 10-13. In both neonates receiving (RER) or denied (DER) the expected reward, exposure to the memory test in the absence of the mother resulted in a remarkable increase in the number of pCREB immunopositive cells, when compared to their corresponding levels 2 h after the completion of the training process, but also to the levels of naïve animals. In the CA3 area, the pattern of pCREB immunoreactivity, when evaluated 2 h after the completion of the training on postnatal day 13 seemed to distinguish between the two different neonatal experiences in the T-maze, with the DER pups showing higher levels of pCREB immunopositive cells than the RER. Exposure to the Morris Water Maze (MWM) during adulthood revealed a memory advantage of the DER animals compared to the RER and the animals not exposed to the neonatal experience. Relevantly, in the DER animals an increased number of pCREB immunopositive cells was observed in the CA3 area even 24 h after the end of MWM training. When also measured after exposure to the probe trial, the number of pCREB immunopositive cells was again higher in the DER compared to the RER animals. In conclusion, we show that a learning experience involving discrepancy during the particularly plastic neonatal period is able to induce long-term effects, which result in enhanced adult hippocampal dependent spatial memory. Furthermore, our data document a role of plasticity molecules like pCREB in mediating hippocampal dependent learning and detection of novelty not only in adulthood, but also more importantly in the neonatal period of the rat. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Dual DNA binding property of ABA insensitive 3 like factors targeted to promoters responsive to ABA and auxin.

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Nag, Ronita; Maity, Manas Kanti; Dasgupta, Maitrayee

2005-11-01

The ABA responsive ABI3 and the auxin responsive ARF family of transcription factors bind the CATGCATG (Sph) and TGTCTC core motifs in ABA and auxin response elements (ABRE and AuxRE), respectively. Several evidences indicate ABI3s to act downstream to auxin too. Because DNA binding domain of ABI3s shows significant overlap with ARFs we enquired whether auxin responsiveness through ABI3s could be mediated by their binding to canonical AuxREs. Investigations were undertaken through in vitro gel mobility shift assays (GMSA) using the DNA binding domain B3 of PvAlf (Phaseolus vulgaris ABI3 like factor) and upstream regions of auxin responsive gene GH3 (-267 to -141) and ABA responsive gene Em (-316 to -146) harboring AuxRE and ABRE, respectively. We demonstrate that B3 domain of PvAlf could bind AuxRE only when B3 was associated with its flanking domain B2 (B2B3). Such strict requirement of B2 domain was not observed with ABRE, where B3 could bind with or without being associated with B2. This dual specificity in DNA binding of ABI3s was also demonstrated with nuclear extracts of cultured cells of Arachis hypogea. Supershift analysis of ABRE and AuxRE bound nuclear proteins with antibodies raised against B2B3 domains of PvAlf revealed that ABI3 associated complexes were detectable in association with both cis elements. Competition GMSA confirmed the same complexes to bind ABRE and AuxRE. This dual specificity of ABI3 like factors in DNA binding targeted to natural promoters responsive to ABA and auxin suggests them to have a potential role in conferring crosstalk between these two phytohormones.

Deletion of creB in Aspergillus oryzae increases secreted hydrolytic enzyme activity.

Science.gov (United States)

Hunter, A J; Morris, T A; Jin, B; Saint, C P; Kelly, J M

2013-09-01

Aspergillus oryzae has been used in the food and beverage industry for centuries, and industrial strains have been produced by multiple rounds of selection. Targeted gene deletion technology is particularly useful for strain improvement in such strains, particularly when they do not have a well-characterized meiotic cycle. Phenotypes of an Aspergillus nidulans strain null for the CreB deubiquitinating enzyme include effects on growth and repression, including increased activity levels of various enzymes. We show that Aspergillus oryzae contains a functional homologue of the CreB deubiquitinating enzyme and that a null strain shows increased activity levels of industrially important secreted enzymes, including cellulases, xylanases, amylases, and proteases, as well as alleviated inhibition of spore germination on glucose medium. Reverse transcription-quantitative PCR (RT-qPCR) analysis showed that the increased levels of enzyme activity in both Aspergillus nidulans and Aspergillus oryzae are mirrored at the transcript level, indicating transcriptional regulation. We report that Aspergillus oryzae DAR3699, originally isolated from soy fermentation, has a similar phenotype to that of a creB deletion mutant of the RIB40 strain, and it contains a mutation in the creB gene. Collectively, the results for Aspergillus oryzae, Aspergillus nidulans, Trichoderma reesei, and Penicillium decumbens show that deletion of creB may be broadly useful in diverse fungi for increasing production of a variety of enzymes.

Alterations in transcription factor binding in radioresistant human melanoma cells after ionizing radiation

International Nuclear Information System (INIS)

Sahijdak, W.M.; Yang, Chin-Rang; Zuckerman, J.S.; Meyers, M.; Boothman, D.A.

1994-01-01

We analyzed alterations in transcription factor binding to specific, known promoter DNA consensus sequences between irradiated and unirradiated radioresistant human melanoma (U1-Mel) cells. The goal of this study was to begin to investigate which transcription factors and DNA-binding sites are responsible for the induction of specific transcripts and proteins after ionizing radiation. Transcription factor binding was observed using DNA band-shift assays and oligonucleotide competition analyses. Confluence-arrested U1-Mel cells were irradiated (4.5 Gy) and harvested at 4 h. Double-stranded oligonucleotides containing known DNA-binding consensus sites for specific transcription factors were used. Increased DNA binding activity after ionizing radiation was noted with oligonucleotides containing the CREB, NF-kB and Sp1 consensus sites. No changes in protein binding to AP-1, AP-2, AP-3, or CTF/NF1, GRE or Oct-1 consensus sequences were noted. X-ray activation of select transcription factors, which bind certain consensus sites in promoters, may cause specific induction or repression of gene transcription. 22 refs., 2 figs

ACGT-containing abscisic acid response element (ABRE) and coupling element 3 (CE3) are functionally equivalent.

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Hobo, T; Asada, M; Kowyama, Y; Hattori, T

1999-09-01

ACGT-containing ABA response elements (ABREs) have been functionally identified in the promoters of various genes. In addition, single copies of ABRE have been found to require a cis-acting, coupling element to achieve ABA induction. A coupling element 3 (CE3) sequence, originally identified as such in the barley HVA1 promoter, is found approximately 30 bp downstream of motif A (ACGT-containing ABRE) in the promoter of the Osem gene. The relationship between these two elements was further defined by linker-scan analyses of a 55 bp fragment of the Osem promoter, which is sufficient for ABA-responsiveness and VP1 activation. The analyses revealed that both motif A and CE3 sequence were required not only for ABA-responsiveness but also for VP1 activation. Since the sequences of motif A and CE3 were found to be similar, motif-exchange experiments were carried out. The experiments demonstrated that motif A and CE3 were interchangeable by each other with respect to both ABA and VP1 regulation. In addition, both sequences were shown to be recognized by a VP1-interacting, ABA-responsive bZIP factor TRAB1. These results indicate that ACGT-containing ABREs and CE3 are functionally equivalent cis-acting elements. Furthermore, TRAB1 was shown to bind two other non-ACGT ABREs. Based on these results, all these ABREs including CE3 are proposed to be categorized into a single class of cis-acting elements.

Maize DRE-binding proteins DBF1 and DBF2 are involved in rab17 regulation through the drought-responsive element in an ABA-dependent pathway.

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Kizis, Dimosthenis; Pagès, Montserrat

2002-06-01

The abscisic acid-responsive gene rab17 of maize is expressed during late embryogenesis, and is induced by ABA and desiccation in embryo and vegetative tissues. ABRE and DRE cis-elements are involved in regulation of the gene by ABA and drought. Using yeast one-hybrid screening, we isolated two cDNAs encoding two new DRE-binding proteins, designated DBF1 and DBF2, that are members of the AP2/EREBP transcription factor family. Analysis of mRNA accumulation profiles showed that DBF1 is induced during maize embryogenesis and after desiccation, NaCl and ABA treatments in plant seedlings, whereas the DBF2 mRNA is not induced. DNA-binding preferences of DBFs were analysed by electrophoretic mobility shift assays, and showed that both DBF1 and DBF2 bound to the wild-type DRE2 element, but not to the DRE2 mutant or to the DRE1 element which differs only in a single nucleotide. Transactivation activity using particle bombardment showed that DBF1 functioned as activator of DRE2-dependent transcription of rab17 promoter by ABA, whereas DBF2 overexpression had a repression action downregulating not only the basal promoter activity, but also the ABA effect. These results show that ABA plays a role in the regulation of DBF activity, and suggests the existence of an ABA-dependent pathway for the regulation of genes through the C-repeat/DRE element.

An ABA-responsive DRE-binding protein gene from Setaria italica, SiARDP, the target gene of SiAREB, plays a critical role under drought stress

OpenAIRE

Li, Cong; Yue, Jing; Wu, Xiaowei; Xu, Cong; Yu, Jingjuan

2014-01-01

The DREB (dehydration-responsive element binding)-type transcription factors regulate the expression of stress-inducible genes by binding the DRE/CRT cis-elements in promoter regions. The upstream transcription factors that regulate the transcription of DREB transcription factors have not been clearly defined, although the function of DREB transcription factors in abiotic stress is known. In this study, an abscisic acid (ABA)-responsive DREB-binding protein gene (SiARDP) was cloned from foxta...

The Specificity of Innate Immune Responses Is Enforced by Repression of Interferon Response Elements by NF-κB p50

Science.gov (United States)

Cheng, Christine S.; Feldman, Kristyn E.; Lee, James; Verma, Shilpi; Huang, De-Bin; Huynh, Kim; Chang, Mikyoung; Ponomarenko, Julia V.; Sun, Shao-Cong; Benedict, Chris A.; Ghosh, Gourisankar; Hoffmann, Alexander

2011-01-01

The specific binding of transcription factors to cognate sequence elements is thought to be critical for the generation of specific gene expression programs. Members of the nuclear factor κB (NF-κB) and interferon (IFN) regulatory factor (IRF) transcription factor families bind to the κB site and the IFN response element (IRE), respectively, of target genes, and they are activated in macrophages after exposure to pathogens. However, how these factors produce pathogen-specific inflammatory and immune responses remains poorly understood. Combining top-down and bottom-up systems biology approaches, we have identified the NF-κB p50 homodimer as a regulator of IRF responses. Unbiased genome-wide expression and biochemical and structural analyses revealed that the p50 homodimer repressed a subset of IFN-inducible genes through a previously uncharacterized subclass of guanine-rich IRE (G-IRE) sequences. Mathematical modeling predicted that the p50 homodimer might enforce the stimulus specificity of composite promoters. Indeed, the production of the antiviral regulator IFN-β was rendered stimulus-specific by the binding of the p50 homodimer to the G-IRE–containing IFNβ enhancer to suppress cytotoxic IFN signaling. Specifically, a deficiency in p50 resulted in the inappropriate production of IFN-β in response to bacterial DNA sensed by Toll-like receptor 9. This role for the NF-κB p50 homodimer in enforcing the specificity of the cellular response to pathogens by binding to a subset of IRE sequences alters our understanding of how the NF-κB and IRF signaling systems cooperate to regulate antimicrobial immunity. PMID:21343618

Gene targeting by the vitamin D response element binding protein reveals a role for vitamin D in osteoblast mTOR signaling.

Science.gov (United States)

Lisse, Thomas S; Liu, Ting; Irmler, Martin; Beckers, Johannes; Chen, Hong; Adams, John S; Hewison, Martin

2011-03-01

Transcriptional regulation by hormonal 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] involves occupancy of vitamin D response elements (VDREs) by the VDRE binding protein (VDRE-BP) or 1,25(OH)(2)D(3)-bound vitamin D receptor (VDR). This relationship is disrupted by elevated VDRE-BP, causing a form of hereditary vitamin D-resistant rickets (HVDRR). DNA array analysis showed that of 114 genes regulated by 1,25(OH)(2)D(3) in control cells, almost all (113) were rendered insensitive to the hormone in VDRE-BP-overexpressing HVDRR cells. Among these was the gene for DNA-damage-inducible transcript 4 (DDIT4), an inhibitor of mammalian target of rapamycin (mTOR) signaling. Chromatin immunoprecipitation PCR using 1,25(OH)(2)D(3)-treated osteoblasts confirmed that VDR and VDRE-BP compete for binding to the DDIT4 gene promoter. Expression of DDIT4 mRNA in these cells was induced (1.6-6 fold) by 1,25(OH)(2)D(3) (10-100 nM), and Western blot and flow cytometry analysis showed that this response involved suppression of phosphorylated S6K1(T389) (a downstream target of mTOR) similar to rapamycin treatment. siRNA knockdown of DDIT4 completely abrogated antiproliferative responses to 1,25(OH)(2)D(3), whereas overexpression of VDRE-BP exerted a dominant-negative effect on transcription of 1,25(OH)(2)D(3)-target genes. DDIT4, an inhibitor of mTOR signaling, is a direct target for 1,25(OH)(2)D(3) and VDRE-BP, and functions to suppress cell proliferation in response to vitamin D.

Location analysis for the estrogen receptor-α reveals binding to diverse ERE sequences and widespread binding within repetitive DNA elements

Science.gov (United States)

Mason, Christopher E.; Shu, Feng-Jue; Wang, Cheng; Session, Ryan M.; Kallen, Roland G.; Sidell, Neil; Yu, Tianwei; Liu, Mei Hui; Cheung, Edwin; Kallen, Caleb B.

2010-01-01

Location analysis for estrogen receptor-α (ERα)-bound cis-regulatory elements was determined in MCF7 cells using chromatin immunoprecipitation (ChIP)-on-chip. Here, we present the estrogen response element (ERE) sequences that were identified at ERα-bound loci and quantify the incidence of ERE sequences under two stringencies of detection: ERE sequence. We demonstrate that ∼50% of all ERα-bound loci do not have a discernable ERE and show that most ERα-bound EREs are not perfect consensus EREs. Approximately one-third of all ERα-bound ERE sequences reside within repetitive DNA sequences, most commonly of the AluS family. In addition, the 3-bp spacer between the inverted ERE half-sites, rather than being random nucleotides, is C(A/T)G-enriched at bona fide receptor targets. Diverse ERα-bound loci were validated using electrophoretic mobility shift assay and ChIP-polymerase chain reaction (PCR). The functional significance of receptor-bound loci was demonstrated using luciferase reporter assays which proved that repetitive element ERE sequences contribute to enhancer function. ChIP-PCR demonstrated estrogen-dependent recruitment of the coactivator SRC3 to these loci in vivo. Our data demonstrate that ERα binds to widely variant EREs with less sequence specificity than had previously been suspected and that binding at repetitive and nonrepetitive genomic targets is favored by specific trinucleotide spacers. PMID:20047966

Location analysis for the estrogen receptor-alpha reveals binding to diverse ERE sequences and widespread binding within repetitive DNA elements.

Science.gov (United States)

Mason, Christopher E; Shu, Feng-Jue; Wang, Cheng; Session, Ryan M; Kallen, Roland G; Sidell, Neil; Yu, Tianwei; Liu, Mei Hui; Cheung, Edwin; Kallen, Caleb B

2010-04-01

Location analysis for estrogen receptor-alpha (ERalpha)-bound cis-regulatory elements was determined in MCF7 cells using chromatin immunoprecipitation (ChIP)-on-chip. Here, we present the estrogen response element (ERE) sequences that were identified at ERalpha-bound loci and quantify the incidence of ERE sequences under two stringencies of detection: ERE sequence. We demonstrate that approximately 50% of all ERalpha-bound loci do not have a discernable ERE and show that most ERalpha-bound EREs are not perfect consensus EREs. Approximately one-third of all ERalpha-bound ERE sequences reside within repetitive DNA sequences, most commonly of the AluS family. In addition, the 3-bp spacer between the inverted ERE half-sites, rather than being random nucleotides, is C(A/T)G-enriched at bona fide receptor targets. Diverse ERalpha-bound loci were validated using electrophoretic mobility shift assay and ChIP-polymerase chain reaction (PCR). The functional significance of receptor-bound loci was demonstrated using luciferase reporter assays which proved that repetitive element ERE sequences contribute to enhancer function. ChIP-PCR demonstrated estrogen-dependent recruitment of the coactivator SRC3 to these loci in vivo. Our data demonstrate that ERalpha binds to widely variant EREs with less sequence specificity than had previously been suspected and that binding at repetitive and nonrepetitive genomic targets is favored by specific trinucleotide spacers.

Effect of kai xin san on learning and memory in a rat model of paradoxical sleep deprivation.

Science.gov (United States)

Hu, Yuan; Liu, Ming; Liu, Ping; Yan, Juan-Juan; Liu, Ming-Yue; Zhang, Gang-Qiang; Zhou, Xiao-Jiang; Yu, Bing-Ying

2013-04-01

The present study aimed to evaluate the effect of kai xin san (KXS, at doses of 500, 250, and 125 mg/kg body weight per day), a well-known traditional Chinese medicine, on learning and memory in paradoxical sleep deprivation (PSD)-induced cognition deficit rats. Two behavior tests (the Open Field test and the Morris water maze task) were used for testing the effects of KXS on a PSD-induced learning and memory deficit model. Furthermore, its effect on the glutamic acid (GLU) and γ-amino-butyric acid (GABA) levels in the brain tissue, brain-derived neurotrophic factor (BDNF), cyclic AMP response element binding protein (CREB), and phosphorylated-CREB (p-CREB) expression in the hippocampus was also tested. KXS exerted the greatest cognition against the 48 h PSD-induced cognitive deficit and these effects may be mediated by decreasing the GLU and GABA levels and increasing the levels of BDNF, CREB, and p-CREB. This study indicates that the effect of KXS on learning and memory in a rat model of PSD could be associated with the modulation of neurotransmitter levels and the expression of some genes in the brain that contribute to memory functions.

Amino Acid Change in the Carbohydrate Response Element Binding Protein is associated with lower triglycerides and myocardial infarction incidence depending on level of adherence to the Mediterranean diet in the PREDIMED trial

Science.gov (United States)

A variant (rs3812316, C771G, and Gln241His) in the MLXIPL (Max-like protein X interacting protein-like) gene encoding the carbohydrate response element binding protein has been associated with lower triglycerides. However, its association with cardiovascular diseases and gene-diet interactions modul...

Co-suppression of sterol-regulatory element binding protein ...

African Journals Online (AJOL)

Administrator

2011-06-22

Jun 22, 2011 ... In Arabidopsis,. At5g35220 gene being sterol regulatory element-binding protein site 2, protease and metalloendopeptidase activity were required for chloroplast development and play a role in regulation of endodermal plastid size and number that are involved in ethylene-dependent gravitropism of light-.

Intestinal DMBT1 expression is modulated by Crohn's disease-associated IL23R variants and by a DMBT1 variant which influences binding of the transcription factors CREB1 and ATF-2.

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Julia Diegelmann

Full Text Available OBJECTIVES: DMBT is an antibacterial pattern recognition and scavenger receptor. In this study, we analyzed the role of DMBT1 single nucleotide polymorphisms (SNPs regarding inflammatory bowel disease (IBD susceptibility and examined their functional impact on transcription factor binding and downstream gene expression. METHODS: Seven SNPs in the DMBT1 gene region were analyzed in 2073 individuals including 818 Crohn's disease (CD patients and 972 healthy controls in two independent case-control panels. Comprehensive epistasis analyses for the known CD susceptibility genes NOD2, IL23R and IL27 were performed. The influence of IL23R variants on DMBT1 expression was analyzed. Functional analysis included siRNA transfection, quantitative PCR, western blot, electrophoretic mobility shift and luciferase assays. RESULTS: IL-22 induces DMBT1 protein expression in intestinal epithelial cells dependent on STAT3, ATF-2 and CREB1. IL-22 expression-modulating, CD risk-associated IL23R variants influence DMBT1 expression in CD patients and DMBT1 levels are increased in the inflamed intestinal mucosa of CD patients. Several DMBT1 SNPs were associated with CD susceptibility. SNP rs2981804 was most strongly associated with CD in the combined panel (p = 3.0 × 10(-7, OR 1.42; 95% CI 1.24-1.63. All haplotype groups tested showed highly significant associations with CD (including omnibus P-values as low as 6.1 × 10(-18. The most strongly CD risk-associated, non-coding DMBT1 SNP rs2981804 modifies the DNA binding sites for the transcription factors CREB1 and ATF-2 and the respective genomic region comprising rs2981804 is able to act as a transcriptional regulator in vitro. Intestinal DMBT1 expression is decreased in CD patients carrying the rs2981804 CD risk allele. CONCLUSION: We identified novel associations of DMBT1 variants with CD susceptibility and discovered a novel functional role of rs2981804 in regulating DMBT1 expression. Our data suggest an important

Intestinal DMBT1 expression is modulated by Crohn's disease-associated IL23R variants and by a DMBT1 variant which influences binding of the transcription factors CREB1 and ATF-2.

Science.gov (United States)

Diegelmann, Julia; Czamara, Darina; Le Bras, Emmanuelle; Zimmermann, Eva; Olszak, Torsten; Bedynek, Andrea; Göke, Burkhard; Franke, Andre; Glas, Jürgen; Brand, Stephan

2013-01-01

DMBT is an antibacterial pattern recognition and scavenger receptor. In this study, we analyzed the role of DMBT1 single nucleotide polymorphisms (SNPs) regarding inflammatory bowel disease (IBD) susceptibility and examined their functional impact on transcription factor binding and downstream gene expression. Seven SNPs in the DMBT1 gene region were analyzed in 2073 individuals including 818 Crohn's disease (CD) patients and 972 healthy controls in two independent case-control panels. Comprehensive epistasis analyses for the known CD susceptibility genes NOD2, IL23R and IL27 were performed. The influence of IL23R variants on DMBT1 expression was analyzed. Functional analysis included siRNA transfection, quantitative PCR, western blot, electrophoretic mobility shift and luciferase assays. IL-22 induces DMBT1 protein expression in intestinal epithelial cells dependent on STAT3, ATF-2 and CREB1. IL-22 expression-modulating, CD risk-associated IL23R variants influence DMBT1 expression in CD patients and DMBT1 levels are increased in the inflamed intestinal mucosa of CD patients. Several DMBT1 SNPs were associated with CD susceptibility. SNP rs2981804 was most strongly associated with CD in the combined panel (p = 3.0 × 10(-7), OR 1.42; 95% CI 1.24-1.63). All haplotype groups tested showed highly significant associations with CD (including omnibus P-values as low as 6.1 × 10(-18)). The most strongly CD risk-associated, non-coding DMBT1 SNP rs2981804 modifies the DNA binding sites for the transcription factors CREB1 and ATF-2 and the respective genomic region comprising rs2981804 is able to act as a transcriptional regulator in vitro. Intestinal DMBT1 expression is decreased in CD patients carrying the rs2981804 CD risk allele. We identified novel associations of DMBT1 variants with CD susceptibility and discovered a novel functional role of rs2981804 in regulating DMBT1 expression. Our data suggest an important role of DMBT1 in CD pathogenesis.

Signaling cross-talk between peroxisome proliferator-activated receptor/retinoid X receptor and estrogen receptor through estrogen response elements.

Science.gov (United States)

Keller, H; Givel, F; Perroud, M; Wahli, W

1995-07-01

Peroxisome proliferator-activated receptors (PPARs) and retinoid X receptors (RXRs) are nuclear hormone receptors that are activated by fatty acids and 9-cis-retinoic acid, respectively. PPARs and RXRs form heterodimers that activate transcription by binding to PPAR response elements (PPREs) in the promoter of target genes. The PPREs described thus far consist of a direct tandem repeat of the AGGTCA core element with one intervening nucleotide. We show here that the vitellogenin A2 estrogen response element (ERE) can also function as a PPRE and is bound by a PPAR/RXR heterodimer. Although this heterodimer can bind to several other ERE-related palindromic response elements containing AGGTCA half-sites, only the ERE is able to confer transactivation of test reporter plasmids, when the ERE is placed either close to or at a distance from the transcription initiation site. Examination of natural ERE-containing promoters, including the pS2, very-low-density apolipoprotein II and vitellogenin A2 genes, revealed considerable differences in the binding of PPAR/RXR heterodimers to these EREs. In their natural promoter context, these EREs did not allow transcriptional activation by PPARs/RXRs. Analysis of this lack of stimulation of the vitellogenin A2 promoter demonstrated that PPARs/RXRs bind to the ERE but cannot transactivate due to a nonpermissive promoter structure. As a consequence, PPARs/RXRs inhibit transactivation by the estrogen receptor through competition for ERE binding. This is the first example of signaling cross-talk between PPAR/RXR and estrogen receptor.

Downregulation of β-Adrenoceptors in Isoproterenol-Induced Cardiac Remodeling through HuR.

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Qian Yin

Full Text Available β-adrenergic receptors (β-ARs play an important role in cardiac remodeling, which is the key pathological process in various heart diseases and leads to heart failure. However, the regulation of β-AR expression in remodeling hearts is still unclear. This study aims to clarify the possible mechanisms underlying the regulation of β1- and β2-AR expression in cardiac remodeling. The rat model of cardiac remodeling was established by subcutaneous injection of isoproterenol(ISO at the dose of 0.25 mg·kg(-1·d(-1 for 7 days. We found that the expression of β1- and β2-ARs decreased in the remodeling heart. The mechanisms may include the inhibition of DNA transcription and the increase of mRNA degradation. cAMP-response element binding protein(CREB is a well-known transcription factor of β-AR. However, the expression and activation of CREB was not changed in the remodeling heart. Further, human Antigen-R (HuR, a RNA binding protein, which binds to the 3'-untranslated region of the β-AR mRNA and promotes RNA degradation, was increased in the remodeling model. And in vitro, HuR deficiency reversed the reduction of β-AR mRNA induced by ISO. Therefore, the present findings indicate that HuR, but not CREB, is responsible for the reduction of β-AR expression in ISO induced cardiac remodeling.

Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice

OpenAIRE

Yoneda, Mitsugu; Sugimoto, Naotoshi; Katakura, Masanori; Matsuzaki, Kentaro; Tanigami, Hayate; Yachie, Akihiro; Ohno-Shosaku, Takako; Shido, Osamu

2017-01-01

Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and m...

Contributions of individual domains to function of the HIV-1 Rev response element.

Science.gov (United States)

O'Carroll, Ina P; Thappeta, Yashna; Fan, Lixin; Ramirez-Valdez, Edric A; Smith, Sean; Wang, Yun-Xing; Rein, Alan

2017-08-16

The HIV-1 Rev response element (RRE) is a 351-base element in unspliced and partially spliced viral RNA; binding of the RRE by the viral Rev protein induces nuclear export of RRE-containing RNAs, as required for virus replication. It contains one long, imperfect double helix (domain I), one branched domain (domain II) containing a high-affinity Rev-binding site, and two or three additional domains. We previously reported that the RRE assumes an "A" shape in solution and suggested that the location of the Rev binding sites in domains I and II, opposite each other on the two legs of the A, is optimal for Rev binding and explains Rev's specificity for RRE-containing RNAs. Using SAXS and a quantitative functional assay, we have now analyzed a panel of RRE mutants. All the results support the essential role of the A shape for RRE function. Moreover, they suggest that the distal portion of domain I and the three crowning domains all contribute to the maintenance of the A shape. Domains I and II are necessary and sufficient for substantial RRE function, provided they are joined by a flexible linker that allows the two domains to face each other. IMPORTANCE Retroviral replication requires that some of the viral RNAs transcribed in the cell nucleus be exported to the cytoplasm without being spliced. To achieve this, HIV-1 encodes a protein, Rev, which binds to a complex, highly structured element within viral RNA, the Rev Response Element (RRE), and escorts RRE-containing RNAs from the nucleus. We previously reported that the RRE is "A"-shaped and suggested that this architecture, with the 2 legs opposite one another, can explain the specificity of Rev for the RRE. We have analyzed the functional contributions of individual RRE domains, and now report that several domains contribute, with some redundancy, to maintenance of the overall RRE shape. The data strongly support the hypothesis that the opposed placement of the 2 legs is essential for RRE function. Copyright © 2017

H-2RIIBP, a member of the nuclear hormone receptor superfamily that binds to both the regulatory element of major histocompatibility class I genes and the estrogen response element.

OpenAIRE

Hamada, K; Gleason, S L; Levi, B Z; Hirschfeld, S; Appella, E; Ozato, K

1989-01-01

Transcription of major histocompatibility complex (MHC) class I genes is regulated by the conserved MHC class I regulatory element (CRE). The CRE has two factor-binding sites, region I and region II, both of which elicit enhancer function. By screening a mouse lambda gt 11 library with the CRE as a probe, we isolated a cDNA clone that encodes a protein capable of binding to region II of the CRE. This protein, H-2RIIBP (H-2 region II binding protein), bound to the native region II sequence, bu...

Transcription factor CREB is involved in CaSR-mediated cytoskeleton gene expression.

Science.gov (United States)

Huang, Shuaishuai; Ren, Yu; Wang, Ping; Li, Yanyuan; Wang, Xue; Zhuang, Haihui; Fang, Rong; Wang, Yuduo; Liu, Ningsheng; Hehir, Michael; Zhou, Jeff X

2015-03-01

Our previous studies illustrated that a steady increase of intracellular calcium concentration ([Ca2+]i) was important for maintaining microtubules (MTs) rearrangement in apoptotic cells. However, little is known about the effect of calcium sensing receptor (CaSR)-mediated increase in [Ca2+]i on cytoskeleton gene expression. We examined the impact of taxol or CaSR agonist/antagonist on the regulation of [Ca2+]i concentration, cytoskeleton arrangement, phosphorylated CREB and cytoskeleton gene expressions in HeLa cells with dominant negative plasmid of CREB (PM). This study demonstrated that Gdcl3 (a specific CaSR agonist) evoked a rapid increase of [Ca2+]i, formed a rigid bundle of MTs which surrounded the nucleus and decreased the cytoskeleton gene expressions in HeLa cells. These effects were rescued by addition of NPS2390 (a specific CaSR antagonist). Moreover, CaSR activity affected cytoskeleton gene expression through transcription factor CREB. Histoscores of pCREB immunoreactivity in tissues of cervical adenocarcinoma, renal clear cell carcinoma, and diffuse large B-cell lymphoma were markedly increased compared with non malignant tissue. These data demonstrate, for the first time, that CaSR-mediated increase in [Ca2+]i probably modulate cytoskeleton organization and gene expression via transcription factor. © 2014 Wiley Periodicals, Inc.

ATF1 Modulates the Heat Shock Response by Regulating the Stress-Inducible Heat Shock Factor 1 Transcription Complex

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Takii, Ryosuke; Fujimoto, Mitsuaki; Tan, Ke; Takaki, Eiichi; Hayashida, Naoki; Nakato, Ryuichiro; Shirahige, Katsuhiko

2014-01-01

The heat shock response is an evolutionally conserved adaptive response to high temperatures that controls proteostasis capacity and is regulated mainly by an ancient heat shock factor (HSF). However, the regulation of target genes by the stress-inducible HSF1 transcription complex has not yet been examined in detail in mammalian cells. In the present study, we demonstrated that HSF1 interacted with members of the ATF1/CREB family involved in metabolic homeostasis and recruited them on the HSP70 promoter in response to heat shock. The HSF1 transcription complex, including the chromatin-remodeling factor BRG1 and lysine acetyltransferases p300 and CREB-binding protein (CBP), was formed in a manner that was dependent on the phosphorylation of ATF1. ATF1-BRG1 promoted the establishment of an active chromatin state and HSP70 expression during heat shock, whereas ATF1-p300/CBP accelerated the shutdown of HSF1 DNA-binding activity during recovery from acute stress, possibly through the acetylation of HSF1. Furthermore, ATF1 markedly affected the resistance to heat shock. These results revealed the unanticipated complexity of the primitive heat shock response mechanism, which is connected to metabolic adaptation. PMID:25312646

Time of Day Influences Memory Formation and dCREB2 Proteins in Drosophila

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Robin eFropf

2014-03-01

Full Text Available Many biological phenomena oscillate under the control of the circadian system, exhibiting peaks and troughs of activity across the day/night cycle. In most animal models, memory formation also exhibits this property, but the underlying neuronal and molecular mechanisms remain unclear. The dCREB2 transcription factor shows circadian regulated oscillations in its activity, and has been shown to be important for both circadian biology and memory formation. We show that the time-of-day (TOD of behavioral training affects Drosophila memory formation. dCREB2 exhibits complex changes in protein levels across the daytime and nighttime, and these changes in protein abundance are likely to contribute to oscillations in dCREB2 activity and TOD effects on memory formation.

An ABA-responsive DRE-binding protein gene from Setaria italica, SiARDP, the target gene of SiAREB, plays a critical role under drought stress.

Science.gov (United States)

Li, Cong; Yue, Jing; Wu, Xiaowei; Xu, Cong; Yu, Jingjuan

2014-10-01

The DREB (dehydration-responsive element binding)-type transcription factors regulate the expression of stress-inducible genes by binding the DRE/CRT cis-elements in promoter regions. The upstream transcription factors that regulate the transcription of DREB transcription factors have not been clearly defined, although the function of DREB transcription factors in abiotic stress is known. In this study, an abscisic acid (ABA)-responsive DREB-binding protein gene (SiARDP) was cloned from foxtail millet (Setaria italica). The transcript level of SiARDP increased not only after drought, high salt, and low temperature stresses, but also after an ABA treatment in foxtail millet seedlings. Two ABA-responsive elements (ABRE1: ACGTGTC; ABRE2: ACGTGGC) exist in the promoter of SiARDP. Further analyses showed that two ABA-responsive element binding (AREB)-type transcription factors, SiAREB1 and SiAREB2, could physically bind to the ABRE core element in vitro and in vivo. The constitutive expression of SiARDP in Arabidopsis thaliana enhanced drought and salt tolerance during seed germination and seedling development, and overexpression of SiARDP in foxtail millet improved drought tolerance. The expression levels of target genes of SiARDP were upregulated in transgenic Arabidopsis and foxtail millet. These results reveal that SiARDP, one of the target genes of SiAREB, is involved in ABA-dependent signal pathways and plays a critical role in the abiotic stress response in plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Stimulation of p38 (HOG1) kinase pathway by ionizing radiation results in downstream modulation of ATF/CREB transcription factor activity in NIH-3T3 cells

International Nuclear Information System (INIS)

Stevenson, Mary Ann; Yao Jin

1997-01-01

Purpose/Objective:p38 kinase, a member of the MAP kinase family, is activated in response to stresses such as high osmolarity and UV irradiation as well exposure to cytokines such as IL1β and TNFα. The kinase is part of a signal transduction pathway that leads from receptor activation through a three kinase cascade resulting in the activation of p38. p38 activation then leads to the phosphorylation of target proteins that include transcription factors such as nuclear factor of interleukin 6 and members of the activating transcription factor (ATF) family, and in addition, the stress protein, HSP27, via activation of MAPKAP2 kinase. In the present report, we have investigated the potential role of p38 in the response of NIH-3T3 cells to ionizing radiation. Materials and Methods:NIH-3T3 cells were grown to confluence in DMEM+10%CS and then serum deprived for 24 hours in DMEM+0.1%CS. Radiation exposures were delivered using a Philips RT250 (250Kvp X-ray tube). Activated forms of p38 kinase and ATF/CREB transcription factors were identified using immunoblotting techniques employing activation specific antibodies raised against the phosphorylated forms of the kinases/transcription factors. Kinase activity was directly measured using immunokinase assays. DNA binding of transcription factors to their respective consensus sequences was assayed by EMSA. Results:We found that p38 becomes rapidly phosphorylated and activated by exposure to ionizing radiation. Significantly, p38 is activated to a similar degree and with a similar time course by serum derpviation and entry of cells into a non-proliferating G 0 state, suggesting a causal role for p38 in quiescence. Phosphorylation of p38 directly correlated with phosphorylation and activation of ATF/CREB family members as well as DNA binding by these activated factors. Conclusion:Activation of p38 kinase and downstream transcription factors may play an important role in the response of cells to ionizing radiation. We are

Estrogen receptor α L429 and A430 regulate 17β-estradiol-induced cell proliferation via CREB1.

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Pesiri, Valeria; Totta, Pierangela; Segatto, Marco; Bianchi, Fabrizio; Pallottini, Valentina; Marino, Maria; Acconcia, Filippo

2015-12-01

17β-Estradiol (E2)-dependent cell proliferation requires both estrogen receptor α (ERα)-based integrated control of gene transcription and kinase pathways activation. Such coordination of intracellular E2:ERα-dependent signaling mechanisms is finely tuned by receptor association with specific partner proteins. Recently, we identified the leucine (L) 429 and alanine (A) 430 within the ERα ligand binding domain as important residues for receptor non-covalent interaction to ubiquitinated species [i.e., ERα ubiquitin-binding surface (ERα UBS)] and for E2-induced ERα activation. To date, if these two ERα amino acids are involved in the control of E2-dependent pathways required for cell proliferation is unknown. Here, by using stably expressing ERα mutated in L429 and A430 (i.e., L429A,A430G-LAAG) cell lines, we show that L429 and A430 are critical for E2-induced cell proliferation, PI3K/AKT pathway activation, and ERα-mediated transcriptional changes. Moreover, we demonstrate that these two receptor structural determinants direct the E2-induced PI3K/AKT/CREB1 pathway activation and CREB1-mediated transcriptional activity that in turn control the hormone-induced cell proliferation. As a whole, our data demonstrate for the first time that the ERα UBS contributes to the modulation of E2-induced ERα-mediated cell proliferation and provide a novel connection between the receptor structure and the functional molecular mechanisms by which E2:ERα complex can regulate cell processes. Copyright © 2015 Elsevier Inc. All rights reserved.

Hyperosmotic stress strongly potentiates serum response factor (SRF)-dependent transcriptional activity in ehrlich lettré ascites cells through a mechanism involving p38 mitogen-activated protein kinase

DEFF Research Database (Denmark)

Gorbatenko, Andrej; Wiwel, Maria; Klingberg, Henrik

2011-01-01

Long-term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1-ERK1/2 pathway is transien......Long-term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1-ERK1/2 pathway......) and cAMP response element-binding protein (CREB) are differentially regulated in ELA cells. SRF Ser103 phosphorylation and SRF-dependent transcriptional activity were strongly augmented 5–30¿min and 24¿h, respectively, after hyperosmotic stress (50% increase in extracellular ionic strength), in a p38...... dephosphorylated within 5¿min of shrinkage. MSK1 phosphorylation recovered within 30¿min in a p38-MAPK-dependent manner. CREB was transiently dephosphorylated after shrinkage in a manner exacerbated by p38 MAPK inhibition or MSK1 knockdown, but unaffected by inhibition of RSK. In conclusion, in ELA cells...

ATF3 mediates inhibitory effects of ethanol on hepatic gluconeogenesis.

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Tsai, Wen-Wei; Matsumura, Shigenobu; Liu, Weiyi; Phillips, Naomi G; Sonntag, Tim; Hao, Ergeng; Lee, Soon; Hai, Tsonwin; Montminy, Marc

2015-03-03

Increases in circulating glucagon during fasting maintain glucose balance by stimulating hepatic gluconeogenesis. Acute ethanol intoxication promotes fasting hypoglycemia through an increase in hepatic NADH, which inhibits hepatic gluconeogenesis by reducing the conversion of lactate to pyruvate. Here we show that acute ethanol exposure also lowers fasting blood glucose concentrations by inhibiting the CREB-mediated activation of the gluconeogenic program in response to glucagon. Ethanol exposure blocked the recruitment of CREB and its coactivator CRTC2 to gluconeogenic promoters by up-regulating ATF3, a transcriptional repressor that also binds to cAMP-responsive elements and thereby down-regulates gluconeogenic genes. Targeted disruption of ATF3 decreased the effects of ethanol in fasted mice and in cultured hepatocytes. These results illustrate how the induction of transcription factors with overlapping specificity can lead to cross-coupling between stress and hormone-sensitive pathways.

Response and binding elements for ligand-dependent positive transcription factors integrate positive and negative regulation of gene expression

International Nuclear Information System (INIS)

Rosenfeld, M.G.; Glass, C.K.; Adler, S.; Crenshaw, E.B. III; He, X.; Lira, S.A.; Elsholtz, H.P.; Mangalam, H.J.; Holloway, J.M.; Nelson, C.; Albert, V.R.; Ingraham, H.A.

1988-01-01

Accurate, regulated initiation of mRNA transcription by RNA polymerase II is dependent on the actions of a variety of positive and negative trans-acting factors that bind cis-acting promoter and enhancer elements. These transcription factors may exert their actions in a tissue-specific manner or function under control of plasma membrane or intracellular ligand-dependent receptors. A major goal in the authors' laboratory has been to identify the molecular mechanisms responsible for the serial activation of hormone-encoding genes in the pituitary during development and the positive and negative regulation of their transcription. The anterior pituitary gland contains phenotypically distinct cell types, each of which expresses unique trophic hormones: adrenocorticotropic hormone, thyroid-stimulating hormone, prolactin, growth hormone, and follicle-stimulating hormone/luteinizing hormone. The structurally related prolactin and growth hormone genes are expressed in lactotrophs and somatotrophs, respectively, with their expression virtually limited to the pituitary gland. The reported transient coexpression of these two structurally related neuroendocrine genes raises the possibility that the prolactin and growth hormone genes are developmentally controlled by a common factor(s)

A CRE/AP-1-like motif is essential for induced syncytin-2 expression and fusion in human trophoblast-like model.

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Chirine Toufaily

Full Text Available Syncytin-2 is encoded by the envelope gene of Endogenous Retrovirus-FRD (ERVFRD-1 and plays a critical role in fusion of placental trophoblasts leading to the formation of the multinucleated syncytiotrophoblast. Its expression is consequently regulated in a strict manner. In the present study, we have identified a forskolin-responsive region located between positions -300 to -150 in the Syncytin-2 promoter region. This 150 bp region in the context of a minimal promoter mediated an 80-fold induction of promoter activity following forskolin stimulation. EMSA analyses with competition experiments with nuclear extracts from forskolin-stimulated BeWo cells demonstrated that the -211 to -177 region specifically bound two forskolin-induced complexes, one of them containing a CRE/AP-1-like motif. Site-directed mutagenesis of the CRE/AP-1 binding site in the context of the Syncytin-2 promoter or a heterologous promoter showed that this motif was mostly essential for forskolin-induced promoter activity. Transfection experiments with dominant negative mutants and constitutively activated CREB expression vectors in addition to Chromatin Immunoprecipitation suggested that a CREB family member, CREB2 was binding and acting through the CRE/AP-1 motif. We further demonstrated the binding of JunD to this same motif. Similar to forskolin and soluble cAMP, CREB2 and JunD overexpression induced Syncytin-2 promoter activity in a CRE/AP-1-dependent manner and Syncytin-2 expression. In addition, BeWo cell fusion was induced by both CREB2 and JunD overexpression, while being repressed following silencing of either gene. These results thereby demonstrate that induced expression of Syncytin-2 is highly dependent on the interaction of bZIP-containing transcription factors to a CRE/AP-1 motif and that this element is important for the regulation of Syncytin-2 expression, which results in the formation of the peripheral syncytiotrophoblast layer.

Effects of Electroacupuncture on N-Methyl-D-aspartate Receptor-Related Signaling Pathway in the Spinal Cord of Normal Rats

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Ha-Neui Kim

2012-01-01

rats. Bilateral 2 Hz EA stimulations (1-2-3.0 mA were delivered at acupoints corresponding to Zusanli (ST36 and Sanyinjiao (SP6 in men for 30 min. Thermal sensitization was strongly inhibited by EA, but this analgesia was reduced by preintrathecal injection of the NMDAR antagonist, MK801. Phosphorylation of the NMDAR NR2B subunit, cAMP response element-binding protein (CREB, and especially phosphatidylinositol 3-kinase (PI3K were significantly induced by EA. However, these marked phosphorylations were not observed in MK801-pretreated rats. EA analgesia was reduced by preintrathecal injection with the calcium chelators Quin2 and TMB8, similar to the results evident using MK801. Phosphorylation of PI3K and CREB induced by EA was also inhibited by TMB8. Calcium influx by NMDAR activation may play an important role in EA analgesia of normal rats through the modulation of the phosphorylation of spinal PI3K and CREB.

A Polymorphic Antioxidant Response Element Links NRF2/sMAF Binding to Enhanced MAPT Expression and Reduced Risk of Parkinsonian Disorders

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Xuting Wang

2016-04-01

Full Text Available The NRF2/sMAF protein complex regulates the oxidative stress response by occupying cis-acting enhancers containing an antioxidant response element (ARE. Integrating genome-wide maps of NRF2/sMAF occupancy with disease-susceptibility loci, we discovered eight polymorphic AREs linked to 14 highly ranked disease-risk SNPs in individuals of European ancestry. Among these SNPs was rs242561, located within a regulatory region of the MAPT gene (encoding microtubule-associated protein Tau. It was consistently occupied by NRF2/sMAF in multiple experiments and its strong-binding allele associated with higher mRNA levels in cell lines and human brain tissue. Induction of MAPT transcription by NRF2 was confirmed using a human neuroblastoma cell line and a Nrf2-deficient mouse model. Most importantly, rs242561 displayed complete linkage disequilibrium with a highly protective allele identified in multiple GWASs of progressive supranuclear palsy, Parkinson’s disease, and corticobasal degeneration. These observations suggest a potential role for NRF2/sMAF in tauopathies and a possible role for NRF2 pathway activators in disease prevention.

Secbase: database module to retrieve secondary structure elements with ligand binding motifs.

Science.gov (United States)

Koch, Oliver; Cole, Jason; Block, Peter; Klebe, Gerhard

2009-10-01

Secbase is presented as a novel extension module of Relibase. It integrates the information about secondary structure elements into the retrieval facilities of Relibase. The data are accessible via the extended Relibase user interface, and integrated retrieval queries can be addressed using an extended version of Reliscript. The primary information about alpha-helices and beta-sheets is used as provided by the PDB. Furthermore, a uniform classification of all turn families, based on recent clustering methods, and a new helix assignment that is based on this turn classification has been included. Algorithms to analyze the geometric features of helices and beta-strands were also implemented. To demonstrate the performance of the Secbase implementation, some application examples are given. They provide new insights into the involvement of secondary structure elements in ligand binding. A survey of water molecules detected next to the N-terminus of helices is analyzed to show their involvement in ligand binding. Additionally, the parallel oriented NH groups at the alpha-helix N-termini provide special binding motifs to bind particular ligand functional groups with two adjacent oxygen atoms, e.g., as found in negatively charged carboxylate or phosphate groups, respectively. The present study also shows that the specific structure of the first turn of alpha-helices provides a suitable explanation for stabilizing charged structures. The magnitude of the overall helix macrodipole seems to have no or only a minor influence on binding. Furthermore, an overview of the involvement of secondary structure elements with the recognition of some important endogenous ligands such as cofactors shows some distinct preference for particular binding motifs and amino acids.

Immunocytochemistry and fluorescence imaging efficiently identify individual neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures.

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Tsunematsu, Hiroto; Uyeda, Akiko; Yamamoto, Nobuhiko; Sugo, Noriyuki

2017-08-01

CRISPR/Cas9 system is a powerful method to investigate the role of genes by introducing a mutation selectively and efficiently to specific genome positions in cell and animal lines. However, in primary neuron cultures, this method is affected by the issue that the effectiveness of CRISPR/Cas9 is different in each neuron. Here, we report an easy, quick and reliable method to identify mutants induced by the CRISPR/Cas9 system at a single neuron level, using immunocytochemistry (ICC) and fluorescence imaging. Dissociated cortical cells were transfected with CRISPR/Cas9 plasmids targeting the transcription factor cAMP-response element binding protein (CREB). Fluorescence ICC with CREB antibody and quantitative analysis of fluorescence intensity demonstrated that CREB expression disappeared in a fraction of the transfected neurons. The downstream FOS expression was also decreased in accordance with suppressed CREB expression. Moreover, dendritic arborization was decreased in the transfected neurons which lacked CREB immunoreactivity. Detection of protein expression is efficient to identify individual postmitotic neurons with CRISPR/Cas9-mediated gene disruption in primary cortical cultures. The present method composed of CRISPR/Cas9 system, ICC and fluorescence imaging is applicable to study the function of various genes at a single-neuron level.

Cardioprotection against experimental myocardial ischemic injury using cornin

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Y. Xu

2016-01-01

Full Text Available Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt.

Sex differences in feeding behavior in rats: the relationship with neuronal activation in the hypothalamus

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Atsushi eFukushima

2015-03-01

Full Text Available There is general agreement that the central nervous system in rodents differs between sexes due to the presence of gonadal steroid hormone during differentiation. Sex differences in feeding seem to occur among species, and responses to fasting (i.e., starvation, gonadal steroids (i.e., testosterone and estradiol, and diet (i.e., western-style diet vary significantly between sexes. The hypothalamus is the center for controlling feeding behavior. We examined the activation of feeding-related peptides in neurons in the hypothalamus. Phosphorylation of cyclic AMP response element-binding protein (CREB is a good marker for neural activation, as is the Fos antigen. Therefore, we predicted that sex differences in the activity of melanin-concentrating hormone (MCH neurons would be associated with feeding behavior. We determined the response of MCH neurons to glucose in the lateral hypothalamic area (LHA and our results suggested MCH neurons play an important role in sex differences in feeding behavior. In addition, fasting increased the number of orexin neurons harboring phosphorylated CREB in female rats (regardless of the estrous day, but not male rats. Glucose injection decreased the number of these neurons with phosphorylated CREB in fasted female rats. Finally, under normal spontaneous food intake, MCH neurons, but not orexin neurons, expressed phosphorylated CREB. These sex differences in response to fasting and glucose, as well as under normal conditions, suggest a vulnerability to metabolic challenges in females.

Thyroid Hormone Receptor β (TRβ) and Liver X Receptor (LXR) Regulate Carbohydrate-response Element-binding Protein (ChREBP) Expression in a Tissue-selective Manner*

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Gauthier, Karine; Billon, Cyrielle; Bissler, Marie; Beylot, Michel; Lobaccaro, Jean-Marc; Vanacker, Jean-Marc; Samarut, Jacques

2010-01-01

Thyroid hormone (TR) and liver X (LXR) receptors are transcription factors involved in lipogenesis. Both receptors recognize the same consensus DNA-response element in vitro. It was previously shown that their signaling pathways interact in the control of cholesterol elimination in the liver. In the present study, carbohydrate-response element-binding protein (ChREBP), a major transcription factor controlling the activation of glucose-induced lipogenesis in liver, is characterized as a direct target of thyroid hormones (TH) in liver and white adipose tissue (WAT), the two main lipogenic tissues in mice. Using genetic and molecular approaches, ChREBP is shown to be specifically regulated by TRβ but not by TRα in vivo, even in WAT where both TR isoforms are expressed. However, this isotype specificity is not found in vitro. This TRβ specific regulation correlates with the loss of TH-induced lipogenesis in TRβ−/− mice. Fasting/refeeding experiments show that TRβ is not required for the activation of ChREBP expression particularly marked in WAT following refeeding. However, TH can stimulate ChREBP expression in WAT even under fasting conditions, suggesting completely independent pathways. Because ChREBP has been described as an LXR target, the interaction of LXR and TRβ in ChREBP regulation was assayed both in vitro and in vivo. Each receptor recognizes a different response element on the ChREBP promoter, located only 8 bp apart. There is a cross-talk between LXR and TRβ signaling on the ChREBP promoter in liver but not in WAT where LXR does not regulate ChREBP expression. The molecular basis for this cross-talk has been determined in in vitro systems. PMID:20615868

Depression-like effect of prenatal buprenorphine exposure in rats.

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Chih-Jen Hung

Full Text Available Studies indicate that perinatal opioid exposure produces a variety of short- and long-term neurobehavioral consequences. However, the precise modes of action are incompletely understood. Buprenorphine, a mixed agonist/antagonist at the opioid receptors, is currently being used in clinical trials for managing pregnant opioid addicts. This study provides evidence of depression-like consequence following prenatal exposure to supra-therapeutic dose of buprenorphine and sheds light on potential mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant Sprague-Dawley rats starting from gestation day 7 and lasting for 14 days. Results showed that pups at postnatal day 21 but not the dams had worse parameters of depression-like neurobehaviors using a forced swimming test and tail suspension test, independent of gender. Neurobehavioral changes were accompanied by elevation of oxidative stress, reduction of plasma levels of brain-derived neurotrophic factor (BDNF and serotonin, and attenuation of tropomyosin-related kinase receptor type B (TrkB phosphorylation, extracellular signal-regulated kinase (ERK phosphorylation, protein kinase A activity, cAMP response element-binding protein (CREB phosphorylation, and CREB DNA-binding activity. Since BDNF/serotonin and CREB signaling could orchestrate a positive feedback loop, our findings suggest that the induction of oxidative stress, reduction of BDNF and serotonin expression, and attenuation of CREB signaling induced by prenatal exposure to supra-therapeutic dose of buprenorphine provide evidence of potential mechanism for the development of depression-like neurobehavior.

The yeast genome may harbor hypoxia response elements (HRE).

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Ferreira, Túlio César; Hertzberg, Libi; Gassmann, Max; Campos, Elida Geralda

2007-01-01

The hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription factor activated when cells are submitted to hypoxia. The heterodimer is composed of two subunits, HIF-1alpha and the constitutively expressed HIF-1beta. During normoxia, HIF-1alpha is degraded by the 26S proteasome, but hypoxia causes HIF-1alpha to be stabilized, enter the nucleus and bind to HIF-1beta, thus forming the active complex. The complex then binds to the regulatory sequences of various genes involved in physiological and pathological processes. The specific regulatory sequence recognized by HIF-1 is the hypoxia response element (HRE) that has the consensus sequence 5'BRCGTGVBBB3'. Although the basic transcriptional regulation machinery is conserved between yeast and mammals, Saccharomyces cerevisiae does not express HIF-1 subunits. However, we hypothesized that baker's yeast has a protein analogous to HIF-1 which participates in the response to changes in oxygen levels by binding to HRE sequences. In this study we screened the yeast genome for HREs using probabilistic motif search tools. We described 24 yeast genes containing motifs with high probability of being HREs (p-value<0.1) and classified them according to biological function. Our results show that S. cerevisiae may harbor HREs and indicate that a transcription factor analogous to HIF-1 may exist in this organism.

Nuclear calcium signaling induces expression of the synaptic organizers Lrrtm1 and Lrrtm2.

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Hayer, Stefanie N; Bading, Hilmar

2015-02-27

Calcium transients in the cell nucleus evoked by synaptic activity in hippocampal neurons function as a signaling end point in synapse-to-nucleus communication. As an important regulator of neuronal gene expression, nuclear calcium is involved in the conversion of synaptic stimuli into functional and structural changes of neurons. Here we identify two synaptic organizers, Lrrtm1 and Lrrtm2, as targets of nuclear calcium signaling. Expression of both Lrrtm1 and Lrrtm2 increased in a synaptic NMDA receptor- and nuclear calcium-dependent manner in hippocampal neurons within 2-4 h after the induction of action potential bursting. Induction of Lrrtm1 and Lrrtm2 occurred independently of the need for new protein synthesis and required calcium/calmodulin-dependent protein kinases and the nuclear calcium signaling target CREB-binding protein. Analysis of reporter gene constructs revealed a functional cAMP response element in the proximal promoter of Lrrtm2, indicating that at least Lrrtm2 is regulated by the classical nuclear Ca(2+)/calmodulin-dependent protein kinase IV-CREB/CREB-binding protein pathway. These results suggest that one mechanism by which nuclear calcium signaling controls neuronal network function is by regulating the expression of Lrrtm1 and Lrrtm2. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Nuclear Calcium Signaling Induces Expression of the Synaptic Organizers Lrrtm1 and Lrrtm2*

Science.gov (United States)

Hayer, Stefanie N.; Bading, Hilmar

2015-01-01

Calcium transients in the cell nucleus evoked by synaptic activity in hippocampal neurons function as a signaling end point in synapse-to-nucleus communication. As an important regulator of neuronal gene expression, nuclear calcium is involved in the conversion of synaptic stimuli into functional and structural changes of neurons. Here we identify two synaptic organizers, Lrrtm1 and Lrrtm2, as targets of nuclear calcium signaling. Expression of both Lrrtm1 and Lrrtm2 increased in a synaptic NMDA receptor- and nuclear calcium-dependent manner in hippocampal neurons within 2–4 h after the induction of action potential bursting. Induction of Lrrtm1 and Lrrtm2 occurred independently of the need for new protein synthesis and required calcium/calmodulin-dependent protein kinases and the nuclear calcium signaling target CREB-binding protein. Analysis of reporter gene constructs revealed a functional cAMP response element in the proximal promoter of Lrrtm2, indicating that at least Lrrtm2 is regulated by the classical nuclear Ca2+/calmodulin-dependent protein kinase IV-CREB/CREB-binding protein pathway. These results suggest that one mechanism by which nuclear calcium signaling controls neuronal network function is by regulating the expression of Lrrtm1 and Lrrtm2. PMID:25527504

Human T cell lymphotropic virus type I genomic expression and impact on intracellular signaling pathways during neurodegenerative disease and leukemia.

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Yao, J; Wigdahl, B

2000-01-01

HTLV-I has been identified as the etiologic agent of neoplasia within the human peripheral blood T lymphocyte population, and a progressive neurologic disorder based primarily within the central nervous system. We have examined the role of HTLV-I in these two distinctly different clinical syndromes by examining the life cycle of the virus, with emphasis on the regulation of viral gene expression within relevant target cell populations. In particular, we have examined the impact of specific viral gene products, particularly Tax, on cellular metabolic function. Tax is a highly promiscuous and pleiotropic viral oncoprotein, and is the most important factor contributing to the initial stages of viral-mediated transformation of T cells after HTLV-I infection. Tax, which weakly binds to Tax response element 1 (TRE-1) in the viral long terminal repeat (LTR), can dramatically trans-activate viral gene expression by interacting with cellular transcription factors, such as activated transcription factors and cyclic AMP response element binding proteins (ATF/CREB), CREB binding protein (CBP/p300), and factors involved with the basic transcription apparatus. At the same time, Tax alters cellular gene expression by directly or indirectly interacting with a variety of cellular transcription factors, cell cycle control elements, and cellular signal transduction molecules ultimately resulting in dysregulated cell proliferation. The mechanisms associated with HTLV-I infection, leading to tropical spastic paraparesis (TSP) are not as clearly resolved. Possible explanations of viral-induced neurologic disease range from central nervous system (CNS) damage caused by direct viral invasion of the CNS to bystander CNS damage caused by the immune response to HTLV-I infection. It is interesting to note that it is very rare for an HTLV-I infected individual to develop both adult T cell leukemia (ATL) and TSP in his/her life time, suggesting that the mechanisms governing development of these

Modulation of opiate-related signaling molecules in morphine-dependent conditioned behavior: conditioned place preference to morphine induces CREB phosphorylation.

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Morón, José A; Gullapalli, Srinivas; Taylor, Chirisse; Gupta, Achla; Gomes, Ivone; Devi, Lakshmi A

2010-03-01

Opiate addiction is a chronic, relapsing behavioral disorder where learned associations that develop between the abused opiate and the environment in which it is consumed are brought about through Pavlovian (classical) conditioning processes. However, the signaling mechanisms/pathways regulating the mechanisms that underlie the responses to opiate-associated cues or the development of sensitization as a consequence of repeated context-independent administration of opiates are unknown. In this study we examined the phosphorylation levels of various classic signaling molecules in brain regions implicated in addictive behaviors after acute and repeated morphine administration. An unbiased place conditioning protocol was used to examine changes in phosphorylation that are associated with (1) the expression of the rewarding effects of morphine and (2) the sensitization that develops to this effect. We also examined the effects of a delta-receptor antagonist on morphine-induced conditioned behavior and on the phosphorylation of classic signaling molecules in view of data showing that blockade of delta-opioid receptor (deltaOR) prevents the development of sensitization to the rewarding effects of morphine. We find that CREB phosphorylation is specifically induced upon the expression of a sensitized response to morphine-induced conditioned behavior in brain areas related to memory consolidation, such as the hippocampus and cortex. A similar effect is also observed, albeit to a lesser extent, in the case of the GluR1 subunit of AMPA glutamate receptor. These increases in the phosphorylation levels of CREB and pGluR1 are significantly blocked by pretreatment with a deltaOR antagonist. These results indicate a critical role for phospho-CREB, AMPA, and deltaOR activities in mediating the expression of a sensitized response to morphine-dependent conditioned behavior.

Ginseng Total Saponins Reverse Corticosterone-Induced Changes in Depression-Like Behavior and Hippocampal Plasticity-Related Proteins by Interfering with GSK-3β-CREB Signaling Pathway

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Lin Chen

2014-01-01

Full Text Available This study aimed to explore the antidepressant mechanisms of ginseng total saponins (GTS in the corticosterone-induced mouse depression model. In Experiment 1, GTS (50, 25, and 12.5 mg kg−1 d−1, intragastrically were given for 3 weeks. In Experiment 2, the same doses of GTS were administrated after each corticosterone (20 mg kg−1 d−1, subcutaneously injection for 22 days. In both experiments, mice underwent a forced swimming test and a tail suspension test on day 20 and day 21, respectively, and were sacrificed on day 22. Results of Experiment 1 revealed that GTS (50 and 25 mg kg−1 d−1 exhibited antidepressant activity and not statistically altered hippocampal protein levels of brain-derived neurotrophic factor (BDNF and neurofilament light chain (NF-L. Results of Experiment 2 showed that GTS (50 and 25 mg kg−1 d−1 ameliorated depression-like behavior without normalizing hypercortisolism. The GTS treatments reversed the corticosterone-induced changes in mRNA levels of BDNF and NF-L, and protein levels of BDNF NF-L, phosphor-cAMP response element-binding protein (Ser133, and phosphor-glycogen synthase kinase-3β (Ser9 in the hippocampus. These findings imply that the effect of GTS on corticosterone-induced depression-like behavior may be mediated partly through interfering with hippocampal GSK-3β-CREB signaling pathway and reversing decrease of some plasticity-related proteins.

The interaction between the iron-responsive element binding protein and its cognate RNA is highly dependent upon both RNA sequence and structure.

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Jaffrey, S R; Haile, D J; Klausner, R D; Harford, J B

1993-09-25

To assess the influence of RNA sequence/structure on the interaction RNAs with the iron-responsive element binding protein (IRE-BP), twenty eight altered RNAs were tested as competitors for an RNA corresponding to the ferritin H chain IRE. All changes in the loop of the predicted IRE hairpin and in the unpaired cytosine residue characteristically found in IRE stems significantly decreased the apparent affinity of the RNA for the IRE-BP. Similarly, alteration in the spacing and/or orientation of the loop and the unpaired cytosine of the stem by either increasing or decreasing the number of base pairs separating them significantly reduced efficacy as a competitor. It is inferred that the IRE-BP forms multiple contacts with its cognate RNA, and that these contacts, acting in concert, provide the basis for the high affinity of this interaction.

Melatonin regulates CRE-dependent gene transcription underlying osteoblast proliferation by activating Src and PKA in parallel.

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Tao, Lin; Zhu, Yue

2018-01-01

Several studies have indicated a relationship between melatonin and idiopathic scoliosis, including our previous work which demonstrated that melatonin can inhibit osteoblast proliferation; however, the mechanism remains unclear. Here, we utilized a MTT assay to show that melatonin significantly reduces osteoblast proliferation in a concentration-and time-dependent manner. Through a combination of techniques, including real-time PCR, MTT assays, immunofluorescence, and luciferase assays, we confirmed that melatonin-induced changes in phosphorylated cAMP response element-binding protein (CREB) reduced transcriptional activity in a melatonin receptor-dependent manner. Surprisingly, treatment of osteoblasts with the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor PD98059 up-regulated other cascades upstream of CREB. We next treated cells with PKA and Src inhibitors and observed that melatonin can also activate the protein kinase A (PKA) and Src pathways. To examine whether Src is upstream from the cAMP-PKA pathway, we measured cAMP levels in response to melatonin with and without a Src inhibitor (PP2) and found that PP2 had no additional effect. Therefore, the transcription-dependent mechanisms involved in CREB phosphorylation, along with melatonin, activated Src via a parallel signaling pathway that was separate from that of PKA. Finally, we transfected osteoblasts with lentiviral CREB short hairpin (sh) RNAs and found a decrease in the expression of proliferating cell nuclear antigen (PCNA) and osteoblast proliferation. These results suggest that CREB and PCNA are downstream targets of melatonin signaling, and that the down-regulation of CREB, which is regulated via PKA and Src pathways, contributes to the melatonin-induced inhibition of osteoblast proliferation.

Flavonoid fisetin promotes ERK-dependent long-term potentiation and enhances memory

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Maher, Pamela; Akaishi, Tatsuhiro; Abe, Kazuho

2006-01-01

Small molecules that activate signaling pathways used by neurotrophic factors could be useful for treating CNS disorders. Here we show that the flavonoid fisetin activates ERK and induces cAMP response element-binding protein (CREB) phosphorylation in rat hippocampal slices, facilitates long-term potentiation in rat hippocampal slices, and enhances object recognition in mice. Together, these data demonstrate that the natural product fisetin can facilitate long-term memory, and therefore it may be useful for treating patients with memory disorders. PMID:17050681

Identification of an estrogen response element in the 3'-flanking region of the murine c-fos protooncogene.

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Hyder, S M; Stancel, G M; Nawaz, Z; McDonnell, D P; Loose-Mitchell, D S

1992-09-05

We have used transient transfection assays with reporter plasmids expressing chloramphenicol acetyltransferase, linked to regions of mouse c-fos, to identify a specific estrogen response element (ERE) in this protooncogene. This element is located in the untranslated 3'-flanking region of the c-fos gene, 5 kilobases (kb) downstream from the c-fos promoter and 1.5 kb downstream of the poly(A) signal. This element confers estrogen responsiveness to chloramphenicol acetyltransferase reporters linked to both the herpes simplex virus thymidine kinase promoter and the homologous c-fos promoter. Deletion analysis localized the response element to a 200-base pair fragment which contains the element GGTCACCACAGCC that resembles the consensus ERE sequence GGTCACAGTGACC originally identified in Xenopus vitellogenin A2 gene. A synthetic 36-base pair oligodeoxynucleotide containing this c-fos sequence conferred estrogen inducibility to the thymidine kinase promoter. The corresponding sequence also induced reporter activity when present in the c-fos gene fragment 3 kb from the thymidine kinase promoter. Gel-shift experiments demonstrated that synthetic oligonucleotides containing either the consensus ERE or the c-fos element bind human estrogen receptor obtained from a yeast expression system. However, the mobility of the shifted band is faster for the fos-ERE-complex than the consensus ERE complex suggesting that the three-dimensional structure of the protein-DNA complexes is different or that other factors are differentially involved in the two reactions. When the 5'-GGTCA sequence present in the c-fos ERE is mutated to 5'-TTTCA, transcriptional activation and receptor binding activities are both lost. Mutation of the CAGCC-3' element corresponding to the second half-site of the c-fos sequence also led to the loss of receptor binding activity, suggesting that both half-sites of this element are involved in this function. The estrogen induction mediated by either the c-fos or

AGO2 Negatively Regulates Type I Interferon Signaling Pathway by Competition Binding IRF3 with CBP/p300

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Shengyu Wang

2017-05-01

Full Text Available Viral infection triggers a series of signaling cascades and host innate immune responses, including interferon (IFN production, which depends on coordinated activity of multiple transcription factors. IFN regulatory factor 3 (IRF3 and transcriptional coactivator CREB binding protein (CBP and/or p300 are core factors that participate in transcriptional complex formation in the nucleus. In general, cells balance the production of IFNs through suppressive and stimulative mechanisms, but viral infections can disrupt such equilibrium. This study determined that H5N1 viral infection reduced the distribution of human argonaute 2 (AGO2 in A549 cell nucleus. AGO2 did not block phosphorylation, nuclear translocation, and DNA binding ability of IRF3 but inhibited its association with CBP. Therefore, this newly revealed mechanism shows that cellular response leads to transfer of AGO2 from cell nucleus and promotes IFN-β expression to increase host survival during viral infection.

Cytoplasmic location of α1A voltage-gated calcium channel C-terminal fragment (Cav2.1-CTF aggregate is sufficient to cause cell death.

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Makoto Takahashi

Full Text Available The human α1A voltage-dependent calcium channel (Cav2.1 is a pore-forming essential subunit embedded in the plasma membrane. Its cytoplasmic carboxyl(C-tail contains a small poly-glutamine (Q tract, whose length is normally 4∼19 Q, but when expanded up to 20∼33Q, the tract causes an autosomal-dominant neurodegenerative disorder, spinocerebellar ataxia type 6 (SCA6. A recent study has shown that a 75-kDa C-terminal fragment (CTF containing the polyQ tract remains soluble in normal brains, but becomes insoluble mainly in the cytoplasm with additional localization to the nuclei of human SCA6 Purkinje cells. However, the mechanism by which the CTF aggregation leads to neurodegeneration is completely elusive, particularly whether the CTF exerts more toxicity in the nucleus or in the cytoplasm. We tagged recombinant (rCTF with either nuclear-localization or nuclear-export signal, created doxycyclin-inducible rat pheochromocytoma (PC12 cell lines, and found that the CTF is more toxic in the cytoplasm than in the nucleus, the observations being more obvious with Q28 (disease range than with Q13 (normal-length. Surprisingly, the CTF aggregates co-localized both with cAMP response element-binding protein (CREB and phosphorylated-CREB (p-CREB in the cytoplasm, and Western blot analysis showed that the quantity of CREB and p-CREB were both decreased in the nucleus when the rCTF formed aggregates in the cytoplasm. In human brains, polyQ aggregates also co-localized with CREB in the cytoplasm of SCA6 Purkinje cells, but not in other conditions. Collectively, the cytoplasmic Cav2.1-CTF aggregates are sufficient to cause cell death, and one of the pathogenic mechanisms may be abnormal CREB trafficking in the cytoplasm and reduced CREB and p-CREB levels in the nuclei.

Cytoplasmic Location of α1A Voltage-Gated Calcium Channel C-Terminal Fragment (Cav2.1-CTF) Aggregate Is Sufficient to Cause Cell Death

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Takahashi, Makoto; Obayashi, Masato; Ishiguro, Taro; Sato, Nozomu; Niimi, Yusuke; Ozaki, Kokoro; Mogushi, Kaoru; Mahmut, Yasen; Tanaka, Hiroshi; Tsuruta, Fuminori; Dolmetsch, Ricardo; Yamada, Mitsunori; Takahashi, Hitoshi; Kato, Takeo; Mori, Osamu; Eishi, Yoshinobu; Mizusawa, Hidehiro; Ishikawa, Kinya

2013-01-01

The human α1A voltage-dependent calcium channel (Cav2.1) is a pore-forming essential subunit embedded in the plasma membrane. Its cytoplasmic carboxyl(C)-tail contains a small poly-glutamine (Q) tract, whose length is normally 4∼19 Q, but when expanded up to 20∼33Q, the tract causes an autosomal-dominant neurodegenerative disorder, spinocerebellar ataxia type 6 (SCA6). A recent study has shown that a 75-kDa C-terminal fragment (CTF) containing the polyQ tract remains soluble in normal brains, but becomes insoluble mainly in the cytoplasm with additional localization to the nuclei of human SCA6 Purkinje cells. However, the mechanism by which the CTF aggregation leads to neurodegeneration is completely elusive, particularly whether the CTF exerts more toxicity in the nucleus or in the cytoplasm. We tagged recombinant (r)CTF with either nuclear-localization or nuclear-export signal, created doxycyclin-inducible rat pheochromocytoma (PC12) cell lines, and found that the CTF is more toxic in the cytoplasm than in the nucleus, the observations being more obvious with Q28 (disease range) than with Q13 (normal-length). Surprisingly, the CTF aggregates co-localized both with cAMP response element-binding protein (CREB) and phosphorylated-CREB (p-CREB) in the cytoplasm, and Western blot analysis showed that the quantity of CREB and p-CREB were both decreased in the nucleus when the rCTF formed aggregates in the cytoplasm. In human brains, polyQ aggregates also co-localized with CREB in the cytoplasm of SCA6 Purkinje cells, but not in other conditions. Collectively, the cytoplasmic Cav2.1-CTF aggregates are sufficient to cause cell death, and one of the pathogenic mechanisms may be abnormal CREB trafficking in the cytoplasm and reduced CREB and p-CREB levels in the nuclei. PMID:23505410

Interaction between two cis-acting elements, ABRE and DRE, in ABA-dependent expression of Arabidopsis rd29A gene in response to dehydration and high-salinity stresses.

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Narusaka, Yoshihiro; Nakashima, Kazuo; Shinwari, Zabta K; Sakuma, Yoh; Furihata, Takashi; Abe, Hiroshi; Narusaka, Mari; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2003-04-01

Many abiotic stress-inducible genes contain two cis-acting elements, namely a dehydration-responsive element (DRE; TACCGACAT) and an ABA-responsive element (ABRE; ACGTGG/TC), in their promoter regions. We precisely analyzed the 120 bp promoter region (-174 to -55) of the Arabidopsis rd29A gene whose expression is induced by dehydration, high-salinity, low-temperature, and abscisic acid (ABA) treatments and whose 120 bp promoter region contains the DRE, DRE/CRT-core motif (A/GCCGAC), and ABRE sequences. Deletion and base substitution analyses of this region showed that the DRE-core motif functions as DRE and that the DRE/DRE-core motif could be a coupling element of ABRE. Gel mobility shift assays revealed that DRE-binding proteins (DREB1s/CBFs and DREB2s) bind to both DRE and the DRE-core motif and that ABRE-binding proteins (AREBs/ABFs) bind to ABRE in the 120 bp promoter region. In addition, transactivation experiments using Arabidopsis leaf protoplasts showed that DREBs and AREBs cumulatively transactivate the expression of a GUS reporter gene fused to the 120 bp promoter region of rd29A. These results indicate that DRE and ABRE are interdependent in the ABA-responsive expression of the rd29A gene in response to ABA in Arabidopsis.

A petunia ethylene-responsive element binding factor, PhERF2, plays an important role in antiviral RNA silencing.

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Sun, Daoyang; Nandety, Raja Sekhar; Zhang, Yanlong; Reid, Michael S; Niu, Lixin; Jiang, Cai-Zhong

2016-05-01

Virus-induced RNA silencing is involved in plant antiviral defense and requires key enzyme components, including RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonaute proteins (AGOs). However, the transcriptional regulation of these critical components is largely unknown. In petunia (Petunia hybrida), an ethylene-responsive element binding factor, PhERF2, is induced by Tobacco rattle virus (TRV) infection. Inclusion of a PhERF2 fragment in a TRV silencing construct containing reporter fragments of phytoene desaturase (PDS) or chalcone synthase (CHS) substantially impaired silencing efficiency of both the PDS and CHS reporters. Silencing was also impaired in PhERF2- RNAi lines, where TRV-PhPDS infection did not show the expected silencing phenotype (photobleaching). In contrast, photobleaching in response to infiltration with the TRV-PhPDS construct was enhanced in plants overexpressing PhERF2 Transcript abundance of the RNA silencing-related genes RDR2, RDR6, DCL2, and AGO2 was lower in PhERF2-silenced plants but higher in PhERF2-overexpressing plants. Moreover, PhERF2-silenced lines showed higher susceptibility to Cucumber mosaic virus (CMV) than wild-type (WT) plants, while plants overexpressing PhERF2 exhibited increased resistance. Interestingly, growth and development of PhERF2-RNAi lines were substantially slower, whereas the overexpressing lines were more vigorous than the controls. Taken together, our results indicate that PhERF2 functions as a positive regulator in antiviral RNA silencing. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

A novel radiation responsive cis-acting element regulates gene induction and mediates tissue injury

International Nuclear Information System (INIS)

Hallahan, Dennis E.; Virudachalam, Subbulakshmi; Kuchibahtla, Jaya

1997-01-01

containing binding domains for the transcription factors AP-1 and Ets. This DNA sequence (TGCCTCAGTTTCCC) is similar to antioxidant responsive element. X-ray- mediated transcriptional activation of the 5' regulatory region of ICAM-1 required the antioxidant responsive element (ARE). Electrophoretic mobility shift analysis of nuclear proteins from irradiated endothelial cells incubated with the ARE binding domain (5'-GCTGCTGCCTCAGTTTCCC-3') showed increased protein-DNA complexes at 60 and 120 minutes after irradiation. Conclusions: 1) ICAM induction in irradiated tissue occurs in the microvascular endothelium. 2) ICAM expression contributes to the pathogenesis of radiation-mediated tissue injury and the ICAM knockout serves as a model for the study of the pathogenesis of tissue injury. 3) ICAM expression is regulated by a novel radiation-inducible cis-acting element that has homology to previously identified antioxidant responsive elements

Identification of high-confidence RNA regulatory elements by combinatorial classification of RNA-protein binding sites.

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Li, Yang Eric; Xiao, Mu; Shi, Binbin; Yang, Yu-Cheng T; Wang, Dong; Wang, Fei; Marcia, Marco; Lu, Zhi John

2017-09-08

Crosslinking immunoprecipitation sequencing (CLIP-seq) technologies have enabled researchers to characterize transcriptome-wide binding sites of RNA-binding protein (RBP) with high resolution. We apply a soft-clustering method, RBPgroup, to various CLIP-seq datasets to group together RBPs that specifically bind the same RNA sites. Such combinatorial clustering of RBPs helps interpret CLIP-seq data and suggests functional RNA regulatory elements. Furthermore, we validate two RBP-RBP interactions in cell lines. Our approach links proteins and RNA motifs known to possess similar biochemical and cellular properties and can, when used in conjunction with additional experimental data, identify high-confidence RBP groups and their associated RNA regulatory elements.

Abscisic acid-activated SNRK2 protein kinases function in the gene-regulation pathway of ABA signal transduction by phosphorylating ABA response element-binding factors.

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Kobayashi, Yuhko; Murata, Michiharu; Minami, Hideyuki; Yamamoto, Shuhei; Kagaya, Yasuaki; Hobo, Tokunori; Yamamoto, Akiko; Hattori, Tsukaho

2005-12-01

The plant hormone abscisic acid (ABA) induces gene expression via the ABA-response element (ABRE) present in the promoters of ABA-regulated genes. A group of bZIP proteins have been identified as ABRE-binding factors (ABFs) that activate transcription through this cis element. A rice ABF, TRAB1, has been shown to be activated via ABA-dependent phosphorylation. While a large number of signalling factors have been identified that are involved in stomatal regulation by ABA, relatively less is known about the ABA-signalling pathway that leads to gene expression. We have shown recently that three members of the rice SnRK2 protein kinase family, SAPK8, SAPK9 and SAPK10, are activated by ABA signal as well as by hyperosmotic stress. Here we show that transient overexpression in cultured cell protoplasts of these ABA-activated SnRK2 protein kinases leads to the activation of an ABRE-regulated promoter, suggesting that these kinases are involved in the gene-regulation pathway of ABA signalling. We further show several lines of evidence that these ABA-activated SnRK2 protein kinases directly phosphorylate TRAB1 in response to ABA. Kinetic analysis of SAPK10 activation and TRAB1 phosphorylation indicated that the latter immediately followed the former. TRAB1 was found to be phosphorylated not only in response to ABA, but also in response to hyperosmotic stress, which was interpreted as the consequence of phosphorylation of TRAB1 by hyperosmotically activated SAPKs. Physical interaction between TRAB1 and SAPK10 in vivo was demonstrated by a co-immunoprecipitation experiment. Finally, TRAB1 was phosphorylated in vitro by the ABA-activated SnRK2 protein kinases at Ser102, which is phosphorylated in vivo in response to ABA and is critical for the activation function.

Lost time: Bindings do not represent temporal order information.

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Moeller, Birte; Frings, Christian

2018-06-04

Many accounts of human action control assume bindings between features of stimuli and responses of individual events. One widely accepted assumption about these bindings is that they do not contain temporal-order representations regarding the integrated elements. Even though several theories either explicitly or implicitly include it, this assumption has never been tested directly. One reason for this lack of evidence is likely that typical stimulus-response binding paradigms are inapt for such a test. Adapting a new paradigm of response-response binding to include order switches between response integration and retrieval, we were able to analyze possible representation of order information in bindings for the first time. Binding effects were identical for intact and switched response orders, indicating that bindings indeed include no temporal-order information.

A retinoic acid response element that overlaps an estrogen response element mediates multihormonal sensitivity in transcriptional activation of the lactoferrin gene.

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Lee, M O; Liu, Y; Zhang, X K

1995-08-01

The lactoferrin gene is highly expressed in many different tissues, and its expression is controlled by different regulators. In this report, we have defined a retinoic acid response element (RARE) in the 5'-flanking region of the lactoferrin gene promoter. The lactoferrin-RARE is composed of two AGGTCA-like motifs arranged as a direct repeat with 1-bp spacing (DR-1). A gel retardation assay demonstrated that it bound strongly with retinoid X receptor (RXR) homodimers and RXR-retinoic acid receptor (RAR) heterodimers as well as chicken ovalbumin upstream promoter transcription factor (COUP-TF) orphan receptor. In CV-1 cells, the lactoferrin-RARE linked with a heterologous thymidine kinase promoter was strongly activated by RXR homodimers in response to 9-cis-retinoic acid (9-cis-RA) but not to all-trans-RA. When the COUP-TF orphan receptor was cotransfected, the 9-cis-RA-induced RXR homodimer activity was strongly repressed. A unique feature of the lactoferrin-RARE is that it has an AGGTCA-like motif in common with an estrogen-responsive element (ERE). The composite RARE/ERE contributes to the functional interaction between retinoid receptors and the estrogen receptor (ER) and their ligands. In CV-1 cells, cotransfection of the retinoid and estrogen receptors led to mutual inhibition of the other's activity, while an RA-dependent inhibition of ER activity was observed in breast cancer cells. Furthermore, the lactoferrin-RARE/ERE showed differential transactivation activity in different cell types. RAs could activate the lactoferrin-RARE/ERE in human leukemia HL-60 cells and U937 cells but not in human breast cancer cells. By gel retardation analyses, we demonstrated that strong binding of the endogenous COUP-TF in breast cancer cells to the composite element contributed to diminished RA response in these cells. Thus, the lactoferrin-RARE/ERE functions as a signaling switch module that mediates multihormonal responsiveness in the regulation of lactoferrin gene

Conformational control of the binding of the transactivation domain of the MLL protein and c-Myb to the KIX domain of CREB.

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Elif Nihal Korkmaz

Full Text Available The KIX domain of CBP is a transcriptional coactivator. Concomitant binding to the activation domain of proto-oncogene protein c-Myb and the transactivation domain of the trithorax group protein mixed lineage leukemia (MLL transcription factor lead to the biologically active ternary MLL∶KIX∶c-Myb complex which plays a role in Pol II-mediated transcription. The binding of the activation domain of MLL to KIX enhances c-Myb binding. Here we carried out molecular dynamics (MD simulations for the MLL∶KIX∶c-Myb ternary complex, its binary components and KIX with the goal of providing a mechanistic explanation for the experimental observations. The dynamic behavior revealed that the MLL binding site is allosterically coupled to the c-Myb binding site. MLL binding redistributes the conformational ensemble of KIX, leading to higher populations of states which favor c-Myb binding. The key element in the allosteric communication pathways is the KIX loop, which acts as a control mechanism to enhance subsequent binding events. We tested this conclusion by in silico mutations of loop residues in the KIX∶MLL complex and by comparing wild type and mutant dynamics through MD simulations. The loop assumed MLL binding conformation similar to that observed in the KIX∶c-Myb state which disfavors the allosteric network. The coupling with c-Myb binding site faded, abolishing the positive cooperativity observed in the presence of MLL. Our major conclusion is that by eliciting a loop-mediated allosteric switch between the different states following the binding events, transcriptional activation can be regulated. The KIX system presents an example how nature makes use of conformational control in higher level regulation of transcriptional activity and thus cellular events.

Signaling dynamics of palmitate-induced ER stress responses mediated by ATF4 in HepG2 cells

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Cho Hyunju

2013-01-01

Full Text Available Abstract Background Palmitic acid, the most common saturated free fatty acid, has been implicated in ER (endoplasmic reticulum stress-mediated apoptosis. This lipoapotosis is dependent, in part, on the upregulation of the activating transcription factor-4 (ATF4. To better understand the mechanisms by which palmitate upregulates the expression level of ATF4, we integrated literature information on palmitate-induced ER stress signaling into a discrete dynamic model. The model provides an in silico framework that enables simulations and predictions. The model predictions were confirmed through further experiments in human hepatocellular carcinoma (HepG2 cells and the results were used to update the model and our current understanding of the signaling induced by palmitate. Results The three key things from the in silico simulation and experimental results are: 1 palmitate induces different signaling pathways (PKR (double-stranded RNA-activated protein kinase, PERK (PKR-like ER kinase, PKA (cyclic AMP (cAMP-dependent protein kinase A in a time dependent-manner, 2 both ATF4 and CREB1 (cAMP-responsive element-binding protein 1 interact with the Atf4 promoter to contribute to a prolonged accumulation of ATF4, and 3 CREB1 is involved in ER-stress induced apoptosis upon palmitate treatment, by regulating ATF4 expression and possibly Ca2+ dependent-CaM (calmodulin signaling pathway. Conclusion The in silico model helped to delineate the essential signaling pathways in palmitate-mediated apoptosis.

An IFNG SNP with an estrogen-like response element selectively enhances promoter expression in peripheral but not lamina propria T cells.

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Gonsky, R; Deem, R L; Bream, J H; Young, H A; Targan, S R

2006-07-01

This study examines mucosa-specific regulatory pathways involved in modulation of interferon-gamma (IFN-gamma) in lamina propria T cells. Previous studies identified mucosa-specific CD2 cis-elements within the -204 to -108 bp IFNG promoter. Within this region, a single-site nucleotide polymorphism, -179G/T, imparts tumor necrosis factor-alpha stimulation of IFNG in peripheral blood lymphocytes, and is linked with accelerated AIDS progression. We discovered a putative estrogen response element (ERE) introduced by the -179T, which displays selective activation in peripheral blood mononuclear cells (PBMC) vs lamina propria mononuclear cells (LPMC). Transfection of PBMC with constructs containing the -179G or -179T site revealed CD2-mediated enhancement of the -179T compared to -179G allele, although, in LPMC, a similar level of expression was detected. Electrophoretic mobility shift assay (EMSA) analysis demonstrated CD2-mediated nucleoprotein binding to the -179T but not the -179G in PBMC. In LPMC, binding is constitutive to both -179G and -179T regions. Sequence and EMSA analysis suggests that the -179T allele creates an ERE-like binding site capable of binding recombinant estrogen receptor. Estrogen response element transactivation is enhanced by CD2 signaling, but inhibited by estrogen in PBMC but not in LPMC, although expression of estrogen receptor was similar. This is the first report to describe a potential molecular mechanism responsible for selectively controlling IFN-gamma production in LPMC.

Distinctly different dynamics and kinetics of two steroid receptors at the same response elements in living cells.

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Hatice Z Nenseth

Full Text Available Closely related transcription factors (TFs can bind to the same response elements (REs with similar affinities and activate transcription. However, it is unknown whether transcription is similarly orchestrated by different TFs bound at the same RE. Here we have compared the recovery half time (t1/2, binding site occupancy and the resulting temporal changes in transcription upon binding of two closely related steroid receptors, the androgen and glucocorticoid receptors (AR and GR, to their common hormone REs (HREs. We show that there are significant differences at all of these levels between AR and GR at the MMTV HRE when activated by their ligands. These data show that two TFs bound at the same RE can have significantly different modes of action that can affect their responses to environmental cues.

Endoplasmic Reticulum Lipid Flux Influences Enterocyte Nuclear Morphology and Lipid-dependent Transcriptional Responses.

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Zeituni, Erin M; Wilson, Meredith H; Zheng, Xiaobin; Iglesias, Pablo A; Sepanski, Michael A; Siddiqi, Mahmud A; Anderson, Jennifer L; Zheng, Yixian; Farber, Steven A

2016-11-04

Responding to a high-fat meal requires an interplay between multiple digestive tissues, sympathetic response pathways, and the gut microbiome. The epithelial enterocytes of the intestine are responsible for absorbing dietary nutrients and preparing them for circulation to distal tissues, which requires significant changes in cellular activity, including both morphological and transcriptional responses. Following a high-fat meal, we observe morphological changes in the enterocytes of larval zebrafish, including elongation of mitochondria, formation and expansion of lipid droplets, and the rapid and transient ruffling of the nuclear periphery. Dietary and pharmacological manipulation of zebrafish larvae demonstrated that these subcellular changes are specific to triglyceride absorption. The transcriptional changes that occur simultaneously with these morphological changes were determined using RNA sequencing, revealing a cohort of up-regulated genes associated with lipid droplet formation and lipid transport via lipoprotein particles. Using a microsomal triglyceride transfer protein (MTP) inhibitor to block β-lipoprotein particle formation, we demonstrate that the transcriptional response to a high-fat meal is associated with the transfer of ER triglyceride to nascent β-lipoproteins, possibly through the activation of Creb3l3/cyclic AMP-responsive element-binding protein. These data suggest that a transient increase in ER lipids is the likely mediator of the initial physiological response of intestinal enterocytes to dietary lipid. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Endoplasmic Reticulum Lipid Flux Influences Enterocyte Nuclear Morphology and Lipid-dependent Transcriptional Responses*

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Zeituni, Erin M.; Wilson, Meredith H.; Zheng, Xiaobin; Iglesias, Pablo A.; Sepanski, Michael A.; Siddiqi, Mahmud A.; Anderson, Jennifer L.; Zheng, Yixian; Farber, Steven A.

2016-01-01

Responding to a high-fat meal requires an interplay between multiple digestive tissues, sympathetic response pathways, and the gut microbiome. The epithelial enterocytes of the intestine are responsible for absorbing dietary nutrients and preparing them for circulation to distal tissues, which requires significant changes in cellular activity, including both morphological and transcriptional responses. Following a high-fat meal, we observe morphological changes in the enterocytes of larval zebrafish, including elongation of mitochondria, formation and expansion of lipid droplets, and the rapid and transient ruffling of the nuclear periphery. Dietary and pharmacological manipulation of zebrafish larvae demonstrated that these subcellular changes are specific to triglyceride absorption. The transcriptional changes that occur simultaneously with these morphological changes were determined using RNA sequencing, revealing a cohort of up-regulated genes associated with lipid droplet formation and lipid transport via lipoprotein particles. Using a microsomal triglyceride transfer protein (MTP) inhibitor to block β-lipoprotein particle formation, we demonstrate that the transcriptional response to a high-fat meal is associated with the transfer of ER triglyceride to nascent β-lipoproteins, possibly through the activation of Creb3l3/cyclic AMP-responsive element-binding protein. These data suggest that a transient increase in ER lipids is the likely mediator of the initial physiological response of intestinal enterocytes to dietary lipid. PMID:27655916

Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice.

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Yoneda, Mitsugu; Sugimoto, Naotoshi; Katakura, Masanori; Matsuzaki, Kentaro; Tanigami, Hayate; Yachie, Akihiro; Ohno-Shosaku, Takako; Shido, Osamu

2017-01-01

Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and memory. Thus, cAMP/CREB/BDNF pathways play an important role in learning and memory. Here, we investigated whether orally administered theobromine could act as a PDE inhibitor centrally and affect cAMP/CREB/BDNF pathways and learning behavior in mice. The mice were divided into two groups. The control group (CN) was fed a normal diet, whereas the theobromine group (TB) was fed a diet supplemented with 0.05% theobromine for 30 days. We measured the levels of theobromine, phosphorylated vasodilator-stimulated phosphoprotein (p-VASP), phosphorylated CREB (p-CREB), and BDNF in the brain. p-VASP was used as an index of cAMP increases. Moreover, we analyzed the performance of the mice on a three-lever motor learning task. Theobromine was detectable in the brains of TB mice. The brain levels of p-VASP, p-CREB, and BDNF were higher in the TB mice compared with those in the CN mice. In addition, the TB mice performed better on the three-lever task than the CN mice did. These results strongly suggested that orally administered theobromine acted as a PDE inhibitor in the brain, and it augmented the cAMP/CREB/BDNF pathways and motor learning in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of curcumin on the brain-gut axis in rat model of irritable bowel syndrome: involvement of 5-HT-dependent signaling.

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Yu, Yingcong; Wu, Shujuan; Li, Jianxin; Wang, Renye; Xie, Xupei; Yu, Xuefeng; Pan, Jianchun; Xu, Ying; Zheng, Liang

2015-02-01

Irritable bowel syndrome (IBS) is induced by dysfunction of central nervous and peripheral intestinal systems, which affects an estimated 10-15% population worldwide annually. Stress-related psychiatric disorders including depression and anxiety are often comorbid with gastrointestinal function disorder, such as IBS. However, the mechanism of IBS still remains unknown. Curcumin is a biologically active phytochemical presents in turmeric and has pharmacological actions that benefit patients with depression and anxiety. Our study found that IBS rats showed depression- and anxiety-like behaviors associated with decreased 5-HT (serotonin), BDNF (Brain-derived neurotrophic factor) and pCREB (phosphorylation of cAMP response element-binding protein) expression in the hippocampus after chronic acute combining stress (CAS). However, these decreased parameters were obviously increased in the colonic after CAS. Curcumin (40 mg/kg) reduced the immobility time of forced swimming and the number of buried marbles in behavioral tests of CAS rats. Curcumin also decreased the number of fecal output and abdominal withdrawal reflex (AWR) scores in response to graded distention. Moreover, curcumin increased serotonin, BDNF and pCREB levels in the hippocampus, but they were decreased in the colonic of CAS rats. 5-HT(1A) receptor antagonist NAN-190 reversed the effects of curcumin on behaviors and the changes of intestine, pCREB and BDNF expression, which are related to IBS. These results suggested that curcumin exerts the effects on IBS through regulating neurotransmitters, BDNF and CREB signaling both in the brain and peripheral intestinal system.

RFX Transcription Factor DAF-19 Regulates 5-HT and Innate Immune Responses to Pathogenic Bacteria in Caenorhabditis elegans

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Choi, Sunju; Xu, Lu; Sze, Ji Ying

2013-01-01

In Caenorhabditis elegans the Toll-interleukin receptor domain adaptor protein TIR-1 via a conserved mitogen-activated protein kinase (MAPK) signaling cascade induces innate immunity and upregulates serotonin (5-HT) biosynthesis gene tph-1 in a pair of ADF chemosensory neurons in response to infection. Here, we identify transcription factors downstream of the TIR-1 signaling pathway. We show that common transcription factors control the innate immunity and 5-HT biosynthesis. We demonstrate that a cysteine to tyrosine substitution in an ARM motif of the HEAT/Arm repeat region of the TIR-1 protein confers TIR-1 hyperactivation, leading to constitutive tph-1 upregulation in the ADF neurons, increased expression of intestinal antimicrobial genes, and enhanced resistance to killing by the human opportunistic pathogen Pseudomonas aeruginosa PA14. A forward genetic screen for suppressors of the hyperactive TIR-1 led to the identification of DAF-19, an ortholog of regulatory factor X (RFX) transcription factors that are required for human adaptive immunity. We show that DAF-19 concerts with ATF-7, a member of the activating transcription factor (ATF)/cAMP response element-binding B (CREB) family of transcription factors, to regulate tph-1 and antimicrobial genes, reminiscent of RFX-CREB interaction in human immune cells. daf-19 mutants display heightened susceptibility to killing by PA14. Remarkably, whereas the TIR-1-MAPK-DAF-19/ATF-7 pathway in the intestinal immunity is regulated by DKF-2/protein kinase D, we found that the regulation of tph-1 expression is independent of DKF-2 but requires UNC-43/Ca2+/calmodulin-dependent protein kinase (CaMK) II. Our results suggest that pathogenic cues trigger a common core-signaling pathway via tissue-specific mechanisms and demonstrate a novel role for RFX factors in neuronal and innate immune responses to infection. PMID:23505381

Small molecule kaempferol modulates PDX-1 protein expression and subsequently promotes pancreatic β-cell survival and function via CREB

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Zhang, Yanling.; Zhen, Wei.; Maechler, Pierre; Liu, Dongmin

2013-01-01

Chronic hyperlipidemia causes β-cell apoptosis and dysfunction, thereby contributing to the pathogenesis of T2D. Thus, searching for agents to promote pancreatic β-cell survival and improve its function could be a promising strategy to prevent and treat T2D. We investigated the effects of kaempferol, a small molecule isolated from ginkgo biloba, on apoptosis and function of β-cells and further determined the mechanism underlying its actions. Kaempferol treatment promoted viability, inhibited apoptosis, and reduced caspase-3 activity in INS-1E cells and human islets chronically exposed to palmitate. In addition, kaempferol prevented the lipotoxicity-induced down-regulation of anti-apoptotic proteins Akt and Bcl-2. The cytoprotective effects of kaempferol were associated with improved insulin secretion, synthesis, and PDX-1 expression. Chronic hyperlipidemia significantly diminished cAMP production, PKA activation, and CREB phosphorylation and its regulated transcriptional activity in β-cells, all of which were restored by kaempferol treatment. Disruption of CREB expression by transfection of CREB siRNA in INS-1E cells or adenoviral transfer of dominant-negative forms of CREB in human islets ablated kaempferol protection of β-cell apoptosis and dysfunction caused by palmitate. Incubation of INS-1E cells or human islets with kaempferol for 48 h induced PDX-1 expression. This effect of kaempferol on PDX-1 expression was not shared by a host of structurally related flavonoid compounds. PDX-1 gene knockdown reduced kaempferol–stimulated cAMP generation and CREB activation in INS-1E cells. These findings demonstrate that kaempferol is a novel survivor factor for pancreatic β-cells via up-regulating the PDX-1/cAMP/PKA/CREB signaling cascade. PMID:22819546

Neuroprotective effects of α-iso-cubebene against glutamate-induced damage in the HT22 hippocampal neuronal cell line.

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Park, Sun Young; Jung, Won Jung; Kang, Jum Soon; Kim, Cheol-Min; Park, Geuntae; Choi, Young-Whan

2015-02-01

Since oxidative stress is critically involved in excitotoxic damage, we sought to determine whether the activation of the transcription factors, cAMP-responsive element binding protein (CREB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2, also known as NFE2L2), by α-iso-cubebene is involved in its protective effects against glutamate-induced neuronal cell death. Pre-treatment with α-iso-cubebene significantly attenuated glutamate-induced cytotoxicity in mouse hippocampus-derived neuronal cells. α-iso-cubebene also reduced the glutamate-induced generation of reactive oxygen species and calcium influx, thus preventing apoptotic cell death. α-iso-cubebene inhibited glutamate-induced mitochondrial membrane depolarization and, consequently, inhibited the release of the apoptosis-inducing factor from the mitochondria. Immunoblot anlaysis revealed that the phosphorylation of extracellular signal-regulated kinase (ERK) by glutamate was reduced in the presence of α-iso-cubebene. α-iso-cubebene activated protein kinase A (PKA), CREB and Nrf2, which mediate the expression of the antioxidant enzymes, heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1), involved in neuroprotection. In addition, α-iso-cubebene induced the expression of antioxidant responsive element and CRE transcriptional activity, thus conferring neuroprotection against glutamate-induced oxidative injury. α-iso-cubebene also induced the expression of Nrf2-dependent genes encoding HO-1 and NQO1. Furthermore, the knockdown of CREB and Nrf2 by small interfering RNA attenuated the neuroprotective effects of α-iso-cubebene. Taken together, our results indicate that α-iso-cubebene protects HT22 cells from glutamate-induced oxidative damage through the activation of Nrf2/HO-1/NQO-1, as well as through the PKA and CREB signaling pathways.

Neurons efficiently repair glutamate-induced oxidative DNA damage by a process involving CREB-mediated up-regulation of apurinic endonuclease 1

DEFF Research Database (Denmark)

Yang, Jenq-Lin; Tadokoro, Takashi; Keijzers, Guido

2010-01-01

inhibitor (KN-93) blocked the ability of glutamate to induce CREB phosphorylation and APE1 expression. Selective depletion of CREB using RNA interference prevented glutamate-induced up-regulation of APE1. Thus, glutamate receptor stimulation triggers Ca(2+)- and mitochondrial reactive oxygen species...

Antioxidant response elements: Discovery, classes, regulation and potential applications

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Azhwar Raghunath

2018-07-01

Full Text Available Exposure to antioxidants and xenobiotics triggers the expression of a myriad of genes encoding antioxidant proteins, detoxifying enzymes, and xenobiotic transporters to offer protection against oxidative stress. This articulated universal mechanism is regulated through the cis-acting elements in an array of Nrf2 target genes called antioxidant response elements (AREs, which play a critical role in redox homeostasis. Though the Keap1/Nrf2/ARE system involves many players, AREs hold the key in transcriptional regulation of cytoprotective genes. ARE-mediated reporter constructs have been widely used, including xenobiotics profiling and Nrf2 activator screening. The complexity of AREs is brought by the presence of other regulatory elements within the AREs. The diversity in the ARE sequences not only bring regulatory selectivity of diverse transcription factors, but also confer functional complexity in the Keap1/Nrf2/ARE pathway. The different transcription factors either homodimerize or heterodimerize to bind the AREs. Depending on the nature of partners, they may activate or suppress the transcription. Attention is required for deeper mechanistic understanding of ARE-mediated gene regulation. The computational methods of identification and analysis of AREs are still in their infancy. Investigations are required to know whether epigenetics mechanism plays a role in the regulation of genes mediated through AREs. The polymorphisms in the AREs leading to oxidative stress related diseases are warranted. A thorough understanding of AREs will pave the way for the development of therapeutic agents against cancer, neurodegenerative, cardiovascular, metabolic and other diseases with oxidative stress. Keywords: Antioxidant response elements, Antioxidant genes, ARE-reporter constructs, ARE SNPs, Keap1/Nrf2/ARE pathway, Oxidative stress

Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

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Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

2005-01-01

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium.

LENUS (Irish Health Repository)

Dooley, Ruth

2012-02-01

BACKGROUND: Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. RESULTS: Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. CONCLUSION: Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

LENUS (Irish Health Repository)

Dooley, Ruth

2011-08-22

Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

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Hatt Hanns

2011-08-01

Full Text Available Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Targeted disruption of the CREB coactivator Crtc2 increases insulin sensitivity

DEFF Research Database (Denmark)

Wang, Yiguo; Inoue, Hiroshi; Ravnskjær, Kim

2010-01-01

Under fasting conditions, increases in circulating concentrations of pancreatic glucagon maintain glucose homeostasis through induction of gluconeogenic genes by the CREB coactivator CRTC2. Hepatic CRTC2 activity is elevated in obesity, although the extent to which this cofactor contributes to at...

Relevance of the palatal protein kinase A pathway to the pathogenesis of cleft palate by secalonic acid D in mice

International Nuclear Information System (INIS)

Dhulipala, Vamsidhara C.; Hanumegowda, Umesh M.; Balasubramanian, Ganesh; Reddy, Chada S.

2004-01-01

Secalonic acid-D (SAD) is a teratogenic mycotoxin inducing cleft palate (CP) in the offspring of the exposed mice by reducing palatal shelf size secondary to reduced proliferation of the palatal mesenchymal (PM) cells. Co-administration of dimethylsulfoxide (DMSO) reversed the CP-inducing effect of SAD. Although SAD has been shown to affect both protein kinases A (PKA) and C (PKC) pathways, the relevance of each of these pathways to its CP induction is unknown. The present studies were designed to test the hypothesis that the protective effect of DMSO is mediated by its specific reversal of the effect(s) of SAD on one of these two pathways using ELISA-based activity assays, Western blot analysis, electrophoretic mobility shift assays (EMSA), and murine embryonic PM (MEPM) cell growth in culture. Within the PKA pathway, SAD inhibited the activity of the catalytic subunit of PKA and its migration into the nucleus, elevated phosphorylated cyclic AMP (cAMP) response element (CRE)-binding protein (pCREB) level, and reduced the binding of CREB to CRE. In the PKC pathway, SAD reduced the activity of PKC and the binding of transcription factors (TF) to 12-O-tetradecanoate-13 phorbol acetate-response element (TRE). SAD also inhibited MEPM cell growth and the expression of the CRE- and TRE-containing gene, proliferating cell nuclear antigen (PCNA). Reversal, by DMSO, of the effects of SAD on MEPM cell growth, on PCNA expression and on all components of the PKA, but not of PKC, pathway suggests that the perturbation of the PKA pathway by SAD is relevant to its induction of CP in mice

Involvement of TORC2, a CREB co-activator, in the in vivo-specific transcriptional control of HTLV-1

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Furuta Rika A

2009-08-01

Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 causes adult T -cell leukemia (ATL but the expression of HTLV-1 is strongly suppressed in the peripheral blood of infected people. However, such suppression, which may explain the long latency in the development of ATL, is readily reversible, and viral expression resumes quickly with ex vivo culture of infected T -cells. To investigate the mechanism of in vivo -specific transcriptional suppression, we established a mouse model in which mice were intraperitoneally administered syngeneic EL4 T -lymphoma cells transduced with a recombinant retrovirus expressing a GFP-Tax fusion protein, Gax, under the control of the HTLV-1 enhancer (EL4-Gax. Results Gax gene transcription was silenced in vivo but quickly up-regulated in ex vivo culture. Analysis of integrated Gax reporter gene demonstrated that neither CpG methylation of the promoter DNA nor histone modification was associated with the reversible suppression. ChIP-analysis of LTR under suppression revealed reduced promoter binding of TFIIB and Pol-II, but no change in the binding of CREB or CBP/p300 to the viral enhancer sequence. However, the expression of TORC2, a co-activator of CREB, decreased substantially in the EL4-Gax cells in vivo, and this returned to normal levels in ex vivo culture. The reduced expression of TORC2 was associated with translocation from the nucleus to the cytoplasm. A knock-down experiment with siRNA confirmed that TORC2 was the major functional protein of the three TORC-family proteins (TORC1, 2, 3 in EL4-Gax cells. Conclusion These results suggest that the TORC2 may play an important role in the in vivo -specific transcriptional control of HTLV-1. This study provides a new model for the reversible mechanism that suppresses HTLV-1 expression in vivo without the DNA methylation or hypoacetylated histones that is observed in the primary cells of most HTLV-1 -infected carriers and a substantial number of ATL

Integration of growth factor signals at the c-fos serum response element.

Science.gov (United States)

Price, M A; Hill, C; Treisman, R

1996-04-29

A transcription factor ternary complex composed of serum response factor (SRF) and a second factor, ternary complex factor (TCF), mediates the response of the c-fos Serum Response Element to growth factors and mitogens. In NIH3T3 fibroblasts, TCF binding is required for transcriptional activation by the SRE in response to activation of the Ras-Raf-ERK pathway. We compared the properties of three members of the TCF family, Elk-1, SAP-1 and SAP-2 (ERP/NET). Although all the proteins contain sequences required for ternary complex formation with SRF, only Elk-1 and SAP-1 appear to interact with the c-fos SRE efficiently in vivo. Each TCF contains a C-terminal activation domain capable of transcriptional activation in response to activation of the Ras-Raf-ERK pathway, and this is dependent on the integrity of S/T-P motifs conserved between all the TCF family members. In contrast, activation of the SRE by whole serum and the mitogenic phospholipid LPA requires SRF binding alone. Constitutively activated members of the Rho subfamily of Ras-like GTPases are also capable of inducing activation of the SRE in the absence of TCF; unlike activated Ras itself, these proteins do not activate the TCFs in NIH3T3 cells. At the SRE, SRF- and TCF-linked signalling pathways act synergistically to potentiate transcription.

The dense core vesicle protein IA-2, but not IA-2β, is required for active avoidance learning.

Science.gov (United States)

Carmona, G N; Nishimura, T; Schindler, C W; Panlilio, L V; Notkins, A L

2014-06-06

The islet-antigens IA-2 and IA-2β are major autoantigens in type-1 diabetes and transmembrane proteins in dense core vesicles (DCV). Recently we showed that deletion of both IA-2 and IA-2β alters the secretion of hormones and neurotransmitters and impairs behavior and learning. The present study was designed to evaluate the contribution to learning of each of these genes by using single knockout (SKO) and double knockout (DKO) mice in an active avoidance test. After 5 days of training, wild-type (WT) mice showed 60-70% active avoidance responses, whereas the DKO mice showed only 10-15% active avoidance responses. The degree of active avoidance responses in the IA-2 SKO mice was similar to that of the DKO mice, but in contrast, the IA-2β SKO mice behaved like WT mice showing 60-70% active avoidance responses. Molecular studies revealed a marked decrease in the phosphorylation of the cAMP response element-binding protein (CREB) and Ca(2+)/calmodulin-dependent protein kinase II (CAMKII) in the striatum and hippocampus of the IA-2 SKO and DKO mice, but not in the IA-2β SKO mice. To evaluate the role of CREB and CAMKII in the SKO and DKO mice, GBR-12909, which selectively blocks the dopamine uptake transporter and increases CREB and CAMKII phosphorylation, was administered. GBR-12909 restored the phosphorylation of CREB and CAMKII and increased active avoidance learning in the DKO and IA-2 SKO to near the normal levels found in the WT and IA-2β SKO mice. We conclude that in the absence of the DCV protein IA-2, active avoidance learning is impaired. Published by Elsevier Ltd.

Activation of Gαq Signaling Enhances Memory Consolidation and Slows Cognitive Decline.

Science.gov (United States)

Arey, Rachel N; Stein, Geneva M; Kaletsky, Rachel; Kauffman, Amanda; Murphy, Coleen T

2018-05-02

Perhaps the most devastating decline with age is the loss of memory. Therefore, identifying mechanisms to restore memory function with age is critical. Using C. elegans associative learning and memory assays, we identified a gain-of-function G αq signaling pathway mutant that forms a long-term (cAMP response element binding protein [CREB]-dependent) memory following one conditioned stimulus-unconditioned stimulus (CS-US) pairing, which usually requires seven CS-US pairings. Increased CREB activity in AIM interneurons reduces the threshold for memory consolidation through transcription of a set of previously identified "long-term memory" genes. Enhanced G αq signaling in the AWC sensory neuron is both necessary and sufficient for improved memory and increased AIM CREB activity, and activation of G αq specifically in aged animals rescues the ability to form memory. Activation of G αq in AWC sensory neurons non-cell autonomously induces consolidation after one CS-US pairing, enabling both cognitive function maintenance with age and restoration of memory function in animals with impaired memory performance without decreased longevity. Copyright © 2018 Elsevier Inc. All rights reserved.

Electroacupuncture Ameliorates Learning and Memory and Improves Synaptic Plasticity via Activation of the PKA/CREB Signaling Pathway in Cerebral Hypoperfusion

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Cai-Xia Zheng

2016-01-01

Full Text Available Electroacupuncture (EA has shown protective effects on cognitive decline. However, the underlying molecular mechanisms are ill-understood. The present study was undertaken to determine whether the cognitive function was ameliorated in cerebral hypoperfusion rats following EA and to investigate the role of PKA/CREB pathway. We used a rat 2-vessel occlusion (2VO model and delivered EA at Baihui (GV20 and Dazhui (GV14 acupoints. Morris water maze (MWM task, electrophysiological recording, Golgi silver stain, Nissl stain, Western blot, and real-time PCR were employed. EA significantly (1 ameliorated the spatial learning and memory deficits, (2 alleviated long-term potentiation (LTP impairment and the reduction of dendritic spine density, (3 suppressed the decline of phospho-CREB (pCREB protein, brain-derived neurotrophic factor (BDNF protein, and microRNA132 (miR132, and (4 reduced the increase of p250GAP protein of 2VO rats. These changes were partially blocked by a selective protein kinase A (PKA inhibitor, N-[2-(p-bromocinnamylaminoethyl]-5-isoquinoline-sulfonamide (H89, suggesting that the PKA/CREB pathway is potentially involved in the effects of EA. Moreover, any significant damage to the pyramidal cell layer of CA1 subregion was absent. These results demonstrated that EA could ameliorate learning and memory deficits and alleviate hippocampal synaptic plasticity impairment of cerebral hypoperfusion rats, potentially mediated by PKA/CREB signaling pathway.

Binding among Select Episodic Elements Is Altered via Active Short-Term Retrieval

Science.gov (United States)

Bridge, Donna J.; Voss, Joel L.

2015-01-01

Of the many elements that comprise an episode, are any disproportionately bound to the others? We tested whether active short-term retrieval selectively increases binding. Individual objects from multiobject displays were retrieved after brief delays. Memory was later tested for the other objects. Cueing with actively retrieved objects facilitated…

Direct binding of microRNA-21 pre-element with Regorafenib: An alternative mechanism for anti-colorectal cancer chemotherapy?

Science.gov (United States)

Chen, Xiaobing; Xie, Bojian; Cao, Liang; Zhu, Feng; Chen, Beibei; Lv, Huifang; Fan, Xingxing; Han, Lili; Bie, Liangyu; Cao, Xinguang; Shen, Xiaokun; Cao, Feilin

2017-05-01

The Regorafenib is a broad-spectrum kinase inhibitor that has been approved to treat colorectal cancer (CRC). However, evidences have shown that the agent is also implicated in drug interaction with microRNA-21 (miR-21), an oncogenic miRNA which plays a key role in resisting programmed cell death in CRC cells. Here, we supposed that, instead of kinase inhibition, Regorafenib can directly bind to and then stabilize miR-21 pre-element, thus preventing RNase Dicer-meditated cleavage of the pre-element to mature miR-21. In order to verify the notion, an in silico-in vitro integrated investigation of the direct intermolecular interaction between Regorafenib and miR-21 pre-element was performed by using active pocket identification, RNA-ligand docking, molecular dynamics (MD) simulation, binding energetic analysis, and fluorescence-based assay. It was revealed that the Regorafenib can bind at the major groove-like stem region of miR-21 pre-element through three geometrically satisfactory hydrogen bonds (H-bonds) as well as a number of hydrophobic forces and π-π stacking, conferring strong specificity and high stability to the RNA-ligand complex system (K d =0.73μM). Separate inversion mutation of two base pairs (G6C, C12G) and (A13U, U4A) that are involved in the H-bonding can considerably impair the affinity of Regorafenib to miR-21 pre-element, with K d increase to 27 and 96μM, respectively. All these supported that Regorafenib can directly bind to miR-21 pre-element at molecular level and the binding mode can be properly modeled by using the proposed integrated strategy. This study would provide a potential, alternative mechanism for anti-colorectal cancer chemotherapy with Regorafenib. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucose-6-phosphate mediates activation of the carbohydrate responsive binding protein (ChREBP)

International Nuclear Information System (INIS)

Li, Ming V.; Chen, Weiqin; Harmancey, Romain N.; Nuotio-Antar, Alli M.; Imamura, Minako; Saha, Pradip; Taegtmeyer, Heinrich; Chan, Lawrence

2010-01-01

Carbohydrate response element binding protein (ChREBP) is a Mondo family transcription factor that activates a number of glycolytic and lipogenic genes in response to glucose stimulation. We have previously reported that high glucose can activate the transcriptional activity of ChREBP independent of the protein phosphatase 2A (PP2A)-mediated increase in nuclear entry and DNA binding. Here, we found that formation of glucose-6-phosphate (G-6-P) is essential for glucose activation of ChREBP. The glucose response of GAL4-ChREBP is attenuated by D-mannoheptulose, a potent hexokinase inhibitor, as well as over-expression of glucose-6-phosphatase (G6Pase); kinetics of activation of GAL4-ChREBP can be modified by exogenously expressed GCK. Further metabolism of G-6-P through the two major glucose metabolic pathways, glycolysis and pentose-phosphate pathway, is not required for activation of ChREBP; over-expression of glucose-6-phosphate dehydrogenase (G6PD) diminishes, whereas RNAi knockdown of the enzyme enhances, the glucose response of GAL4-ChREBP, respectively. Moreover, the glucose analogue 2-deoxyglucose (2-DG), which is phosphorylated by hexokinase, but not further metabolized, effectively upregulates the transcription activity of ChREBP. In addition, over-expression of phosphofructokinase (PFK) 1 and 2, synergistically diminishes the glucose response of GAL4-ChREBP. These multiple lines of evidence support the conclusion that G-6-P mediates the activation of ChREBP.

Characterization of an estrogen-responsive element implicated in regulation of the rainbow trout estrogen receptor gene.

Science.gov (United States)

Le Dréan, Y; Lazennec, G; Kern, L; Saligaut, D; Pakdel, F; Valotaire, Y

1995-08-01

We previously reported that the expression of the rainbow trout estrogen receptor (rtER) gene is markedly increased by estradiol (E2). In this paper, we have used transient transfection assays with reporter plasmids expressing chloramphenicol acetyl transferase (CAT), linked to 5' flanking regions of the rtER gene promoter, to identify cis-elements responsible for E2 inducibility. Deletion analysis localized an estrogen-responsive element (ERE), at position +242, with one mutation on the first base compared with the consensus sequence. This element confers estrogen responsiveness to CAT reporter linked to both the herpes simplex virus thymidine kinase promoter and the homologous rtER promoter. Moreover, using a 0.2 kb fragment of the rtER promoter encompassing the ERE and the rtER DNA binding domain obtained from a bacterial expression system, DNase I footprinting experiments demonstrated a specific protection covering 20 bp (+240/+260) containing the ERE sequence. Based on these studies, we believe that this ERE sequence, identified in the rtER gene promoter, may be a major cis-acting element involved in the regulation of the gene by estrogen.

Isolation and functional characterization of CE1 binding proteins

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Yu Ji-hyun

2010-12-01

Full Text Available Abstract Background Abscisic acid (ABA is a plant hormone that controls seed germination, protective responses to various abiotic stresses and seed maturation. The ABA-dependent processes entail changes in gene expression. Numerous genes are regulated by ABA, and promoter analyses of the genes revealed that cis-elements sharing the ACGTGGC consensus sequence are ubiquitous among ABA-regulated gene promoters. The importance of the core sequence, which is generally known as ABA response element (ABRE, has been demonstrated by various experiments, and its cognate transcription factors known as ABFs/AREBs have been identified. Although necessary, ABRE alone is not sufficient, and another cis-element known as "coupling element (CE" is required for full range ABA-regulation of gene expression. Several CEs are known. However, despite their importance, the cognate transcription factors mediating ABA response via CEs have not been reported to date. Here, we report the isolation of transcription factors that bind one of the coupling elements, CE1. Results To isolate CE1 binding proteins, we carried out yeast one-hybrid screens. Reporter genes containing a trimer of the CE1 element were prepared and introduced into a yeast strain. The yeast was transformed with library DNA that represents RNA isolated from ABA-treated Arabidopsis seedlings. From the screen of 3.6 million yeast transformants, we isolated 78 positive clones. Analysis of the clones revealed that a group of AP2/ERF domain proteins binds the CE1 element. We investigated their expression patterns and analyzed their overexpression lines to investigate the in vivo functions of the CE element binding factors (CEBFs. Here, we show that one of the CEBFs, AtERF13, confers ABA hypersensitivity in Arabidopsis, whereas two other CEBFs enhance sugar sensitivity. Conclusions Our results indicate that a group of AP2/ERF superfamily proteins interacts with CE1. Several CEBFs are known to mediate defense or

Isolation and functional characterization of CE1 binding proteins.

Science.gov (United States)

Lee, Sun-ji; Park, Ji Hye; Lee, Mi Hun; Yu, Ji-hyun; Kim, Soo Young

2010-12-16

Abscisic acid (ABA) is a plant hormone that controls seed germination, protective responses to various abiotic stresses and seed maturation. The ABA-dependent processes entail changes in gene expression. Numerous genes are regulated by ABA, and promoter analyses of the genes revealed that cis-elements sharing the ACGTGGC consensus sequence are ubiquitous among ABA-regulated gene promoters. The importance of the core sequence, which is generally known as ABA response element (ABRE), has been demonstrated by various experiments, and its cognate transcription factors known as ABFs/AREBs have been identified. Although necessary, ABRE alone is not sufficient, and another cis-element known as "coupling element (CE)" is required for full range ABA-regulation of gene expression. Several CEs are known. However, despite their importance, the cognate transcription factors mediating ABA response via CEs have not been reported to date. Here, we report the isolation of transcription factors that bind one of the coupling elements, CE1. To isolate CE1 binding proteins, we carried out yeast one-hybrid screens. Reporter genes containing a trimer of the CE1 element were prepared and introduced into a yeast strain. The yeast was transformed with library DNA that represents RNA isolated from ABA-treated Arabidopsis seedlings. From the screen of 3.6 million yeast transformants, we isolated 78 positive clones. Analysis of the clones revealed that a group of AP2/ERF domain proteins binds the CE1 element. We investigated their expression patterns and analyzed their overexpression lines to investigate the in vivo functions of the CE element binding factors (CEBFs). Here, we show that one of the CEBFs, AtERF13, confers ABA hypersensitivity in Arabidopsis, whereas two other CEBFs enhance sugar sensitivity. Our results indicate that a group of AP2/ERF superfamily proteins interacts with CE1. Several CEBFs are known to mediate defense or abiotic stress response, but the physiological functions

The EP4 receptor antagonist, L-161,982, blocks prostaglandin E2-induced signal transduction and cell proliferation in HCA-7 colon cancer cells

International Nuclear Information System (INIS)

Cherukuri, Durga Prasad; Chen, Xiao B.O.; Goulet, Anne-Christine; Young, Robert N.; Han, Yongxin; Heimark, Ronald L.; Regan, John W.; Meuillet, Emmanuelle; Nelson, Mark A.

2007-01-01

Accumulating evidence indicates that elevated levels of prostaglandin E 2 (PGE 2 ) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE 2 exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE 2 to stimulate cell proliferation of human colon cancer cells. However, the EP receptor(s) that are involved in this process remain unknown. We provide evidence that L-161,982, a selective EP4 receptor antagonist, completely blocks PGE 2 -induced ERK phosphorylation and cell proliferation of HCA-7 cells. In order to identify downstream target genes of ERK1/2 signaling, we found that PGE 2 induces expression of early growth response gene-1 (EGR-1) downstream of ERK1/2 and regulates its expression at the level of transcription. PGE 2 treatment induces phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 residue and CRE-mediated luciferase activity in HCA-7 cells. Studies with dominant-negative CREB mutant (ACREB) provide clear evidence for the involvement of CREB in PGE 2 driven egr-1 transcription in HCA-7 cells. In conclusion, this study reveals that egr-1 is a target gene of PGE 2 in HCA-7 cells and is regulated via the newly identified EP4/ERK/CREB pathway. Finally our results support the notion that antagonizing EP4 receptors may provide a novel therapeutic approach to the treatment of colon cancer

PKC/CREB pathway mediates the expressions of GABAA receptor subunits in cultured hippocampal neurons after low-Mg2+ solution treatment.

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Wu, Guofeng; Yu, Jinpeng; Wang, Likun; Ren, Siying; Zhang, Yixia

2018-02-01

To investigate the potential effects of the PKC/CREB pathway on the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg 2+ ). A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg 2+ solutions to generate a low Mg 2+ model of epilepsy. The low Mg 2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABA A receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABA A receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. After the neurons were exposed to a low-Mg 2+ solution for 3 h, GABA A receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg 2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABA A receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABA A subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. The PKC/CREB pathway may negatively regulate the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg 2+ model of

Structure-based stabilization of HIV-1 gp120 enhances humoral immune responses to the induced co-receptor binding site.

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Barna Dey

2009-05-01

Full Text Available The human immunodeficiency virus type 1 (HIV-1 exterior envelope glycoprotein, gp120, possesses conserved binding sites for interaction with the primary virus receptor, CD4, and also for the co-receptor, generally CCR5. Although gp120 is a major target for virus-specific neutralizing antibodies, the gp120 variable elements and its malleable nature contribute to evasion of effective host-neutralizing antibodies. To understand the conformational character and immunogenicity of the gp120 receptor binding sites as potential vaccine targets, we introduced structure-based modifications to stabilize gp120 core proteins (deleted of the gp120 major variable regions into the conformation recognized by both receptors. Thermodynamic analysis of the re-engineered core with selected ligands revealed significant stabilization of the receptor-binding regions. Stabilization of the co-receptor-binding region was associated with a marked increase in on-rate of ligand binding to this site as determined by surface plasmon resonance. Rabbit immunization studies showed that the conformational stabilization of core proteins, along with increased ligand affinity, was associated with strikingly enhanced humoral immune responses against the co-receptor-binding site. These results demonstrate that structure-based approaches can be exploited to stabilize a conformational site in a large functional protein to enhance immunogenic responses specific for that region.

The finite element response matrix method

International Nuclear Information System (INIS)

Nakata, H.; Martin, W.R.

1983-02-01

A new technique is developed with an alternative formulation of the response matrix method implemented with the finite element scheme. Two types of response matrices are generated from the Galerkin solution to the weak form of the diffusion equation subject to an arbitrary current and source. The piecewise polynomials are defined in two levels, the first for the local (assembly) calculations and the second for the global (core) response matrix calculations. This finite element response matrix technique was tested in two 2-dimensional test problems, 2D-IAEA benchmark problem and Biblis benchmark problem, with satisfatory results. The computational time, whereas the current code is not extensively optimized, is of the same order of the well estabilished coarse mesh codes. Furthermore, the application of the finite element technique in an alternative formulation of response matrix method permits the method to easily incorporate additional capabilities such as treatment of spatially dependent cross-sections, arbitrary geometrical configurations, and high heterogeneous assemblies. (Author) [pt

Nemo-like kinase as a negative regulator of nuclear receptor Nurr1 gene transcription in prostate cancer

International Nuclear Information System (INIS)

Wang, Jian; Yang, Zhi-Hong; Chen, Hua; Li, Hua-Hui; Chen, Li-Yong; Zhu, Zhu; Zou, Ying; Ding, Cong-Cong; Yang, Jing; He, Zhi-Wei

2016-01-01

Nurr1, a member of the orphan receptor family, plays an important role in several types of cancer. Our previous work demonstrated that increased expression of Nurr1 plays a significant role in the initiation and progression of prostate cancer (PCa), though the mechanisms for regulation of Nurr1 expression remain unknown. In this study, we investigated the hypothesis that Nemo-like kinase (NLK) is a key regulator of Nurr1 expression in PCa. Immunohistochemistry and Western blot analysis were used to evaluate levels of NLK and Nurr1 in prostatic tissues and cell lines. The effects of overexpression or knockdown of Nurr1 were evaluated in PCa cells through use of PCR, Western blots and promoter reporter assays. The role of Nurr1 promoter cis element was studied by creation of two mutant Nurr1 promoter luciferase constructs, one with a mutated NF-κB binding site and one with a mutated CREB binding site. In addition, three specific inhibitors were used to investigate the roles of these proteins in transcriptional activation of Nurr1, including BAY 11–7082 (NF-κB inhibitor), KG-501 (CREB inhibitor) and ICG-001 (CREB binding protein, CBP, inhibitor). The function of CBP in NLK-mediated regulation of Nurr1 expression was investigated using immunofluorescence, co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation assays (ChIPs). NLK expression was inversely correlated with Nurr1 expression in prostate cancer tissues and cell lines. Overexpression of NLK suppressed Nurr1 promoter activity, leading to downregulation of Nurr1 expression. In contrast, knockdown of NLK demonstrated opposite results, leading to upregulation of Nurr1. When compared with the wild-type Nurr1 promoter, mutation of NF-κB- and CREB-binding sites of the Nurr1 promoter region significantly reduced the upregulation of Nurr1 induced by knockdown of NLK in LNCaP cells; treatment with inhibitors of CREB, CBP and NF-κB led to similar results. We also found that NLK directly interacts with CBP

Paired hormone response elements predict caveolin-1 as a glucocorticoid target gene.

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Marinus F van Batenburg

2010-01-01

Full Text Available Glucocorticoids act in part via glucocorticoid receptor binding to hormone response elements (HREs, but their direct target genes in vivo are still largely unknown. We developed the criterion that genomic occurrence of paired HREs at an inter-HRE distance less than 200 bp predicts hormone responsiveness, based on synergy of multiple HREs, and HRE information from known target genes. This criterion predicts a substantial number of novel responsive genes, when applied to genomic regions 10 kb upstream of genes. Multiple-tissue in situ hybridization showed that mRNA expression of 6 out of 10 selected genes was induced in a tissue-specific manner in mice treated with a single dose of corticosterone, with the spleen being the most responsive organ. Caveolin-1 was strongly responsive in several organs, and the HRE pair in its upstream region showed increased occupancy by glucocorticoid receptor in response to corticosterone. Our approach allowed for discovery of novel tissue specific glucocorticoid target genes, which may exemplify responses underlying the permissive actions of glucocorticoids.

PKA-CREB-BDNF signaling pathway mediates propofol-induced long-term learning and memory impairment in hippocampus of rats.

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Zhong, Yu; Chen, Jing; Li, Li; Qin, Yi; Wei, Yi; Pan, Shining; Jiang, Yage; Chen, Jialin; Xie, Yubo

2018-04-20

Studies have found that propofol can induce widespread neuroapoptosis in developing brains, which leads to cause long-term learning and memory abnormalities. However, the specific cellular and molecular mechanisms underlying propofol-induced neuroapoptosis remain elusive. The aim of the present study was to explore the role of PKA-CREB-BDNF signaling pathway in propofol-induced long-term learning and memory impairment during brain development. Seven-day-old rats were randomly assigned to control, intralipid and three treatment groups (n = 5). Rats in control group received no treatment. Intralipid (10%, 10 mL/kg) for vehicle control and different dosage of propofol for three treatment groups (50, 100 and 200 mg/kg) were administered intraperitoneally. FJB staining, immunohistochemistry analysis for neuronal nuclei antigen and transmission electron microscopy were used to detect neuronal apoptosis and structure changes. MWM test examines the long-term spatial learning and memory impairment. The expression of PKA, pCREB and BDNF was quantified using western blots. Propofol induced significant increase of FJB-positive cells and decrease of PKA, pCREB and BDNF protein levels in the immature brain of P7 rats. Using the MWM test, propofol-treated rats demonstrated long-term spatial learning and memory impairment. Moreover, hippocampal NeuN-positive cell loss, long-lasting ultrastructural abnormalities of the neurons and synapses, and long-term down-regulation of PKA, pCREB and BDNF protein expression in adult hippocampus were also found. Our results indicated that neonatal propofol exposure can significantly result in long-term learning and memory impairment in adulthood. The possible mechanism involved in the propofol-induced neuroapoptosis was related to down-regulation of PKA-CREB-BDNF signaling pathway. Copyright © 2018. Published by Elsevier B.V.

Control of energy balance by hypothalamic gene circuitry involving two nuclear receptors, neuron-derived orphan receptor 1 and glucocorticoid receptor.

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Kim, Sun-Gyun; Lee, Bora; Kim, Dae-Hwan; Kim, Juhee; Lee, Seunghee; Lee, Soo-Kyung; Lee, Jae W

2013-10-01

Nuclear receptors (NRs) regulate diverse physiological processes, including the central nervous system control of energy balance. However, the molecular mechanisms for the central actions of NRs in energy balance remain relatively poorly defined. Here we report a hypothalamic gene network involving two NRs, neuron-derived orphan receptor 1 (NOR1) and glucocorticoid receptor (GR), which directs the regulated expression of orexigenic neuropeptides agouti-related peptide (AgRP) and neuropeptide Y (NPY) in response to peripheral signals. Our results suggest that the anorexigenic signal leptin induces NOR1 expression likely via the transcription factor cyclic AMP response element-binding protein (CREB), while the orexigenic signal glucocorticoid mobilizes GR to inhibit NOR1 expression by antagonizing the action of CREB. Also, NOR1 suppresses glucocorticoid-dependent expression of AgRP and NPY. Consistently, relative to wild-type mice, NOR1-null mice showed significantly higher levels of AgRP and NPY and were less responsive to leptin in decreasing the expression of AgRP and NPY. These results identify mutual antagonism between NOR1 and GR to be a key rheostat for peripheral metabolic signals to centrally control energy balance.

Impaired memory of eyeblink conditioning in CaMKIV KO mice.

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Lee, Ka Hung; Chatila, Talal A; Ram, Rana A; Thompson, Richard F

2009-04-01

The calcium/calmodulin-dependent protein kinase type IV (CaMKIV) is highly expressed in cerebellar cortical granule cells and deep nuclear neurons in the cerebellum. It mediates the phosphorylation and activation of the cAMP-dependent response element binding protein (CREB). In several paradigms CREB-dependent transcription is required for cellular events underlying long-term memory processes. Also, CaMKIV deficiency results in impaired long-term depression (LTD) induction in cerebellar cortex. To investigate the function of CaMKIV in the cerebellum, Wild-type (WT) and CaMKIV KO mice were tested with delay eyeblink conditioning. KO and WT mice did not differ in acquisition, but the KO mice showed a significantly lower conditioned response (CR) percentage than the WT mice in the retention testing and retraining period. The CR peak latencies for the two groups did not differ in acquisition but were shorter for the KO mice in the testing period. No significant differences were found between KO and WT mice in spontaneous eyeblink activity, auditory brainstem response (ABR) amplitudes, and tail-flick latency. The results suggest an important role for CaMKIV in long-term memory in the cerebellum. (c) 2009 APA, all rights reserved.

Plasticity-related genes in brain development and amygdala-dependent learning.

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Ehrlich, D E; Josselyn, S A

2016-01-01

Learning about motivationally important stimuli involves plasticity in the amygdala, a temporal lobe structure. Amygdala-dependent learning involves a growing number of plasticity-related signaling pathways also implicated in brain development, suggesting that learning-related signaling in juveniles may simultaneously influence development. Here, we review the pleiotropic functions in nervous system development and amygdala-dependent learning of a signaling pathway that includes brain-derived neurotrophic factor (BDNF), extracellular signaling-related kinases (ERKs) and cyclic AMP-response element binding protein (CREB). Using these canonical, plasticity-related genes as an example, we discuss the intersection of learning-related and developmental plasticity in the immature amygdala, when aversive and appetitive learning may influence the developmental trajectory of amygdala function. We propose that learning-dependent activation of BDNF, ERK and CREB signaling in the immature amygdala exaggerates and accelerates neural development, promoting amygdala excitability and environmental sensitivity later in life. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Upregulated miR-132 in Lgr5+ gastric cancer stem cell-like cells contributes to cisplatin-resistance via SIRT1/CREB/ABCG2 signaling pathway.

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Zhang, Lanfang; Guo, Xiaohe; Zhang, Dezhong; Fan, Yingying; Qin, Lei; Dong, Shuping; Zhang, Lanfang

2017-09-01

Cisplatin resistance has long been a major problem that restricts its use. A novel paradigm in tumor biology suggests that gastric tumor chemo-resistance is driven by gastric cancer stem cell-like (GCSCs). Growing evidence has indicated that microRNAs (miRNAs) contributes to chemo-resistance in gastric cancer (GC). Here, Lgr5 + cells derived from gastric cancer cell lines displayed stem cell-like features. Flow cytometry demonstrated the presence of a variable fraction of Lgr5 in 19 out of 20 GC specimens. By comparing the miRNA expression profiles of Lgr5 + GCSCs and Lrg5 - cells, we established the upregulation of miR-132 in Lgr5 + GCSCs. The enhanced miR-132 expression correlated chemo-resistance in GC patients. Kaplan-Meier survival curve showed that patients with low miR-132 expression survived obviously longer. Functional assays results indicated that miR-132 promoted cisplatin resistance in Lgr5 + GCSCs in vitro and in vivo. Further dual-luciferase reporter gene assays revealed that SIRT1 was the direct target of miR-132. The expression of miR-132 was inversely correlated with SIRT1 in gastric cancer specimens. Furthermore, through PCR array we discovered ABCG2 was one of the downstream targets of SIRT1. Overexpression of SIRT1 down-regulated ABCG2 expression by promoting the de-acetylation of the transcription factor CREB. CREB was further activated ABCG2 via binding to the promoter of ABCG2 to induce transcription. Thus, we concluded that miR-132 regulated SIRT1/CREB/ABCG2 signaling pathway contributing to the cisplatin resistance and might serve as a novel therapeutic target against gastric cancer. © 2017 Wiley Periodicals, Inc.

Sterol regulatory element-binding proteins are regulators of the rat thyroid peroxidase gene in thyroid cells.

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Christine Rauer

Full Text Available Sterol regulatory element-binding proteins (SREBPs-1c and -2, which were initially discovered as master transcriptional regulators of lipid biosynthesis and uptake, were recently identified as novel transcriptional regulators of the sodium-iodide symporter gene in the thyroid, which is essential for thyroid hormone synthesis. Based on this observation that SREBPs play a role for thyroid hormone synthesis, we hypothesized that another gene involved in thyroid hormone synthesis, the thyroid peroxidase (TPO gene, is also a target of SREBP-1c and -2. Thyroid epithelial cells treated with 25-hydroxycholesterol, which is known to inhibit SREBP activation, had about 50% decreased mRNA levels of TPO. Similarly, the mRNA level of TPO was reduced by about 50% in response to siRNA mediated knockdown of both, SREBP-1 and SREBP-2. Reporter gene assays revealed that overexpression of active SREBP-1c and -2 causes a strong transcriptional activation of the rat TPO gene, which was localized to an approximately 80 bp region in the intron 1 of the rat TPO gene. In vitro- and in vivo-binding of both, SREBP-1c and SREBP-2, to this region in the rat TPO gene could be demonstrated using gel-shift assays and chromatin immunoprecipitation. Mutation analysis of the 80 bp region of rat TPO intron 1 revealed two isolated and two overlapping SREBP-binding elements from which one, the overlapping SRE+609/InvSRE+614, was shown to be functional in reporter gene assays. In connection with recent findings that the rat NIS gene is also a SREBP target gene in the thyroid, the present findings suggest that SREBPs may be possible novel targets for pharmacological modulation of thyroid hormone synthesis.

Sterol regulatory element binding protein-1 (SREBP1) gene expression is similarly increased in polycystic ovary syndrome and endometrial cancer.

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Shafiee, Mohamad N; Mongan, Nigel; Seedhouse, Claire; Chapman, Caroline; Deen, Suha; Abu, Jafaru; Atiomo, William

2017-05-01

Women with polycystic ovary syndrome have a three-fold higher risk of endometrial cancer. Insulin resistance and hyperlipidemia may be pertinent factors in the pathogenesis of both conditions. The aim of this study was to investigate endometrial sterol regulatory element binding protein-1 gene expression in polycystic ovary syndrome and endometrial cancer endometrium, and to correlate endometrial sterol regulatory element binding protein-1 gene expression with serum lipid profiles. A cross-sectional study was performed at Nottingham University Hospital, UK. A total of 102 women (polycystic ovary syndrome, endometrial cancer and controls; 34 participants in each group) were recruited. Clinical and biochemical assessments were performed before endometrial biopsies were obtained from all participants. Taqman real-time polymerase chain reaction for endometrial sterol regulatory element binding protein-1 gene and its systemic protein expression were analyzed. The body mass indices of women with polycystic ovary syndrome (29.28 ± 2.91 kg/m 2 ) and controls (28.58 ± 2.62 kg/m 2 ) were not significantly different. Women with endometrial cancer had a higher mean body mass index (32.22 ± 5.70 kg/m 2 ). Sterol regulatory element binding protein-1 gene expression was significantly increased in polycystic ovary syndrome and endometrial cancer endometrium compared with controls (p ovary syndrome, but this was not statistically significant. Similarly, statistically insignificant positive correlations were found between endometrial sterol regulatory element binding protein-1 gene expression and body mass index in endometrial cancer (r = 0.643, p = 0.06) and waist-hip ratio (r = 0.096, p = 0.073). Sterol regulatory element binding protein-1 gene expression was significantly positively correlated with triglyceride in both polycystic ovary syndrome and endometrial cancer (p = 0.028 and p = 0.027, respectively). Quantitative serum sterol regulatory element

Single nucleotide polymorphism near CREB1, rs7591784, is associated with pretreatment methamphetamine use frequency and outcome of outpatient treatment for methamphetamine use disorder.

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Heinzerling, Keith G; Demirdjian, Levon; Wu, Yingnian; Shoptaw, Steven

2016-03-01

Although stimulant dependence is highly heritable, few studies have examined genetic influences on methamphetamine dependence. We performed a candidate gene study of 52 SNPs and pretreatment methamphetamine use frequency among 263 methamphetamine dependent Hispanic and Non-Hispanic White participants of several methamphetamine outpatient clinical trials in Los Angeles. One SNP, rs7591784 was significantly associated with pretreatment methamphetamine use frequency following Bonferroni correction (p methamphetamine urine drug screen results during 12 weeks of outpatient treatment among males with treatment outcome data available (N = 94) and found rs7591784 was significantly associated with methamphetamine use during treatment controlling for pretreatment methamphetamine use. rs7591784 is near CREB1 and in a linkage disequilibrium block with rs2952768, previously shown to influence CREB1 expression. The CREB signaling pathway is involved in gene expression changes related to chronic use of multiple drugs of abuse including methamphetamine and these results suggest that variability in CREB signaling may influence pretreatment frequency of methamphetamine use as well as outcomes of outpatient treatment. Medications targeting the CREB pathway, including phosphodiesterase inhibitors, warrant investigation as pharmacotherapies for methamphetamine use disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single nucleotide polymorphism near CREB1, rs7591784, is associated with pretreatment methamphetamine use frequency and outcome of outpatient treatment for methamphetamine use disorder

Science.gov (United States)

Heinzerling, Keith G.; Demirdjian, Levon; Wu, Yingnian; Shoptaw, Steven

2016-01-01

Although stimulant dependence is highly heritable, few studies have examined genetic influences on methamphetamine dependence. We performed a candidate gene study of 52 SNPs and pretreatment methamphetamine use frequency among 263 methamphetamine dependent Hispanic and Non-Hispanic White participants of several methamphetamine outpatient clinical trials in Los Angeles. One SNP, rs7591784 was significantly associated with pretreatment methamphetamine use frequency following Bonferroni correction (p methamphetamine urine drug screen results during 12 weeks of outpatient treatment among males with treatment outcome data available (N = 94) and found rs7591784 was significantly associated with methamphetamine use during treatment controlling for pretreatment methamphetamine use. rs7591784 is near CREB1 and in a linkage disequilibrium block with rs2952768, previously shown to influence CREB1 expression. The CREB signaling pathway is involved in gene expression changes related to chronic use of multiple drugs of abuse including methamphetamine and these results suggest that variability in CREB signaling may influence pretreatment frequency of methamphetamine use as well as outcomes of outpatient treatment. Medications targeting the CREB pathway, including phosphodiesterase inhibitors, warrant investigation as pharmacotherapies for methamphetamine use disorders. PMID:26736037

An ethylene-responsive enhancer element is involved in the senescence-related expression of the carnation glutathione-S-transferase (GST1) gene.

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Itzhaki, H; Maxson, J M; Woodson, W R

1994-09-13

The increased production of ethylene during carnation petal senescence regulates the transcription of the GST1 gene encoding a subunit of glutathione-S-transferase. We have investigated the molecular basis for this ethylene-responsive transcription by examining the cis elements and trans-acting factors involved in the expression of the GST1 gene. Transient expression assays following delivery of GST1 5' flanking DNA fused to a beta-glucuronidase receptor gene were used to functionally define sequences responsible for ethylene-responsive expression. Deletion analysis of the 5' flanking sequences of GST1 identified a single positive regulatory element of 197 bp between -667 and -470 necessary for ethylene-responsive expression. The sequences within this ethylene-responsive region were further localized to 126 bp between -596 and -470. The ethylene-responsive element (ERE) within this region conferred ethylene-regulated expression upon a minimal cauliflower mosaic virus-35S TATA-box promoter in an orientation-independent manner. Gel electrophoresis mobility-shift assays and DNase I footprinting were used to identify proteins that bind to sequences within the ERE. Nuclear proteins from carnation petals were shown to specifically interact with the 126-bp ERE and the presence and binding of these proteins were independent of ethylene or petal senescence. DNase I footprinting defined DNA sequences between -510 and -488 within the ERE specifically protected by bound protein. An 8-bp sequence (ATTTCAAA) within the protected region shares significant homology with promoter sequences required for ethylene responsiveness from the tomato fruit-ripening E4 gene.

A novel comparative pattern count analysis reveals a chronic ethanol-induced dynamic shift in immediate early NF-κB genome-wide promoter binding during liver regeneration.

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Kuttippurathu, Lakshmi; Patra, Biswanath; Hoek, Jan B; Vadigepalli, Rajanikanth

2016-03-01

Liver regeneration after partial hepatectomy is a clinically important process that is impaired by adaptation to chronic alcohol intake. We focused on the initial time points following partial hepatectomy (PHx) to analyze the genome-wide binding activity of NF-κB, a key immediate early regulator. We investigated the effect of chronic alcohol intake on immediate early NF-κB genome-wide localization, in the adapted state as well as in response to partial hepatectomy, using chromatin immunoprecipitation followed by promoter microarray analysis. We found many ethanol-specific NF-κB binding target promoters in the ethanol-adapted state, corresponding to the regulation of biosynthetic processes, oxidation-reduction and apoptosis. Partial hepatectomy induced a diet-independent shift in NF-κB binding loci relative to the transcription start sites. We employed a novel pattern count analysis to exhaustively enumerate and compare the number of promoters corresponding to the temporal binding patterns in ethanol and pair-fed control groups. The highest pattern count corresponded to promoters with NF-κB binding exclusively in the ethanol group at 1 h post PHx. This set was associated with the regulation of cell death, response to oxidative stress, histone modification, mitochondrial function, and metabolic processes. Integration with the global gene expression profiles to identify putative transcriptional consequences of NF-κB binding patterns revealed that several of ethanol-specific 1 h binding targets showed ethanol-specific differential expression through 6 h post PHx. Motif analysis yielded co-incident binding loci for STAT3, AP-1, CREB, C/EBP-β, PPAR-γ and C/EBP-α, likely participating in co-regulatory modules with NF-κB in shaping the immediate early response to PHx. We conclude that adaptation to chronic ethanol intake disrupts the NF-κB promoter binding landscape with consequences for the immediate early gene regulatory response to the acute challenge of PHx.

Identification of sumoylation sites in CCDC6, the first identified RET partner gene in papillary thyroid carcinoma, uncovers a mode of regulating CCDC6 function on CREB1 transcriptional activity.

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Chiara Luise

Full Text Available CCDC6 was originally identified in chimeric genes as caused by chromosomal translocation involving the RET protooncogene in some thyroid tumors. Recognised as a 65 kDa pro-apoptotic phosphoprotein, CCDC6 has been enrolled as an ATM substrate that contribute to protect genome integrity by modulating PP4c activity in response to genotoxic stress. Recently, CCDC6 has been identified as a repressor of CREB1-dependent transcription. Sumoylation has emerged as an important mechanism in transcriptional control. Here, we report the identification and characterization of three sites of sumoylation in CCDC6 (K74, K266 and K424 which are highly conserved in vertebrates. We demonstrate that the post-translational modifications by SUMO2 constrain most of the CCDC6 protein in the cytosol and affect its functional interaction with CREB1 with a decrease of CCDC6 repressive function on CREB1 transcriptional activity. Indeed, the impairment of functional outcome of sumoylated CCDC6 is obtained knocking down all three the sumoylation sites. Interestingly, in thyroid cells the SUMO2-mediated CCDC6 post-translational modifications are induced by Forskolin, a cAMP analog. Signal transduction via the cAMP pathway is known to be ubiquitous and represents a major line of communication between many organisms and their environment. We believe that CCDC6 could be an important player in the dynamics of cAMP signaling by fine regulating CREB1 transcriptional activity in normal and transformed thyroid cells.

A Jacob/Nsmf Gene Knockout Results in Hippocampal Dysplasia and Impaired BDNF Signaling in Dendritogenesis.

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Christina Spilker

2016-03-01

Full Text Available Jacob, the protein encoded by the Nsmf gene, is involved in synapto-nuclear signaling and docks an N-Methyl-D-Aspartate receptor (NMDAR-derived signalosome to nuclear target sites like the transcription factor cAMP-response-element-binding protein (CREB. Several reports indicate that mutations in NSMF are related to Kallmann syndrome (KS, a neurodevelopmental disorder characterized by idiopathic hypogonadotropic hypogonadism (IHH associated with anosmia or hyposmia. It has also been reported that a protein knockdown results in migration deficits of Gonadotropin-releasing hormone (GnRH positive neurons from the olfactory bulb to the hypothalamus during early neuronal development. Here we show that mice that are constitutively deficient for the Nsmf gene do not present phenotypic characteristics related to KS. Instead, these mice exhibit hippocampal dysplasia with a reduced number of synapses and simplification of dendrites, reduced hippocampal long-term potentiation (LTP at CA1 synapses and deficits in hippocampus-dependent learning. Brain-derived neurotrophic factor (BDNF activation of CREB-activated gene expression plays a documented role in hippocampal CA1 synapse and dendrite formation. We found that BDNF induces the nuclear translocation of Jacob in an NMDAR-dependent manner in early development, which results in increased phosphorylation of CREB and enhanced CREB-dependent Bdnf gene transcription. Nsmf knockout (ko mice show reduced hippocampal Bdnf mRNA and protein levels as well as reduced pCREB levels during dendritogenesis. Moreover, BDNF application can rescue the morphological deficits in hippocampal pyramidal neurons devoid of Jacob. Taken together, the data suggest that the absence of Jacob in early development interrupts a positive feedback loop between BDNF signaling, subsequent nuclear import of Jacob, activation of CREB and enhanced Bdnf gene transcription, ultimately leading to hippocampal dysplasia.

In situ detection of a heat-shock regulatory element binding protein using a soluble short synthetic enhancer sequence

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Harel-Bellan, A; Brini, A T; Farrar, W L [National Cancer Institute, Frederick, MD (USA); Ferris, D K [Program Resources, Inc., Frederick, MD (USA); Robin, P [Institut Gustave Roussy, Villejuif (France)

1989-06-12

In various studies, enhancer binding proteins have been successfully absorbed out by competing sequences inserted into plasmids, resulting in the inhibition of the plasmid expression. Theoretically, such a result could be achieved using synthetic enhancer sequences not inserted into plasmids. In this study, a double stranded DNA sequence corresponding to the human heat shock regulatory element was chemically synthesized. By in vitro retardation assays, the synthetic sequence was shown to bind specifically a protein in extracts from the human T cell line Jurkat. When the synthetic enhancer was electroporated into Jurkat cells, not only the enhancer was shown to remain undegraded into the cells for up to 2 days, but also its was shown to bind intracellularly a protein. The binding was specific and was modulated upon heat shock. Furthermore, the binding protein was shown to be of the expected molecular weight by UV crosslinking. However, when the synthetic enhancer element was co-electroporated with an HSP 70-CAT reporter construct, the expression of the reporter plasmid was consistently enhanced in the presence of the exogenous synthetic enhancer.

Phosphodiesterase 10A inhibition attenuates sleep deprivation-induced deficits in long-term fear memory.

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Guo, Lengqiu; Guo, Zhuangli; Luo, Xiaoqing; Liang, Rui; Yang, Shui; Ren, Haigang; Wang, Guanghui; Zhen, Xuechu

2016-12-02

Sleep, particularly rapid eye movement (REM) sleep, is implicated in the consolidation of emotional memories. In the present study, we investigated the protective effects of a phosphodiesterase 10A (PDE10A) inhibitor MP-10 on deficits in long-term fear memory induced by REM sleep deprivation (REM-SD). REM-SD caused deficits in long-term fear memory, however, MP-10 administration ameliorated the deleterious effects of REM-SD on long term fear memory. Brain-derived neurotropic factor (BDNF) and phosphorylated cAMP response element-binding protein (pCREB) were altered in specific brain regions associated with learning and memory in REM-SD rats. Accordingly, REM-SD caused a significant decrease of pCREB in hippocampus and striatum and a significant decrease of BDNF in the hippocampus, striatum and amygdala, however, MP-10 reversed the effects of REM-SD in a dose-dependent manner. Our findings suggest that REM-SD disrupts the consolidation of long-term fear memory and that administration of MP-10 protects the REM-SD-induced deficits in fear memory, which may be due to the MP-10-induced expression of BDNF in the hippocampus, striatum and amygdala, and phosphorylation of CREB in the hippocampus and striatum. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Inhibition of both HIV-1 reverse transcription and gene expression by a cyclic peptide that binds the Tat-transactivating response element (TAR RNA.

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Matthew S Lalonde

2011-05-01

Full Text Available The RNA response element TAR plays a critical role in HIV replication by providing a binding site for the recruitment of the viral transactivator protein Tat. Using a structure-guided approach, we have developed a series of conformationally-constrained cyclic peptides that act as structural mimics of the Tat RNA binding region and block Tat-TAR interactions at nanomolar concentrations in vitro. Here we show that these compounds block Tat-dependent transcription in cell-free systems and in cell-based reporter assays. The compounds are also cell permeable, have low toxicity, and inhibit replication of diverse HIV-1 strains, including both CXCR4-tropic and CCR5-tropic primary HIV-1 isolates of the divergent subtypes A, B, C, D and CRF01_AE. In human peripheral blood mononuclear cells, the cyclic peptidomimetic L50 exhibited an IC(50 ∼250 nM. Surprisingly, inhibition of LTR-driven HIV-1 transcription could not account for the full antiviral activity. Timed drug-addition experiments revealed that L-50 has a bi-phasic inhibition curve with the first phase occurring after HIV-1 entry into the host cell and during the initiation of HIV-1 reverse transcription. The second phase coincides with inhibition of HIV-1 transcription. Reconstituted reverse transcription assays confirm that HIV-1 (- strand strong stop DNA synthesis is blocked by L50-TAR RNA interactions in-vitro. These findings are consistent with genetic evidence that TAR plays critical roles both during reverse transcription and during HIV gene expression. Our results suggest that antiviral drugs targeting TAR RNA might be highly effective due to a dual inhibitory mechanism.

The bZIP protein from Tamarix hispida, ThbZIP1, is ACGT elements binding factor that enhances abiotic stress signaling in transgenic Arabidopsis.

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Ji, Xiaoyu; Liu, Guifeng; Liu, Yujia; Zheng, Lei; Nie, Xianguang; Wang, Yucheng

2013-10-04

Tamarix spp. are woody halophyte, which are very tolerant to abiotic stresses such as salinity and drought, but little is known about their specific stress response systems. Basic leucine zipper proteins (bZIPs) play important roles in the ability of plants to withstand adverse environmental conditions. However, their exact roles in abiotic stress tolerance are still not fully known. In the current study, we functionally characterized a bZIP gene (ThbZIP1) from Tamarix hispida in response to abiotic stresses. We addressed the regulatory network of ThbZIP1 in three levels, i.e. its upstream regulators, the cis-acting elements recognized by ThbZIP1, and its downstream target genes. Two MYCs were found to bind to E-box, in the promoter of ThbZIP1 to activate its expression. Expression of ThbZIP1 is induced by ABA, salt, drought, methyl viologen and cold. ThbZIP1 can specifically bind to ACGT elements, with the highest binding affinity to the C-box, followed by the G-box and lastly the A-box. Compared with wild-type (Col-0) Arabidopsis, transgenic plants expressing ThbZIP1 had an increased tolerance to drought and salt, but had an increased sensitivity to ABA during seed germination and root growth; meanwhile, ROS level, cell death and water loss rate in transgenic plants were significantly reduced. Microarray analyses showed that many ROS scavenging genes were up-regulated by ThbZIP1 under salt stress conditions. Based on these data, we suggest that ThbZIP1 confers abiotic stress tolerance through activating stress tolerance genes to modulate ROS scavenging ability and other physiological changes involved in stress tolerance, and plays an important role in the ABA-mediated stress response of T. hispida.

O-linked N-acetylglucosamine transferase enhances secretory clusterin expression via liver X receptors and sterol response element binding protein regulation in cervical cancer.

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Kim, Min Jun; Choi, Mee Young; Lee, Dong Hoon; Roh, Gu Seob; Kim, Hyun Joon; Kang, Sang Soo; Cho, Gyeong Jae; Kim, Yoon Sook; Choi, Wan Sung

2018-01-12

O-linked N-acetylglucosamine transferase (OGT) expression is increased in various cancer types, indicating the potential importance of O-GlcNAcylation in tumorigenesis. Secretory clusterin (sCLU) is involved in cancer cell proliferation and drug resistance, and recently, liver X receptors (LXRs) and sterol response element binding protein-1 (SREBP-1) were reported to regulate sCLU transcription. Here, we found that sCLU is significantly increased in cervical cancer cell lines, which have higher expression levels of O-GlcNAc and OGT than keratinocytes. OGT knockdown decreased expression of LXRs, SREBP-1 and sCLU through hypo-O-GlcNAcylation of LXRs. Additionally, treatment with Thiamet G, O-GlcNAcase OGA inhibitor, increased expression of O-GlcNAcylation and sCLU, and high glucose increased levels of LXRs, SREBP-1 and sCLU in HeLa cells. Moreover, OGT knockdown induced G 0 /G 1 phase cell cycle arrest and late apoptosis in cisplatin-treated HeLa cells, and decreased viability compared to OGT intact HeLa cells. Taken together, these findings suggest that OGT, O-GlcNAcylated LXRs, and SREBP-1 increase sCLU expression in cervical cancer cells, which contributes to drug resistance.

Immature osteoblastic MG63 cells possess two calcitonin gene-related peptide receptor subtypes that respond differently to [Cys(Acm)(2,7)] calcitonin gene-related peptide and CGRP(8-37).

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Kawase, Tomoyuki; Okuda, Kazuhiro; Burns, Douglas M

2005-10-01

Calcitonin gene-related peptide (CGRP) is clearly an anabolic factor in skeletal tissue, but the distribution of CGRP receptor (CGRPR) subtypes in osteoblastic cells is poorly understood. We previously demonstrated that the CGRPR expressed in osteoblastic MG63 cells does not match exactly the known characteristics of the classic subtype 1 receptor (CGRPR1). The aim of the present study was to further characterize the MG63 CGRPR using a selective agonist of the putative CGRPR2, [Cys(Acm)(2,7)]CGRP, and a relatively specific antagonist of CGRPR1, CGRP(8-37). [Cys(Acm)(2,7)]CGRP acted as a significant agonist only upon ERK dephosphorylation, whereas this analog effectively antagonized CGRP-induced cAMP production and phosphorylation of cAMP response element-binding protein (CREB) and p38 MAPK. Although it had no agonistic action when used alone, CGRP(8-37) potently blocked CGRP actions on cAMP, CREB, and p38 MAPK but had less of an effect on ERK. Schild plot analysis of the latter data revealed that the apparent pA2 value for ERK is clearly distinguishable from those of the other three plots as judged using the 95% confidence intervals. Additional assays using 3-isobutyl-1-methylxanthine or the PKA inhibitor N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinolinesulfonamide hydrochloride (H-89) indicated that the cAMP-dependent pathway was predominantly responsible for CREB phosphorylation, partially involved in ERK dephosphorylation, and not involved in p38 MAPK phosphorylation. Considering previous data from Scatchard analysis of [125I]CGRP binding in connection with these results, these findings suggest that MG63 cells possess two functionally distinct CGRPR subtypes that show almost identical affinity for CGRP but different sensitivity to CGRP analogs: one is best characterized as a variation of CGRPR1, and the second may be a novel variant of CGRPR2.

Nuclear responses in INTOR plasma stabilization elements

International Nuclear Information System (INIS)

Gohar, Y.; Gilligan, J.; Jung, J.; Mattas, R.F.; Miley, G.H.; Wiffen, F.W.; Yang, S.

1985-01-01

Nuclear responses in the plasma stabilization elements were studied in a parametric fashion as a part of the transient electromagnetics critical issue C of ETR/INTOR activity. The main responses are neutron fluence and radiation dose in the insulator material, induced resistivity and atomic displacement in the conductor material, nuclear heating and life analysis for the elements. Copper and aluminum conductors with either MgAl 2 O 4 or MgO insulating material were investigated. Radiation damage and life analysis for these elements were also discussed

Ibuprofen and lipoic acid conjugate neuroprotective activity is mediated by Ngb/Akt intracellular signaling pathway in Alzheimer's disease rat model.

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Zara, Susi; De Colli, Marianna; Rapino, Monica; Pacella, Stephanie; Nasuti, Cinzia; Sozio, Piera; Di Stefano, Antonio; Cataldi, Amelia

2013-01-01

Alzheimer's disease (AD) is a frequent form of senile dementia. Neuroglobin (Ngb) has a neuroprotective role and decreases Aβ peptide levels. Ngb, promoting Akt phosphorylation, activates cell survival involving cyclic-nucleotide response element-binding protein (CREB). A new molecule (IBU-LA) was synthetized and administered to an AD rat model to counteract AD progression. The aim of this study was to investigate the IBU-LA-mediated induction of Ngb neuroprotective and antiapoptotic activities. Brain morphology was analyzed through Bielschowsky staining, Aβ(1-40) and Ngb expression by immunohistochemistry. Akt, p-Akt, CREB and p-CREB expression was evaluated by Western blot, apoptosis through cytochrome C/Apaf 1 immunocomplex formation, and TUNEL analysis. Bielschowsky staining and Aβ(1-40) expression show few nerve connections and Aβ(1-40) expression in an Aβ sample, preserved neuronal cells and Aβ(1-40) expression lowering in an IBU sample, mostly in IBU-LA. The Ngb level decreases in Aβ samples, compared to control and IBU-LA samples. p-Akt/Akt and p-CREB/CREB ratios reveal a reduction in Aβ sample, going back to the basal level in control and IBU-LA samples. Cytochrome C/Apaf 1 co-immunoprecipitate occurs and TUNEL-positive nuclei percentage decreases in Aβ sample. Probe test performance shows an increased spatial reference memory in the IBU-LA compared to the Aβ sample; no significant differences were seen between the IBU-LA and IBU samples. This evidence reveals that IBU-LA administration has the capability to maintain a high Ngb level allowing Ngb to perform a neuroprotective and antiapoptotic role, representing a valid tool in the therapeutic strategy of AD progression. Copyright © 2013 S. Karger AG, Basel.

Effects of sterol regulatory element-binding protein (SREBP in chickens

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Alipour Fahimeh

2012-02-01

Full Text Available Abstract Sterol regulatory element binding protein- 1 and -2 (SREBP-1 and -2 are key transcription factors involved in the biosynthesis of cholesterol and fatty acids. The SREBP have mostly been studied in rodents in which lipogenesis is regulated in both liver and adipose tissue. There is, though, a paucity of information on birds, in which lipogenesis occurs essentially in the liver as in humans. Since a prelude to the investigation of the role of SREBP in lipid metabolism regulation in chicken, we review Size and Tissue expression Pattern of SREBP and role of this protein in chickens.

CREB Binding Protein Functions During Successive Stages of Eye Development in Drosophila

OpenAIRE

Kumar, Justin P.; Jamal, Tazeen; Doetsch, Alex; Turner, F. Rudolf; Duffy, Joseph B.

2004-01-01

During the development of the compound eye of Drosophila several signaling pathways exert both positive and inhibitory influences upon an array of nuclear transcription factors to produce a near-perfect lattice of unit eyes or ommatidia. Individual cells within the eye are exposed to many extracellular signals, express multiple surface receptors, and make use of a large complement of cell-subtype-specific DNA-binding transcription factors. Despite this enormous complexity, each cell will make...

Aluminium chloride impairs long-term memory and downregulates cAMP-PKA-CREB signalling in rats.

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Zhang, Lifeng; Jin, Cuihong; Lu, Xiaobo; Yang, Jinghua; Wu, Shengwen; Liu, Qiufang; Chen, Rong; Bai, Chunyu; Zhang, Di; Zheng, Linlin; Du, Yanqiu; Cai, Yuan

2014-09-02

Epidemiological investigations have indicated that aluminium (Al) is an important environmental neurotoxicant that may be involved in the aetiology of the cognitive dysfunction associated with neurodegenerative diseases. Additionally, exposure to Al is known to cause neurobehavioural abnormalities in animals. Previous studies demonstrated that Al impaired early-phase long-term potentiation (E-LTP) in vivo and in vitro. Our previous research revealed that Al could impair long-term memory via the impairment of late-phase long-term potentiation (L-LTP) in vivo. However, the exact mechanism by which Al impairs long-term memory has been poorly studied thus far. This study was designed not only to observe the effects of subchronic Al treatment on long-term memory and hippocampal ultrastructure but also to explore a possible underlying mechanism (involving the cAMP-PKA-CREB signalling pathway) in the hippocampus of rats.. Pregnant Wistar rats were assigned to four groups. Neonatal rats were exposed to Al by parental lactation for 3 weeks and then fed with distilled water containing 0, 0.2%, 0.4% or 0.6% Al chloride (AlCl3) for 3 postnatal months. The levels of Al in the blood and hippocampus were quantified by atomic absorption spectrophotometry. The shuttle-box test was performed to detect long-term memory. The hippocampus was collected for ultrastructure observation, and the level of cAMP-PKA-CREB signalling was examined. The results showed that the Al concentrations in the blood and hippocampus of Al-treated rats were higher than those of the control rats. Al may impair the long-term memory of rats. Hippocampal cAMP, cPKA, pCREB, BDNF and c-jun expression decreased significantly, and the neuronal and synaptic ultrastructure exhibited pathological changes after Al treatment. These results indicated that Al may induce long-term memory damage in rats by inhibiting cAMP-PKA-CREB signalling and altering the synaptic and neuronal ultrastructure in the hippocampus. Copyright

Aluminium chloride impairs long-term memory and downregulates cAMP-PKA-CREB signalling in rats

International Nuclear Information System (INIS)

Zhang, Lifeng; Jin, Cuihong; Lu, Xiaobo; Yang, Jinghua; Wu, Shengwen; Liu, Qiufang; Chen, Rong; Bai, Chunyu; Zhang, Di; Zheng, Linlin; Du, Yanqiu; Cai, Yuan

2014-01-01

Epidemiological investigations have indicated that aluminium (Al) is an important environmental neurotoxicant that may be involved in the aetiology of the cognitive dysfunction associated with neurodegenerative diseases. Additionally, exposure to Al is known to cause neurobehavioural abnormalities in animals. Previous studies demonstrated that Al impaired early-phase long-term potentiation (E-LTP) in vivo and in vitro. Our previous research revealed that Al could impair long-term memory via the impairment of late-phase long-term potentiation (L-LTP) in vivo. However, the exact mechanism by which Al impairs long-term memory has been poorly studied thus far. This study was designed not only to observe the effects of subchronic Al treatment on long-term memory and hippocampal ultrastructure but also to explore a possible underlying mechanism (involving the cAMP-PKA-CREB signalling pathway) in the hippocampus of rats.. Pregnant Wistar rats were assigned to four groups. Neonatal rats were exposed to Al by parental lactation for 3 weeks and then fed with distilled water containing 0, 0.2%, 0.4% or 0.6% Al chloride (AlCl 3 ) for 3 postnatal months. The levels of Al in the blood and hippocampus were quantified by atomic absorption spectrophotometry. The shuttle–box test was performed to detect long-term memory. The hippocampus was collected for ultrastructure observation, and the level of cAMP-PKA-CREB signalling was examined. The results showed that the Al concentrations in the blood and hippocampus of Al-treated rats were higher than those of the control rats. Al may impair the long-term memory of rats. Hippocampal cAMP, cPKA, pCREB, BDNF and c-jun expression decreased significantly, and the neuronal and synaptic ultrastructure exhibited pathological changes after Al treatment. These results indicated that Al may induce long-term memory damage in rats by inhibiting cAMP-PKA-CREB signalling and altering the synaptic and neuronal ultrastructure in the hippocampus

The cis decoy against the estrogen response element suppresses breast cancer cells via target disrupting c-fos not mitogen-activated protein kinase activity.

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Wang, Li Hua; Yang, Xiao Yi; Zhang, Xiaohu; Mihalic, Kelly; Xiao, Weihua; Farrar, William L

2003-05-01

Breast cancer, the most common malignancy in women, has been demonstrated to be associated with the steroid hormone estrogen and its receptor (ER), a ligand-activated transcription factor. Therefore, we developed a phosphorothiolate cis-element decoy against the estrogen response element (ERE decoy) to target disruption of ER DNA binding and transcriptional activity. Here, we showed that the ERE decoy potently ablated the 17beta-estrogen-inducible cell proliferation and induced apoptosis of human breast carcinoma cells by functionally affecting expression of c-fos gene and AP-1 luciferase gene reporter activity. Specificity of the decoy was demonstrated by its ability to directly block ER binding to a cis-element probe and transactivation. Moreover, the decoy failed to inhibit ER-mediated mitogen-activated protein kinase signaling pathways and cell growth of ER-negative breast cancer cells. Taken together, these data suggest that estrogen-mediated cell growth of breast cancer cells can be preferentially restricted via targeted disruption of ER at the level of DNA binding by a novel and specific decoy strategy applied to steroid nuclear receptors.

Steamed and Fermented Ethanolic Extract from Codonopsis lanceolata Attenuates Amyloid-β-Induced Memory Impairment in Mice

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Jin Bae Weon

2016-01-01

Full Text Available Codonopsis lanceolata (C. lanceolata is a traditional medicinal plant used for the treatment of certain inflammatory diseases such as asthma, tonsillitis, and pharyngitis. We evaluated whether steamed and fermented C. lanceolata (SFC extract improves amyloid-β- (Aβ- induced learning and memory impairment in mice. The Morris water maze and passive avoidance tests were used to evaluate the effect of SFC extract. Moreover, we investigated acetylcholinesterase (AChE activity and brain-derived neurotrophic factor (BDNF, cyclic AMP response element-binding protein (CREB, and extracellular signal-regulated kinase (ERK signaling in the hippocampus of mice to determine a possible mechanism for the cognitive-enhancing effect. Saponin compounds in SFC were identified by Ultra Performance Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry (UPLC-Q-TOF-MS. SFC extract ameliorated amyloid-β-induced memory impairment in the Morris water maze and passive avoidance tests. SFC extract inhibited AChE activity and also significantly increased the level of CREB phosphorylation, BDNF expression, and ERK activation in hippocampal tissue of amyloid-β-treated mice. Lancemasides A, B, C, D, E, and G and foetidissimoside A compounds present in SFC were determined by UPLC-Q-TOF-MS. These results indicate that SFC extract improves Aβ-induced memory deficits and that AChE inhibition and CREB/BDNF/ERK expression is important for the effect of the SFC extract. In addition, lancemaside A specifically may be responsible for efficacious effect of SFC.

Fisetin Ameliorated Photodamage by Suppressing the Mitogen-Activated Protein Kinase/Matrix Metalloproteinase Pathway and Nuclear Factor-κB Pathways.

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Chiang, Hsiu-Mei; Chan, Shih-Yun; Chu, Yin; Wen, Kuo-Ching

2015-05-13

Ultraviolet (UV) irradiation is one of the most important extrinsic factors contributing to skin photodamage. After UV irradiation, a series of signal transductions in the skin will be activated, leading to inflammatory response and photoaged skin. In this study, fisetin, a flavonol that exists in fruits and vegetables, was investigated for its photoprotective effects. The results revealed that 5-25 μM fisetin inhibits cyclooxygenase-2 (COX-2) and matrix metalloproteinase (MMP)-1, MMP-3, MMP-9 expression induced by ultraviolet B (UVB) irradiation in human skin fibroblasts. In addition, fisetin suppressed UVB-induced collagen degradation. With regard to its effect on upper-stream signal transduction, we found that fisetin reduced the expression of ultraviolet (UV)-induced ERK, JNK, and p38 phosphorylation in the mitogen-activated protein kinase (MAP kinase) pathway. Furthermore, fisetin reduced inhibitor κB (IκB) degradation and increased the amount of p65, which is a major subunit of nuclear factor-κB (NF-κB), in cytoplasm. It also suppressed NF-κB translocated to the nucleus and inhibited cAMP response element-binding protein (CREB) Ser-133 phosphorylation level in the phosphoinositide 3-kinase/protein kinase B/CREB (PI3K/AKT/CREB) pathway. Finally, fisetin inhibited UV-induced intracellular reactive oxygen species (ROS), prostaglandin E2 (PGE2), and nitric oxide (NO) generation. The mentioned effects and mechanisms suggest that fisetin can be used in the development of photoprotective agents.

MicroRNAs in addiction: adaptation’s middlemen?

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Li, MD; van der Vaart, AD

2014-01-01

A central question in addiction is how drug-induced changes in synaptic signaling are converted into long-term neuroadaptations. Emerging evidence reveals that microRNAs (miRNAs) have a distinct role in this process through rapid response to cellular signals and dynamic regulation of local mRNA transcripts. Because each miRNA can target hundreds of mRNAs, relative changes in the expression of miRNAs can greatly impact cellular responsiveness, synaptic plasticity and transcriptional events. These diverse consequences of miRNA action occur through coordination with genes implicated in addictions, the most compelling of these being the neurotrophin BDNF, the transcription factor cAMP-responsive element-binding protein (CREB) and the DNA-binding methyl CpG binding protein 2 (MeCP2). In this study, we review the recent progress in the understanding of miRNAs in general mechanisms of plasticity and neuroadaptation and then focus on specific examples of miRNA regulation in the context of addiction. We conclude that miRNA-mediated gene regulation is a conserved means of converting environmental signals into neuronal response, which holds significant implications for addiction and other psychiatric illnesses. PMID:21606928

MicroRNAs in addiction: adaptation's middlemen?

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Li, M D; van der Vaart, A D

2011-12-01

A central question in addiction is how drug-induced changes in synaptic signaling are converted into long-term neuroadaptations. Emerging evidence reveals that microRNAs (miRNAs) have a distinct role in this process through rapid response to cellular signals and dynamic regulation of local mRNA transcripts. Because each miRNA can target hundreds of mRNAs, relative changes in the expression of miRNAs can greatly impact cellular responsiveness, synaptic plasticity and transcriptional events. These diverse consequences of miRNA action occur through coordination with genes implicated in addictions, the most compelling of these being the neurotrophin BDNF, the transcription factor cAMP-responsive element-binding protein (CREB) and the DNA-binding methyl CpG binding protein 2 (MeCP2). In this study, we review the recent progress in the understanding of miRNAs in general mechanisms of plasticity and neuroadaptation and then focus on specific examples of miRNA regulation in the context of addiction. We conclude that miRNA-mediated gene regulation is a conserved means of converting environmental signals into neuronal response, which holds significant implications for addiction and other psychiatric illnesses.

Dissecting stimulus-response binding effects: Grouping by color separately impacts integration and retrieval processes.

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Laub, Ruth; Frings, Christian; Moeller, Birte

2018-04-23

In selection tasks, target and distractor features can be encoded together with the response into the same short-lived memory trace, or event file (see Hommel, 2004), leading to bindings between stimulus and response features. The repetition of a stored target or distractor feature can lead to the retrieval of the entire episode, including the response-so-called "binding effects." Binding effects due to distractor repetition are stronger for grouped than for nongrouped target and distractor stimulus configurations. Modulation of either of two mechanisms that lead to the observed binding effects might be responsible here: Grouping may influence either stimulus-response integration or stimulus-response retrieval. In the present study we investigated the influences of grouping on both mechanisms independently. In two experiments, target and distractor letters were grouped (or nongrouped) via color (dis)similarity separately during integration and retrieval. Grouping by color similarity affected integration and retrieval mechanisms independently and in different ways. Color dissimilarity enhanced distractor-based retrieval, whereas color similarity enhanced distractor integration. We concluded that stimulus grouping is relevant for binding effects, but that the mechanisms that contribute to binding effects should be carefully separated.

Identification of a High Affinity Nucleocapsid Protein Binding Element from The Bovine Leukemia Virus Genome

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Yildiz, F. Zehra; Babalola, Kathleen; Summers, Michael F.

2012-01-01

Retroviral genome recognition is mediated by interactions between the nucleocapsid (NC) domain of the virally encoded Gag polyprotein and cognate RNA packaging elements that, for most retroviruses, appear to reside primarily within the 5′-untranslated region (5′-UTR) of the genome. Recent studies suggest that a major packaging determinant of Bovine Leukemia Virus (BLV), a member of the human T-cell leukemia virus (HTLV)/BLV family and a non-primate animal model for HTLV-induced leukemogenesis, resides within the gag open reading frame. We have prepared and purified the recombinant BLV NC protein and conducted electrophoretic mobility shift and isothermal titration calorimetry studies with RNA fragments corresponding to these proposed packaging elements. The gag-derived RNAs did not exhibit significant affinity for NC, suggesting an alternate role in packaging. However, an 83-nucleotide fragment of the 5′-UTR that resides just upstream of the gag start codon binds NC stoichiometrically and with high affinity (Kd = 136 ± 21 nM). These nucleotides were predicted to form tandem hairpin structures, and studies with smaller fragments indicate that the NC binding site resides exclusively within the distal hairpin (residues G369- U399, Kd = 67 ± 8 nM at physiological ionic strength). Unlike all other structurally characterized retroviral NC binding RNAs, this fragment is not expected to contain exposed guanosines, suggesting that RNA binding may be mediated by a previously uncharacterized mechanism. PMID:22846919

Functional Elements on SIRPα IgV domain Mediate Cell Surface Binding to CD47

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Liu, Yuan; Tong, Qiao; Zhou, Yubin; Lee, Hsiau-Wei; Yang, Jenny J.; Bühring, Hans-Jörg; Chen, Yi-Tien; Ha, Binh; Chen, Celia X-J.; Zen, Ke

2007-01-01

Summary SIRPα and SIRPβ1, the two major isoforms of the signal regulatory protein (SIRP) family, are co-expressed in human leukocytes but mediate distinct extracellular binding interactions and divergent cell signaling responses. Previous studies have demonstrated that binding of SIRPα with CD47, another important cell surface molecule, through the extracellular IgV domain regulates important leukocyte functions including macrophage recognition, leukocyte adhesion and transmigration. Although SIRPβ1 shares highly homologous extracellular IgV structure with SIRPα, it does not bind to CD47. In this study, we defined key amino acid residues exclusively expressing in the IgV domain of SIRPα, but not SIRPβ1, which determine the extracellular binding interaction of SIRPα to CD47. These key residues include Gln67, a small hydrophobic amino acid (Ala or Val) at the 57th position and Met102. We found that Gln67 and Ala/Val57 are critical. Mutation of either of these residues abates SIRPα directly binding to CD47. Functional cell adhesion and leukocyte transmigration assays further demonstrated central roles of Gln67 and Ala/Val57 in SIRPα extracellular binding mediated cell interactions and cell migration. Another SIRPα-specific residue, Met102, appears to assist SIRPα IgV binding through Gln67 and Ala/Val57. An essential role of these amino acids in SIRPα binding to CD47 was further confirmed by introducing these residues into the SIRPβ1 IgV domain, which dramatically converts SIRPβ1 into a CD47-binding molecule. Our results thus revealed the molecular basis by which SIRPα selectively binds to CD47 and shed new light into the structural mechanisms of SIRP isoform mediated distinctive extracellular interactions and cellular responses. PMID:17070842

Functional elements on SIRPalpha IgV domain mediate cell surface binding to CD47.

Science.gov (United States)

Liu, Yuan; Tong, Qiao; Zhou, Yubin; Lee, Hsiau-Wei; Yang, Jenny J; Bühring, Hans-Jörg; Chen, Yi-Tien; Ha, Binh; Chen, Celia X-J; Yang, Yang; Zen, Ke

2007-01-19

SIRPalpha and SIRPbeta1, the two major isoforms of the signal regulatory protein (SIRP) family, are co-expressed in human leukocytes but mediate distinct extracellular binding interactions and divergent cell signaling responses. Previous studies have demonstrated that binding of SIRPalpha with CD47, another important cell surface molecule, through the extracellular IgV domain regulates important leukocyte functions including macrophage recognition, leukocyte adhesion and transmigration. Although SIRPbeta1 shares highly homologous extracellular IgV structure with SIRPalpha, it does not bind to CD47. Here, we defined key amino acid residues exclusively expressing in the IgV domain of SIRPalpha, but not SIRPbeta1, which determine the extracellular binding interaction of SIRPalpha to CD47. These key residues include Gln67, a small hydrophobic amino acid (Ala or Val) at the 57th position and Met102. We found that Gln67 and Ala/Val57 are critical. Mutation of either of these residues abates SIRPalpha directly binding to CD47. Functional cell adhesion and leukocyte transmigration assays further demonstrated central roles of Gln67 and Ala/Val57 in SIRPalpha extracellular binding mediated cell interactions and cell migration. Another SIRPalpha-specific residue, Met102, appears to assist SIRPalpha IgV binding through Gln67 and Ala/Val57. An essential role of these amino acid residues in SIRPalpha binding to CD47 was further confirmed by introducing these residues into the SIRPbeta1 IgV domain, which dramatically converts SIRPbeta1 into a CD47-binding molecule. Our results thus revealed the molecular basis by which SIRPalpha binds to CD47 and shed new light into the structural mechanisms of SIRP isoform mediated distinctive extracellular interactions and cellular responses.

Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

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Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C-C; Cole, S W

2016-05-24

Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

The impact of a diphenyl diselenide-supplemented diet and aerobic exercise on memory of middle-aged rats.

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Cechella, José L; Leite, Marlon R; Gai, Rafaela M; Zeni, Gilson

2014-08-01

Selenium is an essential trace element for human health and has received attention for its role as a nutrient. The combination of exercise and nutrients has been proposed to promote health. The aim of this study was to determine the effects of a diet supplemented with diphenyl diselenide (PhSe)2 and swimming exercise on memory of middle-aged rats. Male Wistar rats (12months) received standard diet chow supplemented with 1ppm of (PhSe)2 for 4weeks. Rats were submitted to swimming training (20min per day for 4weeks). After 4weeks, memory was evaluated in the object recognition test (ORT) and in the object location test (OLT). The hippocampal levels of phosphorylated cAMP-response element-binding protein (CREB) were determined. The results of the present study demonstrated that the association of (PhSe)2-supplemented diet and swimming exercise improved short-term memory, long-term memory and spatial learning, and this effect was not related to the increase in hippocampal p-CREB levels in middle-age rats. This study also revealed that middle-aged rats in the swimming exercise group had the best performance in short- and long-term memory. In conclusion, we demonstrated that swimming exercise, (PhSe)2-supplemented diet or the association of these factors improved learning and memory functioning. The hippocampal levels of CREB were not directly related to the benefits of swimming exercise and (PhSe)2-supplemented diet association in memory of middle-aged rats. Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular and genetic substrates linking stress and addiction.

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Briand, Lisa A; Blendy, Julie A

2010-02-16

Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction. Copyright 2009 Elsevier B.V. All rights reserved.

HuR binding to AU-rich elements present in the 3' untranslated region of Classical swine fever virus

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Huang Chin-Cheng

2011-07-01

Full Text Available Abstract Background Classical swine fever virus (CSFV is the member of the genus Pestivirus under the family Flaviviridae. The 5' untranslated region (UTR of CSFV contains the IRES, which is a highly structured element that recruits the translation machinery. The 3' UTR is usually the recognition site of the viral replicase to initiate minus-strand RNA synthesis. Adenosine-uridine rich elements (ARE are instability determinants present in the 3' UTR of short-lived mRNAs. However, the presence of AREs in the 3' UTR of CSFV conserved in all known strains has never been reported. This study inspects a possible role of the ARE in the 3' UTR of CSFV. Results Using RNA pull-down and LC/MS/MS assays, this study identified at least 32 possible host factors derived from the cytoplasmic extracts of PK-15 cells that bind to the CSFV 3' UTR, one of which is HuR. HuR is known to bind the AREs and protect the mRNA from degradation. Using recombinant GST-HuR, this study demonstrates that HuR binds to the ARE present in the 3' UTR of CSFV in vitro and that the binding ability is conserved in strains irrespective of virulence. Conclusions This study identified one of the CSFV 3' UTR binding proteins HuR is specifically binding to in the ARE region.

Antioxidant response elements: Discovery, classes, regulation and potential applications.

Science.gov (United States)

Raghunath, Azhwar; Sundarraj, Kiruthika; Nagarajan, Raju; Arfuso, Frank; Bian, Jinsong; Kumar, Alan P; Sethi, Gautam; Perumal, Ekambaram

2018-07-01

Exposure to antioxidants and xenobiotics triggers the expression of a myriad of genes encoding antioxidant proteins, detoxifying enzymes, and xenobiotic transporters to offer protection against oxidative stress. This articulated universal mechanism is regulated through the cis-acting elements in an array of Nrf2 target genes called antioxidant response elements (AREs), which play a critical role in redox homeostasis. Though the Keap1/Nrf2/ARE system involves many players, AREs hold the key in transcriptional regulation of cytoprotective genes. ARE-mediated reporter constructs have been widely used, including xenobiotics profiling and Nrf2 activator screening. The complexity of AREs is brought by the presence of other regulatory elements within the AREs. The diversity in the ARE sequences not only bring regulatory selectivity of diverse transcription factors, but also confer functional complexity in the Keap1/Nrf2/ARE pathway. The different transcription factors either homodimerize or heterodimerize to bind the AREs. Depending on the nature of partners, they may activate or suppress the transcription. Attention is required for deeper mechanistic understanding of ARE-mediated gene regulation. The computational methods of identification and analysis of AREs are still in their infancy. Investigations are required to know whether epigenetics mechanism plays a role in the regulation of genes mediated through AREs. The polymorphisms in the AREs leading to oxidative stress related diseases are warranted. A thorough understanding of AREs will pave the way for the development of therapeutic agents against cancer, neurodegenerative, cardiovascular, metabolic and other diseases with oxidative stress. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Quantification of transcription factor-DNA binding affinity in a living cell.

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Belikov, Sergey; Berg, Otto G; Wrange, Örjan

2016-04-20

The apparent dissociation constant (Kd) for specific binding of glucocorticoid receptor (GR) and androgen receptor (AR) to DNA was determined in vivo in Xenopus oocytes. The total nuclear receptor concentration was quantified as specifically retained [(3)H]-hormone in manually isolated oocyte nuclei. DNA was introduced by nuclear microinjection of single stranded phagemid DNA, chromatin is then formed during second strand synthesis. The fraction of DNA sites occupied by the expressed receptor was determined by dimethylsulphate in vivo footprinting and used for calculation of the receptor-DNA binding affinity. The forkhead transcription factor FoxA1 enhanced the DNA binding by GR with an apparent Kd of ∼1 μM and dramatically stimulated DNA binding by AR with an apparent Kd of ∼0.13 μM at a composite androgen responsive DNA element containing one FoxA1 binding site and one palindromic hormone receptor binding site known to bind one receptor homodimer. FoxA1 exerted a weak constitutive- and strongly cooperative DNA binding together with AR but had a less prominent effect with GR, the difference reflecting the licensing function of FoxA1 at this androgen responsive DNA element. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Glutaredoxin 1 (GRX1) inhibits oxidative stress and apoptosis of chondrocytes by regulating CREB/HO-1 in osteoarthritis.

Science.gov (United States)

Sun, Jie; Wei, Xuelei; Lu, Yandong; Cui, Meng; Li, Fangguo; Lu, Jie; Liu, Yunjiao; Zhang, Xi

2017-10-01

GRX1 (glutaredoxin1), a sulfhydryl disulfide oxidoreductase, is involved in many cellular processes, including anti-oxidation, anti-apoptosis, and regulation of cell differentiation. However, the role of GRX1 in the oxidative stress and apoptosis of osteoarthritis chondrocytes remains unclear, prompting the current study. Protein and mRNA expressions were measured by Western blot and RT-qPCR. Oxidative stress was detected by the measurement of MDA and SOD contents. Cells apoptosis were detected by Annexin V-FITC/PI and caspase-3 activity assays. We found that the mRNA and protein expressions of GRX1 were significantly down-regulated in osteoarthritis tissues and cells. GRX1 overexpression increased the mRNA and protein expression of CREB and HO-1. Meanwhile, GRX1 overexpression inhibited oxidative stress and apoptosis in osteoarthritis chondrocytes. Furthermore, we found that GRX1 overexpression regulated HO-1 by increasing CREB, and that HO-1 regulated oxidative stress and apoptosis in osteoarthritis chondrocytes. Thus, GRX1 overexpression constrains oxidative stress and apoptosis in osteoarthritis chondrocytes by regulating CREB/HO-1, providing a novel insight into the molecular mechanism and potential treatment of osteoarthritis. Copyright © 2017. Published by Elsevier Ltd.

Identification of hookworm DAF-16/FOXO response elements and direct gene targets.

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Xin Gao

2010-08-01

Full Text Available The infective stage of the parasitic nematode hookworm is developmentally arrested in the environment and needs to infect a specific host to complete its life cycle. The canine hookworm (Ancylostoma caninum is an excellent model for investigating human hookworm infections. The transcription factor of A. caninum, Ac-DAF-16, which has a characteristic fork head or "winged helix" DNA binding domain (DBD, has been implicated in the resumption of hookworm development in the host. However, the precise roles of Ac-DAF-16 in hookworm parasitism and its downstream targets are unknown. In the present study, we combined molecular techniques and bioinformatics to identify a group of Ac-DAF-16 binding sites and target genes.The DNA binding domain of Ac-DAF-16 was used to select genomic fragments by in vitro genomic selection. Twenty four bound genomic fragments were analyzed for the presence of the DAF-16 family binding element (DBE and possible alternative Ac-DAF-16 bind motifs. The 22 genes linked to these genomic fragments were identified using bioinformatics tools and defined as candidate direct gene targets of Ac-DAF-16. Their developmental stage-specific expression patterns were examined. Also, a new putative DAF-16 binding element was identified.Our results show that Ac-DAF-16 is involved in diverse biological processes throughout hookworm development. Further investigation of these target genes will provide insights into the molecular basis by which Ac-DAF-16 regulates its downstream gene network in hookworm infection.

Stress-related hormone norepinephrine induces interleukin-6 expression in GES-1 cells

International Nuclear Information System (INIS)

Yang, R.; Lin, Q.; Gao, H.B.; Zhang, P.

2014-01-01

In the current literature, there is evidence that psychological factors can affect the incidence and progression of some cancers. Interleukin 6 (IL-6) is known to be elevated in individuals experiencing chronic stress and is also involved in oncogenesis and cancer progression. However, the precise mechanism of IL-6 induction by the stress-related hormone norepinephrine (NE) is not clear, and, furthermore, there are no reports about the effect of NE on IL-6 expression in gastric epithelial cells. In this study, we examined the effect of NE on IL-6 expression in immortalized human gastric epithelial cells (GES-1 cells). Using real-time PCR and enzyme-linked immunoassay, we demonstrated that NE can induce IL-6 mRNA and protein expression in GES-1 cells. The induction is through the β-adrenergic receptor-cAMP-protein kinase A pathway and mainly at the transcriptional level. Progressive 5′-deletions and site-directed mutagenesis of the parental construct show that, although activating-protein-1 (AP-1), cAMP-responsive element binding protein (CREB), CCAAT-enhancer binding protein-β (C/EBP-β), and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) binding sites are all required in the basal transcription of IL-6, only AP-1 and CREB binding sites in the IL-6 promoter are required in NE-induced IL-6 expression. The results suggest that chronic stress may increase IL-6 secretion of human gastric epithelial cells, at least in part, by the stress-associated hormone norepinephrine, and provides basic data on stress and gastric cancer progression

Stress-related hormone norepinephrine induces interleukin-6 expression in GES-1 cells

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Yang, R.; Lin, Q.; Gao, H.B.; Zhang, P. [Department of Biochemistry and Molecular Cell Biology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, Department of Biochemistry and Molecular Cell Biology, School of Medicine, Shanghai Jiao Tong University, Shanghai (China)

2014-02-17

In the current literature, there is evidence that psychological factors can affect the incidence and progression of some cancers. Interleukin 6 (IL-6) is known to be elevated in individuals experiencing chronic stress and is also involved in oncogenesis and cancer progression. However, the precise mechanism of IL-6 induction by the stress-related hormone norepinephrine (NE) is not clear, and, furthermore, there are no reports about the effect of NE on IL-6 expression in gastric epithelial cells. In this study, we examined the effect of NE on IL-6 expression in immortalized human gastric epithelial cells (GES-1 cells). Using real-time PCR and enzyme-linked immunoassay, we demonstrated that NE can induce IL-6 mRNA and protein expression in GES-1 cells. The induction is through the β-adrenergic receptor-cAMP-protein kinase A pathway and mainly at the transcriptional level. Progressive 5′-deletions and site-directed mutagenesis of the parental construct show that, although activating-protein-1 (AP-1), cAMP-responsive element binding protein (CREB), CCAAT-enhancer binding protein-β (C/EBP-β), and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) binding sites are all required in the basal transcription of IL-6, only AP-1 and CREB binding sites in the IL-6 promoter are required in NE-induced IL-6 expression. The results suggest that chronic stress may increase IL-6 secretion of human gastric epithelial cells, at least in part, by the stress-associated hormone norepinephrine, and provides basic data on stress and gastric cancer progression.

Development of a procedure for the sequential extraction of substances binding trace elements in plant biomass

Czech Academy of Sciences Publication Activity Database

Pavlíková, D.; Pavlík, Milan; Vašíčková, Soňa; Száková, J.; Vokáč, Karel; Balík, J.; Tlustoš, P.

2005-01-01

Roč. 381, - (2005), s. 863-872 ISSN 1618-2642 Institutional research plan: CEZ:AV0Z4055905 Keywords : organic compounds binding trace elements * spinach plant * sequential extraction Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.695, year: 2005

Treadmill exercise alleviates stress-induced impairment of social interaction through 5-hydroxytryptamine 1A receptor activation in rats.

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Kim, Tae-Woon; Lim, Baek-Vin; Kim, Kijeong; Seo, Jin-Hee; Kim, Chang-Ju

2015-08-01

Brain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

CREB mediates ICAM-3: inducing radio-resistance, cell growth and migration/invasion of the human nonsmall cell lung cancer cell

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Park, Jong Kuk; So, Kwang Sup; Bae, In Hwa; Um, Hong Duck [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2009-05-15

The ICAM family proteins comprises cell surface molecules that are homologous to NCAM and are members of the single passed type 1 immunoglobulin superfamily (IgSF) that are anchored at the cellular membrane. The ICAM family consists of five subfamilies (ICAM-1 to ICAM-5) of heavily glycosylated cell surface receptors with common functional or structural homology. The extracellular domains of ICAM protein have roles in immune response and inflammation through various cell-cell interactions. The cytoplasmic tail residues of ICAM-3 participate in intracellular signaling such as calcium mobilization and tyrosine phosphorylation. Interestingly, the ICAM proteins appear to have a dual role in cancer. ICAM molecules may target and block tumor progression by stimulation of an immune response such as leukocyte activation. Conversely, other investigations have shown that ICAM molecules are involved in cancer malignancy because their increased expressions are associated with a poor diagnosis, lower survival rates and invasion in several cancers including melanoma, breast cancer and leukemia. We have also reported that an increase of ICAM-3 expression in several cancer cells and specimens of cervical cancer patient induce enhanced radio-resistance by the activation of focal adhesion kinase (FAK) and promote cancer cell proliferation by the activation of Akt and p44/42 MAPK. Therefore, these previous reports imply that ICAM-3 has various undefined roles in cancer. In this study, we investigated whether ICAM-3 increase cell migration and invasion through CREB activation and CREB has a role of increase of radioresistance and cell growth.

A potent inhibitor of SIK2, 3, 3', 7-trihydroxy-4'-methoxyflavon (4'-O-methylfisetin, promotes melanogenesis in B16F10 melanoma cells.

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Ayako Kumagai

Full Text Available Flavonoids, which are plant polyphenols, are now widely used in supplements and cosmetics. Here, we report that 4'-methylflavonoids are potent inducers of melanogenesis in B16F10 melanoma cells and in mice. We recently identified salt inducible kinase 2 (SIK2 as an inhibitor of melanogenesis via the suppression of the cAMP-response element binding protein (CREB-specific coactivator 1 (TORC1. Using an in vitro kinase assay targeting SIK2, we identified fisetin as a candidate inhibitor, possibly being capable of promoting melanogenesis. However, fisetin neither inhibited the CREB-inhibitory activity of SIK2 nor promoted melanogenesis in B16F10 melanoma cells. Conversely, mono-methyl-flavonoids, such as diosmetin (4'-O-metlylluteolin, efficiently inhibited SIK2 and promoted melanogenesis in this cell line. The cAMP-CREB system is impaired in A(y/a mice and these mice have yellow hair as a result of pheomelanogenesis, while Sik2(+/-; A(y/a mice also have yellow hair, but activate eumelanogenesis when they are exposed to CREB stimulators. Feeding Sik2(+/-; A(y/a mice with diets supplemented with fisetin resulted in their hair color changing to brown, and metabolite analysis suggested the presence of mono-methylfisetin in their feces. Thus, we decided to synthesize 4'-O-methylfisetin (4'MF and found that 4'MF strongly induced melanogenesis in B16F10 melanoma cells, which was accompanied by the nuclear translocation of TORC1, and the 4'-O-methylfisetin-induced melanogenic programs were inhibited by the overexpression of dominant negative TORC1. In conclusion, compounds that modulate SIK2 cascades are helpful to regulate melanogenesis via TORC1 without affecting cAMP levels, and the combined analysis of Sik2(+/- mice and metabolites from these mice is an effective strategy to identify beneficial compounds to regulate CREB activity in vivo.

Role of hippocampal and prefrontal cortical signaling pathways in dextromethorphan effect on morphine-induced memory impairment in rats.

Science.gov (United States)

Ghasemzadeh, Zahra; Rezayof, Ameneh

2016-02-01

Evidence suggests that dextromethorphan (DM), an NMDA receptor antagonist, induces memory impairment. Considering that DM is widely used in cough-treating medications, and the co-abuse of DM with morphine has recently been reported, the aims of the present study was (1) to investigate whether there is a functional interaction between morphine and DM in passive avoidance learning and (2) to assess the possible role of the hippocampal and prefrontal cortical (PFC) signaling pathways in the effects of the drugs on memory formation. Our findings indicated that post-training or pre-test administration of morphine (2 and 6 mg/kg) or DM (10-30 mg/kg) impaired memory consolidation and retrieval which was associated with the attenuation of the levels of phosphorylated Ca(2+)/calmodulin-dependent protein kinase II (p-CAMKII) and cAMP responsive element-binding protein (p-CREB) in the targeted sites. Moreover, the memory impairment induced by post-training administration of morphine was reversed by pre-test administration of the same dose of morphine or DM (30 mg/kg), indicating state-dependent learning (SDL) and a cross-SDL between the drugs. It is important to note that the levels of p-CAMKII/CAMKII and p-CREB/CREB in the hippocampus and the PFC increased in drugs-induced SDL. In addition, DM administration potentiated morphine-induced SDL which was related to the enhanced levels of hippocampal and PFC CAMKII-CREB signaling pathways. It can be concluded that there is a relationship between the hippocampus and the PFC in the effect of DM and/or morphine on memory retrieval. Moreover, a cross SDL can be induced between the co-administration of DM and morphine. Interestingly, CAMKII-CREB signaling pathways also mediate the drugs-induced SDL. Copyright © 2015 Elsevier Inc. All rights reserved.

Identification of 5-(1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)thiophene-2-Carboxamides as Novel and Selective Monoamine Oxidase B Inhibitors Used to Improve Memory and Cognition.

Science.gov (United States)

Kaplan, Alan P; Keenan, Terence; Scott, Roderick; Zhou, Xianbo; Bourchouladze, Rusiko; McRiner, Andrew J; Wilson, Mark E; Romashko, Darlene; Miller, Regina; Bletsch, Matthew; Anderson, Gary; Stanley, Jennifer; Zhang, Adia; Lee, Dong; Nikpur, John

2017-12-20

Initial work in Drosophila and mice demonstrated that the transcription factor cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) is a master control gene for memory formation. The relationship between CREB and memory has also been found to be true in other species, including aplysia and rats. It is thus well-established that CREB activation plays a central role in memory enhancement and that CREB is activated during memory formation. On the basis of these findings, a phenotypic high-throughput screening campaign utilizing a CRE-luciferase (CRE-Luci) SK-N-MC cell line was performed to identify compounds that enhance transcriptional activation of the CRE promoter with a suboptimal dose of forskolin. A number of small-molecule hits of unknown mechanisms of action were identified in the screening campaign, including HT-0411. Follow-up studies suggested that the CREB activation by HT-0411 is attributed to its specific and selective inhibition of monoamine oxidase B (MAO-B). Further, HT-0411 was shown to improve 24 h memory in rodents in a contextual fear conditioning model. This report describes the lead optimization of a series of 5-(1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl) thiophene-2-carboxamides that were identified as novel, potent, and selective inhibitors of MAO-B. Extensive SAR studies and in vivo behavioral evaluations of this and other related analogue series identified a number of potential clinical development candidates; ultimately, compound 8f was identified as a candidate molecule with high selectivity toward MAO-B (29-56 nM) over MAO-A (19% inhibition at a screening concentration of 50 μM), an excellent profile against a panel of other enzymes and receptors, good pharmacokinetic properties in rodents and dogs, and efficacy in multiple rodent memory models.

Photoelectron binding energy shifts observed during oxidation of group IIA, IIIA and IVA elemental surfaces

International Nuclear Information System (INIS)

Heide, P.A.W. van der

2006-01-01

An extensive re-evaluation of XPS binding energies (BE's) and binding energy shifts (ΔBE's) from metals, oxides and the carbonates of the group II, III and IVA elements (exceptions are Be, Mg and Hf) has been carried out using a substrate specific BE referencing approach. From this, O-1s BE's are found to fall into surface oxide, bulk oxide and carbonate groupings, with bulk oxides showing the lowest BE's followed by surface oxides (+∼1.5 eV) and then carbonates (+∼3.0 eV). The O-1s BE's from the bulk oxides also appear to scale with 1/d, where d is inter-atomic distance. The same is noted in the ΔBE's observed from the metallic counterparts during oxidation of the elemental surfaces. This, and the decreasing BE exhibited by Ca, Sr and Ba on oxidation is explained within the charge potential model as resulting from competing inter- and intra-atomic effects, and is shown to be consistent with partial covalency arguments utilizing Madulung potentials. The ΔBE's also fall into groups according to the elements location in the periodic table, i.e. s, p or d block. These trends open up the possibility of approximating ΔBE's arising from initial and final state effects, and bond distances

GSK-3β Inhibition Attenuates CLP-Induced Liver Injury by Reducing Inflammation and Hepatic Cell Apoptosis

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Hui Zhang

2014-01-01

Full Text Available Liver dysfunction has been known to occur frequently in cases of sepsis. Excessive inflammation and apoptosis are pathological features of acute liver failure. Recent studies suggest that activation of glycogen synthase kinase- (GSK- 3β is involved in inflammation and apoptosis. We aimed to investigate the protective effects of GSK-3β inhibition on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP, and SB216763 was used to inhibit GSK-3β in C57BL/6 mice. GSK-3β was activated following CLP. Administration of SB216763 decreased mortality, ameliorated liver injury, and reduced hepatic apoptosis. The inhibition of GSK-3β also reduced leukocyte infiltration and hepatic inflammatory cytokine expression and release. Moreover, GSK-3β inhibition suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB but enhanced the transcriptional activity of cAMP response element binding protein (CREB in the liver. In in vitro studies, GSK-3β inhibition reduced inflammatory cytokine production via modulation of NF-κB and CREB signaling pathways in lipopolysaccharide-stimulated macrophages. In conclusion, these findings suggest that GSK-3β blockade protects against CLP-induced liver via inhibition of inflammation by modulating NF-κB and CREB activity and suppression of hepatic apoptosis.

Flexible goal imitation: Vicarious feedback influences stimulus-response binding by observation.

Science.gov (United States)

Giesen, Carina; Scherdin, Kerstin; Rothermund, Klaus

2017-06-01

This study investigated whether vicarious feedback influences binding processes between stimuli and observed responses. Two participants worked together in a shared color categorization task, taking the roles of actor and observer in turns. During a prime trial, participants saw a word while observing the other person executing a specific response. Automatic binding of words and observed responses into stimulus-response (S-R) episodes was assessed via word repetition effects in a subsequent probe trial in which either the same (compatible) or a different (incompatible) response had to be executed by the participants in response to the same or a different word. Results showed that vicarious prime feedback (i.e., the feedback that the other participant received for her or his response in the prime) modulated S-R retrieval effects: After positive vicarious prime feedback, typical S-R retrieval effects emerged (i.e., performance benefits for stimulus repetition probes with compatible responses, but performance costs for stimulus repetition probes with incompatible responses emerged). Notably, however, S-R-retrieval effects were reversed after vicarious negative prime feedback (meaning that stimulus repetition in the probe resulted in performance costs if prime and probe responses were compatible, and in performance benefits for incompatible responses). Findings are consistent with a flexible goal imitation account, according to which imitation is based on an interpretative and therefore feedback-sensitive reconstruction of action goals from observed movements. In concert with earlier findings, this data support the conclusion that transient S-R binding and retrieval processes are involved in social learning phenomena.

Effects of gamma irradiation on the DNA-protein complex between the estrogen response element and the estrogen receptor

Energy Technology Data Exchange (ETDEWEB)

Stisova, Viktorie [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 18086 Praha 8 (Czech Republic); Goffinont, Stephane; Spotheim-Maurizot, Melanie [Centre de Biophysique Moleculaire CNRS, rue Charles Sadron, 45071 Orleans Cedex 2 (France); Davidkova, Marie, E-mail: davidkova@ujf.cas.c [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 18086 Praha 8 (Czech Republic)

2010-08-15

Signaling by estrogens, risk factors in breast cancer, is mediated through their binding to the estrogen receptor protein (ER), followed by the formation of a complex between ER and a DNA sequence, called estrogen response element (ERE). Anti-estrogens act as competitive inhibitors by blocking the signal transduction. We have studied in vitro the radiosensitivity of the complex between ERalpha, a subtype of this receptor, and a DNA fragment bearing ERE, as well as the influence of an estrogen (estradiol) or an anti-estrogen (tamoxifen) on this radiosensitivity. We observe that the complex is destabilized upon irradiation with gamma rays in aerated aqueous solution. The analysis of the decrease of binding abilities of the two partners shows that destabilization is mainly due to the damage to the protein. The destabilization is reduced when irradiating in presence of tamoxifen and is increased in presence of estradiol. These effects are due to opposite influences of the ligands on the loss of binding ability of ER. The mechanism that can account for our results is: binding of estradiol or tamoxifen induces distinct structural changes of the ER ligand-binding domain that can trigger (by allostery) distinct structural changes of the ER DNA-binding domains and thus, can differently affect ER-ERE interaction.

Cis-regulatory element based targeted gene finding: genome-wide identification of abscisic acid- and abiotic stress-responsive genes in Arabidopsis thaliana.

Science.gov (United States)

Zhang, Weixiong; Ruan, Jianhua; Ho, Tuan-Hua David; You, Youngsook; Yu, Taotao; Quatrano, Ralph S

2005-07-15

A fundamental problem of computational genomics is identifying the genes that respond to certain endogenous cues and environmental stimuli. This problem can be referred to as targeted gene finding. Since gene regulation is mainly determined by the binding of transcription factors and cis-regulatory DNA sequences, most existing gene annotation methods, which exploit the conservation of open reading frames, are not effective in finding target genes. A viable approach to targeted gene finding is to exploit the cis-regulatory elements that are known to be responsible for the transcription of target genes. Given such cis-elements, putative target genes whose promoters contain the elements can be identified. As a case study, we apply the above approach to predict the genes in model plant Arabidopsis thaliana which are inducible by a phytohormone, abscisic acid (ABA), and abiotic stress, such as drought, cold and salinity. We first construct and analyze two ABA specific cis-elements, ABA-responsive element (ABRE) and its coupling element (CE), in A.thaliana, based on their conservation in rice and other cereal plants. We then use the ABRE-CE module to identify putative ABA-responsive genes in A.thaliana. Based on RT-PCR verification and the results from literature, this method has an accuracy rate of 67.5% for the top 40 predictions. The cis-element based targeted gene finding approach is expected to be widely applicable since a large number of cis-elements in many species are available.

Binding of chemical warfare agent simulants as guests in a coordination cage: contributions to binding and a fluorescence-based response.

Science.gov (United States)

Taylor, Christopher G P; Piper, Jerico R; Ward, Michael D

2016-05-07

Cubic coordination cages act as competent hosts for several alkyl phosphonates used as chemical warfare agent simulants; a range of cage/guest structures have been determined, contributions to guest binding analysed, and a fluorescent response to guest binding demonstrated.

The finite element response Matrix method