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Sample records for deacetylases controls g1

  1. Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells induced by hybrid-compound histone deacetylase inhibitor

    SciTech Connect

    Fujii, Seiko; Okinaga, Toshinori; Ariyoshi, Wataru; Takahashi, Osamu; Iwanaga, Kenjiro; Nishino, Norikazu; Tominaga, Kazuhiro; Nishihara, Tatsuji

    2013-05-10

    Highlights: •Novel histone deacetylase inhibitor Ky-2, remarkably inhibits myeloma cell growth. •Ky-2 demonstrates no cytotoxicity against normal lymphocytic cells. •Ky-2 induces cell cycle arrest through the cell cycle-associated proteins. •Ky-2 induces Bcl-2-inhibitable apoptosis through a caspase-dependent cascade. -- Abstract: Objectives: Histone deacetylase (HDAC) inhibitors are new therapeutic agents, used to treat various types of malignant cancers. In the present study, we investigated the effects of Ky-2, a hybrid-compound HDAC inhibitor, on the growth of mouse myeloma cells. Materials and methods: Myeloma cells, HS-72, P3U1, and mouse normal cells were used in this study. Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle regulatory and the apoptosis associated proteins were examined by Western blot analysis. Hoechst’s staining was used to detect apoptotic cells. Results: Our findings showed that Ky-2 decreased the levels of HDACs, while it enhanced acetylation of histone H3. Myeloma cell proliferation was inhibited by Ky-2 treatment. Interestingly, Ky-2 had no cytotoxic effects on mouse normal cells. Ky-2 treatment induced G1-phase cell cycle arrest and accumulation of a sub-G1 phase population, while Western blotting analysis revealed that expressions of the cell cycle-associated proteins were up-regulated. Also, Ky-2 enhanced the cleavage of caspase-9 and -3 in myeloma cells, followed by DNA fragmentation. In addition, Ky-2 was not found to induce apoptosis in bcl-2 overexpressing myeloma cells. Conclusion: These findings suggest that Ky-2 induces apoptosis via a caspase-dependent cascade and Bcl-2-inhibitable mechanism in myeloma cells.

  2. Singularity-conquering ZG controllers of z2g1 type for tracking control of the IPC system

    NASA Astrophysics Data System (ADS)

    Zhang, Yunong; Yu, Xiaotian; Yin, Yonghua; Peng, Chen; Fan, Zhengping

    2014-09-01

    With wider investigations and applications of autonomous robotics and intelligent vehicles, the inverted pendulum on a cart (IPC) system has become more attractive for numerous researchers due to its concise and representative structure. In this article, the tracking-control problem of the IPC system is considered and investigated. Based on Zhang dynamics (ZD) and gradient dynamics (GD), a novel kind of ZG controllers are developed and investigated for achieving the tracking-control purpose, which contains controllers of z2g0 and z2g1 types according to the number of times of using the ZD and GD methods. Besides, theoretical analyses are presented to guarantee the global and exponential convergence performance of both z2g0 and z2g1 controllers. Computer simulations are further performed to substantiate the feasibility and effectiveness of ZG controllers. More importantly, comparative simulation results demonstrate that controllers of z2g1 type can conquer the singularity problem (i.e. the division-by-zero problem).

  3. First passage times in M2[X ]|G |1 |R queue with hysteretic overload control policy

    NASA Astrophysics Data System (ADS)

    Pechinkin, Alexander V.; Razumchik, Rostislav R.; Zaryadov, Ivan S.

    2016-06-01

    One of the reported approaches towards the solution of overload problem in networks of SIP servers is the implementation of multi-level hysteretic control of arrivals in SIP servers. Each level, being the parameter of the policy, specifies operation mode of SIP server i.e. it implicitly indicates what SIP server must do with the arriving packets. The choice of parameters' values is not guided by standards and is usually left for the network owner. In general, all operation modes of the considered policy can be grouped into two groups: normal mode (when all arriving packets are accepted) and congested mode (when part or all arriving packets are being dropped). Such grouping may serve as the criteria for choosing parameters' values of the policy: pick those values which minimize SIP server sojourn time in congested mode. In this short note we propose some analytical results which facilitate the solution of stated minimization problem. The considered mathematical model of SIP server is the queueing system M2[X ]|G |1 |R with batch arrivals and bi-level hysteretic control policy, which specifies three operation modes: normal (customers both flows are accepted), overload (only customers from one flow are accepted), discard (customers from both flows are blocked/lost)). The switching between modes can occur only on service completions. Analytical method allowing computation of stationary sojourn times in different operation modes (as well as first passage times between modes) is presented in brief. Numerical example is given.

  4. Whi5 phosphorylation embedded in the G1/S network dynamically controls critical cell size and cell fate

    PubMed Central

    Palumbo, Pasquale; Vanoni, Marco; Cusimano, Valerio; Busti, Stefano; Marano, Francesca; Manes, Costanzo; Alberghina, Lilia

    2016-01-01

    In budding yeast, overcoming of a critical size to enter S phase and the mitosis/mating switch—two central cell fate events—take place in the G1 phase of the cell cycle. Here we present a mathematical model of the basic molecular mechanism controlling the G1/S transition, whose major regulatory feature is multisite phosphorylation of nuclear Whi5. Cln3–Cdk1, whose nuclear amount is proportional to cell size, and then Cln1,2–Cdk1, randomly phosphorylate both decoy and functional Whi5 sites. Full phosphorylation of functional sites releases Whi5 inhibitory activity, activating G1/S transcription. Simulation analysis shows that this mechanism ensures coherent release of Whi5 inhibitory action and accounts for many experimentally observed properties of mitotically growing or conjugating G1 cells. Cell cycle progression and transcriptional analyses of a Whi5 phosphomimetic mutant verify the model prediction that coherent transcription of the G1/S regulon and ensuing G1/S transition requires full phosphorylation of Whi5 functional sites. PMID:27094800

  5. Whi5 phosphorylation embedded in the G1/S network dynamically controls critical cell size and cell fate.

    PubMed

    Palumbo, Pasquale; Vanoni, Marco; Cusimano, Valerio; Busti, Stefano; Marano, Francesca; Manes, Costanzo; Alberghina, Lilia

    2016-01-01

    In budding yeast, overcoming of a critical size to enter S phase and the mitosis/mating switch--two central cell fate events--take place in the G1 phase of the cell cycle. Here we present a mathematical model of the basic molecular mechanism controlling the G1/S transition, whose major regulatory feature is multisite phosphorylation of nuclear Whi5. Cln3-Cdk1, whose nuclear amount is proportional to cell size, and then Cln1,2-Cdk1, randomly phosphorylate both decoy and functional Whi5 sites. Full phosphorylation of functional sites releases Whi5 inhibitory activity, activating G1/S transcription. Simulation analysis shows that this mechanism ensures coherent release of Whi5 inhibitory action and accounts for many experimentally observed properties of mitotically growing or conjugating G1 cells. Cell cycle progression and transcriptional analyses of a Whi5 phosphomimetic mutant verify the model prediction that coherent transcription of the G1/S regulon and ensuing G1/S transition requires full phosphorylation of Whi5 functional sites. PMID:27094800

  6. HISTONE DEACETYLASE6 Controls Gene Expression Patterning and DNA Methylation-Independent Euchromatic Silencing1[OPEN

    PubMed Central

    Hristova, Emilija; Fal, Kateryna; Klemme, Laurin; Windels, David; Bucher, Etienne

    2015-01-01

    To investigate the role of chromatin regulators in patterning gene expression, we employed a unique epigenetically controlled and highly tissue-specific green fluorescent protein reporter line in Arabidopsis (Arabidopsis thaliana). Using a combination of forward and reverse genetic approaches on this line, we show here that distinct epigenetic regulators are involved in silencing the transgene in different tissues. The forward genetic screen led to the identification of a novel HISTONE DEACETYLASE6 (HDA6) mutant allele (epigenetic control1, hda6-8). This allele differs from the previously reported alleles, as it did not affect DNA methylation and only had a very modest effect on the release of transposable elements and other heterochromatic transcripts. Overall, our data shows that HDA6 has at least two clearly separable activities in different genomic regions. In addition, we present an unexpected role for HDA6 in the control of DNA methylation at CG dinucleotides. PMID:25918117

  7. G1 phase regulation, area-specific cell cycle control, and cytoarchitectonics in the primate cortex

    PubMed Central

    Lukaszewicz, Agnès; Savatier, Pierre; Cortay, Véronique; Giroud, Pascale; Huissoud, Cyril; Berland, Michel; Kennedy, Henry; Dehay, Colette

    2005-01-01

    We have investigated the cell-cycle related mechanisms that lead to the emergence of the primate areas 17 and 18. These areas are characterized by striking differences in cytoarchitectonics and neuron number. We show in vivo that (i) area 17 precursors of supragranular neurons exhibit a shorter cell-cycle duration, a reduced G1 phase and a higher rate of cell-cycle re-entry than area 18 precursors (ii) area-specific levels of expression of Cyclin E (high in area 17, low in area 18) and p27Kip1 (low in area 17, high in area 18) (iii) Ex vivo up and down modulation of Cyclin E and p27Kip1 show that both regulators influence cell-cycle kinetics by modifying rates of cell-cycle progression and cell-cycle re-entry (iv) Modeling the areal differences in cell-cycle parameters suggests that they contribute to areal differences in numbers of precursors and neuron production. PMID:16055060

  8. Murine hematopoietic stem cell dormancy controlled by induction of a novel short form of PSF1 by histone deacetylase inhibitors

    SciTech Connect

    Han, Yinglu; Gong, Zhi-Yuan; Takakura, Nobuyuki

    2015-06-10

    Hematopoietic stem cells (HSCs) can survive long-term in a state of dormancy. Little is known about how histone deacetylase inhibitors (HDACi) affect HSC kinetics. Here, we use trichostatin A (TSA), a histone deacetylase inhibitor, to enforce histone acetylation and show that this suppresses cell cycle entry by dormant HSCs. Previously, we found that haploinsufficiency of PSF1, a DNA replication factor, led to attenuation of the bone marrow (BM) HSC pool size and lack of acute proliferation after 5-FU ablation. Because PSF1 protein is present in CD34{sup +} transiently amplifying HSCs but not in CD34{sup −} long-term reconstituting-HSCs which are resting in a dormant state, we analyzed the relationship between dormancy and PSF1 expression, and how a histone deacetylase inhibitor affects this. We found that CD34{sup +} HSCs produce long functional PSF1 (PSF1a) but CD34{sup −} HSCs produce a shorter possibly non-functional PSF1 (PSF1b, c, dominantly PSF1c). Using PSF1a-overexpressing NIH-3T3 cells in which the endogenous PSF1 promoter is suppressed, we found that TSA treatment promotes production of the shorter form of PSF1 possibly by inducing recruitment of E2F family factors upstream of the PSF1 transcription start site. Our data document one mechanism by which histone deacetylase inhibitors affect the dormancy of HSCs by regulating the DNA replication factor PSF1. - Highlights: • Hematopoetic stem cell dormancy is controlled by histone deacetylation inhibitors. • Dormancy of HSCs is associated with a shorter form of non-functional PSF1. • Histone deacetylase inhibitors suppress PSF1 promoter activity.

  9. A Novel Histone Deacetylase Complex in the Control of Transcription and Genome Stability

    PubMed Central

    Zilio, Nicola; Codlin, Sandra; Vashisht, Ajay A.; Bitton, Danny A.; Head, Steven R.; Wohlschlegel, James A.; Bähler, Jürg

    2014-01-01

    The acetylation state of histones, controlled by histone acetyltransferases (HATs) and deacetylases (HDACs), profoundly affects DNA transcription and repair by modulating chromatin accessibility to the cellular machinery. The Schizosaccharomyces pombe HDAC Clr6 (human HDAC1) binds to different sets of proteins that define functionally distinct complexes: I, I′, and II. Here, we determine the composition, architecture, and functions of a new Clr6 HDAC complex, I′′, delineated by the novel proteins Nts1, Mug165, and Png3. Deletion of nts1 causes increased sensitivity to genotoxins and deregulated expression of Tf2 elements, long noncoding RNA, and subtelomeric and stress-related genes. Similar, but more pervasive, phenotypes are observed upon Clr6 inactivation, supporting the designation of complex I′′ as a mediator of a key subset of Clr6 functions. We also reveal that with the exception of Tf2 elements, the genome-wide loading sites and loci regulated by Clr6 I″ do not correlate. Instead, Nts1 loads at genes that are expressed in midmeiosis, following oxidative stress, or are periodically expressed. Collective data suggest that Clr6 I′′ has (i) indirect effects on gene expression, conceivably by mediating higher-order chromatin organization of subtelomeres and Tf2 elements, and (ii) direct effects on the transcription of specific genes in response to certain cellular or environmental stimuli. PMID:25002536

  10. Cyclin D1 is dispensable for G1 control in retinoblastoma gene-deficient cells independently of cdk4 activity.

    PubMed Central

    Lukas, J; Bartkova, J; Rohde, M; Strauss, M; Bartek, J

    1995-01-01

    To elucidate the regulator-versus-target relationship in the cyclin D1/cdk4/retinoblastoma protein (pRB) pathway, we examined fibroblasts from RB-1 gene-deficient and RB-1 wild-type littermate mouse embryos (ME) and in human tumor cell lines that differed in the status of the RB-1 gene. The RB+/+ and RB-/- ME fibroblasts expressed similar protein levels of D-type cyclins, cdk4, and cdk6, showed analogous spectra and abundance of cellular proteins complexed with cdk4 and/or cyclins D1 and D2, and exhibited comparable associated kinase activities. Of the two human cell lines established from the same sarcoma biopsy, the RB-positive SKUT1B cells contained cdk4 that was mainly associated with D-type cyclins, contrary to a predominant cdk4-p16INK4 complex in the RB-deficient SKUT1A cells. Antibody-mediated neutralization of cyclin D1 arrested the RB-positive ME and SKUT1B cells in G1, whereas this cyclin appeared dispensable in the RB-deficient ME and SKUT1A cells. Lack of requirement for cyclin D1 therefore correlated with absence of functional pRB, regardless of whether active cyclin D1/cdk4 holoenzyme was present in the cells under study. Consistent with a potential role of cyclin D/cdk4 in phosphorylation of pRB, monoclonal anti-cyclin D1 antibodies supporting the associated kinase activity failed to significantly affect proliferation of RB-positive cells, whereas the antibody DCS-6, unable to coprecipitate cdk4, efficiently inhibited G1 progression and prevented pRB phosphorylation in vivo. These data provide evidence for an upstream control function of cyclin D1/cdk4, and a downstream role for pRB, in the order of events regulating transition through late G1 phase of the mammalian cell division cycle. PMID:7739541

  11. Histone Deacetylases

    PubMed Central

    Parbin, Sabnam; Kar, Swayamsiddha; Shilpi, Arunima; Sengupta, Dipta; Deb, Moonmoon; Rath, Sandip Kumar

    2014-01-01

    In the current era of genomic medicine, diseases are identified as manifestations of anomalous patterns of gene expression. Cancer is the principal example among such maladies. Although remarkable progress has been achieved in the understanding of the molecular mechanisms involved in the genesis and progression of cancer, its epigenetic regulation, particularly histone deacetylation, demands further studies. Histone deacetylases (HDACs) are one of the key players in the gene expression regulation network in cancer because of their repressive role on tumor suppressor genes. Higher expression and function of deacetylases disrupt the finely tuned acetylation homeostasis in both histone and non-histone target proteins. This brings about alterations in the genes implicated in the regulation of cell proliferation, differentiation, apoptosis and other cellular processes. Moreover, the reversible nature of epigenetic modulation by HDACs makes them attractive targets for cancer remedy. This review summarizes the current knowledge of HDACs in tumorigenesis and tumor progression as well as their contribution to the hallmarks of cancer. The present report also describes briefly various assays to detect histone deacetylase activity and discusses the potential role of histone deacetylase inhibitors as emerging epigenetic drugs to cure cancer. PMID:24051359

  12. Cytoplasmic-nuclear trafficking of G1/S cell cycle molecules and adult human β-cell replication: a revised model of human β-cell G1/S control.

    PubMed

    Fiaschi-Taesch, Nathalie M; Kleinberger, Jeffrey W; Salim, Fatimah G; Troxell, Ronnie; Wills, Rachel; Tanwir, Mansoor; Casinelli, Gabriella; Cox, Amy E; Takane, Karen K; Srinivas, Harish; Scott, Donald K; Stewart, Andrew F

    2013-07-01

    Harnessing control of human β-cell proliferation has proven frustratingly difficult. Most G1/S control molecules, generally presumed to be nuclear proteins in the human β-cell, are in fact constrained to the cytoplasm. Here, we asked whether G1/S molecules might traffic into and out of the cytoplasmic compartment in association with activation of cell cycle progression. Cdk6 and cyclin D3 were used to drive human β-cell proliferation and promptly translocated into the nucleus in association with proliferation. In contrast, the cell cycle inhibitors p15, p18, and p19 did not alter their location, remaining cytoplasmic. Conversely, p16, p21, and p27 increased their nuclear frequency. In contrast once again, p57 decreased its nuclear frequency. Whereas proliferating β-cells contained nuclear cyclin D3 and cdk6, proliferation generally did not occur in β-cells that contained nuclear cell cycle inhibitors, except p21. Dynamic cytoplasmic-nuclear trafficking of cdk6 was confirmed using green fluorescent protein-tagged cdk6 and live cell imaging. Thus, we provide novel working models describing the control of cell cycle progression in the human β-cell. In addition to known obstacles to β-cell proliferation, cytoplasmic-to-nuclear trafficking of G1/S molecules may represent an obstacle as well as a therapeutic opportunity for human β-cell expansion. PMID:23493571

  13. Histone deacetylase 3 supports endochondral bone formation by controlling cytokine signaling and matrix remodeling.

    PubMed

    Carpio, Lomeli R; Bradley, Elizabeth W; McGee-Lawrence, Meghan E; Weivoda, Megan M; Poston, Daniel D; Dudakovic, Amel; Xu, Ming; Tchkonia, Tamar; Kirkland, James L; van Wijnen, Andre J; Oursler, Merry Jo; Westendorf, Jennifer J

    2016-01-01

    Histone deacetylase (HDAC) inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, each of these drugs inhibits multiple HDACs and has detrimental effects on the skeleton. To better understand how HDAC inhibitors affect endochondral bone formation, we conditionally deleted one of their targets, Hdac3, pre- and postnatally in type II collagen α1 (Col2α1)-expressing chondrocytes. Embryonic deletion was lethal, but postnatal deletion of Hdac3 delayed secondary ossification center formation, altered maturation of growth plate chondrocytes, and increased osteoclast activity in the primary spongiosa. HDAC3-deficient chondrocytes exhibited increased expression of cytokine and matrix-degrading genes (Il-6, Mmp3, Mmp13, and Saa3) and a reduced abundance of genes related to extracellular matrix production, bone development, and ossification (Acan, Col2a1, Ihh, and Col10a1). Histone acetylation increased at and near genes that had increased expression. The acetylation and activation of nuclear factor κB (NF-κB) were also increased in HDAC3-deficient chondrocytes. Increased cytokine signaling promoted autocrine activation of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and NF-κB pathways to suppress chondrocyte maturation, as well as paracrine activation of osteoclasts and bone resorption. Blockade of interleukin-6 (IL-6)-JAK-STAT signaling, NF-κB signaling, and bromodomain extraterminal proteins, which recognize acetylated lysines and promote transcriptional elongation, significantly reduced Il-6 and Mmp13 expression in HDAC3-deficient chondrocytes and secondary activation in osteoclasts. The JAK inhibitor ruxolitinib also reduced osteoclast activity in Hdac3 conditional knockout mice. Thus, HDAC3 controls the temporal and spatial expression of tissue-remodeling genes and inflammatory responses in chondrocytes to ensure proper endochondral ossification during development. PMID:27507649

  14. NAD+-dependent deacetylase Hst1p controls biosynthesis and cellular NAD+ levels in Saccharomyces cerevisiae.

    PubMed

    Bedalov, Antonio; Hirao, Maki; Posakony, Jeffrey; Nelson, Melisa; Simon, Julian A

    2003-10-01

    Nicotine adenine dinucleotide (NAD(+)) performs key roles in electron transport reactions, as a substrate for poly(ADP-ribose) polymerase and NAD(+)-dependent protein deacetylases. In the latter two processes, NAD(+) is consumed and converted to ADP-ribose and nicotinamide. NAD(+) levels can be maintained by regeneration of NAD(+) from nicotinamide via a salvage pathway or by de novo synthesis of NAD(+) from tryptophan. Both pathways are conserved from yeast to humans. We describe a critical role of the NAD(+)-dependent deacetylase Hst1p as a sensor of NAD(+) levels and regulator of NAD(+) biosynthesis. Using transcript arrays, we show that low NAD(+) states specifically induce the de novo NAD(+) biosynthesis genes while the genes in the salvage pathway remain unaffected. The NAD(+)-dependent deacetylase activity of Hst1p represses de novo NAD(+) biosynthesis genes in the absence of new protein synthesis, suggesting a direct effect. The known Hst1p binding partner, Sum1p, is present at promoters of highly inducible NAD(+) biosynthesis genes. The removal of HST1-mediated repression of the NAD(+) de novo biosynthesis pathway leads to increased cellular NAD(+) levels. Transcript array analysis shows that reduction in cellular NAD(+) levels preferentially affects Hst1p-regulated genes in comparison to genes regulated with other NAD(+)-dependent deacetylases (Sir2p, Hst2p, Hst3p, and Hst4p). In vitro experiments demonstrate that Hst1p has relatively low affinity toward NAD(+) in comparison to other NAD(+)-dependent enzymes. These findings suggest that Hst1p serves as a cellular NAD(+) sensor that monitors and regulates cellular NAD(+) levels. PMID:12972620

  15. G1/S Inhibitors and the SWI/SNF Complex Control Cell-Cycle Exit during Muscle Differentiation.

    PubMed

    Ruijtenberg, Suzan; van den Heuvel, Sander

    2015-07-16

    The transition from proliferating precursor cells to post-mitotic differentiated cells is crucial for development, tissue homeostasis, and tumor suppression. To study cell-cycle exit during differentiation in vivo, we developed a conditional knockout and lineage-tracing system for Caenorhabditis elegans. Combined lineage-specific gene inactivation and genetic screening revealed extensive redundancies between previously identified cell-cycle inhibitors and the SWI/SNF chromatin-remodeling complex. Muscle precursor cells missing either SWI/SNF or G1/S inhibitor function could still arrest cell division, while simultaneous inactivation of these regulators caused continued proliferation and a C. elegans tumor phenotype. Further genetic analyses support that SWI/SNF acts in concert with hlh-1 MyoD, antagonizes Polycomb-mediated transcriptional repression, and suppresses cye-1 Cyclin E transcription to arrest cell division of muscle precursors. Thus, SWI/SNF and G1/S inhibitors provide alternative mechanisms to arrest cell-cycle progression during terminal differentiation, which offers insight into the frequent mutation of SWI/SNF genes in human cancers.

  16. Overexpression of histone deacetylases in cancer cells is controlled by interplay of transcription factors and epigenetic modulators

    PubMed Central

    Yang, Hui; Salz, Tal; Zajac-Kaye, Maria; Liao, Daiqing; Huang, Suming; Qiu, Yi

    2014-01-01

    Histone deacetylases (HDACs) that deacetylate histone and nonhistone proteins play crucial roles in a variety of cellular processes. The overexpression of HDACs is reported in many cancer types and is directly linked to accelerated cell proliferation and survival. However, little is known about how HDAC expression is regulated in cancer cells. In this study, we found that HDAC1 and HDAC2 promoters are regulated through collaborative binding of transcription factors Sp1/Sp3 and epigenetic modulators, including histone H3K4 methyltransferase SET1 and histone acetyltransferase p300, whose levels are also elevated in colon cancer cell lines and patient samples. Interestingly, Sp1 and Sp3 differentially regulate HDAC1 and HDAC2 promoter activity. In addition, Sp1/Sp3 recruits SET1 and p300 to the promoters. SET1 knockdown (KD) results in a loss of the H3K4 trimethylation mark at the promoters, as well as destabilizes p300 at the promoters. Conversely, p300 also influences SET1 recruitment and H3K4me3 level, indicating a crosstalk between p300 and SET1. Further, SET1 KD reduces Sp1 binding to the HDAC1 promoter through the increase of Sp1 acetylation. These results indicate that interactions among transcription factors and epigenetic modulators orchestrate the activation of HDAC1 and HDAC2 promoter activity in colon cancer cells.—Yang, H., Salz, T., Zajac-Kaye, M., Liao, D., Huang, S., and Qiu, Y. Overexpression of histone deacetylases in cancer cells is controlled by interplay of transcription factors and epigenetic modulators. PMID:24948597

  17. An Old Story Retold: Loss of G1 Control Defines A Distinct Genomic Subtype of Esophageal Squamous Cell Carcinoma

    PubMed Central

    Wang, Qiyan; Bai, Jian; Abliz, Amir; Liu, Ying; Gong, Kenan; Li, Jingjing; Shi, Wenjie; Pan, Yaqi; Liu, Fangfang; Lai, Shujuan; Yang, Haijun; Lu, Changdong; Zhang, Lixin; Chen, Wei; Xu, Ruiping; Cai, Hong; Ke, Yang; Zeng, Changqing

    2015-01-01

    Esophageal squamous cell carcinoma (ESCC) has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exonic mutations and structural alterations. The clinical implications of these genetic alterations were also analyzed. Exome sequencing and verification were performed for nine pairs of ESCC and the matched blood samples, followed by validation with additional samples using Sanger sequencing. Whole-genome SNP arrays were employed to detect copy number alteration (CNA) and loss of heterozygosity (LOH) in 55 cases, including the nine ESCC samples subjected to exome sequencing. A total of 108 non-synonymous somatic mutations (NSSMs) in 102 genes were verified in nine patients. The chromatin modification process was found to be enriched in our gene ontology (GO) analysis. Tumor genomes with TP53 mutations were significantly more unstable than those without TP53 mutations. In terms of the landscape of genomic alterations, deletion of 9p21.3 covering CDKN2A/2B (30.9%), amplification of 11q13.3 covering CCND1 (30.9%), and TP53 point mutation (50.9%) occurred in two-thirds of the cases. These results suggest that the deregulation of the G1 phase during the cell cycle is a key event in ESCC. Furthermore, six minimal common regions were found to be significantly altered in ESCC samples and three of them, 9p21.3, 7p11.2, and 3p12.1, were associated with lymph node metastasis. With the high correlation of TP53 mutation and genomic instability in ESCC, the amplification of CCND1, the deletion of CDKN2A/2B, and the somatic mutation of TP53 appear to play pivotal roles via G1 deregulation and therefore helps to classify this cancer into different genomic subtypes. These findings provide clinical significance that could be useful in future molecular diagnoses and therapeutic targeting. PMID:26386145

  18. Histone deacetylase enzymes as drug targets for the control of the sheep blowfly, Lucilia cuprina.

    PubMed

    Kotze, Andrew C; Hines, Barney M; Bagnall, Neil H; Anstead, Clare A; Gupta, Praveer; Reid, Robert C; Ruffell, Angela P; Fairlie, David P

    2015-12-01

    The Australian sheep blowfly, Lucilia cuprina, is an ecto-parasite that causes significant economic losses in the sheep industry. Emerging resistance to insecticides used to protect sheep from this parasite is driving the search for new drugs that act via different mechanisms. Inhibitors of histone deacetylases (HDACs), enzymes essential for regulating eukaryotic gene transcription, are prospective new insecticides based on their capacity to kill human parasites. The blowfly genome was found here to contain five HDAC genes corresponding to human HDACs 1, 3, 4, 6 and 11. The catalytic domains of blowfly HDACs 1 and 3 have high sequence identity with corresponding human and other Dipteran insect HDACs (Musca domestica and Drosophila melanogaster). On the other hand, HDACs 4, 6 and 11 from the blowfly and the other Dipteran species showed up to 53% difference in catalytic domain amino acids from corresponding human sequences, suggesting the possibility of developing HDAC inhibitors specific for insects as desired for a commercial insecticide. Differences in transcription patterns for different blowfly HDACs through the life cycle, and between the sexes of adult flies, suggest different functions in regulating gene transcription within this organism and possibly different vulnerabilities. Data that supports HDACs as possible new insecticide targets is the finding that trichostatin A and suberoylanilide hydroxamic acid retarded growth of early instar blowfly larvae in vitro, and reduced the pupation rate. Trichostatin A was 8-fold less potent than the commercial insecticide cyromazine in inhibiting larval growth. Our results support further development of inhibitors of blowfly HDACs with selectivity over human and other mammalian HDACs as a new class of prospective insecticides for sheep blowfly. PMID:27120067

  19. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes

    PubMed Central

    Elías-Villalobos, Alberto; Fernández-Álvarez, Alfonso; Moreno-Sánchez, Ismael; Helmlinger, Dominique; Ibeas, José I.

    2015-01-01

    Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs) play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis. PMID:26317403

  20. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

    PubMed

    Elías-Villalobos, Alberto; Fernández-Álvarez, Alfonso; Moreno-Sánchez, Ismael; Helmlinger, Dominique; Ibeas, José I

    2015-08-01

    Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs) play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

  1. Knockdown of Sec8 promotes cell-cycle arrest at G1/S phase by inducing p21 via control of FOXO proteins.

    PubMed

    Tanaka, Toshiaki; Iino, Mituyoshi

    2014-02-01

    p21(Cip1) protein inhibits the activity of cyclins at the G(1) checkpoint and influences transition of cells from the G(1) to the S phase of the cell cycle. Moreover, expression of members of the FOXO family (active form of forkhead transcription factors of the O class) in dividing cells promotes cell-cycle arrest at the G(1)/S boundary via regulation of p21(Cip1). Recently, the exocyst complex, including Sec8, has been implicated in various roles independent of its role in secretion, such as cell migration, invadopodia formation, cytokinesis, glucose uptake and neural development. Given the essential roles of the exocyst complex in cellular and developmental processes, disruption of its function may be involved in various diseases such as cancer, diabetes and neuronal disorders. However, the relationship between Sec8 and the cell cycle remains to be elucidated. In this study, knockdown of Sec8 inhibited cell growth and promoted cell-cycle arrest at the G(1)/S phase by control of p21 expression and retinoblastoma protein phosphorylation. Furthermore, Sec8 regulated FOXO family proteins via ubiquitin-proteasome degradation by regulating the expression of the murine double minute 2 (Mdm2) protein but not S-phase kinase-associated protein 2 (Skp2).

  2. Geothermal district G1

    SciTech Connect

    Not Available

    1988-12-01

    Geothermal District G1 includes 37 northeastern California counties and six geothermal fields: Lake City, Susanville, Litchfield, Wendel, Amedee, and Casa Diablo. Electrical generation from geothermal resources occurs in three of the fields: Wendel, Amedee, and Casa Diablo. Low-temperature geothermal projects are underway throughout the district and are described in a road log format. The ten projects described are located at Big Bend, Glass Mountain, Bieber, Alturas, Cedarville, Lake City, Honey Lake Valley, Greenville, and in Sierra and Mono Counties.

  3. Antiepileptic drugs with histone deacetylase inhibition activity and prostate cancer risk: a population-based case-control study.

    PubMed

    Salminen, Jukka K; Tammela, Teuvo L J; Auvinen, Anssi; Murtola, Teemu J

    2016-05-01

    Previous studies suggest that antiepileptic drugs with histone deacetylase (HDAC) inhibitor properties may have prostate cancer preventive effects. We evaluated the association between antiepileptic drug use and prostate cancer risk in a population-based case-control study. The study included all new prostate cancer cases diagnosed in Finland in 1995-2002 and matched controls (24,657 case-control pairs) identified from the Finnish Cancer Registry and the Population Register Center, respectively. Information on antiepileptic drug purchases was obtained from the national prescription reimbursement database. Odds ratios and their 95 % confidence intervals were estimated using age-adjusted and multivariable-adjusted conditional logistic regression analysis. Compared to never-users of antiepileptic drugs, the overall prostate cancer risk was decreased among users of phenobarbital, carbamazepine, and valproic acid (multivariable-adjusted odds ratio (OR) 0.47, 95 % CI 0.24-0.92; OR 0.82, 95 % CI 0.71-0.94, and OR 0.62, 95 % CI 0.42-0.92, respectively), but not among users of other antiepileptic drugs. Overall prostate cancer risk decreased in a dose-dependent manner by cumulative amount, duration and yearly dosage (intensity) of HDAC inhibitors valproic acid and carbamazepine. The risk of advanced prostate cancer was decreased only among carbamazepine users (OR 0.65, 95 % CI 0.44-0.96). Our results support possible prostate cancer preventive effects of HDAC inhibitors. However, also phenobarbital use was associated with decreased prostate cancer risk, despite not having HDAC inhibiting activity. The mechanism of action for antiepileptic drugs in prostate cancer deserves further study. PMID:27038166

  4. Deregulated G1–S control and energy stress contribute to the synthetic-lethal interactions between inactivation of RB and TSC1 or TSC2

    PubMed Central

    Gordon, Gabriel M.; Zhang, Tianyi; Zhao, Jiong; Du, Wei

    2013-01-01

    Summary Synthetic lethality is a potential strategy for cancer treatment by specifically promoting the death of cancer cells with particular defects such as the loss of the RB (RB1) tumor suppressor. We previously showed that inactivation of both RB and TSC2 induces synergistic apoptosis during the development of Drosophila melanogaster and in cancer cells. However, the in vivo mechanism of this synthetic-lethal interaction is not clear. Here, we show that synergistic cell death in tissues that have lost the RB and TSC orthologs rbf and dtsc1/gig, respectively, or overexpress Rheb and dE2F1, are correlated with synergistic defects in G1–S control, which causes cells to accumulate DNA damage. Coexpression of the G1–S inhibitor Dap, but not the G2–M inhibitor dWee1, decreases DNA damage and reduces cell death. In addition, we show that rbf and dtsc1 mutant cells are under energy stress, are sensitive to decreased energy levels and depend on the cellular energy stress-response pathway for survival. Decreasing mitochondrial ATP synthesis by inactivating cova or abrogating the energy-stress response by removing the metabolic regulator LKB1 both enhance the elimination of cells lacking either rbf or dtsc1. These observations, in conjunction with the finding that deregulation of TORC1 induces activation of JNK, indicate that multiple cellular stresses are induced and contribute to the synthetic-lethal interactions between RB and TSC1/TSC2 inactivation. The insights gained from this study suggest new approaches for targeting RB-deficient cancers. PMID:23447678

  5. Transformed mammalian cells are deficient in kinase-mediated control of progression through the G1 phase of the cell cycle.

    PubMed Central

    Crissman, H A; Gadbois, D M; Tobey, R A; Bradbury, E M

    1991-01-01

    To investigate the role of kinase-mediated mechanisms in regulating mammalian cell proliferation, we determined the effects of the general protein kinase inhibitor staurosporine on the proliferation of a series of nontransformed and transformed cultured rodent and human cells. Levels of staurosporine as low as 1 ng/ml prevented nontransformed cells from entering S phase (i.e., induced G1 arrest), indicating that kinase-mediated processes are essential for commitment to DNA replication in normal cells. At higher concentrations of staurosporine (50-75 ng/ml), nontransformed mammalian cells were arrested in both G1 and G2. The period of sensitivity of nontransformed human diploid fibroblasts to low levels of the drug commenced 3 hr later than the G0/G1 boundary and extended through the G1/S boundary. Interference with activity of the G1-essential kinase(s) caused nontransformed human cells traversing mid-to-late G1 at the time of staurosporine addition to be "set back" to the initial staurosporine block point, suggesting the existence of a kinase-dependent "G1 clock" mechanism that must function continuously throughout the early cycle in normal cells. The initial staurosporine block point at 3 hr into G1 corresponds to neither the serum nor the amino acid restriction point. In marked contrast to the behavior of nontransformed cells, neither low nor high concentrations of staurosporine affected G1 progression in transformed cultures; high drug concentrations caused transformed cells to be arrested solely in G2. These results indicate that kinase-mediated regulation of DNA replication is lost as the result of neoplastic transformation, but the G2-arrest mechanism remains intact. Images PMID:1652754

  6. Fus3p and Kss1p control G1 arrest in Saccharomyces cerevisiae through a balance of distinct arrest and proliferative functions that operate in parallel with Far1p.

    PubMed Central

    Cherkasova, V; Lyons, D M; Elion, E A

    1999-01-01

    In Saccharomyces cerevisiae, mating pheromones activate two MAP kinases (MAPKs), Fus3p and Kss1p, to induce G1 arrest prior to mating. Fus3p is known to promote G1 arrest by activating Far1p, which inhibits three Clnp/Cdc28p kinases. To analyze the contribution of Fus3p and Kss1p to G1 arrest that is independent of Far1p, we constructed far1 CLN strains that undergo G1 arrest from increased activation of the mating MAP kinase pathway. We find that Fus3p and Kss1p both control G1 arrest through multiple functions that operate in parallel with Far1p. Fus3p and Kss1p together promote G1 arrest by repressing transcription of G1/S cyclin genes (CLN1, CLN2, CLB5) by a mechanism that blocks their activation by Cln3p/Cdc28p kinase. In addition, Fus3p and Kss1p counteract G1 arrest through overlapping and distinct functions. Fus3p and Kss1p together increase the expression of CLN3 and PCL2 genes that promote budding, and Kss1p inhibits the MAP kinase cascade. Strikingly, Fus3p promotes proliferation by a novel function that is not linked to reduced Ste12p activity or increased levels of Cln2p/Cdc28p kinase. Genetic analysis suggests that Fus3p promotes proliferation through activation of Mcm1p transcription factor that upregulates numerous genes in G1 phase. Thus, Fus3p and Kss1p control G1 arrest through a balance of arrest functions that inhibit the Cdc28p machinery and proliferative functions that bypass this inhibition. PMID:10049917

  7. The histone deacetylase SIRT6 controls embryonic stem cell fate via TET-mediated production of 5-hydroxymethylcytosine.

    PubMed

    Etchegaray, Jean-Pierre; Chavez, Lukas; Huang, Yun; Ross, Kenneth N; Choi, Jiho; Martinez-Pastor, Barbara; Walsh, Ryan M; Sommer, Cesar A; Lienhard, Matthias; Gladden, Adrianne; Kugel, Sita; Silberman, Dafne M; Ramaswamy, Sridhar; Mostoslavsky, Gustavo; Hochedlinger, Konrad; Goren, Alon; Rao, Anjana; Mostoslavsky, Raul

    2015-05-01

    How embryonic stem cells (ESCs) commit to specific cell lineages and yield all cell types of a fully formed organism remains a major question. ESC differentiation is accompanied by large-scale histone and DNA modifications, but the relations between these epigenetic categories are not understood. Here we demonstrate the interplay between the histone deacetylase sirtuin 6 (SIRT6) and the ten-eleven translocation enzymes (TETs). SIRT6 targets acetylated histone H3 at Lys 9 and 56 (H3K9ac and H3K56ac), while TETs convert 5-methylcytosine into 5-hydroxymethylcytosine (5hmC). ESCs derived from Sirt6 knockout (S6KO) mice are skewed towards neuroectoderm development. This phenotype involves derepression of OCT4, SOX2 and NANOG, which causes an upregulation of TET-dependent production of 5hmC. Genome-wide analysis revealed neural genes marked with 5hmC in S6KO ESCs, thereby implicating TET enzymes in the neuroectoderm-skewed differentiation phenotype. We demonstrate that SIRT6 functions as a chromatin regulator safeguarding the balance between pluripotency and differentiation through Tet-mediated production of 5hmC.

  8. Overexpression of histone deacetylases in cancer cells is controlled by interplay of transcription factors and epigenetic modulators.

    PubMed

    Yang, Hui; Salz, Tal; Zajac-Kaye, Maria; Liao, Daiqing; Huang, Suming; Qiu, Yi

    2014-10-01

    Histone deacetylases (HDACs) that deacetylate histone and nonhistone proteins play crucial roles in a variety of cellular processes. The overexpression of HDACs is reported in many cancer types and is directly linked to accelerated cell proliferation and survival. However, little is known about how HDAC expression is regulated in cancer cells. In this study, we found that HDAC1 and HDAC2 promoters are regulated through collaborative binding of transcription factors Sp1/Sp3 and epigenetic modulators, including histone H3K4 methyltransferase SET1 and histone acetyltransferase p300, whose levels are also elevated in colon cancer cell lines and patient samples. Interestingly, Sp1 and Sp3 differentially regulate HDAC1 and HDAC2 promoter activity. In addition, Sp1/Sp3 recruits SET1 and p300 to the promoters. SET1 knockdown (KD) results in a loss of the H3K4 trimethylation mark at the promoters, as well as destabilizes p300 at the promoters. Conversely, p300 also influences SET1 recruitment and H3K4me3 level, indicating a crosstalk between p300 and SET1. Further, SET1 KD reduces Sp1 binding to the HDAC1 promoter through the increase of Sp1 acetylation. These results indicate that interactions among transcription factors and epigenetic modulators orchestrate the activation of HDAC1 and HDAC2 promoter activity in colon cancer cells. PMID:24948597

  9. The Histone Deacetylase Sirt6 Controls Embryonic Stem Cell Fate Via Tet-Mediated Production of 5-Hydroxymethylcytosine

    PubMed Central

    Etchegaray, Jean-Pierre; Chavez, Lukas; Huang, Yun; Ross, Kenneth N.; Choi, Jiho; Martinez-Pastor, Barbara; Walsh, Ryan M.; Sommer, Cesar A.; Lienhard, Matthias; Kugel, Sita; Silberman, Dafne M.; Ramaswamy, Sridhar; Mostoslavsky, Gustavo; Hochedlinger, Konrad; Goren, Alon; Rao, Anjana; Mostoslavsky, Raul

    2015-01-01

    How embryonic stem cells (ESC) commit to specific cell lineages and ultimately yield all cell types of a fully formed organism remains a major question. ESC differentiation is accompanied by large-scale histone and DNA modifications, but the relations between these two categories of epigenetic changes are not understood. Here we demonstrate the hierarchical interplay between the histone deacetylase, sirtuin 6 (Sirt6), which targets acetylated histone H3 at lysines 9 and 56 (H3K9ac and H3K56ac), and the Tet (Ten-eleven translocation) enzymes, which convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). ESCs derived from Sirt6 knockout (S6KO) mice are skewed towards neuroectoderm development. This phenotype is associated with derepression of Oct4, Sox2 and Nanog, which in turn causes an upregulation of Tet enzymes and elevated production of 5hmC. Genome-wide analysis revealed an upregulation of neuroectoderm genes marked with 5hmC in S6KO ESCs, thereby implicating Tet enzymes in the neuroectoderm-skewed differentiation phenotype of S6KO ESCs, which is fully rescued upon knockdown of Tets. We demonstrate a new role for Sirt6 as a chromatin regulator safeguarding the balance between pluripotency and differentiation through Tet-dependent regulation of 5hmC levels. PMID:25915124

  10. Valproic Acid, a Histone Deacetylase Inhibitor, in Combination with Paclitaxel for Anaplastic Thyroid Cancer: Results of a Multicenter Randomized Controlled Phase II/III Trial

    PubMed Central

    Pugliese, Mariateresa; Gallo, Marco; Brignardello, Enrico; Milla, Paola; Orlandi, Fabio; Limone, Paolo Piero; Arvat, Emanuela; Boccuzzi, Giuseppe; Piovesan, Alessandro

    2016-01-01

    Anaplastic thyroid cancer (ATC) has a median survival less than 5 months and, to date, no effective therapy exists. Taxanes have recently been stated as the main drug treatment for ATC, and the histone deacetylase inhibitor valproic acid efficiently potentiates the effects of paclitaxel in vitro. Based on these data, this trial assessed the efficacy and safety of the combination of paclitaxel and valproic acid for the treatment of ATC. This was a randomized, controlled phase II/III trial, performed on 25 ATC patients across 5 centers in northwest Italy. The experimental arm received the combination of paclitaxel (80 mg/m2/weekly) and valproic acid (1,000 mg/day); the control arm received paclitaxel alone. Overall survival and disease progression, evaluated in terms of progression-free survival, were the primary outcomes. The secondary outcome was the pharmacokinetics of paclitaxel. The coadministration of valproic acid did not influence the pharmacokinetics of paclitaxel. Neither median survival nor median time to progression was statistically different in the two arms. Median survival of operated-on patients was significantly better than that of patients who were not operated on. The present trial demonstrates that the addition of valproic acid to paclitaxel has no effect on overall survival and disease progression of ATC patients. This trial is registered with EudraCT 2008-005221-11. PMID:27766105

  11. Histone deacetylases and atherosclerosis.

    PubMed

    Zheng, Xia-xia; Zhou, Tian; Wang, Xin-An; Tong, Xiao-hong; Ding, Jia-wang

    2015-06-01

    Atherosclerosis is the most common pathological process that leads to cardiovascular diseases, a disease of large- and medium-sized arteries that is characterized by a formation of atherosclerotic plaques consisting of necrotic cores, calcified regions, accumulated modified lipids, smooth muscle cells (SMCs), endothelial cells, leukocytes, and foam cells. Recently, the question about how to suppress the occurrence of atherosclerosis and alleviate the progress of cardiovascular disease becomes the hot topic. Accumulating evidence suggests that histone deacetylases(HDACs) play crucial roles in arteriosclerosis. This review summarizes the effect of HDACs and HDAC inhibitors(HDACi) on the progress of atherosclerosis.

  12. Role of RhoA, mDia, and ROCK in cell shape-dependent control of the Skp2-p27kip1 pathway and the G1/S transition.

    PubMed

    Mammoto, Akiko; Huang, Sui; Moore, Kimberly; Oh, Philmo; Ingber, Donald E

    2004-06-18

    Cell shape-dependent control of cell-cycle progression underlies the spatial differentials of growth that drive tissue morphogenesis, yet little is known about how cell distortion impacts the biochemical signaling machinery that is responsible for growth control. Here we show that the Rho family GTPase, RhoA, conveys the "cell shape signal" to the cell-cycle machinery in human capillary endothelial cells. Cells accumulating p27(kip1) and arrested in mid G(1) phase when spreading were inhibited by restricted extracellular matrix adhesion, whereas constitutively active RhoA increased expression of the F-box protein Skp2 required for ubiquitination-dependent degradation of p27(kip1) and restored G(1) progression in these cells. Studies with dominant-negative and constitutively active forms of mDia1, a downstream effector of RhoA, and with a pharmacological inhibitor of ROCK, another RhoA target, revealed that RhoA promoted G(1) progression by altering the balance of activities between these two downstream effectors. These data indicate that signaling proteins such as mDia1 and ROCK, which are thought to be involved primarily in cytoskeletal remodeling, also mediate cell growth regulation by coupling cell shape to the cell-cycle machinery at the level of signal transduction.

  13. Uterine Natural Killer Cell and Human Leukocyte Antigen-G1 and Human Leukocyte Antigen-G5 Expression in Vaginal Discharge of Threatened-Abortion Women: A Case-Control Study.

    PubMed

    Shobeiri, Saeideh Sadat; Rahmani, Zahra; Hossein Nataj, Hadi; Ranjbaran, Hossein; Mohammadi, Masoud; Abediankenari, Saeid

    2015-01-01

    The immunotolerant human leukocyte antigen-G (HLA-G) molecules have a major role in fetal-maternal tolerance during pregnancy. Interaction between these molecules and uterine natural killer (uNK) cells inhibitory receptors prevents NK cell invasion against fetus trophoblast cells. The aim of this study was to evaluate the percentages of uNK cells and HLA-G1 and HLA-G5 isoforms expression in vaginal discharge of threatened-abortion women in comparison with control. In a case-control study, we investigated 30 threatened-abortion women with bleeding or spotting less than 20 weeks of pregnancy as compared to 30 normal pregnant women. uNK cells percentage was assessed by flow cytometry. Furthermore, we evaluated HLA-G1 and HLA-G5 isoforms expression by Real-Time PCR in these groups. The results of this study showed that threatened-abortion women had increased uNK cells and decreased T cells percentage in vaginal discharge in comparison with normal pregnant women (p = 0.01, p = 0.003, resp.). In addition, HLA-G1 isoform had lower expression in threatened-abortion women in comparison with control group (p = 0.0001). The increase of uNK cells level with the decrease of HLA-G expression in vaginal discharge of threatened-abortion pregnant women is an indicator of mother's immune dysregulation. It is concluded that HLA-G expression level with uNK cells percentage can be determined as a diagnostic marker for threatened-abortion women. PMID:26509178

  14. Uterine Natural Killer Cell and Human Leukocyte Antigen-G1 and Human Leukocyte Antigen-G5 Expression in Vaginal Discharge of Threatened-Abortion Women: A Case-Control Study

    PubMed Central

    Shobeiri, Saeideh Sadat; Rahmani, Zahra; Hossein Nataj, Hadi; Ranjbaran, Hossein; Mohammadi, Masoud; Abediankenari, Saeid

    2015-01-01

    The immunotolerant human leukocyte antigen-G (HLA-G) molecules have a major role in fetal-maternal tolerance during pregnancy. Interaction between these molecules and uterine natural killer (uNK) cells inhibitory receptors prevents NK cell invasion against fetus trophoblast cells. The aim of this study was to evaluate the percentages of uNK cells and HLA-G1 and HLA-G5 isoforms expression in vaginal discharge of threatened-abortion women in comparison with control. In a case-control study, we investigated 30 threatened-abortion women with bleeding or spotting less than 20 weeks of pregnancy as compared to 30 normal pregnant women. uNK cells percentage was assessed by flow cytometry. Furthermore, we evaluated HLA-G1 and HLA-G5 isoforms expression by Real-Time PCR in these groups. The results of this study showed that threatened-abortion women had increased uNK cells and decreased T cells percentage in vaginal discharge in comparison with normal pregnant women (p = 0.01, p = 0.003, resp.). In addition, HLA-G1 isoform had lower expression in threatened-abortion women in comparison with control group (p = 0.0001). The increase of uNK cells level with the decrease of HLA-G expression in vaginal discharge of threatened-abortion pregnant women is an indicator of mother's immune dysregulation. It is concluded that HLA-G expression level with uNK cells percentage can be determined as a diagnostic marker for threatened-abortion women. PMID:26509178

  15. Role for histone deacetylase 1 in human tumor cell proliferation.

    PubMed

    Senese, Silvia; Zaragoza, Katrin; Minardi, Simone; Muradore, Ivan; Ronzoni, Simona; Passafaro, Alfonso; Bernard, Loris; Draetta, Giulio F; Alcalay, Myriam; Seiser, Christian; Chiocca, Susanna

    2007-07-01

    Posttranslational modifications of core histones are central to the regulation of gene expression. Histone deacetylases (HDACs) repress transcription by deacetylating histones, and class I HDACs have a crucial role in mouse, Xenopus laevis, zebra fish, and Caenorhabditis elegans development. The role of individual class I HDACs in tumor cell proliferation was investigated using RNA interference-mediated protein knockdown. We show here that in the absence of HDAC1 cells can arrest either at the G(1) phase of the cell cycle or at the G(2)/M transition, resulting in the loss of mitotic cells, cell growth inhibition, and an increase in the percentage of apoptotic cells. On the contrary, HDAC2 knockdown showed no effect on cell proliferation unless we concurrently knocked down HDAC1. Using gene expression profiling analysis, we found that inactivation of HDAC1 affected the transcription of specific target genes involved in proliferation and apoptosis. Furthermore, HDAC2 downregulation did not cause significant changes compared to control cells, while inactivation of HDAC1, HDAC1 plus HDAC2, or HDAC3 resulted in more distinct clusters. Loss of these HDACs might impair cell cycle progression by affecting not only the transcription of specific target genes but also other biological processes. Our data support the idea that a drug targeting specific HDACs could be highly beneficial in the treatment of cancer.

  16. Rho-kinase signaling controls nucleocytoplasmic shuttling of class IIa histone deacetylase (HDAC7) and transcriptional activation of orphan nuclear receptor NR4A1.

    PubMed

    Compagnucci, Claudia; Barresi, Sabina; Petrini, Stefania; Bertini, Enrico; Zanni, Ginevra

    2015-04-01

    Rho-kinase (ROCK) has been well documented to play a key role in RhoA-induced actin remodeling. ROCK activation results in myosin light chain (MLC) phosphorylation either by direct action on MLC kinase (MLCK) or by inhibition of MLC phosphatase (MLCP), modulating actin-myosin contraction. We found that inhibition of the ROCK pathway in induced pluripotent stem cells, leads to nuclear export of HDAC7 and transcriptional activation of the orphan nuclear receptor NR4A1 while in cells with constitutive ROCK hyperactivity due to loss of function of the RhoGTPase activating protein Oligophrenin-1 (OPHN1), the orphan nuclear receptor NR4A1 is downregulated. Our study identify a new target of ROCK signaling via myosin phosphatase subunit (MYPT1) and Histone Deacetylase (HDAC7) at the nuclear level and provide new insights in the cellular functions of ROCK.

  17. Saccharomyces cerevisiae TORC1 Controls Histone Acetylation by Signaling Through the Sit4/PP6 Phosphatase to Regulate Sirtuin Deacetylase Nuclear Accumulation

    PubMed Central

    Workman, Jason J.; Chen, Hongfeng; Laribee, R. Nicholas

    2016-01-01

    The epigenome responds to changes in the extracellular environment, yet how this information is transmitted to the epigenetic regulatory machinery is unclear. Using a Saccharomyces cerevisiae yeast model, we demonstrate that target of rapamycin complex 1 (TORC1) signaling, which is activated by nitrogen metabolism and amino acid availability, promotes site-specific acetylation of histone H3 and H4 N-terminal tails by opposing the activity of the sirtuin deacetylases Hst3 and Hst4. TORC1 does so through suppression of the Tap42-regulated Sit4 (PP6) phosphatase complex, as sit4Δ rescues histone acetylation under TORC1-repressive conditions. We further demonstrate that TORC1 inhibition, and subsequent PP6 activation, causes a selective, rapid, nuclear accumulation of Hst4, which correlates with decreased histone acetylation. This increased Hst4 nuclear localization precedes an elevation in Hst4 protein expression, which is attributed to reduced protein turnover, suggesting that nutrient signaling through TORC1 may limit Hst4 nuclear accumulation to facilitate Hst4 degradation and maintain histone acetylation. This pathway is functionally relevant to TORC1 signaling since the stress sensitivity of a nonessential TORC1 mutant (tco89Δ) to hydroxyurea and arsenic can be reversed by combining tco89Δ with either hst3Δ, hst4Δ, or sit4Δ. Surprisingly, while hst3Δ or hst4Δ rescues the sensitivity tco89Δ has to low concentrations of the TORC1 inhibitor rapamycin, sit4Δ fails to do so. These results suggest Sit4 provides an additional function necessary for TORC1-dependent cell growth and proliferation. Collectively, this study defines a novel mechanism by which TORC1 suppresses a PP6-regulated sirtuin deacetylase pathway to couple nutrient signaling to epigenetic regulation. PMID:27343235

  18. Beyond Histone and Deacetylase: An Overview of Cytoplasmic Histone Deacetylases and Their Nonhistone Substrates

    PubMed Central

    Yao, Ya-Li; Yang, Wen-Ming

    2011-01-01

    Acetylation of lysines is a prominent form of modification in mammalian proteins. Deacetylation of proteins is catalyzed by histone deacetylases, traditionally named after their role in histone deacetylation, transcriptional modulation, and epigenetic regulation. Despite the link between histone deacetylases and chromatin structure, some of the histone deacetylases reside in various compartments in the cytoplasm. Here, we review how these cytoplasmic histone deacetylases are regulated, the identification of nonhistone substrates, and the functional implications of their nondeacetylase enzymatic activities. PMID:21234400

  19. Rho-kinase signaling controls nucleocytoplasmic shuttling of class IIa Histone Deacetylase (HDAC7) and transcriptional activation of orphan nuclear receptor NR4A1

    SciTech Connect

    Compagnucci, Claudia; Barresi, Sabina; Petrini, Stefania; Bertini, Enrico; Zanni, Ginevra

    2015-04-03

    Rho-kinase (ROCK) has been well documented to play a key role in RhoA-induced actin remodeling. ROCK activation results in myosin light chain (MLC) phosphorylation either by direct action on MLC kinase (MLCK) or by inhibition of MLC phosphatase (MLCP), modulating actin–myosin contraction. We found that inhibition of the ROCK pathway in induced pluripotent stem cells, leads to nuclear export of HDAC7 and transcriptional activation of the orphan nuclear receptor NR4A1 while in cells with constitutive ROCK hyperactivity due to loss of function of the RhoGTPase activating protein Oligophrenin-1 (OPHN1), the orphan nuclear receptor NR4A1 is downregulated. Our study identify a new target of ROCK signaling via myosin phosphatase subunit (MYPT1) and Histone Deacetylase (HDAC7) at the nuclear level and provide new insights in the cellular functions of ROCK. - Highlights: • ROCK regulates nucleocytoplasmic shuttling of HDAC7 via phosphorylation of MYPT1. • Nuclear export of HDAC7 and upregulation of NR4A1 occurs with low ROCK activity. • High levels of ROCK activity due to OPHN1 loss of function downregulate NR4A1.

  20. Knockdown of Selenocysteine-Specific Elongation Factor in Amblyomma maculatum Alters the Pathogen Burden of Rickettsia parkeri with Epigenetic Control by the Sin3 Histone Deacetylase Corepressor Complex

    PubMed Central

    Adamson, Steven W.; Browning, Rebecca E.; Budachetri, Khemraj; Ribeiro, José M. C.; Karim, Shahid

    2013-01-01

    Selenocysteine is the 21st naturally-occurring amino acid. Selenoproteins have diverse functions and many remain uncharacterized, but they are typically associated with antioxidant activity. The incorporation of selenocysteine into the nascent polypeptide chain recodes the TGA stop codon and this process depends upon a number of essential factors including the selenocysteine elongation factor (SEF). The transcriptional expression of SEF did not change significantly in tick midguts throughout the blood meal, but decreased in salivary glands to 20% at the end of the fast feeding phase. Since selenoprotein translation requires this specialized elongation factor, we targeted this gene for knockdown by RNAi to gain a global view of the role selenoproteins play in tick physiology. We found no significant differences in tick engorgement and embryogenesis but detected no antioxidant capacity in tick saliva. The transcriptional profile of selenoproteins in R. parkeri-infected Amblyomma maculatum revealed declined activity of selenoprotein M and catalase and increased activity of selenoprotein O, selenoprotein S, and selenoprotein T. Furthermore, the pathogen burden was significantly altered in SEF-knockdowns. We then determined the global impact of SEF-knockdown by RNA-seq, and mapped huge shifts in secretory gene expression that could be the result of downregulation of the Sin3 histone deacetylase corepressor complex. PMID:24282621

  1. Strategic cell-cycle regulatory features that provide mammalian cells with tunable G1 length and reversible G1 arrest.

    PubMed

    Pfeuty, Benjamin

    2012-01-01

    Transitions between consecutive phases of the eukaryotic cell cycle are driven by the catalytic activity of selected sets of cyclin-dependent kinases (Cdks). Yet, their occurrence and precise timing is tightly scheduled by a variety of means including Cdk association with inhibitory/adaptor proteins (CKIs). Here we focus on the regulation of G1-phase duration by the end of which cells of multicelled organisms must decide whether to enter S phase or halt, and eventually then, differentiate, senesce or die to obey the homeostatic rules of their host. In mammalian cells, entry in and progression through G1 phase involve sequential phosphorylation and inactivation of the retinoblastoma Rb proteins, first, by cyclin D-Cdk4,6 with the help of CKIs of the Cip/Kip family and, next, by the cyclin E-Cdk2 complexes that are negatively regulated by Cip/Kip proteins. Using a dynamical modeling approach, we show that the very way how the Rb and Cip/Kip regulatory modules interact differentially with cyclin D-Cdk4,6 and cyclin E-Cdk2 provides to mammalian cells a powerful means to achieve an exquisitely-sensitive control of G1-phase duration and fully reversible G1 arrests. Consistently, corruption of either one of these two modules precludes G1 phase elongation and is able to convert G1 arrests from reversible to irreversible. This study unveils fundamental design principles of mammalian G1-phase regulation that are likely to confer to mammalian cells the ability to faithfully control the occurrence and timing of their division process in various conditions.

  2. FoxO3 transcription factor and Sirt6 deacetylase regulate low density lipoprotein (LDL)-cholesterol homeostasis via control of the proprotein convertase subtilisin/kexin type 9 (Pcsk9) gene expression.

    PubMed

    Tao, Rongya; Xiong, Xiwen; DePinho, Ronald A; Deng, Chu-Xia; Dong, X Charlie

    2013-10-11

    Elevated LDL-cholesterol is a risk factor for the development of cardiovascular disease. Thus, proper control of LDL-cholesterol homeostasis is critical for organismal health. Genetic analysis has identified PCSK9 (proprotein convertase subtilisin/kexin type 9) as a crucial gene in the regulation of LDL-cholesterol via control of LDL receptor degradation. Although biochemical characteristics and clinical implications of PCSK9 have been extensively investigated, epigenetic regulation of this gene is largely unknown. In this work we have discovered that Sirt6, an NAD(+)-dependent histone deacetylase, plays a critical role in the regulation of the Pcsk9 gene expression in mice. Hepatic Sirt6 deficiency leads to elevated Pcsk9 gene expression and LDL-cholesterol as well. Mechanistically, we have demonstrated that Sirt6 can be recruited by forkhead transcription factor FoxO3 to the proximal promoter region of the Pcsk9 gene and deacetylates histone H3 at lysines 9 and 56, thereby suppressing the gene expression. Also remarkably, overexpression of Sirt6 in high fat diet-fed mice lowers LDL-cholesterol. Overall, our data suggest that FoxO3 and Sirt6, two longevity genes, can reduce LDL-cholesterol levels through regulation of the Pcsk9 gene.

  3. Histone deacetylase inhibitors as cancer therapeutics.

    PubMed

    Clawson, Gary A

    2016-08-01

    Cancer cells contain significant alterations in their epigenomic landscape, which several enzyme families reversibly contribute to. One class of epigenetic modifying enzymes is that of histone deacetylases (HDAC), which are receiving considerable scrutiny clinically as a therapeutic target in many cancers. The underlying rationale is that inhibiting HDACs will reverse dysregulated target gene expression by modulating functional histone (or other) acetylation marks. This perspective will discuss a recent paper by Markozashvili and co-workers which appeared in Gene, which indicates that the mechanisms by which HDAC inhibitors (HDACis) alter the epigenetic landscape include widespread alternative effects beyond simply controlling regional epigenetic marks. HDACs are involved in many processes/diseases, and it is not surprising that HDACis have considerable off-target effects, and thus a major effort is being directed toward identification of inhibitors which are selective for HDAC isoforms often uniquely implicated in various cancers. This Perspective will also discuss some representative work with inhibitors targeting individual HDAC classes or isoforms. At present, it is not really clear that isoform-specific HDACis will avoid non-selective effects on other unrecognized activities of HDACs. PMID:27568481

  4. Histone deacetylase inhibitors as cancer therapeutics

    PubMed Central

    2016-01-01

    Cancer cells contain significant alterations in their epigenomic landscape, which several enzyme families reversibly contribute to. One class of epigenetic modifying enzymes is that of histone deacetylases (HDAC), which are receiving considerable scrutiny clinically as a therapeutic target in many cancers. The underlying rationale is that inhibiting HDACs will reverse dysregulated target gene expression by modulating functional histone (or other) acetylation marks. This perspective will discuss a recent paper by Markozashvili and co-workers which appeared in Gene, which indicates that the mechanisms by which HDAC inhibitors (HDACis) alter the epigenetic landscape include widespread alternative effects beyond simply controlling regional epigenetic marks. HDACs are involved in many processes/diseases, and it is not surprising that HDACis have considerable off-target effects, and thus a major effort is being directed toward identification of inhibitors which are selective for HDAC isoforms often uniquely implicated in various cancers. This Perspective will also discuss some representative work with inhibitors targeting individual HDAC classes or isoforms. At present, it is not really clear that isoform-specific HDACis will avoid non-selective effects on other unrecognized activities of HDACs. PMID:27568481

  5. Human fibroblast commitment to a senescence-like state in response to histone deacetylase inhibitors is cell cycle dependent.

    PubMed Central

    Ogryzko, V V; Hirai, T H; Russanova, V R; Barbie, D A; Howard, B H

    1996-01-01

    Human diploid fibroblasts (HDF) complete a limited number of cell divisions before entering a growth arrest state that is termed replicative senescence. Two histone deacetylase inhibitors, sodium butyrate and trichostatin A, dramatically reduce the HDF proliferative life span in a manner that is dependent on one or more cell doublings in the presence of these agents. Cells arrested and subsequently released from histone deacetylase inhibitors display markers of senescence and exhibit a persistent G1 block but remain competent to initiate a round of DNA synthesis in response to simian virus 40 T antigen. Average telomere length in prematurely arrested cells is greater than in senescent cells, reflecting a lower number of population doublings completed by the former. Taken together, these results support the view that one component of HDF senescence mimics a cell cycle-dependent drift in differentiation state and that propagation of HDF in histone deacetylase inhibitors accentuates this component. PMID:8756678

  6. Post-translational Modifications Regulate Class IIa Histone Deacetylase (HDAC) Function in Health and Disease*

    PubMed Central

    Mathias, Rommel A.; Guise, Amanda J.; Cristea, Ileana M.

    2015-01-01

    Class IIa histone deacetylases (HDACs4, -5, -7, and -9) modulate the physiology of the human cardiovascular, musculoskeletal, nervous, and immune systems. The regulatory capacity of this family of enzymes stems from their ability to shuttle between nuclear and cytoplasmic compartments in response to signal-driven post-translational modification. Here, we review the current knowledge of modifications that control spatial and temporal histone deacetylase functions by regulating subcellular localization, transcriptional functions, and cell cycle-dependent activity, ultimately impacting on human disease. We discuss the contribution of these modifications to cardiac and vascular hypertrophy, myoblast differentiation, neuronal cell survival, and neurodegenerative disorders. PMID:25616866

  7. Modulation of histone deacetylase 6 (HDAC6) nuclear import and tubulin deacetylase activity through acetylation.

    PubMed

    Liu, Yuanjing; Peng, Lirong; Seto, Edward; Huang, Suming; Qiu, Yi

    2012-08-17

    The reversible acetylation of histones and non-histone proteins by histone acetyltransferases and deacetylases (HDACs) plays a critical role in many cellular processes in eukaryotic cells. HDAC6 is a unique histone deacetylase with two deacetylase domains and a C-terminal zinc finger domain. HDAC6 resides mainly in the cytoplasm and regulates many important biological processes, including cell migration and degradation of misfold proteins. HDAC6 has also been shown to localize in the nucleus to regulate transcription. However, how HDAC6 shuttles between the nucleus and cytoplasm is largely unknown. In addition, it is not clear how HDAC6 enzymatic activity is modulated. Here, we show that HDAC6 can be acetylated by p300 on five clusters of lysine residues. One cluster (site B) of acetylated lysine is in the N-terminal nuclear localization signal region. These lysine residues in site B were converted to glutamine to mimic acetylated lysines. The mutations significantly reduced HDAC6 tubulin deacetylase activity and further impaired cell motility, but had no effect on histone deacetylase activity. More interestingly, these mutations retained HDAC6 in the cytoplasm by blocking the interaction with the nuclear import protein importin-α. The retention of HDAC6 in the cytoplasm by acetylation eventually affects histone deacetylation. Thus, we conclude that acetylation is an important post-translational modification that regulates HDAC6 tubulin deacetylase activity and nuclear import.

  8. Targeting Lysine Deacetylases (KDACs) in Parasites.

    PubMed

    Wang, Qi; Rosa, Bruce A; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  9. Histone Deacetylases and Mechanisms of Regulation of Gene Expression (Histone deacetylases in cancer)

    PubMed Central

    Chen, Hong Ping; Zhao, Yu Tina; Zhao, Ting C

    2016-01-01

    In recent years, it has become widely recognized that histone modification plays a pivotal role in controlling gene expression, and is involved in a wide spectrum of disease regulation. Histone acetylation is a major modification that affects gene transcription and is controlled by histone acetyltransferases (HATs) and histone deacetylases (HDAC). HATs acetylate lysines of histone proteins, resulting in relaxation of chromatin structure, and they also facilitate gene activation. Conversely, HDACs remove acetyl groups from hyperacetylated histones and suppress general gene transcription. In addition to histones, numerous non-histone proteins can be acetylated and deacetylated, and they are also involved in a wide range of disease regulation. To date, there are 18 HDACs in mammals classified into four classes based on homology to yeast HDACs. Accumulating evidence has revealed that HDACs play crucial roles in a variety of biological processes including inflammation, cell proliferation, apoptosis, and carcinogenesis. In this review, we summarize the current state of knowledge of HDACs in carcinogenesis and describe the involvement of HDACs in cancer-associated molecular processes. It is hoped than our understanding of the role of HDACs in cancer will lead to the design of more potent and specific drugs targeting selective HDAC proteins for the treatment of the disease. PMID:25746103

  10. Increased Expression of Bcl11b Leads to Chemoresistance Accompanied by G1 Accumulation

    PubMed Central

    Grabarczyk, Piotr; Nähse, Viola; Delin, Martin; Przybylski, Grzegorz; Depke, Maren; Hildebrandt, Petra; Völker, Uwe; Schmidt, Christian A.

    2010-01-01

    Background The expression of BCL11B was reported in T-cells, neurons and keratinocytes. Aberrations of BCL11B locus leading to abnormal gene transcription were identified in human hematological disorders and corresponding animal models. Recently, the elevated levels of Bcl11b protein have been described in a subset of squameous cell carcinoma cases. Despite the rapidly accumulating knowledge concerning Bcl11b biology, the contribution of this protein to normal or transformed cell homeostasis remains open. Methodology/Principal Findings Here, by employing an overexpression strategy we revealed formerly unidentified features of Bcl11b. Two different T-cell lines were forced to express BCL11B at levels similar to those observed in primary T-cell leukemias. This resulted in markedly increased resistance to radiomimetic drugs while no influence on death-receptor apoptotic pathway was observed. Apoptosis resistance triggered by BCL11B overexpression was accompanied by a cell cycle delay caused by accumulation of cells at G1. This cell cycle restriction was associated with upregulation of CDKN1C (p57) and CDKN2C (p18) cyclin dependent kinase inhibitors. Moreover, p27 and p130 proteins accumulated and the SKP2 gene encoding a protein of the ubiquitin-binding complex responsible for their degradation was repressed. Furthermore, the expression of the MYCN oncogene was silenced which resulted in significant depletion of the protein in cells expressing high BCL11B levels. Both cell cycle restriction and resistance to DNA-damage-induced apoptosis coincided and required the histone deacetylase binding N-terminal domain of Bcl11b. The sensitivity to genotoxic stress could be restored by the histone deacetylase inhibitor trichostatine A. Conclusions The data presented here suggest a potential role of BCL11B in tumor survival and encourage developing Bcl11b-inhibitory approaches as a potential tool to specifically target chemoresistant tumor cells. PMID:20824091

  11. 26 CFR 1.167(g)-1 - Basis for depreciation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Basis for depreciation. 1.167(g)-1 Section 1.167(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Itemized Deductions for Individuals and Corporations § 1.167(g)-1...

  12. 26 CFR 301.6503(g)-1 - Suspension pending correction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Suspension pending correction. 301.6503(g)-1 Section 301.6503(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Collection § 301.6503(g)-1 Suspension pending correction. The running of the periods of limitations...

  13. Cactin is essential for G1 progression in Toxoplasma gondii

    PubMed Central

    Szatanek, Tomasz; Anderson-White, Brooke R.; Faugno-Fusci, David M.; White, Michael; Saeij, Jeroen P.J.; Gubbels, Marc-Jan

    2012-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite whose rapid lytic replication cycles define its pathogenicity. We identified a temperature sensitive growth mutant, FV-P6, which irreversibly arrests before the middle of the G1 stage of the tachyzoite cell cycle. This arrest is caused by a point mutation in a gene conserved across eukaryotes, Cactin, whose product localizes to the nucleus. To elucidate the role of TgCactin we performed genome-wide expression profiling. Besides the expected G1 expression profile, many genes associated with the extracellular state as well as with the bradyzoite cyst stage were identified. Consistent with these profiles were the expression of AP2 transcription factors typically associated with extracellular and bradyzoite stage parasites. This suggests a role for TgCactin in control of gene expression. Since TgCactin does not contain any functionally defined domains we reasoned TgCactin exerts its function through interactions with other proteins. In support of this model we demonstrated that TgCactin is present in a protein complex and can oligomerize. Taken together, these results suggest that TgCactin acts as a pivotal protein potentially regulating gene expression at several transition points in parasite development. PMID:22486860

  14. Targeting Histone Deacetylases in Diseases: Where Are We?

    PubMed Central

    Benedetti, Rosaria; Conte, Mariarosaria

    2015-01-01

    Abstract Significance: Epigenetic inactivation of pivotal genes involved in cell growth is a hallmark of human pathologies, in particular cancer. Histone acetylation balance obtained through opposing actions of histone deacetylases (HDACs) and histone acetyltransferases is one epigenetic mechanism controlling gene expression and is, thus, associated with disease etiology and progression. Interfering pharmacologically with HDAC activity can correct abnormalities in cell proliferation, migration, vascularization, and death. Recent Advances: Histone deacetylase inhibitors (HDACi) represent a new class of cytostatic agents that interfere with the function of HDACs and are able to increase gene expression by indirectly inducing histone acetylation. Several HDACi, alone or in combination with DNA-demethylating agents, chemopreventive, or classical chemotherapeutic drugs, are currently being used in clinical trials for solid and hematological malignancies, and are, thus, promising candidates for cancer therapy. Critical Issues: (i) Non-specific (off-target) HDACi effects due to activities unassociated with HDAC inhibition. (ii) Advantages/disadvantages of non-selective or isoform-directed HDACi. (iii) Limited number of response-predictive biomarkers. (iv) Toxicity leading to dysfunction of critical biological processes. Future Directions: Selective HDACi could achieve enhanced clinical utility by reducing or eliminating the serious side effects associated with current first-generation non-selective HDACi. Isoform-selective and pan-HDACi candidates might benefit from the identification of biomarkers, enabling better patient stratification and prediction of response to treatment. Antioxid. Redox Signal. 23, 99–126. PMID:24382114

  15. Histone deacetylase 3 indirectly modulates tubulin acetylation.

    PubMed

    Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

    2015-12-15

    Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3-silencing mediator of retinoic and thyroid receptors (SMRT)-deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation.

  16. Histone deacetylase inhibitors and cell death

    PubMed Central

    Zhang, Jing; Zhong, Qing

    2014-01-01

    Histone deacetylases (HDACs) are a vast family of enzymes involved in chromatin remodeling and have crucial roles in numerous biological processes, largely through their repressive influence on transcription. In addition to modifying histones, HDACs also target many other non-histone protein substrates to regulate gene expression. Recently, HDACs have gained growing attention as HDAC-inhibiting compounds are being developed as promising cancer therapeutics. Histone deacetylase inhibitors (HDACi) have been shown to induce differentiation, cell cycle arrest, apoptosis, autophagy and necrosis in a variety of transformed cell lines. In this review, we mainly discuss how HDACi may elicit a therapeutic response to human cancers through different cell death pathways, in particular, apoptosis and autophagy. PMID:24898083

  17. Most of the G1 period in hamster cells is eliminated by lengthening the S period.

    PubMed Central

    Stancel, G M; Prescott, D M; Liskay, R M

    1981-01-01

    Two Chinese hamster cell lines, G1+-1 and CHO, have been grown in the presence of low concentrations of hydroxyurea to determine how a slowing DNA synthesis (i.e., a lengthening of the S period) affects the length of the G1 period. Hydroxyurea concentrations of approximately 10 microM do not alter the generation times of these cell lines but do cause increases in S with corresponding decreases in G1. In both cell lines, 10 microM hydroxyurea reduces G1 to an absolute value of 1 hr, which represents decreases of 70% (G1+-1) and 60% (CHO) from control values. Higher concentrations of hydroxyurea increase the generation times and lengths of S for both cell lines but do not reduce G1 below the minimum value of 1 hr. These observations indicate that the majority of G1 is expendable and most of G1 therefore cannot contain specific events required for the initiation of DNA synthesis. This result supports the hypothesis that G1 is a portion of the cell growth cycle but not of the chromosome cycle. PMID:6947230

  18. Structure of Prokaryotic Polyamine Deacetylase Reveals Evolutionary Functional Relationships with Eukaryotic Histone Deacetylases

    SciTech Connect

    P Lombardi; H Angell; D Whittington; E Flynn; K Rajashankar; D Christianson

    2011-12-31

    Polyamines are a ubiquitous class of polycationic small molecules that can influence gene expression by binding to nucleic acids. Reversible polyamine acetylation regulates nucleic acid binding and is required for normal cell cycle progression and proliferation. Here, we report the structures of Mycoplana ramosa acetylpolyamine amidohydrolase (APAH) complexed with a transition state analogue and a hydroxamate inhibitor and an inactive mutant complexed with two acetylpolyamine substrates. The structure of APAH is the first of a histone deacetylase-like oligomer and reveals that an 18-residue insert in the L2 loop promotes dimerization and the formation of an 18 {angstrom} long 'L'-shaped active site tunnel at the dimer interface, accessible only to narrow and flexible substrates. The importance of dimerization for polyamine deacetylase function leads to the suggestion that a comparable dimeric or double-domain histone deacetylase could catalyze polyamine deacetylation reactions in eukaryotes.

  19. Targeting Lysine Deacetylases (KDACs) in Parasites

    PubMed Central

    Wang, Qi; Rosa, Bruce A.; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R.; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  20. Targeting Lysine Deacetylases (KDACs) in Parasites.

    PubMed

    Wang, Qi; Rosa, Bruce A; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  1. 26 CFR 1.475(g)-1 - Effective dates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (ii) A taxpayer may rely on the rules set out in § 1.475(c)-1T(b) (as contained in 26 CFR part 1... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Effective dates. 1.475(g)-1 Section 1.475(g)-1...) INCOME TAXES Inventories § 1.475(g)-1 Effective dates. (a)-(b) (c) Section 1.475(a)-3...

  2. 26 CFR 1.280G-1 - Golden parachute payments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....280G-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Items Not Deductible § 1.280G-1 Golden parachute payments. The following questions... Revenue Code of 1986, as added by section 67 of the Tax Reform Act of 1984 (Pub. L. No. 98-369; 98...

  3. 26 CFR 1.514(g)-1 - Business lease indebtedness.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Business lease indebtedness. 1.514(g)-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations § 1.514(g)-1 Business lease indebtedness. (a) Definition. The term business lease indebtedness means, with respect...

  4. 26 CFR 1.514(g)-1 - Business lease indebtedness.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Business lease indebtedness. 1.514(g)-1 Section... TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations § 1.514(g)-1 Business lease indebtedness. (a) Definition. The term business lease indebtedness...

  5. 26 CFR 1.514(g)-1 - Business lease indebtedness.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Business lease indebtedness. 1.514(g)-1 Section 1.514(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations §...

  6. NARSTO SOS99NASH G-1 AIR CHEMISTRY DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO SOS99NASH G-1 AIR CHEMISTRY DATA Project Title:  NARSTO ... Carbon Monoxide Ultraviolet Radiation Atmospheric Pressure Atmospheric Temperature Dew Point Upper Level Winds ... Data Guide Documents:  SOS99Nash G-1 Air Guide Related Data:  Southern Oxidants Study ...

  7. Histone deacetylase 9 regulates breast cancer cell proliferation and the response to histone deacetylase inhibitors

    PubMed Central

    Lapierre, Marion; Linares, Aurélien; Dalvai, Mathieu; Duraffourd, Céline; Bonnet, Sandrine; Boulahtouf, Abdelhay; Rodriguez, Carmen; Jalaguier, Stéphan; Assou, Said; Orsetti, Beatrice; Balaguer, Patrick; Maudelonde, Thierry; Blache, Philippe; Bystricky, Kerstin; Boulle, Nathalie; Cavaillès, Vincent

    2016-01-01

    Histone lysine acetylation is an epigenetic mark regulated by histone acetyltransferases and histone deacetylases (HDAC) which plays an important role in tumorigenesis. In this study, we observed a strong overexpression of class IIa HDAC9, at the mRNA and protein levels, in the most aggressive human breast cancer cell lines (i.e. in basal breast cancer cells vs luminal ones or in malignant vs begnin MCF10A breast epithelial cell lines). HDAC9 overexpression was associated with higher rates of gene transcription and increased epigenetic marks on the HDAC9 promoter. Ectopic expression of HDAC9 in MCF7 luminal breast cancer cells led to an increase in cell proliferation and to a decrease in apoptosis. These effects were associated with a deregulated expression of several genes controlled by HDAC inhibitors such as CDKN1A, BAX and TNFRSF10A. Inversely, knock-down of HDAC9 expression in MDA-MB436 basal breast cancer cells reduced cell proliferation. Moreover, high HDAC9 expression decreased the efficacy of HDAC inhibitors to reduce cell proliferation and to regulate CDKN1A gene expression. Interestingly, the gene encoding the transcription factor SOX9 was identified by a global transcriptomic approach as an HDAC9 target gene. In stably transfected MCF7 cells, SOX9 silencing significantly decreased HDAC9 mitogenic activity. Finally, in a large panel of breast cancer biopsies, HDAC9 expression was significantly increased in tumors of the basal subtype, correlated with SOX9 expression and associated with poor prognosis. Altogether, these results indicate that HDAC9 is a key factor involved in mammary carcinogenesis and in the response to HDAC inhibitors. PMID:26930713

  8. Functional overlap among distinct G1/S inhibitory pathways allows robust G1 arrest by yeast mating pheromones

    PubMed Central

    Pope, Patricia A.; Pryciak, Peter M.

    2013-01-01

    In budding yeast, mating pheromones arrest the cell cycle in G1 phase via a pheromone-activated Cdk-inhibitor (CKI) protein, Far1. Alternate pathways must also exist, however, because deleting the cyclin CLN2 restores pheromone arrest to far1∆ cells. Here we probe whether these alternate pathways require the G1/S transcriptional repressors Whi5 and Stb1 or the CKI protein Sic1, whose metazoan analogues (Rb or p27) antagonize cell cycle entry. Removing Whi5 and Stb1 allows partial escape from G1 arrest in far1∆ cln2∆ cells, along with partial derepression of G1/S genes, which implies a repressor-independent route for inhibiting G1/S transcription. This route likely involves pheromone-induced degradation of Tec1, a transcriptional activator of the cyclin CLN1, because Tec1 stabilization also causes partial G1 escape in far1∆ cln2∆ cells, and this is additive with Whi5/Stb1 removal. Deleting SIC1 alone strongly disrupts Far1-independent G1 arrest, revealing that inhibition of B-type cyclin-Cdk activity can empower weak arrest pathways. Of interest, although far1∆ cln2∆ sic1∆ cells escaped G1 arrest, they lost viability during pheromone exposure, indicating that G1 exit is deleterious if the arrest signal remains active. Overall our findings illustrate how multiple distinct G1/S-braking mechanisms help to prevent premature cell cycle commitment and ensure a robust signal-induced G1 arrest. PMID:24088572

  9. Histone Deacetylase Inhibitors from Burkholderia Thailandensis

    PubMed Central

    Klausmeyer, Paul; Shipley, Suzanne; Zuck, Karina M.; McCloud, Thomas G.

    2011-01-01

    Bioactivity guided fractionation of an extract of Burkholderia thailandensis led to the isolation and identification of a new cytotoxic depsipeptide and its dimer. Both compounds potently inhibited the function of histone deacetylases 1 and 4. The monomer, spiruchostatin C (2), was tested side-by-side with the clinical depsipeptide FK228 (1, Istodax®, romidepsin) in a murine hollow fiber assay consisting of 12 implanted tumor cell lines. Spiruchostatin C (2) showed good activity towards LOX IMVI melanoma cells and NCI-H522 non small cell lung cancer cells. Overall, however, FK228 (1) showed a superior in vivo antitumor profile compared to the new compound. PMID:21967146

  10. Histone deacetylase 3 indirectly modulates tubulin acetylation

    PubMed Central

    Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

    2015-01-01

    Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3–silencing mediator of retinoic and thyroid receptors (SMRT)–deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. PMID:26450925

  11. [G1 and G2 chalones of the gastric mucosa].

    PubMed

    Aruin, L I; Smotrova, I A; Gorodinskaia, V S

    1984-04-01

    A study was made of the action of human gastric mucosa G1 and G2 chalones on cellular regeneration of mouse gastric mucosa and of the duration of their maximal effect. Chalone fractions were obtained from the mucous membranes of 21 stomachs resected for peptic ulcer by the method of fractional ethanol precipitation. The data indicate that the maximal inhibitory action of G1 chalone occurs in 3, whereas that of chalone G2 in 6 hours. Some specificity of the action of chalones was discovered depending on the part of the gastric mucosa from which they were obtained. PMID:6232965

  12. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1.

    PubMed

    Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X

    2015-10-30

    Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.

  13. SNAILs promote G1 phase in selected cancer cells.

    PubMed

    Wu, Ya-Lan; Xue, Jian-Xin; Zhou, Lin; Deng, Lei; Shang, Yan-Na; Liu, Fang; Mo, Xian-Ming; Lu, You

    2015-11-01

    Cells can acquire a stem-like cell phenotype through epithelial-mesenchymal transition (EMT). However, it is not known which of the stem-like cancer cells are generated by these phenotype transitions. We studied the EMT-inducing roles of SNAILs (the key inducers for the onset of EMT) in selected cancer cells (lung cancer cell line with relatively stable genome), in order to provide more implications for the investigation of EMT-related phenotype transitions in cancer. However, SNAILs fail to induce completed EMT. In addition, we proved that Snail accelerates the early G1 phase whereas Slug accelerates the late G1 phase. Blocking G1 phase is one of the basic conditions for the onset of EMT-related phenotype transitions (e.g., metastasis, acquiring stemness). The discovery of this unexpected phenomenon (promoting G1 phase) typically reveals the heterogeneity of cancer cells. The onset of EMT-related phenotype transitions in cancer needs not only the induction and activation of SNAILs, but also some particular heredity alterations (genetic or epigenetic alterations, which cause heterogeneity). The new connection between heredity alteration (heterogeneity) and phenotype transition suggests a novel treatment strategy, the heredity alteration-directed specific target therapy. Further investigations need to be conducted to study the relevant heredity alterations.

  14. NARSTO EPA SS HOUSTON TEXAQS2000 DOE G-1 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 DOE G-1 DATA Project Title:  NARSTO ... Fluorometer Ion Chromatograph Location:  Houston, Texas Spatial Resolution:  Point Measurements ... Parameters:  Atmospheric Pressure Air Temperature Dew Point Flight Level Winds Nitrogen Oxides Ozone ...

  15. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1.

    PubMed

    Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X

    2015-10-30

    Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation. PMID:25938642

  16. 26 CFR 1.149(g)-1 - Hedge bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) INCOME TAXES (CONTINUED) Tax Exemption Requirements for State and Local Bonds § 1.149(g)-1 Hedge bonds... of replacement proceeds (other than amounts in a bona fide debt service fund or a reasonably required... realize debt service savings or to relieve the issuer of significantly burdensome document provisions,...

  17. 26 CFR 1.149(g)-1 - Hedge bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) INCOME TAXES (CONTINUED) Tax Exemption Requirements for State and Local Bonds § 1.149(g)-1 Hedge bonds... of replacement proceeds (other than amounts in a bona fide debt service fund or a reasonably required... realize debt service savings or to relieve the issuer of significantly burdensome document provisions,...

  18. A novel histone deacetylase inhibitor Chidamide induces apoptosis of human colon cancer cells

    SciTech Connect

    Liu, Lin; Chen, Baoan; Qin, Shukui; Li, Suyi; He, Xiangming; Qiu, Shaomin; Zhao, Wei; Zhao, Hong

    2010-02-05

    Many studies have demonstrated that histone deacetylase (HDAC) inhibitors induce various tumor cells to undergo apoptosis, and such inhibitors have been used in different clinical trials against different human cancers. In this study, we designed and synthesized a novel HDAC inhibitor, Chidamide. We showed that Chidamide was able to increase the acetylation levels of histone H3 and to inhibit the PI3K/Akt and MAPK/Ras signaling pathways, which resulted in arresting colon cancer cells at the G1 phase of the cell cycle and promoting apoptosis. As a result, the proliferation of colon cancer cells was suppressed in vitro. Our data support the potential application of Chidamide as an anticancer agent in treating colon cancer. Future studies are needed to demonstrate its in vivo efficacy.

  19. Role of Deacetylase Activity of N-Deacetylase/N-Sulfotransferase 1 in Forming N-Sulfated Domain in Heparan Sulfate*

    PubMed Central

    Dou, Wenfang; Xu, Yongmei; Pagadala, Vijayakanth; Pedersen, Lars C.; Liu, Jian

    2015-01-01

    Heparan sulfate (HS) is a highly sulfated polysaccharide that plays important physiological roles. The biosynthesis of HS involves a series of enzymes, including glycosyltransferases (or HS polymerase), epimerase, and sulfotransferases. N-Deacetylase/N-Sulfotransferase isoform 1 (NDST-1) is a critical enzyme in this pathway. NDST-1, a bifunctional enzyme, displays N-deacetylase and N-sulfotransferase activities to convert an N-acetylated glucosamine residue to an N-sulfo glucosamine residue. Here, we report the cooperative effects between N-deacetylase and N-sulfotransferase activities. Using baculovirus expression in insect cells, we obtained three recombinant proteins: full-length NDST-1 and the individual N-deacetylase and N-sulfotransferase domains. Structurally defined oligosaccharide substrates were synthesized to test the substrate specificities of the enzymes. We discovered that N-deacetylation is the limiting step and that interplay between the N-sulfotransferase and N-deacetylase accelerates the reaction. Furthermore, combining the individually expressed N-deacetylase and N-sulfotransferase domains produced different sulfation patterns when compared with that made by the NDST-1 enzyme. Our data demonstrate the essential role of domain cooperation within NDST-1 in producing HS with specific domain structures. PMID:26109066

  20. Regulation of Runx2 by Histone Deacetylases in Bone.

    PubMed

    Vishal, Mohanakrishnan; Ajeetha, Ramachandran; Keerthana, Rajendran; Selvamurugan, Nagarajan

    2016-01-01

    Osteogenesis involves a cascade of processes wherein mesenchymal stem cells differentiate towards osteoblasts, strictly controlled by a number of regulatory factors. Runx2 protein is a key transcription factor which serves as a master regulator for osteogenesis by activating the promoters of various osteoblastic genes. Runx2 is regulated by several cofactors, including the histone deacetylase enzymes known as HDACs. HDACs are a family of proteins that regulate gene expression and/or activity through the mechanism of deacetylation and they can be divided into four classes, namely classes I, II, III and IV HDACs based on their sequence identity and nuclear or cytoplasmic localization. Knockout studies of all classes of HDACs showed their specific developmental roles. Evidence has proved Runx2 to be a repressible target of HDACs and this interplay is found to be a crucial factor controlling osteoblast differentiation. Further, another level of osteogenic regulation involves microRNAs (miRNAs), which are small, non-coding endogenous molecules capable of gene silencing by partial or complete complementary binding of their seed sequences to the 3' untranslated region (UTR) of target mRNAs. In this study, the recent developments on identifying the function of HDACs on Runx2 expression/activity and the impact of miRNAs on HDACs in regulation of osteogenesis are reviewed. PMID:27072566

  1. Type-II histone deacetylases: elusive plant nuclear signal transducers.

    PubMed

    Grandperret, Vincent; Nicolas-Francès, Valérie; Wendehenne, David; Bourque, Stéphane

    2014-06-01

    Since the beginning of the 21st century, numerous studies have concluded that the plant cell nucleus is one of the cellular compartments that define the specificity of the cellular response to an external stimulus or to a specific developmental stage. To that purpose, the nucleus contains all the enzymatic machinery required to carry out a wide variety of nuclear protein post-translational modifications (PTMs), which play an important role in signal transduction pathways leading to the modulation of specific sets of genes. PTMs include protein (de)acetylation which is controlled by the antagonistic activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). Regarding protein deacetylation, plants are of particular interest: in addition to the RPD3-HDA1 and Sir2 HDAC families that they share with other eukaryotic organisms, plants have developed a specific family called type-II HDACs (HD2s). Interestingly, these HD2s are well conserved in plants and control fundamental biological processes such as seed germination, flowering or the response to pathogens. The aim of this review was to summarize current knowledge regarding this fascinating, but still poorly understood nuclear protein family. PMID:24236403

  2. Computational Studies on the Histone Deacetylases and the Design of Selective Histone Deacetylase Inhibitors

    PubMed Central

    Wang, Difei

    2009-01-01

    The catalytic activity of the histone deacetylase (HDAC) enzymes is directly relevant to the pathogenesis of cancer as well as several other diseases. HDAC inhibitors have been shown to have the potential to treat several types of cancers. The role of computational study of the HDAC enzymes is reviewed, with particular emphasis on the important role of molecular modeling to the development of HDAC inhibitors with improved efficacy and selectivity. The use of two computational approaches—one structure-based, and the second ligand-based—toward inhibitors against the different HDAC sub-classes, are summarized. PMID:19355989

  3. Compass Measurement of g1 and QCD Fits

    NASA Astrophysics Data System (ADS)

    Kunne, Fabienne

    2016-02-01

    We present the latest COMPASS results on the proton spin structure function g1p(x) at 200GeV. The data improve the statistical precision by a factor of ˜2 at low x. A reevaluation of the Bjorken sum rule based on COMPASS proton and deuteron data confirms its validation to a 9% accuracy. Finally, results from a global NLO QCD fit of g1 world data are shown. The extracted spin singlet distribution leads to an integrated value of 0.26 < ΔΣ < 0.34 at Q2 = 3 (GeV/c)2. The large uncertainty is mainly driven by the unknown shape of the distribution.

  4. Crack azimuths on Europa: The G1 lineament sequence revisited

    USGS Publications Warehouse

    Sarid, A.R.; Greenberg, R.; Hoppa, G.V.; Brown, D.M.; Geissler, P.

    2005-01-01

    The tectonic sequence in the anti-jovian area covered by regional mapping images from Galileo's orbit E15 is determined from a study of cross-cutting relationships among lineament features. The sequence is used to test earlier results from orbit G1, based on lower resolution images, which appeared to display a progressive change in azimuthal orientation over about 90?? in a clockwise sense. Such a progression is consistent with expected stress variations that would accompany plausible non-synchronous rotation. The more recent data provide a more complete record than the G1 data did. We find that to fit the sequence into a continual clockwise change of orientation would require at least 1000?? (> 5 cycles) of azimuthal rotation. If due to non-synchronous rotation of Europa, this result implies that we are seeing back further into the tectonic record than the G1 results had suggested. The three sets of orientations found by Geissler et al. now appear to have been spaced out over several cycles, not during a fraction of one cycle. While our more complete sequence of lineament formation is consistent with non-synchronous rotation, a statistical test shows that it cannot be construed as independent evidence. Other lines of evidence do support non-synchronous rotation, but azimuths of crack sequences do not show it, probably because only a couple of cracks form in a given region in any given non-synchronous rotation period. ?? 2004 Elsevier Inc. All rights reserved.

  5. Interpreting clinical assays for histone deacetylase inhibitors

    PubMed Central

    Martinet, Nadine; Bertrand, Philippe

    2011-01-01

    As opposed to genetics, dealing with gene expressions by direct DNA sequence modifications, the term epigenetics applies to all the external influences that target the chromatin structure of cells with impact on gene expression unrelated to the sequence coding of DNA itself. In normal cells, epigenetics modulates gene expression through all development steps. When “imprinted” early by the environment, epigenetic changes influence the organism at an early stage and can be transmitted to the progeny. Together with DNA sequence alterations, DNA aberrant cytosine methylation and microRNA deregulation, epigenetic modifications participate in the malignant transformation of cells. Their reversible nature has led to the emergence of the promising field of epigenetic therapy. The efforts made to inhibit in particular the epigenetic enzyme family called histone deacetylases (HDACs) are described. HDAC inhibitors (HDACi) have been proposed as a viable clinical therapeutic approach for the treatment of leukemia and solid tumors, but also to a lesser degree for noncancerous diseases. Three epigenetic drugs are already arriving at the patient’s bedside, and more than 100 clinical assays for HDACi are registered on the National Cancer Institute website. They explore the eventual additive benefits of combined therapies. In the context of the pleiotropic effects of HDAC isoforms, more specific HDACi and more informative screening tests are being developed for the benefit of the patients. PMID:21625397

  6. G1/S Cell Cycle Checkpoint Defect in Lymphocytes from Patients with Alzheimer's Disease

    PubMed Central

    Song, Misun; Kwon, Young-Ah; Lee, Yujin; Kim, Hyeran; Yun, Ji Hea; Kim, Seonwoo

    2012-01-01

    Objective We compared the cell responsiveness of activated lymphocytes to rapamycin, which blocks the G1/S transition, between patients with Alzheimer's disease (AD) and normal controls to assess the early phase control defect in cell cycle. Methods Blood samples of 26 patients with AD and 28 normal controls were collected to separate peripheral lymphocytes. We measured the proportion of each cell cycle phase in activated lymphocytes using flow cytometry and evaluated the responsiveness of these lymphocytes to rapamycin. Results The patients with AD were older than the normal controls (AD 74.03±7.90 yr vs. control 68.28±6.21 yr, p=0.004). The proportion of G1 phase cells in the AD group was significantly lower than that in the control group (70.29±6.32% vs. 76.03±9.05%, p=0.01), and the proportion of S phase cells in the AD group was higher than that in control group (12.45±6.09% vs. 6.03±5.11%, p=0.001). Activated lymphocytes in patients with AD were not arrested in the G1 phase and they progressed to the late phase of the cell cycle despite rapamycin treatment, in contrast to those of normal subjects. Conclusion The patients with AD probably have a control defect of early phase cell cycle in peripheral lymphocytes that may be associated with the underlying pathology of neuronal death. PMID:23251208

  7. Enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases

    PubMed Central

    Hamer, Stefanie Nicole; Cord-Landwehr, Stefan; Biarnés, Xevi; Planas, Antoni; Waegeman, Hendrik; Moerschbacher, Bruno Maria; Kolkenbrock, Stephan

    2015-01-01

    Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the influence of the PA on the biological activities, defined chitosan oligomers in sufficient amounts are needed. Chitosan oligomers with specific PA can be produced by enzymatic deacetylation of chitin oligomers, but the diversity is limited by the low number of chitin deacetylases available. We have produced specific chitosan oligomers which are deacetylated at the first two units starting from the non-reducing end by the combined use of two different chitin deacetylases, namely NodB from Rhizobium sp. GRH2 that deacetylates the first unit and COD from Vibrio cholerae that deacetylates the second unit starting from the non-reducing end. Both chitin deacetylases accept the product of each other resulting in production of chitosan oligomers with a novel and defined PA. When extended to further chitin deacetylases, this approach has the potential to yield a large range of novel chitosan oligomers with a fully defined architecture. PMID:25732514

  8. Enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases

    NASA Astrophysics Data System (ADS)

    Hamer, Stefanie Nicole; Cord-Landwehr, Stefan; Biarnés, Xevi; Planas, Antoni; Waegeman, Hendrik; Moerschbacher, Bruno Maria; Kolkenbrock, Stephan

    2015-03-01

    Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the influence of the PA on the biological activities, defined chitosan oligomers in sufficient amounts are needed. Chitosan oligomers with specific PA can be produced by enzymatic deacetylation of chitin oligomers, but the diversity is limited by the low number of chitin deacetylases available. We have produced specific chitosan oligomers which are deacetylated at the first two units starting from the non-reducing end by the combined use of two different chitin deacetylases, namely NodB from Rhizobium sp. GRH2 that deacetylates the first unit and COD from Vibrio cholerae that deacetylates the second unit starting from the non-reducing end. Both chitin deacetylases accept the product of each other resulting in production of chitosan oligomers with a novel and defined PA. When extended to further chitin deacetylases, this approach has the potential to yield a large range of novel chitosan oligomers with a fully defined architecture.

  9. The epigenetic modifier trichostatin A, a histone deacetylase inhibitor, suppresses proliferation and epithelial–mesenchymal transition of lens epithelial cells

    PubMed Central

    Chen, X; Xiao, W; Chen, W; Luo, L; Ye, S; Liu, Y

    2013-01-01

    Proliferation and epithelial–mesenchymal transition (EMT) of lens epithelium cells (LECs) may contribute to anterior subcapsular cataract (ASC) and posterior capsule opacification (PCO), which are important causes of visual impairment. Histone deacetylases (HDACs)-mediated epigenetic mechanism has a central role in controlling cell cycle regulation, cell proliferation and differentiation in a variety of cells and the pathogenesis of some diseases. However, whether HDACs are involved in the regulation of proliferation and EMT in LECs remain unknown. In this study, we evaluated the expression profile of HDAC family (18 genes) and found that class I and II HDACs were upregulated in transforming growth factor β2 (TGFβ2)-induced EMT in human LEC lines SRA01/04 and HLEB3. Tricostatin A (TSA), a class I and II HDAC inhibitor, suppressed the proliferation of LECs by G1 phase cell cycle arrest not only through inhibition of cyclin/CDK complexes and induction of p21 and p27, but also inactivation of the phosphatidylinositol-3-kinase/Akt, p38MAPK and ERK1/2 pathways. Meanwhile, TSA strongly prevented TGFβ2-induced upregulation of fibronectin, collagen type I, collagen type IV, N-cadherin, Snail and Slug. We also demonstrated that the underlying mechanism of TSA affects EMT in LECs through inhibiting the canonical TGFβ/Smad2 and the Jagged/Notch signaling pathways. Finally, we found that TSA completely prevented TGFβ2-induced ASC in the whole lens culture semi-in vivo model. Therefore, this study may provide a new insight into the pathogenesis of ASC and PCO, and suggests that epigenetic treatment with HDAC inhibitors may be a novel therapeutic approach for the prevention and treatment of ASC, PCO and other fibrotic diseases. PMID:24157878

  10. Hypothalamic leptin action is mediated by histone deacetylase 5.

    PubMed

    Kabra, Dhiraj G; Pfuhlmann, Katrin; García-Cáceres, Cristina; Schriever, Sonja C; Casquero García, Veronica; Kebede, Adam Fiseha; Fuente-Martin, Esther; Trivedi, Chitrang; Heppner, Kristy; Uhlenhaut, N Henriette; Legutko, Beata; Kabra, Uma D; Gao, Yuanqing; Yi, Chun-Xia; Quarta, Carmelo; Clemmensen, Christoffer; Finan, Brian; Müller, Timo D; Meyer, Carola W; Paez-Pereda, Marcelo; Stemmer, Kerstin; Woods, Stephen C; Perez-Tilve, Diego; Schneider, Robert; Olson, Eric N; Tschöp, Matthias H; Pfluger, Paul T

    2016-01-01

    Hypothalamic leptin signalling has a key role in food intake and energy-balance control and is often impaired in obese individuals. Here we identify histone deacetylase 5 (HDAC5) as a regulator of leptin signalling and organismal energy balance. Global HDAC5 KO mice have increased food intake and greater diet-induced obesity when fed high-fat diet. Pharmacological and genetic inhibition of HDAC5 activity in the mediobasal hypothalamus increases food intake and modulates pathways implicated in leptin signalling. We show HDAC5 directly regulates STAT3 localization and transcriptional activity via reciprocal STAT3 deacetylation at Lys685 and phosphorylation at Tyr705. In vivo, leptin sensitivity is substantially impaired in HDAC5 loss-of-function mice. Hypothalamic HDAC5 overexpression improves leptin action and partially protects against HFD-induced leptin resistance and obesity. Overall, our data suggest that hypothalamic HDAC5 activity is a regulator of leptin signalling that adapts food intake and body weight to our dietary environment. PMID:26923837

  11. Autophagy Induction by Histone Deacetylase Inhibitors Inhibits HIV Type 1*

    PubMed Central

    Campbell, Grant R.; Bruckman, Rachel S.; Chu, Yen-Lin; Spector, Stephen A.

    2015-01-01

    Histone deacetylase inhibitors (HDACi) are being evaluated in a “shock-and-kill” therapeutic approach to reverse human immunodeficiency virus type-1 (HIV) latency from CD4+ T cells. Using this approach, HDACi have induced HIV RNA synthesis in latently infected cells from some patients. The hope is that the increase in viral production will lead to killing of the infected cell either by the virus itself or by the patient's immune system, a “sterilizing cure.” Although administered within the context of combination antiretroviral therapy, the infection of bystander cells remains a concern. In this study, we investigated the effect of HDACi (belinostat, givinostat, panobinostat, romidepsin, and vorinostat) on the productive infection of macrophages. We demonstrate that the HDACi tested do not alter the initial susceptibility of macrophages to HIV infection. However, we demonstrate that HDACi decrease HIV release from macrophages in a dose-dependent manner (belinostat < givinostat < vorinostat < panobinostat < romidepsin) via degradation of intracellular HIV through the canonical autophagy pathway. This mechanism involves unc-51-like autophagy-activating kinase 1 (ULK1) and the inhibition of the mammalian target of rapamycin and requires the formation of autophagosomes and their maturation into autolysosomes in the absence of increased cell death. These data provide further evidence in support of a role for autophagy in the control of HIV infection and suggest that careful consideration of off-target effects will be essential if HDACi are to be a component of a multipronged approach to eliminate latently infected cells. PMID:25540204

  12. Histone Deacetylases and Their Inhibition in Candida Species

    PubMed Central

    Garnaud, Cécile; Champleboux, Morgane; Maubon, Danièle; Cornet, Muriel; Govin, Jérôme

    2016-01-01

    Fungi are generally benign members of the human mucosal flora or live as saprophytes in the environment. However, they can become pathogenic, leading to invasive and life threatening infections in vulnerable patients. These invasive fungal infections are regarded as a major public health problem on a similar scale to tuberculosis or malaria. Current treatment for these infections is based on only four available drug classes. This limited therapeutic arsenal and the emergence of drug-resistant strains are a matter of concern due to the growing number of patients to be treated, and new therapeutic strategies are urgently needed. Adaptation of fungi to drug pressure involves transcriptional regulation, in which chromatin dynamics and histone modifications play a major role. Histone deacetylases (HDACs) remove acetyl groups from histones and actively participate in controlling stress responses. HDAC inhibition has been shown to limit fungal development, virulence, biofilm formation, and dissemination in the infected host, while also improving the efficacy of existing antifungal drugs toward Candida spp. In this article, we review the functional roles of HDACs and the biological effects of HDAC inhibitors on Candida spp., highlighting the correlations between their pathogenic effects in vitro and in vivo. We focus on how HDAC inhibitors could be used to treat invasive candidiasis while also reviewing recent developments in their clinical evaluation. PMID:27547205

  13. Hypothalamic leptin action is mediated by histone deacetylase 5

    PubMed Central

    Kabra, Dhiraj G.; Pfuhlmann, Katrin; García-Cáceres, Cristina; Schriever, Sonja C.; Casquero García, Veronica; Kebede, Adam Fiseha; Fuente-Martin, Esther; Trivedi, Chitrang; Heppner, Kristy; Uhlenhaut, N. Henriette; Legutko, Beata; Kabra, Uma D.; Gao, Yuanqing; Yi, Chun-Xia; Quarta, Carmelo; Clemmensen, Christoffer; Finan, Brian; Müller, Timo D.; Meyer, Carola W.; Paez-Pereda, Marcelo; Stemmer, Kerstin; Woods, Stephen C.; Perez-Tilve, Diego; Schneider, Robert; Olson, Eric N.; Tschöp, Matthias H.; Pfluger, Paul T.

    2016-01-01

    Hypothalamic leptin signalling has a key role in food intake and energy-balance control and is often impaired in obese individuals. Here we identify histone deacetylase 5 (HDAC5) as a regulator of leptin signalling and organismal energy balance. Global HDAC5 KO mice have increased food intake and greater diet-induced obesity when fed high-fat diet. Pharmacological and genetic inhibition of HDAC5 activity in the mediobasal hypothalamus increases food intake and modulates pathways implicated in leptin signalling. We show HDAC5 directly regulates STAT3 localization and transcriptional activity via reciprocal STAT3 deacetylation at Lys685 and phosphorylation at Tyr705. In vivo, leptin sensitivity is substantially impaired in HDAC5 loss-of-function mice. Hypothalamic HDAC5 overexpression improves leptin action and partially protects against HFD-induced leptin resistance and obesity. Overall, our data suggest that hypothalamic HDAC5 activity is a regulator of leptin signalling that adapts food intake and body weight to our dietary environment. PMID:26923837

  14. Histone Deacetylases and Their Inhibition in Candida Species.

    PubMed

    Garnaud, Cécile; Champleboux, Morgane; Maubon, Danièle; Cornet, Muriel; Govin, Jérôme

    2016-01-01

    Fungi are generally benign members of the human mucosal flora or live as saprophytes in the environment. However, they can become pathogenic, leading to invasive and life threatening infections in vulnerable patients. These invasive fungal infections are regarded as a major public health problem on a similar scale to tuberculosis or malaria. Current treatment for these infections is based on only four available drug classes. This limited therapeutic arsenal and the emergence of drug-resistant strains are a matter of concern due to the growing number of patients to be treated, and new therapeutic strategies are urgently needed. Adaptation of fungi to drug pressure involves transcriptional regulation, in which chromatin dynamics and histone modifications play a major role. Histone deacetylases (HDACs) remove acetyl groups from histones and actively participate in controlling stress responses. HDAC inhibition has been shown to limit fungal development, virulence, biofilm formation, and dissemination in the infected host, while also improving the efficacy of existing antifungal drugs toward Candida spp. In this article, we review the functional roles of HDACs and the biological effects of HDAC inhibitors on Candida spp., highlighting the correlations between their pathogenic effects in vitro and in vivo. We focus on how HDAC inhibitors could be used to treat invasive candidiasis while also reviewing recent developments in their clinical evaluation. PMID:27547205

  15. Loss of histone deacetylase Hdac1 disrupts metabolic processes in intestinal epithelial cells.

    PubMed

    Gonneaud, Alexis; Turgeon, Naomie; Boisvert, François-Michel; Boudreau, François; Asselin, Claude

    2015-09-14

    By using acetyl-CoA as a substrate, acetyltransferases and histone deacetylases regulate protein acetylation by adding or removing an acetyl group on lysines. Nuclear-located Hdac1 is a regulator of intestinal homeostasis. We have previously shown that Hdac1 define specific intestinal epithelial cell basal and inflammatory-dependent gene expression patterns and control cell proliferation. We show here that Hdac1 depletion in cellulo leads to increased histone acetylation after metabolic stresses, and to metabolic disturbances resulting in impaired responses to oxidative stresses, AMPK kinase activation and mitochondrial biogenesis. Thus, nuclear Hdac1 may control intestinal epithelial cell metabolism by regulating the supply of acetyl groups.

  16. Centrosomal AKAP350 modulates the G1/S transition

    PubMed Central

    Mattaloni, Stella M; Ferretti, Anabela C; Tonucci, Facundo M; Favre, Cristián; Goldenring, James R; Larocca, M Cecilia

    2013-01-01

    AKAP350 (AKAP450/AKAP9/CG-NAP) is an A-kinase anchoring protein, which recruits multiple signaling proteins to the Golgi apparatus and the centrosomes. Several proteins recruited to the centrosomes by this scaffold participate in the regulation of the cell cycle. Previous studies indicated that AKAP350 participates in centrosome duplication. In the present study we specifically assessed the role of AKAP350 in the progression of the cell cycle. Our results showed that interference with AKAP350 expression inhibits G1/S transition, decreasing the initiation of both DNA synthesis and centrosome duplication. We identified an AKAP350 carboxyl-terminal domain (AKAP350CTD), which contained the centrosomal targeting domain of AKAP350 and induced the initiation of DNA synthesis. Nevertheless, AKAP350CTD expression did not induce centrosomal duplication. AKAP350CTD partially delocalized endogenous AKAP350 from the centrosomes, but increased the centrosomal levels of the cyclin-dependent kinase 2 (Cdk2). Accordingly, the expression of this AKAP350 domain increased the endogenous phosphorylation of nucleophosmin by Cdk2, which occurs at the G1/S transition and is a marker of the centrosomal activity of the cyclin E-Cdk2 complex. Cdk2 recruitment to the centrosomes is a necessary event for the development of the G1/S transition. Altogether, our results indicate that AKAP350 facilitates the initiation of DNA synthesis by scaffolding Cdk2 to the centrosomes, and enabling its specific activity at this organelle. Although this mechanism could also be involved in AKAP350-dependent modulation of centrosomal duplication, it is not sufficient to account for this process. PMID:24475373

  17. HPV-18 transformed cells fail to arrest in G1 in response to quercetin treatment.

    PubMed

    Beniston, R G; Campo, M S

    2005-05-01

    Previous work with primary human keratinocytes demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 with concomitant elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the human papillomavirus type 16 (HPV-16) E6 and E7 oncoproteins, under transcriptional control of a heterologous promoter, in transformed keratinocytes failed to abrogate this arrest [Beniston, R., Campo, M.S., 2003. Quercetin elevates p27Kip1 and arrests both primary and HPV-16 E6/E7 transformed human keratinocytes in G1. Oncogene 22, 5504-5514]. Given the link between papillomavirus infection, bracken fern in the diet and cancer of the oesophagus in humans, we wished to investigate further whether cells transformed by the whole genome of HPV-16 or HPV-18, with E6 and E7 under the transcriptional control of their respective homologous promoters, would be similarly arrested in G1 by quercetin. In agreement with earlier work, quercetin arrested HPV-16 transformed cells in G1 with an increase in the cyclin-dependent kinase inhibitor p27Kip1. However, HPV-18 transformed cells did not arrest after quercetin treatment. The failure of HPV-18 transformed cells to arrest in G1 was linked to the up-regulation of the HPV-18 long control region (LCR) by quercetin, maintaining high expression of the viral transforming proteins. Transcriptional up-regulation of the HPV-18 LCR was mediated by a "quercetin responsive element" homologous to the one identified previously in the bovine papillomavirus type 4 (BPV-4) LCR.

  18. Suppression of caspase-11 expression by histone deacetylase inhibitors

    SciTech Connect

    Heo, Hyejung; Yoo, Lang; Shin, Ki Soon; Kang, Shin Jung

    2009-01-02

    It has been well documented that histone deacetylase inhibitors suppress inflammatory gene expression. Therefore, we investigated whether histone deacetylase inhibitors modulate the expression of caspase-11 that is known as an inducible caspase regulating both inflammation and apoptosis. In the present study, we show that sodium butyrate and trichostatin A, two structurally unrelated inhibitors of histone deacetylase (HDAC), effectively suppressed the induction of caspase-11 in mouse embryonic fibroblasts stimulated with lipopolysaccharides. Sodium butyrate inhibited the activation of upstream signaling events for the caspase-11 induction such as activation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase, degradation of inhibitor of {kappa}B, and activation of nuclear factor-{kappa}B. These results suggest that the HDAC inhibitor suppressed cytosolic signaling events for the induction of caspase-11 by inhibiting the deacetylation of non-histone proteins.

  19. Inhibition of histone deacetylases in cancer therapy: lessons from leukaemia.

    PubMed

    Ceccacci, Elena; Minucci, Saverio

    2016-03-15

    Histone deacetylases (HDACs) are a key component of the epigenetic machinery regulating gene expression, and behave as oncogenes in several cancer types, spurring the development of HDAC inhibitors (HDACi) as anticancer drugs. This review discusses new results regarding the role of HDACs in cancer and the effect of HDACi on tumour cells, focusing on haematological malignancies, particularly acute myeloid leukaemia. Histone deacetylases may have opposite roles at different stages of tumour progression and in different tumour cell sub-populations (cancer stem cells), highlighting the importance of investigating these aspects for further improving the clinical use of HDACi in treating cancer.

  20. A mechanism for the suppression of homologous recombination in G1 cells.

    PubMed

    Orthwein, Alexandre; Noordermeer, Sylvie M; Wilson, Marcus D; Landry, Sébastien; Enchev, Radoslav I; Sherker, Alana; Munro, Meagan; Pinder, Jordan; Salsman, Jayme; Dellaire, Graham; Xia, Bing; Peter, Matthias; Durocher, Daniel

    2015-12-17

    DNA repair by homologous recombination is highly suppressed in G1 cells to ensure that mitotic recombination occurs solely between sister chromatids. Although many homologous recombination factors are cell-cycle regulated, the identity of the events that are both necessary and sufficient to suppress recombination in G1 cells is unknown. Here we report that the cell cycle controls the interaction of BRCA1 with PALB2-BRCA2 to constrain BRCA2 function to the S/G2 phases in human cells. We found that the BRCA1-interaction site on PALB2 is targeted by an E3 ubiquitin ligase composed of KEAP1, a PALB2-interacting protein, in complex with cullin-3 (CUL3)-RBX1 (ref. 6). PALB2 ubiquitylation suppresses its interaction with BRCA1 and is counteracted by the deubiquitylase USP11, which is itself under cell cycle control. Restoration of the BRCA1-PALB2 interaction combined with the activation of DNA-end resection is sufficient to induce homologous recombination in G1, as measured by RAD51 recruitment, unscheduled DNA synthesis and a CRISPR-Cas9-based gene-targeting assay. We conclude that the mechanism prohibiting homologous recombination in G1 minimally consists of the suppression of DNA-end resection coupled with a multi-step block of the recruitment of BRCA2 to DNA damage sites that involves the inhibition of BRCA1-PALB2-BRCA2 complex assembly. We speculate that the ability to induce homologous recombination in G1 cells with defined factors could spur the development of gene-targeting applications in non-dividing cells. PMID:26649820

  1. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes

    PubMed Central

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1–6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1–6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1–6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1–6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  2. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes.

    PubMed

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1-6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1-6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1-6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1-6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  3. LUMIX DMC-G1 - New Pleasantness of the Camera with Interchangeable Lenses That G1 Provides -

    NASA Astrophysics Data System (ADS)

    Ueda, Hiroshi; Hataji, Shinji; Morishita, Seiki; Inoue, Yoshiyuki

    Panasonic introduced in October 2008 the "LUMIX DMC-G1", which is adopting the Micro Four Thirds standard. This camera was a hot topic from the time of the announcement in September and after the sales start it was highly evaluated not only due to its small size and light weight, but also due to the compact camera like easy operation realized by the mirror-less construction and due to the performance, which is on the same level like conventional consumer SLR cameras. Within this chapter we will explain about the technology behind the high-speed AF, which was seen as difficult to realize in a system based on Live View, and the high resolution Live View Finder, as well as about the new challenge of color variations, presented for the first time for an interchangeable lens camera.

  4. T cell tolerance induced by histone deacetylase inhibitor is mediated by P21cip1.

    PubMed

    Gilbert, Kathleen M; Boger, Susan R; Price, Peter; Fifer, E Kim

    2005-01-01

    MEB [n-butyrate 2-(4-morpholinyl) ethyl butyrate hydrochloride], a histone deacetylase inhibitor and G1 blocker, has been shown to induce unresponsiveness in antigen-activated Th1 cells. MEB was tested for here for its ability to inactivate naive alloantigen-specific T cells from DBA/2 and C57BL/10 mice. Since T cells from these two strains of mice have been shown to differ in their cell cycle regulation, it we hoped that this comparison would provide information concerning the role of cycle regulatory proteins in mediating MEB-induced T cell unresponsiveness. MEB inhibited proliferation in a one-way mixed lymphocyte reaction (MLR) in which spleen cells from DBA/2 mice (H-2d) or C57BL/10 mice (H-2b) were stimulated with spleen cells from C57BL/10 or DBA/2 mice, respectively. C57BL/10 responder T cells isolated from the MEB-treated primary MLR remained unresponsive to alloantigen following restimulation in a secondary MLR that did not contain MEB. T cells from DBA/2 mice were less sensitive to MEB-induced unresponsiveness and required a longer exposure or pretreatment with IL-2 to become tolerant. In all cases responsiveness to MEB-induced tolerance in the alloantigen-stimulated T cells corresponded with the levels of the cyclin-dependent kinase inhibitor p21cip1. Additional experiments showed that T cells from p21cip1-deficient mice, unlike T cells from p21cip1 wild-type littermates, were resistant to MEB-induced tolerance. These results underscore the role of p21cip1 in mediating T cell tolerance induced by the histone deacetylase inhibitor MEB.

  5. G0/G1 Switch Gene 2 Regulates Cardiac Lipolysis*

    PubMed Central

    Heier, Christoph; Radner, Franz P. W.; Moustafa, Tarek; Schreiber, Renate; Grond, Susanne; Eichmann, Thomas O.; Schweiger, Martina; Schmidt, Albrecht; Cerk, Ines K.; Oberer, Monika; Theussl, H.-Christian; Wojciechowski, Jacek; Penninger, Josef M.; Zimmermann, Robert; Zechner, Rudolf

    2015-01-01

    The anabolism and catabolism of myocardial triacylglycerol (TAG) stores are important processes for normal cardiac function. TAG synthesis detoxifies and stockpiles fatty acids to prevent lipotoxicity, whereas TAG hydrolysis (lipolysis) remobilizes fatty acids from endogenous storage pools as energy substrates, signaling molecules, or precursors for complex lipids. This study focused on the role of G0/G1 switch 2 (G0S2) protein, which was previously shown to inhibit the principal TAG hydrolase adipose triglyceride lipase (ATGL), in the regulation of cardiac lipolysis. Using wild-type and mutant mice, we show the following: (i) G0S2 is expressed in the heart and regulated by the nutritional status with highest expression levels after re-feeding. (ii) Cardiac-specific overexpression of G0S2 inhibits cardiac lipolysis by direct protein-protein interaction with ATGL. This leads to severe cardiac steatosis. The steatotic hearts caused by G0S2 overexpression are less prone to fibrotic remodeling or cardiac dysfunction than hearts with a lipolytic defect due to ATGL deficiency. (iii) Conversely to the phenotype of transgenic mice, G0S2 deficiency results in a de-repression of cardiac lipolysis and decreased cardiac TAG content. We conclude that G0S2 acts as a potent ATGL inhibitor in the heart modulating cardiac substrate utilization by regulating cardiac lipolysis. PMID:26350455

  6. Early Evolution of Disrupted Asteroid P/2016 G1 (PANSTARRS)

    NASA Astrophysics Data System (ADS)

    Moreno, F.; Licandro, J.; Cabrera-Lavers, A.; Pozuelos, F. J.

    2016-08-01

    We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4 m Gran Telescopio Canarias (GTC) from 2016 late April to early June. The images are best interpreted as the result of a relatively short-duration event with an onset of about {350}-30+10 days before perihelion (i.e., around 2016 February 10), starting sharply and decreasing with {24}-7+10 days (HWHM). The results of the modeling imply that the emission of ˜1.7 × 107 kg of dust, if composed of particles of 1 μm to 1 cm in radius, is distributed following a power law of index -3 and having a geometric albedo of 0.15. A detailed fitting of a conspicuous westward feature in the head of the comet-like object indicates that a significant fraction of the dust was ejected along a privileged direction right at the beginning of the event, which suggests that the parent body has possibly suffered an impact followed by a partial or total disruption. From the limiting magnitude reachable with the instrumental setup, and assuming a geometric albedo of 0.15 for the parent body, an upper limit for the size of possible fragment debris of ˜50 m in radius is derived.

  7. Early Evolution of Disrupted Asteroid P/2016 G1 (PANSTARRS)

    NASA Astrophysics Data System (ADS)

    Moreno, F.; Licandro, J.; Cabrera-Lavers, A.; Pozuelos, F. J.

    2016-08-01

    We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4 m Gran Telescopio Canarias (GTC) from 2016 late April to early June. The images are best interpreted as the result of a relatively short-duration event with an onset of about {350}-30+10 days before perihelion (i.e., around 2016 February 10), starting sharply and decreasing with {24}-7+10 days (HWHM). The results of the modeling imply that the emission of ˜1.7 × 107 kg of dust, if composed of particles of 1 μm to 1 cm in radius, is distributed following a power law of index ‑3 and having a geometric albedo of 0.15. A detailed fitting of a conspicuous westward feature in the head of the comet-like object indicates that a significant fraction of the dust was ejected along a privileged direction right at the beginning of the event, which suggests that the parent body has possibly suffered an impact followed by a partial or total disruption. From the limiting magnitude reachable with the instrumental setup, and assuming a geometric albedo of 0.15 for the parent body, an upper limit for the size of possible fragment debris of ˜50 m in radius is derived.

  8. The existence of inflection points for generalized log-aesthetic curves satisfying G1 data

    NASA Astrophysics Data System (ADS)

    Karpagavalli, R.; Gobithaasan, R. U.; Miura, K. T.; Shanmugavel, Madhavan

    2015-12-01

    Log-Aesthetic (LA) curves have been implemented in a CAD/CAM system for various design feats. LA curves possess linear Logarithmic Curvature Graph (LCG) with gradient (shape parameter) denoted as α. In 2009, a generalized form of LA curves called Generalized Log-Aesthetic Curves (GLAC) has been proposed which has an extra shape parameter as ν compared to LA curves. Recently, G1 continuous GLAC algorithm has been proposed which utilizes the extra shape parameter using four control points. This paper discusses on the existence of inflection points in a GLAC segment satisfying G1 Hermite data and the effect of inflection point on convex hull property. It is found that the existence of inflection point can be avoided by manipulating the value of α. Numerical experiments show that the increase of α may remove the inflection point (if any) in a GLAC segment.

  9. Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

    SciTech Connect

    Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun; Zheng, Lemin; Zhou, Boda; Zhang, Wei; Lv, He; Yuan, Yun

    2014-03-28

    Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21.

  10. Optimized culture condition for enhancing lytic performance of waste activated sludge by Geobacillus sp. G1.

    PubMed

    Yang, Chunxue; Zhou, Aijuan; Hou, Yanan; Zhang, Xu; Guo, Zechong; Wang, Aijie; Liu, Wenzong

    2014-01-01

    Hydrolysis is known as the rate-limiting step during waste activated sludge (WAS) digestion. The optimization of the culture conditions of Geobacillus sp. G1 for enhancing WAS hydrolysis was conducted in this study with uniform design and response surface methodology. Taking the lysis rate of Escherichia coli as the response, the Plackett-Burman design was used to screen the most important variables. Experimental results showed that the maximum predicted lysis rate of E. coli was 50.9% for 4 h treatment time with concentrations of skim milk, NaCl and NH4SO4 at 10.78, 4.36 and 11.28 g/L, respectively. The optimized dosage ratio of Geobacillus sp. G1 to WAS was 35%:65% (VG1:VWAS). Under this condition, soluble protein was increased to 695 mg chemical oxygen demand (COD)/L, which was 5.0 times higher than that obtained in the control (140 mg COD/L). The corresponding protease activity reached 1.1 Eu/mL. Scanning electron microscopy showed that abundant cells were apparently lysed with treatment of Geobacillus sp. G1.

  11. 26 CFR 1.904(g)-1 - Overall domestic loss and the overall domestic loss account.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... loss account. 1.904(g)-1 Section 1.904(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF... States § 1.904(g)-1 Overall domestic loss and the overall domestic loss account. For further guidance, see § 1.904(g)-1T....

  12. Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells.

    PubMed

    Stark, A; Vachkova, E; Wellnitz, O; Bruckmaier, R; Baumrucker, C

    2013-12-01

    Bovine colostrogenesis is distinguished by the specific transfer of IgG1 from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E2 ) and progesterone (P4 ) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta-2-Microglobulin (β2M). We hypothesized that steroid hormone treatments (E2 and P4 ) of bovine mammary epithelial cells in vitro would induce up-regulation of IgG1 transcytosis candidate gene mRNA expression suggesting involvement in IgG1 transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up-regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG1 transcytosis in bovine mammary cells. PMID:23279563

  13. Aurora B-dependent regulation of class IIa histone deacetylases by mitotic nuclear localization signal phosphorylation.

    PubMed

    Guise, Amanda J; Greco, Todd M; Zhang, Irene Y; Yu, Fang; Cristea, Ileana M

    2012-11-01

    Class IIa histone deacetylases (HDACs 4/5/7/9) are transcriptional regulators with critical roles in cardiac disease and cancer. HDAC inhibitors are promising anticancer agents, and although they are known to disrupt mitotic progression, the underlying mechanisms of mitotic regulation by HDACs are not fully understood. Here we provide the first identification of histone deacetylases as substrates of Aurora B kinase (AurB). Our study identifies class IIa HDACs as a novel family of AurB targets and provides the first evidence that HDACs are temporally and spatially regulated by phosphorylation during the cell cycle. We define the precise site of AurB-mediated phosphorylation as a conserved serine within the nuclear localization signals of HDAC4, HDAC5, and HDAC9 at Ser265, Ser278, and Ser242, respectively. We establish that AurB interacts with these HDACs in vivo, and that this association increases upon disruption of 14-3-3 binding. We observe colocalization of endogenous, phosphorylated HDACs with AurB at the mitotic midzone in late anaphase and the midbody during cytokinesis, complemented by a reduction in HDAC interactions with components of the nuclear corepressor complex. We propose that AurB-dependent phosphorylation of HDACs induces sequestration within a phosphorylation gradient at the midzone, maintaining separation from re-forming nuclei and contributing to transcriptional control.

  14. Targeting histone deacetylases for the treatment of disease

    PubMed Central

    Lawless, M W; Norris, S; O’Byrne, K J; Gray, S G

    2009-01-01

    Abstract The ‘histone code’ is a well-established hypothesis describing the idea that specific patterns of post-translational modifications to histones act like a molecular ‘code’ recognized and used by non-histone proteins to regulate specific chromatin functions. One modification, which has received significant attention, is that of histone acetylation. The enzymes that regulate this modification are described as lysine acetyltransferases or KATs, and histone deacetylases or HDACs. Due to their conserved catalytic domain HDACs have been actively targeted as a therapeutic target. The pro-inflammatory environment is increasingly being recognized as a critical element for both degenerative diseases and cancer. The present review will discuss the current knowledge surrounding the clinical potential and current development of histone deacetylases for the treatment of diseases for which a pro-inflammatory environment plays important roles, and the molecular mechanisms by which such inhibitors may play important functions in modulating the pro-inflammatory environment. PMID:19175682

  15. Activation of p53 Transcriptional Activity by SMRT: a Histone Deacetylase 3-Independent Function of a Transcriptional Corepressor

    PubMed Central

    Adikesavan, Anbu Karani; Karmakar, Sudipan; Pardo, Patricia; Wang, Liguo; Liu, Shuang; Li, Wei

    2014-01-01

    The silencing mediator of retinoic acid and thyroid hormone receptors (SMRT) is an established histone deacetylase 3 (HDAC3)-dependent transcriptional corepressor. Microarray analyses of MCF-7 cells transfected with control or SMRT small interfering RNA revealed SMRT regulation of genes involved in DNA damage responses, and the levels of the DNA damage marker γH2AX as well as poly(ADP-ribose) polymerase cleavage were elevated in SMRT-depleted cells treated with doxorubicin. A number of these genes are established p53 targets. SMRT knockdown decreased the activity of two p53-dependent reporter genes as well as the expression of p53 target genes, such as CDKN1A (which encodes p21). SMRT bound directly to p53 and was recruited to p53 binding sites within the p21 promoter. Depletion of GPS2 and TBL1, components of the SMRT corepressor complex, but not histone deacetylase 3 (HDAC3) decreased p21-luciferase activity. p53 bound to the SMRT deacetylase activation domain (DAD), which mediates HDAC3 binding and activation, and HDAC3 could attenuate p53 binding to the DAD region of SMRT. Moreover, an HDAC3 binding-deficient SMRT DAD mutant coactivated p53 transcriptional activity. Collectively, these data highlight a biological role for SMRT in mediating DNA damage responses and suggest a model where p53 binding to the DAD limits HDAC3 interaction with this coregulator, thereby facilitating SMRT coactivation of p53-dependent gene expression. PMID:24449765

  16. Preferential synthesis of the G1m(1) allotype of IgG1 in the central nervous system of multiple sclerosis patients.

    PubMed

    Salier, J P; Goust, J M; Pandey, J P; Fudenberg, H H

    1981-09-18

    Quantitations of the G1m(1) and G1m(3) allotypic determinants of human immunoglobulin G were performed by radioimmunoassay on cerebrospinal fluid and serum samples from patients with multiple sclerosis and from patients with other neurological disorders. In multiple sclerosis patients that were heterozygous for these determinants, G1m(1) concentration in the cerebrospinal fluid was greatly increased-reflected by an increased ratio of G1m(1)-in comparison with that of patients with other neurological disorders. These results suggest that in the heterozygous multiple sclerosis patients, most of the plasma cells in the central nervous system that secrete oligoclonal immunoglobulin G preferentially synthesize G1m(1) IgG1 molecules. PMID:6973823

  17. Functional characterization of Candida albicans Hos2 histone deacetylase

    PubMed Central

    Karthikeyan, G; Paul-Satyaseela, Maneesh; Dhatchana Moorthy, Nachiappan; Gopalaswamy, Radha; Narayanan, Shridhar

    2014-01-01

    Candida albicans is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of  HOS2 (High Osmolarity  Sensitive) , a gene coding for fungal histone deacetylase from  C. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This  in  vitro enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity. PMID:25110576

  18. Physical and Functional Interactions between the Histone H3K4 Demethylase KDM5A and the Nucleosome Remodeling and Deacetylase (NuRD) Complex*

    PubMed Central

    Nishibuchi, Gohei; Shibata, Yukimasa; Hayakawa, Tomohiro; Hayakawa, Noriyo; Ohtani, Yasuko; Sinmyozu, Kaori; Tagami, Hideaki; Nakayama, Jun-ichi

    2014-01-01

    Histone H3K4 methylation has been linked to transcriptional activation. KDM5A (also known as RBP2 or JARID1A), a member of the KDM5 protein family, is an H3K4 demethylase, previously implicated in the regulation of transcription and differentiation. Here, we show that KDM5A is physically and functionally associated with two histone deacetylase complexes. Immunoaffinity purification of KDM5A confirmed a previously described association with the SIN3B-containing histone deacetylase complex and revealed an association with the nucleosome remodeling and deacetylase (NuRD) complex. Sucrose density gradient and sequential immunoprecipitation analyses further confirmed the stable association of KDM5A with these two histone deacetylase complexes. KDM5A depletion led to changes in the expression of hundreds of genes, two-thirds of which were also controlled by CHD4, the NuRD catalytic subunit. Gene ontology analysis confirmed that the genes commonly regulated by both KDM5A and CHD4 were categorized as developmentally regulated genes. ChIP analyses suggested that CHD4 modulates H3K4 methylation levels at the promoter and coding regions of target genes. We further demonstrated that the Caenorhabditis elegans homologues of KDM5 and CHD4 function in the same pathway during vulva development. These results suggest that KDM5A and the NuRD complex cooperatively function to control developmentally regulated genes. PMID:25190814

  19. Cell cycle transition from S-phase to G1 in Caulobacter is mediated by ancestral virulence regulators

    PubMed Central

    Fumeaux, Coralie; Radhakrishnan, Sunish Kumar; Ardissone, Silvia; Théraulaz, Laurence; Frandi, Antonio; Martins, Daniel; Nesper, Jutta; Abel, Sören; Jenal, Urs; Viollier, Patrick H.

    2014-01-01

    Zinc-finger domain transcriptional regulators regulate a myriad of functions in eukaryotes. Interestingly, ancestral versions (MucR) from Alpha-proteobacteria control bacterial virulence/symbiosis. Whether virulence regulators can also control cell cycle transcription is unknown. Here we report that MucR proteins implement a hitherto elusive primordial S→G1 transcriptional switch. After charting G1-specific promoters in the cell cycle model Caulobacter crescentus by comparative ChIP-seq, we use one such promoter as genetic proxy to unearth two MucR paralogs, MucR1/2, as constituents of a quadripartite and homeostatic regulatory module directing the S→G1 transcriptional switch. Surprisingly, MucR orthologues that regulate virulence and symbiosis gene transcription in Brucella, Agrobacterium or Sinorhizobium support this S→G1 switch in Caulobacter. Pan-genomic ChIP-seq analyses in Sinorhizobium and Caulobacter show that this module indeed targets orthologous genes. We propose that MucR proteins and possibly other virulence regulators primarily control bacterial cell cycle (G1-phase) transcription, rendering expression of target (virulence) genes periodic and in tune with the cell cycle. PMID:24939058

  20. The G1 restriction point as critical regulator of neocortical neuronogenesis

    NASA Technical Reports Server (NTRS)

    Caviness, V. S. Jr; Takahashi, T.; Nowakowski, R. S.

    1999-01-01

    Neuronogenesis in the pseudostratified ventricular epithelium is the initial process in a succession of histogenetic events which give rise to the laminate neocortex. Here we review experimental findings in mouse which support the thesis that the restriction point of the G1 phase of the cell cycle is the critical point of regulation of the overall neuronogenetic process. The neuronogenetic interval in mouse spans 6 days. In the course of these 6 days the founder population and its progeny execute 11 cell cycles. With each successive cycle there is an increase in the fraction of postmitotic cells which leaves the cycle (the Q fraction) and also an increase in the length of the cell cycle due to an increase in the length of the G1 phase of the cycle. Q corresponds to the probability that postmitotic cells will exit the cycle at the restriction point of the G1 phase of the cell cycle. Q increases non-linearly, but the rate of change of Q with cycle (i.e., the first derivative) over the course of the neuronogenetic interval is a constant, k, which appears to be set principally by cell internal mechanisms which are species specific. Q also seems to be modulated, but at low amplitude, by a balance of mitogenic and antimitogenic influences acting from without the cell. We suggest that intracellular signal transduction systems control a general advance of Q during development and thereby determine the general developmental plan (i.e., cell number and laminar composition) of the neocortex and that external mitogens and anti-mitogens modulate this advance regionally and temporally and thereby produce regional modifications of the general plan.

  1. Monoclonal Immunoglobulin G1 Directed against Aspergillus fumigatus Cell Wall Glycoprotein Protects against Experimental Murine Aspergillosis†

    PubMed Central

    Chaturvedi, Ashok K.; Kavishwar, A.; Keshava, G. B. Shiva; Shukla, P. K.

    2005-01-01

    Most of the biological functions related to pathogenicity and virulence reside in the fungal cell wall, which, being the outermost part of the cell, mediates the host-fungus interplay. For these reasons much effort has focused on the discovery of useful inhibitors of cell wall glucan, chitin, and mannoprotein biosynthesis. In the absence of a wide-spectrum, safe, and potent antifungal agent, a new strategy for antifungal therapy is directed towards the development of monoclonal antibodies (MAbs). In the present study the MAb A9 (immunoglobulin G1 [IgG1]) was identified from hybridomas raised in BALB/c mice immunized with cell wall antigen of Aspergillus fumigatus. The immunoreactive epitopes for this IgG1 MAb appeared to be associated with a peptide moiety, and indirect immunofluorescence microscopy revealed its binding to the cell wall surface of hyphae as well as with swollen conidia. MAb A9 inhibited hyphal development as observed by MTT [3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (25.76%), reduced the duration of spore germination, and exerted an in vitro cidal effect against Aspergillus fumigatus. The in vivo protective efficacy of MAb A9 was also evaluated in a murine model of invasive aspergillosis, where a reduction in CFU (>4 log10 units) was observed in kidney tissue of BALB/c mice challenged with A. fumigatus (2 × 105 CFU/ml) and where enhanced mean survival times (19.5 days) compared to the control (7.1 days) and an irrelevant MAb (6.1 days) were also observed. PMID:16148172

  2. Mitotic phosphorylation of eukaryotic initiation factor 4G1 (eIF4G1) at Ser1232 by Cdk1:cyclin B inhibits eIF4A helicase complex binding with RNA.

    PubMed

    Dobrikov, Mikhail I; Shveygert, Mayya; Brown, Michael C; Gromeier, Matthias

    2014-02-01

    During mitosis, global translation is suppressed, while synthesis of proteins with vital mitotic roles must go on. Prior evidence suggests that the mitotic translation shift involves control of initiation. Yet, no signals specifically targeting translation initiation factors during mitosis have been identified. We used phosphoproteomics to investigate the central translation initiation scaffold and "ribosome adaptor," eukaryotic initiation factor 4G1 (eIF4G1) in interphase or nocodazole-arrested mitotic cells. This approach and kinase inhibition assays, in vitro phosphorylation with recombinant kinase, and kinase depletion-reconstitution experiments revealed that Ser1232 in eIF4G1 is phosphorylated by cyclin-dependent kinase 1 (Cdk1):cyclin B during mitosis. Ser1232 is located in an unstructured region of the C-terminal portion of eIF4G1 that coordinates assembly of the eIF4G/-4A/-4B helicase complex and binding of the mitogen-activated protein kinase (MAPK) signal-integrating kinase, Mnk. Intense phosphorylation of Ser1232 in mitosis strongly enhanced the interactions of eIF4A with HEAT domain 2 of eIF4G and decreased association of eIF4G/-4A with RNA. Our findings implicate phosphorylation of eIF4G1(Ser1232) by Cdk1:cyclin B and its inhibitory effects on eIF4A helicase activity in the mitotic translation initiation shift.

  3. 26 CFR 1.143(g)-1 - Requirements related to arbitrage.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... in whole. Except as provided in paragraph (d)(4) of this section, issuers may apply § 1.143(g)-1, in... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Requirements related to arbitrage. 1.143(g)-1 Section 1.143(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY...

  4. 16 CFR Appendix G1 to Part 305 - Furnaces-Gas

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305... RULEâ) Appendix G1 to Part 305—Furnaces—Gas Furnace type Range of annual fuel utilization efficiencies (AFUEs) Low High Gas Furnaces Manufactured Before the Compliance Date of DOE Regional...

  5. 26 CFR 1.642(g)-1 - Disallowance of double deductions; in general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....642(g)-1 Section 1.642(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.642(g)-1 Disallowance..., after a statement is filed under section 642(g) with respect to a particular item or portion of an...

  6. 26 CFR 1.430(g)-1 - Valuation date and valuation of plan assets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....430(g)-1 Section 1.430(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Certain Stock Options § 1.430(g)-1 Valuation date and... valuation date and the valuation of a plan's assets for a plan year under section 430(g). Section 430...

  7. 26 CFR 25.2523(g)-1 - Special rule for charitable remainder trusts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... 25.2523(g)-1 Section 25.2523(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE....2523(g)-1 Special rule for charitable remainder trusts. (a) In general. (1) With respect to gifts made... passing to the spouse qualifies for a marital deduction under section 2523(g) and the value of...

  8. 26 CFR 301.6511(g)-1 - Special rule for partnership items of federally registered partnerships.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... registered partnerships. 301.6511(g)-1 Section 301.6511(g)-1 Internal Revenue INTERNAL REVENUE SERVICE... Limitations on Assessment and Collection § 301.6511(g)-1 Special rule for partnership items of federally...(g) must also be taken into account in applying the various special periods of limitation...

  9. 26 CFR 301.6223(g)-1 - Responsibilities of the tax matters partner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... contained in 26 CFR part 1, revised April 1, 2001. .... 301.6223(g)-1 Section 301.6223(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE....6223(g)-1 Responsibilities of the tax matters partner. (a) Notices described in section...

  10. 26 CFR 1.143(g)-1 - Requirements related to arbitrage.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Requirements related to arbitrage. 1.143(g)-1 Section 1.143(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED....143(g)-1 Requirements related to arbitrage. (a) In general. Under section 143, for an issue to be...

  11. 26 CFR 1.430(g)-1 - Valuation date and valuation of plan assets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....430(g)-1 Section 1.430(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Certain Stock Options § 1.430(g)-1 Valuation date... plan's valuation date and the valuation of a plan's assets for a plan year under section...

  12. 26 CFR 25.2523(g)-1 - Special rule for charitable remainder trusts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... passing to the spouse qualifies for a marital deduction under section 2523(g) and the value of the.... 25.2523(g)-1 Section 25.2523(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE....2523(g)-1 Special rule for charitable remainder trusts. (a) In general. (1) With respect to gifts...

  13. Staurosporine is chemoprotective by inducing G1 arrest in a Chk1- and pRb-dependent manner.

    PubMed

    Murray, Mollianne McGahren; Bui, Tuyen; Smith, Michelle; Bagheri-Yarmand, Rozita; Wingate, Hannah; Hunt, Kelly K; Keyomarsi, Khandan

    2013-10-01

    Chemotherapeutic agents have been the mainstay of cancer therapy for years. However, their effectiveness has been limited by toxicities they impart on normal cells. Staurosporine (ST) has been shown to arrest normal, but not breast cancer, cells in G1. Therefore, ST may become a chemoprotective agent, arresting normal cells while allowing tumor cells to enter cell cycle phases where they are sensitive to chemotherapeutic agents. Understanding the mechanism of ST-mediated G1 arrest may allow for a beneficial chemoprotective treatment strategy for patients. We utilized 76NE6 (pRb+/p53-), 76NF2V (pRb+/p53+) and 76NE7 (pRb-/P53+) non-tumorigenic human mammary epithelial cell lines to understand the role of the Rb and p53 pathways in ST-directed G1 arrest. CDK4 was downregulated by ST in Rb+ cells, but its presence could not reverse the arrest, neither did its stable downregulation alter ST-mediated cellular response. ST-mediated G1 arrest required pRb, which in turn initiated a cascade of events leading to inhibition of CDK4. Further assessment of this pathway revealed that Chk1 expression and activity were required for the Rb-dependent arrest. For example, pRb+ cells with small interfering RNA to Chk1 had approximately 60% less cells in G1 phase compared with controls and pRb- cells do not arrest upon ST. Furthermore, Chk1 expression facilitates the release of the Rb+ cells from G1 arrest. Collectively, our data suggest that pRb cooperates with Chk1 to mediate a G1 arrest only in pRb+ cells. The elucidation of this pathway can help identify novel agents to protect cancer patients against the debilitating effects of chemotherapy.

  14. Histone Deacetylase (HDAC) Inhibitors - Emerging Roles in Neuronal Memory, Learning, Synaptic Plasticity and Neural Regeneration

    PubMed Central

    Ahmad Ganai, Shabir; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

    2016-01-01

    Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed. PMID:26487502

  15. SIRT1 deacetylase in POMC neurons is required for homeostatic defenses against diet-induced obesity

    PubMed Central

    Ramadori, Giorgio; Fujikawa, Teppei; Fukuda, Makoto; Anderson, Jason; Morgan, Donald A.; Mostoslavsky, Raul; Stuart, Ronald C.; Perello, Mario; Vianna, Claudia R.; Nillni, Eduardo A.; Rahmouni, Kamal; Coppari, Roberto

    2010-01-01

    Summary Feeding on high-calorie (HC) diets induces serious metabolic imbalances, including obesity. Understanding the mechanisms against excessive body weight gain is critical for developing effective anti-obesity strategies. Here, we show that lack of nicotinamide adenosine dinucleotide (NAD+)-dependent deacetylase SIRT1 in pro-opiomelanocortin (POMC) neurons causes hypersensitivity to diet-induced obesity due to reduced energy expenditure. The ability of leptin to properly engage the phosphoinositide 3-kinase (PI3K) signaling in POMC neurons and elicit remodeling of perigonadal white adipose tissue (WAT) is severely compromised in mutant mice. Also, electrophysiological and histomorphomolecular analyses indicate a selective reduction in sympathetic nerve activity and brown-fat-like characteristics in perigonadal WAT of mutant mice; suggesting a physiologically important role for POMC neurons in controlling this visceral fat depot. In summary, our results provide direct genetic evidence that SIRT1 in POMC neurons is required for normal autonomic adaptations against diet-induced obesity. PMID:20620997

  16. Dynamic phosphorylation of Histone Deacetylase 1 by Aurora kinases during mitosis regulates zebrafish embryos development.

    PubMed

    Loponte, Sara; Segré, Chiara V; Senese, Silvia; Miccolo, Claudia; Santaguida, Stefano; Deflorian, Gianluca; Citro, Simona; Mattoscio, Domenico; Pisati, Federica; Moser, Mirjam A; Visintin, Rosella; Seiser, Christian; Chiocca, Susanna

    2016-01-01

    Histone deacetylases (HDACs) catalyze the removal of acetyl molecules from histone and non-histone substrates playing important roles in chromatin remodeling and control of gene expression. Class I HDAC1 is a critical regulator of cell cycle progression, cellular proliferation and differentiation during development; it is also regulated by many post-translational modifications (PTMs). Herein we characterize a new mitosis-specific phosphorylation of HDAC1 driven by Aurora kinases A and B. We show that this phosphorylation affects HDAC1 enzymatic activity and it is critical for the maintenance of a proper proliferative and developmental plan in a complex organism. Notably, we find that Aurora-dependent phosphorylation of HDAC1 regulates histone acetylation by modulating the expression of genes directly involved in the developing zebrafish central nervous system. Our data represent a step towards the comprehension of HDAC1 regulation by its PTM code, with important implications in unravelling its roles both in physiology and pathology.

  17. Dynamic phosphorylation of Histone Deacetylase 1 by Aurora kinases during mitosis regulates zebrafish embryos development

    PubMed Central

    Loponte, Sara; Segré, Chiara V.; Senese, Silvia; Miccolo, Claudia; Santaguida, Stefano; Deflorian, Gianluca; Citro, Simona; Mattoscio, Domenico; Pisati, Federica; Moser, Mirjam A.; Visintin, Rosella; Seiser, Christian; Chiocca, Susanna

    2016-01-01

    Histone deacetylases (HDACs) catalyze the removal of acetyl molecules from histone and non-histone substrates playing important roles in chromatin remodeling and control of gene expression. Class I HDAC1 is a critical regulator of cell cycle progression, cellular proliferation and differentiation during development; it is also regulated by many post-translational modifications (PTMs). Herein we characterize a new mitosis-specific phosphorylation of HDAC1 driven by Aurora kinases A and B. We show that this phosphorylation affects HDAC1 enzymatic activity and it is critical for the maintenance of a proper proliferative and developmental plan in a complex organism. Notably, we find that Aurora-dependent phosphorylation of HDAC1 regulates histone acetylation by modulating the expression of genes directly involved in the developing zebrafish central nervous system. Our data represent a step towards the comprehension of HDAC1 regulation by its PTM code, with important implications in unravelling its roles both in physiology and pathology. PMID:27458029

  18. Berberine inhibits growth and induces G1 arrest and apoptosis in human cholangiocarcinoma QBC939 cells.

    PubMed

    He, Wei; Wang, Bin; Zhuang, Yun; Shao, Dong; Sun, Kewen; Chen, Jianping

    2012-01-01

    The chemotherapeutic approach using non-toxic natural products may be one of the strategies for the management of the cholangiocarcinoma. Here we report that in vitro treatment of human cholangiocarcinoma QBC939 cells with berberine, a naturally occurring isoquinoline alkaloid, decreased cell viability and induced cell death in a dose-dependent manner, which was associated with an increase in G1 arrest. Our western blot analysis showed that berberine-induced G1 cell cycle arrest was mediated through the increased expression of cyclin-dependent kinase inhibitors (Cdki) proteins (Cip1/p21 and Kip1/p27); a simultaneous decrease in Cdk2 and Cdk4 and cyclins D1, and reduced activity of the Cyclins-Cdk complex. In additional studies, treatment of QBC939 cells with different concentrations (10, 40, 80 μM) of berberine for 48 h resulted in a significant dose-dependent increase in apoptosis compared to the non-berberine-treated control, which was associated with an increased expression of pro-apoptotic protein Bax and decreased expression of anti-apoptotic proteins Bcl-2 and Bcl-xL. Together, this study for the first time identified berberine as a chemotherapeutic agent against human cholangiocarcinoma cells QBC939 cells in vitro. Further in vivo studies are required to determine whether berberine could be an effective chemotherapeutic agent for the management of cholangiocarcinoma.

  19. Revised direct radiocarbon dating of the Vindija G1 Upper Paleolithic Neandertals.

    PubMed

    Higham, Tom; Ramsey, Christopher Bronk; Karavanić, Ivor; Smith, Fred H; Trinkaus, Erik

    2006-01-17

    The 1998/1999 direct dating of two Neandertal specimens from level G(1) of Vindija Cave in Croatia to approximately 28,000 and approximately 29,000 radiocarbon ((14)C) years ago has led to interpretations concerning the late survival of Neandertals in south-central Europe, patterns of interaction between Neandertals and in-dispersing early modern humans in Europe, and complex biocultural scenarios for the earlier phases of the Upper Paleolithic. Given improvements, particularly in sample pretreatment techniques for bone radiocarbon samples, especially ultrafiltration of collagen samples, these Vindija G(1) Neandertal fossils are redated to approximately 32,000-33,000 (14)C years ago and possibly earlier. These results and the recent redating of a number of purportedly old modern human skeletal remains in Europe to younger time periods highlight the importance of fine chronological control when studying this biocultural time period and the tenuous nature of monolithic scenarios for the establishment of modern humans and earlier phases of the Upper Paleolithic in Europe.

  20. Revised direct radiocarbon dating of the Vindija G1 Upper Paleolithic Neandertals

    PubMed Central

    Higham, Tom; Ramsey, Christopher Bronk; Karavanić, Ivor; Smith, Fred H.; Trinkaus, Erik

    2006-01-01

    The 1998/1999 direct dating of two Neandertal specimens from level G1 of Vindija Cave in Croatia to ≈28,000 and ≈29,000 radiocarbon (14C) years ago has led to interpretations concerning the late survival of Neandertals in south-central Europe, patterns of interaction between Neandertals and in-dispersing early modern humans in Europe, and complex biocultural scenarios for the earlier phases of the Upper Paleolithic. Given improvements, particularly in sample pretreatment techniques for bone radiocarbon samples, especially ultrafiltration of collagen samples, these Vindija G1 Neandertal fossils are redated to ≈32,000–33,000 14C years ago and possibly earlier. These results and the recent redating of a number of purportedly old modern human skeletal remains in Europe to younger time periods highlight the importance of fine chronological control when studying this biocultural time period and the tenuous nature of monolithic scenarios for the establishment of modern humans and earlier phases of the Upper Paleolithic in Europe. PMID:16407102

  1. A series of novel, potent, and selective histone deacetylase inhibitors.

    PubMed

    Jones, Philip; Altamura, Sergio; Chakravarty, Prasun K; Cecchetti, Ottavia; De Francesco, Raffaele; Gallinari, Paola; Ingenito, Raffaele; Meinke, Peter T; Petrocchi, Alessia; Rowley, Michael; Scarpelli, Rita; Serafini, Sergio; Steinkühler, Christian

    2006-12-01

    Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in clinical trials. A structurally novel series of HDAC inhibitors based on the natural cyclic tetrapeptide Apicidin is described. Selected screening of the sample collection looking for L-2-amino-8-oxodecanoic acid (L-Aoda) derivatives identified a small acyclic lead molecule 1 with the unusual ketone zinc binding group. SAR studies around this lead resulted in optimization to potent, low molecular weight, selective, non-hydroxamic acid HDAC inhibitors, equipotent to current clinical candidates.

  2. Histone Deacetylase Inhibitors for Cutaneous T-Cell Lymphoma.

    PubMed

    Duvic, Madeleine

    2015-10-01

    Cutaneous T-cell lymphomas (CTCLs) are non-Hodgkin's T-cell lymphomas that present as skin lesions. Mycosis fungoides with large cell transformation has a 5-year overall survival of 32% with involved skin and 7% with extracutaneous involvement. Failure to cure advanced MF with large cell transformation and peripheral T-cell lymphoma has resulted in a search for novel targeted agents including antibodies and gene modulators. Histone deacetylase inhibitors are small molecules that seem to be particularly active for T-cell lymphoma. PMID:26433847

  3. Crystal Structures of Lipoglycopeptide Antibiotic Deacetylases: Implications for the Biosynthesis of A40926 and Teicoplanin

    SciTech Connect

    Zou, Yaozhong; Brunzelle, Joseph S.; Nair, Satish K.

    2008-07-08

    The lipoglycopeptide antibiotics teicoplanin and A40926 have proven efficacy against Gram-positive pathogens. These drugs are distinguished from glycopeptide antibiotics by N-linked long chain acyl-D-glucosamine decorations that contribute to antibacterial efficacy. During the biosynthesis of lipoglycopeptides, tailoring glycosyltransferases attach an N-acetyl-D-glucosamine to the aglycone, and this N-acetyl-glucosaminyl pseudoaglycone is deacetylated prior to long chain hydrocarbon attachment. Here we present several high-resolution crystal structures of the pseudoaglycone deacetylases from the biosynthetic pathways of teicoplanin and A40926. The cocrystal structure of the teicoplanin pseudoaglycone deacetylase with a fatty acid product provides further insights into the roles of active-site residues, and suggests mechanistic similarities with structurally distinct zinc deacetylases, such as peptidoglycan deacetylase and LpxC. A unique, structurally mobile capping lid, located at the apex of these pseudoaglycone deacetylases, likely serves as a determinant of substrate specificity.

  4. The flare activity of G1 718 = BD + 22 deg 3406

    NASA Astrophysics Data System (ADS)

    Chugainov, P. F.

    The results of 58.8 hours of photoelectric U-band observations of the red dwarf G1 718 are presented. The observations were carried out in order to confirm the conclusion of Mahmoud and Soliman (1980) that G1 718 is experiencing high flare activity. It is shown that the mean rate of energy release from G1 718 is approximately the same as that of G1 825. Both G1 718 and G1 825 show a deviation from the correlation between mean energy release rate and luminosity which has been established for young red dwarfs. No BY Dra variations were found for G1 718. The complete observational results are given in a table.

  5. Histone deacetylases and their role in motor neuron degeneration

    PubMed Central

    Lazo-Gómez, Rafael; Ramírez-Jarquín, Uri N.; Tovar-y-Romo, Luis B.; Tapia, Ricardo

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized by the progressive loss of motor neurons. The cause of this selective neuronal death is unknown, but transcriptional dysregulation is recently emerging as an important factor. The physical substrate for the regulation of the transcriptional process is chromatin, a complex assembly of histones and DNA. Histones are subject to several post-translational modifications, like acetylation, that are a component of the transcriptional regulation process. Histone acetylation and deacetylation is performed by a group of enzymes (histone acetyltransferases (HATs) and deacetylases, respectively) whose modulation can alter the transcriptional state of many regions of the genome, and thus may be an important target in diseases that share this pathogenic process, as is the case for ALS. This review will discuss the present evidence of transcriptional dysregulation in ALS, the role of histone deacetylases (HDACs) in disease pathogenesis, and the novel pharmacologic strategies that are being comprehensively studied to prevent motor neuron death, with focus on sirtuins (SIRT) and their effectors. PMID:24367290

  6. Histone deacetylase inhibition abolishes stress-induced spatial memory impairment.

    PubMed

    Vargas-López, Viviana; Lamprea, Marisol R; Múnera, Alejandro

    2016-10-01

    Acute stress induced before spatial training impairs memory consolidation. Although non-epigenetic underpinning of such effect has been described, the epigenetic mechanisms involved have not yet been studied. Since spatial training and intense stress have opposite effects on histone acetylation balance, it is conceivable that disruption of such balance may underlie acute stress-induced spatial memory consolidation impairment and that inhibiting histone deacetylases prevents such effect. Trichostatin-A (TSA, a histone deacetylase inhibitor) was used to test its effectiveness in preventing stress' deleterious effect on memory. Male Wistar rats were trained in a spatial task in the Barnes maze; 1-h movement restraint was applied to half of them before training. Immediately after training, stressed and non-stressed animals were randomly assigned to receive either TSA (1mg/kg) or vehicle intraperitoneal injection. Twenty-four hours after training, long-term spatial memory was tested; plasma and brain tissue were collected immediately after the memory test to evaluate corticosterone levels and histone H3 acetylation in several brain areas. Stressed animals receiving vehicle displayed memory impairment, increased plasma corticosterone levels and markedly reduced histone H3 acetylation in prelimbic cortex and hippocampus. Such effects did not occur in stressed animals treated with TSA. The aforementioned results support the hypothesis that acute stress induced-memory impairment is related to histone deacetylation.

  7. Histone deacetylase inhibition abolishes stress-induced spatial memory impairment.

    PubMed

    Vargas-López, Viviana; Lamprea, Marisol R; Múnera, Alejandro

    2016-10-01

    Acute stress induced before spatial training impairs memory consolidation. Although non-epigenetic underpinning of such effect has been described, the epigenetic mechanisms involved have not yet been studied. Since spatial training and intense stress have opposite effects on histone acetylation balance, it is conceivable that disruption of such balance may underlie acute stress-induced spatial memory consolidation impairment and that inhibiting histone deacetylases prevents such effect. Trichostatin-A (TSA, a histone deacetylase inhibitor) was used to test its effectiveness in preventing stress' deleterious effect on memory. Male Wistar rats were trained in a spatial task in the Barnes maze; 1-h movement restraint was applied to half of them before training. Immediately after training, stressed and non-stressed animals were randomly assigned to receive either TSA (1mg/kg) or vehicle intraperitoneal injection. Twenty-four hours after training, long-term spatial memory was tested; plasma and brain tissue were collected immediately after the memory test to evaluate corticosterone levels and histone H3 acetylation in several brain areas. Stressed animals receiving vehicle displayed memory impairment, increased plasma corticosterone levels and markedly reduced histone H3 acetylation in prelimbic cortex and hippocampus. Such effects did not occur in stressed animals treated with TSA. The aforementioned results support the hypothesis that acute stress induced-memory impairment is related to histone deacetylation. PMID:27544851

  8. Functional role of eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in NSCLC

    PubMed Central

    Cao, Yueyu; Wei, Mengdan; Li, Bing; Liu, Yali; Lu, Ying; Tang, Zhipeng; Lu, Tianbao; Yin, Yujiao; Qin, Zhiqiang; Xu, Zengguang

    2016-01-01

    Eukaryotic translation initiation factor 4 gamma 1(EIF4G1) is related to tumorigenesis and tumor progression. However, its role and the underlying mechanisms in the regulation of tumor development in non–small cell lung cancers (NSCLC) remain largely unknown. Here we report that the levels of EIF4G1 expression are much higher in NSCLC cell lines and tumor tissues than those in the normal lung cells and adjacent normal tissues from the same patients. Using shRNA to knock down EIF4G1 expression stably, we found EIF4G1 required for NSCLC cell proliferation, anchorage-independent growth, migration and invasion. Furthermore, silencing of EIF4G1 induces NSCLC cell apoptosis and causes G0/G1 cell cycle arrest. To identify the partner protein network of EIF4G1 in NSCLC cells, we found that Ubiquitin-specific protease 10 (USP10) can directly interacts with EIF4G1, while acting as a negative regulator for EIF4G1-mediated functions. Together, our results indicate that EIF4G1 functions as an oncoprotein during NSCLC development, which may represent a novel and promising therapeutic target in lung cancer. PMID:27003362

  9. Functional role of eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in NSCLC.

    PubMed

    Cao, Yueyu; Wei, Mengdan; Li, Bing; Liu, Yali; Lu, Ying; Tang, Zhipeng; Lu, Tianbao; Yin, Yujiao; Qin, Zhiqiang; Xu, Zengguang

    2016-04-26

    Eukaryotic translation initiation factor 4 gamma 1(EIF4G1) is related to tumorigenesis and tumor progression. However, its role and the underlying mechanisms in the regulation of tumor development in non-small cell lung cancers (NSCLC) remain largely unknown. Here we report that the levels of EIF4G1 expression are much higher in NSCLC cell lines and tumor tissues than those in the normal lung cells and adjacent normal tissues from the same patients. Using shRNA to knock down EIF4G1 expression stably, we found EIF4G1 required for NSCLC cell proliferation, anchorage-independent growth, migration and invasion. Furthermore, silencing of EIF4G1 induces NSCLC cell apoptosis and causes G0/G1 cell cycle arrest. To identify the partner protein network of EIF4G1 in NSCLC cells, we found that Ubiquitin-specific protease 10 (USP10) can directly interacts with EIF4G1, while acting as a negative regulator for EIF4G1-mediated functions. Together, our results indicate that EIF4G1 functions as an oncoprotein during NSCLC development, which may represent a novel and promising therapeutic target in lung cancer.

  10. Identification, expression and phylogenetic analysis of EgG1Y162 from Echinococcus granulosus

    PubMed Central

    Zhang, Fengbo; Ma, Xiumin; Zhu, Yuejie; Wang, Hongying; Liu, Xianfei; Zhu, Min; Ma, Haimei; Wen, Hao; Fan, Haining; Ding, Jianbing

    2014-01-01

    Objective: This study was to clone, identify and analyze the characteristics of egG1Y162 gene from Echinococcus granulosus. Methods: Genomic DNA and total RNAs were extracted from four different developmental stages of protoscolex, germinal layer, adult and egg of Echinococcus granulosus, respectively. Fluorescent quantitative PCR was used for analyzing the expression of egG1Y162 gene. Prokaryotic expression plasmid of pET41a-EgG1Y162 was constructed to express recombinant His-EgG1Y162 antigen. Western blot analysis was performed to detect antigenicity of EgG1Y162 antigen. Gene sequence, amino acid alignment and phylogenetic tree of EgG1Y162 were analyzed by BLAST, online Spidey and MEGA4 software, respectively. Results: EgG1Y162 gene was expressed in four developmental stages of Echinococcus granulosus. And, egG1Y162 gene expression was the highest in the adult stage, with the relative value of 19.526, significantly higher than other three stages. Additionally, Western blot analysis revealed that EgG1Y162 recombinant protein had good reaction with serum samples from Echinococcus granulosus infected human and dog. Moreover, EgG1Y162 antigen was phylogenetically closest to EmY162 antigen, with the similarity over 90%. Conclusion: Our study identified EgG1Y162 antigen in Echinococcus granulosus for the first time. EgG1Y162 antigen had a high similarity with EmY162 antigen, with the genetic differences mainly existing in the intron region. And, EgG1Y162 recombinant protein showed good antigenicity. PMID:25337206

  11. Deacetylase inhibitors modulate proliferation and self-renewal properties of leukemic stem and progenitor cells

    PubMed Central

    Romanski, Annette; Schwarz, Kerstin; Keller, Maren; Wietbrauk, Sarah; Vogel, Anja; Roos, Jessica; Oancea, Claudia; Brill, Boris; Krämer, Oliver H.; Serve, Hubert; Ruthardt, Martin; Bug, Gesine

    2012-01-01

    Acute myeloid leukemia (AML) is a highly malignant disease that is not curable in the majority of patients. Numerous non-random genetic abnormalities are known, among which several translocations such as PLZF/RARα or AML1/ETO are known to aberrantly recruit histone deacetylases. Deacetylase inhibitors (DACi) are promising drugs leading to growth inhibition, cell cycle arrest, premature senescence and apoptosis in malignant cells. It is believed that DACi may have clinical efficacy by eradicating the most primitive population of leukemic stem and progenitor cells, possibly by interfering with self-renewal. The aim of the study was to investigate the effects of DACi on leukemic stem and progenitor cells using murine transduction-transplantation models of hematopoietic cells harboring the leukemia-associated fusion proteins (LAFP) PLZF/RARα or a truncated AML1/ETO protein (AML1/ETO exon 9). We show that the self-renewal and short-term repopulation capacity of AML1/ETO- or PLZF/RARα-expressing Sca1+/lin- stem and progenitor cells are profoundly inhibited by clinically applicable concentrations of the DACi dacinostat and vorinostat. To further investigate the mechanisms underlying these effects, we examined the impact of DACi on the transcription factor c-MYC and the Polycomb group protein BMI1, which are induced by LAFP and involved in leukemic transformation. In AML1/ETO or PLZF/RARα-positive 32D cells, DACi-mediated antiproliferative effects were associated with downregulation of BMI1 and c-MYC protein levels. Similar effects were demonstrated in primary samples of cytogenetically defined high-risk AML patients. In conclusion, DACi may be effective as maintenance therapy by negatively interfering with signaling pathways that control survival and proliferation of leukemic stem and progenitor cells. PMID:22895185

  12. Inhibition of maize histone deacetylases by HC toxin, the host-selective toxin of Cochliobolus carbonum.

    PubMed Central

    Brosch, G; Ransom, R; Lechner, T; Walton, J D; Loidl, P

    1995-01-01

    HC toxin, the host-selective toxin of the maize pathogen Cochliobolus carbonum, inhibited maize histone deacetylase (HD) at 2 microM. Chlamydocin, a related cyclic tetrapeptide, also inhibited HD activity. The toxins did not affect histone acetyltransferases. After partial purification of histone deacetylases HD1-A, HD1-B, and HD2 from germinating maize embryos, we demonstrated that the different enzymes were similarly inhibited by the toxins. Inhibitory activities were reversibly eliminated by treating toxins with 2-mercaptoethanol, presumably by modifying the carbonyl group of the epoxide-containing amino acid Aeo (2-amino-9,10-epoxy-8-oxodecanoic acid). Kinetic studies revealed that inhibition of HD was of the uncompetitive type and reversible. HC toxin, in which the epoxide group had been hydrolyzed, completely lost its inhibitory activity; when the carbonyl group of Aeo had been reduced to the corresponding alcohol, the modified toxin was less active than native toxin. In vivo treatment of embryos with HC toxin caused the accumulation of highly acetylated histone H4 subspecies and elevated acetate incorporation into H4 in susceptible-genotype embryos but not in the resistant genotype. HDs from chicken and the myxomycete Physarum polycephalum were also inhibited, indicating that the host selectivity of HC toxin is not determined by its inhibitory effect on HD. Consistent with these results, we propose a model in which HC toxin promotes the establishment of pathogenic compatibility between C. carbonum and maize by interfering with reversible histone acetylation, which is implicated in the control of fundamental cellular processes, such as chromatin structure, cell cycle progression, and gene expression. PMID:8535144

  13. Diversity of VP7 genes of G1 rotaviruses isolated in Iran, 2009-2013.

    PubMed

    Jalilvand, Somayeh; Afchangi, Atefeh; Mohajel, Nasir; Roohvand, Farzin; Shoja, Zabihollah

    2016-01-01

    Genotype G1 of rotaviruses (RVs) is the most prevalent strain in human RV infections around the world. The present study evaluated genetic variations in the VP7 gene of RV G1 genotype isolates from Iran. Genetic and phylogenetic analyses indicated that RV strains from Iran clustered with G1 lineages IA, IC, and IIC, showing highest average of similarity versus reference sequences of the G1 lineages I and II. This study highlights the genetic pattern of G1 RV on the basis of distinct lineages and sublineages and indicates the importance of continuous monitoring on genetic variation and evolution pattern of G1 RV strains across the Iranian population for the final aim of RV vaccine introduction.

  14. Evidence of bovine immunoglobulin G1 (IgG1) protease activity in partially purified culture supernate of Pasteurella haemolytica A1.

    PubMed Central

    Lee, C W; Shewen, P E

    1996-01-01

    In the bovine respiratory tract, IgG1 is a major secretory immunoglobulin (Ig), and both IgG1 and IgG2 are believed to be important in defense against pneumonic pasteurellosis (shipping fever) in calves. Here we provide evidence for hydrolysis of IgG1 in the presence of partially purified culture supernate (ppCS) from the respiratory pathogen Pasteurella haemolytica A1. Bovine IgG1 was hydrolysed sequentially into three distinct bands (approximately 39, 12, and 7 kDa respectively). Furthermore, partial hydrolysis of bovine IgG2 was observed, but neither bovine IgA nor IgM were affected by incubation with ppCS. These findings suggest that the production of an IgG1-specific protease by P. haemolytica A1 may be a virulence mechanism contributing to the pathogenesis of bovine pneumonic pasteurellosis. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. PMID:8785718

  15. Endogenous production of immunoglobulin IgG1 in newborn calves.

    PubMed

    Devery, J E; Davis, C L; Larson, B L

    1979-11-01

    There is a decrease in the specific activity of labeled IgG1 of serum over 3 wk following the feeding of iodine-125 labeled immunoglobulin IgG1 in colostrum to calves at birth. This decrease indicated the appearance of new IgG1 from some source. To determine if this new IgG1 came from endogenous production in the calf or from continued small amount of intestinal absorption from milk, labeled IgG1 was added to normal milk and fed to calves of various ages up to 3 wk after an initial feeding of colostrum at birth. Labeled IgG1 was also added to colostrum fed to calves at birth, and the calves were maintained on a normal milk diet or fed a synthetic milk diet. Determination of iodine-125 in the serum protein fractions of these calves indicated that there was no apparent intestinal absorption of labeled IgG1 from the milk in the period from 2 days to 3 wk. Furthermore, comparable decreases occurred in the specific activity of labeled IgG1 in serum in the calves fed the labeled IgG1 in colostrum at birth and subsequently maintained either on a diet including milk or on the synthetic milk diet devoid of IgG1. The results support the conclusion that the origin of new IgG1 in the calf after about 36 h and up to about 3 wk of age arises from endogenous production at a rate of about 1 g of IgG1 per day.

  16. The paradox of histone deacetylase inhibitor-mediated modulation of cellular responses to radiation.

    PubMed

    Karagiannis, Tom C; El-Osta, Assam

    2006-02-01

    Given the widespread use of radiotherapy in cancer, there has been a longstanding interest in the development of chemical compounds that can modify cellular responses to ionizing radiation. Additionally, recent terrorism threats suggesting attacks with 'dirty bombs' containing combinations of radioactive isotopes with conventional explosives, has increased the interest in compounds that can protect from radiation injury. Histone deacetylase inhibitors represent a new class of compounds that can modulate the effects of radiation. Research with histone deacetylase inhibitors has largely focussed on the consequences of their ability to alter gene transcription via histone acetylation and on their properties as anti-cancer agents. They have been shown to cause cell cycle and growth arrest, differentiation and in certain cases apoptosis in cell cultures and in vivo. In addition to their intrinsic anti-cancer properties, numerous studies have demonstrated that histone deacetylase inhibitors can modulate cellular responses to other toxicity-inducing modalities including ionizing radiation. The consensus is that histone deacetylase inhibitors markedly enhance the sensitivity of cells to radiation by altering numerous molecular pathways. Intriguingly, a report has also shown that histone deacetylase inhibitors can reduce radiation induced acute and late skin damage using a well-established animal model of cutaneous radiation syndrome. Hence, there is an emerging interest in potential use of histone deacetylase inhibitors as radiation sensitizers or protectors. This review focuses on the different mechanisms by which histone deacetylase inhibitors modify cellular responses to ionizing radiation. PMID:16418577

  17. Resetting the epigenetic histone code in the MRL-lpr/lpr mouse model of lupus by histone deacetylase inhibition.

    PubMed

    Garcia, Benjamin A; Busby, Scott A; Shabanowitz, Jeffrey; Hunt, Donald F; Mishra, Nilamadhab

    2005-01-01

    The baseline level of gene expression varies between healthy controls and systemic lupus erythematosus (SLE) patients, and among SLE patients themselves. These variations may explain the different clinical manifestations and severity of disease observed in SLE. Epigenetic mechanisms, which involve DNA and histone modifications, are predictably associated with distinct transcriptional states. To understand the interplay between various histone modifications, including acetylation and methylation, and lupus disease, we performed differential expression histone modification analysis in splenocytes from the MRL-lpr/lpr mouse model of lupus. Using stable isotope labeling in combination with mass spectrometry, we found global site-specific hypermethylation (except H3 K4 methylation) and hypoacetylation in histone H3 and H4 MRL-lpr/lpr mice compared to control MRL/MPJ mice. Moreover, we have identified novel histone modifications such as H3 K18 methylation, H4 K31 methylation, and H4 K31 acetylation that are differentially expressed in MRL-lpr/lpr mice compared to controls. Finally, in vivo administration of the histone deacetylase inhibitor trichostatin A (TSA) corrected the site-specific hypoacetylation states on H3 and H4 in MRL-lpr/lpr mice with improvement of disease phenotype. Thus, this study is the first to establish the association between aberrant histone codes and pathogenesis of autoimmune disease SLE. These aberrant post-translational histone modifications can therefore be reset with histone deacetylase inhibition in vivo.

  18. Retinoic acid receptor agonists regulate expression of ATP-binding cassette transporter G1 in macrophages.

    PubMed

    Ayaori, Makoto; Yakushiji, Emi; Ogura, Masatsune; Nakaya, Kazuhiro; Hisada, Tetsuya; Uto-Kondo, Harumi; Takiguchi, Shunichi; Terao, Yoshio; Sasaki, Makoto; Komatsu, Tomohiro; Iizuka, Maki; Yogo, Makiko; Uehara, Yoshinari; Kagechika, Hiroyuki; Nakanishi, Tsuyoshi; Ikewaki, Katsunori

    2012-04-01

    ABC transporter G1 (ABCG1) plays a pivotal role in HDL-mediated cholesterol efflux and atherogenesis. We investigated whether, and how, retinoic acid receptors (RARs) regulate ABCG1 expression in macrophages. All-trans retinoic acid (ATRA), an RAR ligand, increased ABCG1 protein levels and apoA-I/HDL-mediated cholesterol efflux from the macrophages. Both ATRA and other RAR agonists, TTNPB and Am580, increased major transcripts driven by promoter B upstream of exon 5, though minor transcripts driven by promoter A upstream of exon 1 were only increased by ATRA. The stimulatory effects of ATRA on ABCG1 expression were completely abolished in the presence of RAR/RXR antagonists but were only partially canceled in the presence of an LXR antagonist. Adenovirus with overexpressed oxysterol sulfotransferase abolished the LXR pathway, as previously reported, and ATRA-responsiveness in ABCA1/ABCG1 expressions were respectively attenuated by 38 and 22% compared to the control virus. Promoter assays revealed that ABCG1 levels were regulated more by promoter B than promoter A, and ATRA activated promoter B in a liver X receptor-responsive element (LXRE)-dependent manner. Further, LXRE-B in intron 7, but not LXRE-A in intron 5, enhanced ATRA responsiveness under overexpression of all RAR isoforms-RARα/β/γ. In contrast, the activation of promoter B by TTNPB depended on LXRE-B and RARα, but not on RARβ/γ. Finally, chromatin immunoprecipitation and gel-shift assays revealed a specific and direct repeat 4-dependent binding of RARα to LXRE-B. In conclusion, RAR ligands increase ABCA1/G1 expression and apoA-I/HDL-mediated cholesterol efflux from macrophages, and modulate ABCG1 promoter activity via LXRE-dependent mechanisms.

  19. Whole exome sequencing of rare variants in EIF4G1 and VPS35 in Parkinson disease

    PubMed Central

    Nuytemans, Karen; Bademci, Guney; Inchausti, Vanessa; Dressen, Amy; Kinnamon, Daniel D.; Mehta, Arpit; Wang, Liyong; Züchner, Stephan; Beecham, Gary W.; Martin, Eden R.; Scott, William K.

    2013-01-01

    Objective: Recently, vacuolar protein sorting 35 (VPS35) and eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) have been identified as 2 causal Parkinson disease (PD) genes. We used whole exome sequencing for rapid, parallel analysis of variations in these 2 genes. Methods: We performed whole exome sequencing in 213 patients with PD and 272 control individuals. Those rare variants (RVs) with <5% frequency in the exome variant server database and our own control data were considered for analysis. We performed joint gene-based tests for association using RVASSOC and SKAT (Sequence Kernel Association Test) as well as single-variant test statistics. Results: We identified 3 novel VPS35 variations that changed the coded amino acid (nonsynonymous) in 3 cases. Two variations were in multiplex families and neither segregated with PD. In EIF4G1, we identified 11 (9 nonsynonymous and 2 small indels) RVs including the reported pathogenic mutation p.R1205H, which segregated in all affected members of a large family, but also in 1 unaffected 86-year-old family member. Two additional RVs were found in isolated patients only. Whereas initial association studies suggested an association (p = 0.04) with all RVs in EIF4G1, subsequent testing in a second dataset for the driving variant (p.F1461) suggested no association between RVs in the gene and PD. Conclusions: We confirm that the specific EIF4G1 variation p.R1205H seems to be a strong PD risk factor, but is nonpenetrant in at least one 86-year-old. A few other select RVs in both genes could not be ruled out as causal. However, there was no evidence for an overall contribution of genetic variability in VPS35 or EIF4G1 to PD development in our dataset. PMID:23408866

  20. FoxG1 and TLE2 act cooperatively to regulate ventral telencephalon formation

    PubMed Central

    Roth, Martin; Bonev, Boyan; Lindsay, Jennefer; Lea, Robert; Panagiotaki, Niki; Houart, Corinne; Papalopulu, Nancy

    2010-01-01

    FoxG1 is a conserved transcriptional repressor that plays a key role in the specification, proliferation and differentiation of the telencephalon, and is expressed from the earliest stages of telencephalic development through to the adult. How the interaction with co-factors might influence the multiplicity and diversity of FoxG1 function is not known. Here, we show that interaction of FoxG1 with TLE2, a Xenopus tropicalis co-repressor of the Groucho/TLE family, is crucial for regulating the early activity of FoxG1. We show that TLE2 is co-expressed with FoxG1 in the ventral telencephalon from the early neural plate stage and functionally cooperates with FoxG1 in an ectopic neurogenesis assay. FoxG1 has two potential TLE binding sites: an N-terminal eh1 motif and a C-terminal YWPMSPF motif. Although direct binding seems to be mediated by the N-terminal motif, both motifs appear important for functional synergism. In the neurogenesis assay, mutation of either motif abolishes functional cooperation of TLE2 with FoxG1, whereas in the forebrain deletion of both motifs renders FoxG1 unable to induce the ventral telencephalic marker Nkx2.1. Knocking down either FoxG1 or TLE2 disrupts the development of the ventral telencephalon, supporting the idea that endogenous TLE2 and FoxG1 work together to specify the ventral telencephalon. PMID:20356955

  1. [Histone deacetylase inhibitors: new synergistic third-line option in multiple myeloma].

    PubMed

    Stegmann, Danielle A

    2016-04-01

    Despite advances in drug therapy of the orphan disease multiple myeloma, patients relapse or become refractory to first-line therapy, and the disease remains incurable. Therefore, histone deacetylase inhibitors have emerged as a new class of anti-myeloma drugs, with synergistic results on progression free survival when given in combination to current first-line therapy. Histone deacetylase inhibitors influence gene expression of target genes. Based on results of an extensive multicenter phase III trial, panobinostat was approved by the FDA in February 2015 as the first histone deacetylase inhibitor for the treatment of multiple myeloma. In Europe, panobinostat received marketing authorization by August 2015. PMID:27209894

  2. Histone deacetylase inhibitor screening identifies HC toxin as the most effective in intrahepatic cholangiocarcinoma cells

    PubMed Central

    ZHOU, WENJIE; CHEN, XIAOXUN; HE, KE; XIAO, JINFENG; DUAN, XIAOPENG; HUANG, RUI; XIA, ZHENGLIN; HE, JINGLIANG; ZHANG, JINQIAN; XIANG, GUOAN

    2016-01-01

    Histone deacetylases (HDACs) are highly expressed in intrahepatic cholangiocarcinoma (ICC) and are associated with poor prognosis of these patients. The aim of the present study was to explore the inhibitory effects of HDAC inhibitors on ICC cells and identify effective and sensitive drugs for ICC. Effects of 34 HDAC inhibitors were screened through two rounds of cell viability assays, and HC toxin, a cyclic tetrapeptide first isolated from the secondary metabolite of Helminthosporium carbonum, exhibited an antitumor activity superior to that of the other HDAC inhibitors and gemcitabine. The mechanisms involved in the inhibitory effects of HC toxin on CCLP-1 cells were investigated by cell counting, colony formation assay, cell morphological observation, real-time PCR, western blotting and flow cytometry. It was demonstrated that HC toxin inhibited the cell proliferation and clone formation ability of the CCLP-1 cells. HC toxin increased the acetyl-histone H4 level and this was associated with the inhibitory effect of HC toxin on the CCLP-1 cells. We also found that HC toxin reduced the level of HDAC1 protein in a post-transcriptional manner. Morphological observation showed multiple morphological changes and indicated the possibility of cell differentiation owing to HC toxin. With increasing concentration of HC toxin, the cell cycle was gradually arrested at the G0/G1 stage and the percentage of apoptotic cells increased which was not mainly through the caspase-3-dependent ways. These results indicated that HC toxin was the most effective among the various HDAC inhibitors with multiple functions in the suppression of ICC in vitro. Thus, HC may be a potential chemotherapeutic for ICC. PMID:26935789

  3. Association of Cdk2/cyclin E and NF-kappa B complexes at G1/S phase.

    PubMed

    Chen, E; Li, C C

    1998-08-28

    NF-kappa B/Rel family plays a pivotal role in a wide variety of cellular functions including growth, development, apoptosis and stress responses. Recent studies indicated that NF-kappa B is also involved in the cell cycle regulation, and high expression of c-Rel results in a cell cycle arrest at the G1/S-phase transition (Bash, J., Zong, W,-X., and Gelinas, C. (1997) Mol. Cell. Biol. 17, 6526-6536). Here we report the detection of Cdk2, a critical kinase responsible for the G1/S-phase transition, in immune complexes precipitated by the NF-kappa B antisera. Cdk2 and NF-kappa B association was detected by co-precipitation in the nuclear lysates of the G1/S-phase cells, and was found in cultured cell lines and in T cells purified from human peripheral blood. Using an affinity column containing the C-terminal peptide of human c-Rel, we isolated cyclin E, the regulatory subunit of the Cdk2 complex, as a c-Rel-binding protein. These findings support and provide physical basis for the involvement of NF-kappa B in the G1/S-phase cell cycle control, and suggest an important role played by the C-terminal sequence of c-Rel. PMID:9731206

  4. Antigenic differences between the EG95-related proteins from Echinococcus granulosus G1 and G6 genotypes: implications for vaccination.

    PubMed

    Alvarez Rojas, C A; Gauci, C G; Lightowlers, M W

    2013-02-01

    Cystic echinococcosis caused by Echinococcus granulosus remains an important and neglected issue in public health. The study of the likely efficacy of the currently available EG95 vaccine against other genotypes of the parasite is important to improve the vaccine as a potential tool to be used in control programmes. The recombinant vaccine EG95-1G1 was developed based on the G1 genotype of E. granulosus. Characterization of the eg95 gene family in the G6 genotype by genomic DNA cloning previously produced the first unequivocal information about the composition of the gene family in a different genotype. The information was used in this study to predict and express two EG95-related proteins from the G6 genotype as recombinants, for assessment of their capacity to bind antibodies raised in sheep vaccinated with the EG95-1G1 vaccine. The proteins (EG95-1G6 and EG95-5G6) from the G6 genotype of E. granulosus were unable to bind all the antibodies raised by sheep vaccinated with EG95-1G1. Differences in the amino acid sequence of EG95-related proteins from G6 and likely the differences in the encoded FnIII domain may be responsible for changes in the conformation of these epitopes.

  5. Acrocentric Chromosomes in Cultured Leukocytes from Mothers of Children Affected With the G1- Trisomy Syndrome

    ERIC Educational Resources Information Center

    And Others; Cotton, James E.

    1973-01-01

    Analysis of venous blood samples from 24 mothers of G1-trisomy-affected (Down's Syndrome) children and 23 mothers of chromosomally normal children indicated that mothers of G1-trisomy-affected children had a greater than expected involvement of the G-chromosomes in associations of acrocentric satellited (chromosome configuration) chromosomes.…

  6. Enhanced HIV-1 neutralization by a CD4-VH3-IgG1 fusion protein

    SciTech Connect

    Meyuhas, Ronit; Noy, Hava; Fishman, Sigal; Margalit, Alon; Montefiori, David C.; Gross, Gideon

    2009-08-21

    HIV-1 gp120 is an alleged B cell superantigen, binding certain VH3+ human antibodies. We reasoned that a CD4-VH3 fusion protein could possess higher affinity for gp120 and improved HIV-1 inhibitory capacity. To test this we produced several human IgG1 immunoligands harboring VH3. Unlike VH3-IgG1 or VH3-CD4-IgG1, CD4-VH3-IgG1 bound gp120 considerably stronger than CD4-IgG1. CD4-VH3-IgG1 exhibited {approx}1.5-2.5-fold increase in neutralization of two T-cell laboratory-adapted strains when compared to CD4-IgG1. CD4-VH3-IgG1 improved neutralization of 7/10 clade B primary isolates or pseudoviruses, exceeding 20-fold for JR-FL and 13-fold for Ba-L. It enhanced neutralization of 4/8 clade C viruses, and had negligible effect on 1/4 clade A pseudoviruses. We attribute this improvement to possible pairing of VH3 with CD4 D1 and stabilization of an Ig Fv-like structure, rather than to superantigen interactions. These novel findings support the current notion that CD4 fusion proteins can act as better HIV-1 entry inhibitors with potential clinical implications.

  7. 16 CFR Appendix G1 to Part 305 - Furnaces-Gas

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Furnaces—Gas Manufacturer's rated heating capacities (Btu's/hr.) Range of annual...

  8. 16 CFR Appendix G1 to Part 305 - Furnaces-Gas

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Furnaces—Gas Manufacturer's rated heating capacities (Btu's/hr.) Range of annual...

  9. 16 CFR Appendix G1 to Part 305 - Furnaces-Gas

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Furnaces—Gas Manufacturer's rated heating capacities (Btu's/hr.) Range of annual...

  10. 16 CFR Appendix G1 to Part 305 - Furnaces-Gas

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Furnaces—Gas Manufacturer's rated heating capacities (Btu's/hr.) Range of annual...

  11. Excretion of serotype G1 rotavirus strains by asymptomatic staff: a possible source of nosocomial infection.

    PubMed

    Barnes, Graeme L; Callaghan, Sarah L; Kirkwood, Carl D; Bogdanovic-Sakran, Nada; Johnston, Linda J; Bishop, Ruth F

    2003-06-01

    This study supports the hypothesis that feces from asymptomatic adults may provide a vehicle for the transmission of rotavirus, in addition to aerosols, hands, and fomites. The observed preferential carriage of serotype G1 strains in the adult gastrointestinal tract may explain G1 predominance and persistence in epidemiologic studies worldwide.

  12. 26 CFR 1.402(g)-1 - Limitation on exclusion for elective deferrals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 1, 2006 edition of 26 CFR Part 1). (ii) Method of allocating income. A plan may use any reasonable.... 1.402(g)-1 Section 1.402(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. §...

  13. 26 CFR 301.6323(g)-1 - Refiling of notice of tax lien.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Refiling of notice of tax lien. 301.6323(g)-1 Section 301.6323(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Collection General Provisions §...

  14. 26 CFR 1.404(g)-1 - Deduction of employer liability payments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Termination of Sufficient Plans. See PBGC regulations, 29 CFR 2617.13(b) for rules concerning these...(g)-1 Section 1.404(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. §...

  15. 26 CFR 1.414(g)-1 - Definition of plan administrator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Definition of plan administrator. 1.414(g)-1 Section 1.414(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. §...

  16. 26 CFR 1.415(g)-1 - Disqualification of plans and trusts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Disqualification of plans and trusts. 1.415(g)-1 Section 1.415(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. §...

  17. 26 CFR 25.2523(g)-1 - Special rule for charitable remainder trusts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true Special rule for charitable remainder trusts. 25.2523(g)-1 Section 25.2523(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY...(g). Accordingly, if the transfer to the trust is made prior to October 24, 1992, the spousal...

  18. A hyperactive transcriptional state marks genome reactivation at the mitosis-G1 transition.

    PubMed

    Hsiung, Chris C-S; Bartman, Caroline R; Huang, Peng; Ginart, Paul; Stonestrom, Aaron J; Keller, Cheryl A; Face, Carolyne; Jahn, Kristen S; Evans, Perry; Sankaranarayanan, Laavanya; Giardine, Belinda; Hardison, Ross C; Raj, Arjun; Blobel, Gerd A

    2016-06-15

    During mitosis, RNA polymerase II (Pol II) and many transcription factors dissociate from chromatin, and transcription ceases globally. Transcription is known to restart in bulk by telophase, but whether de novo transcription at the mitosis-G1 transition is in any way distinct from later in interphase remains unknown. We tracked Pol II occupancy genome-wide in mammalian cells progressing from mitosis through late G1. Unexpectedly, during the earliest rounds of transcription at the mitosis-G1 transition, ∼50% of active genes and distal enhancers exhibit a spike in transcription, exceeding levels observed later in G1 phase. Enhancer-promoter chromatin contacts are depleted during mitosis and restored rapidly upon G1 entry but do not spike. Of the chromatin-associated features examined, histone H3 Lys27 acetylation levels at individual loci in mitosis best predict the mitosis-G1 transcriptional spike. Single-molecule RNA imaging supports that the mitosis-G1 transcriptional spike can constitute the maximum transcriptional activity per DNA copy throughout the cell division cycle. The transcriptional spike occurs heterogeneously and propagates to cell-to-cell differences in mature mRNA expression. Our results raise the possibility that passage through the mitosis-G1 transition might predispose cells to diverge in gene expression states.

  19. 26 CFR 1.642(g)-1 - Disallowance of double deductions; in general.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Disallowance of double deductions; in general. 1.642(g)-1 Section 1.642(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Disallowance of double deductions; in general. Amounts allowable under section 2053(a)(2) (relating...

  20. 26 CFR 1.642(g)-1 - Disallowance of double deductions; in general.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Disallowance of double deductions; in general. 1.642(g)-1 Section 1.642(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Disallowance of double deductions; in general. Amounts allowable under section 2053(a)(2) (relating...

  1. 26 CFR 1.642(g)-1 - Disallowance of double deductions; in general.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Disallowance of double deductions; in general. 1.642(g)-1 Section 1.642(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Disallowance of double deductions; in general. Amounts allowable under section 2053(a)(2) (relating...

  2. 26 CFR 1.642(g)-1 - Disallowance of double deductions; in general.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Disallowance of double deductions; in general. 1.642(g)-1 Section 1.642(g)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Disallowance of double deductions; in general. Amounts allowable under section 2053(a)(2) (relating...

  3. Histone deacetylases in cardiac fibrosis: current perspectives for therapy.

    PubMed

    Tao, Hui; Shi, Kai-Hu; Yang, Jing-Jing; Huang, Cheng; Zhan, Hong-Ying; Li, Jun

    2014-03-01

    Cardiac fibrosis is an important pathological feature of cardiac remodeling in heart diseases. The molecular mechanisms of cardiac fibrosis are unknown. Histone deacetylases (HDACs) are enzymes that balance the acetylation activities of histone acetyltransferases on chromatin remodeling and play essential roles in regulating gene transcription. In recent years, the role of HDACs in cardiac fibrosis initiation and progression, as well as the therapeutic effects of HDAC inhibitors, has been well studied. Moreover, numerous studies indicated that HDAC activity is associated with the development and progression of cardiac fibrosis. In this review, the innovative aspects of HDACs are discussed, with respect to biogenesis, their role in cardiac fibrosis. Furthermore, the potential applications of HDAC inhibitors in the treatment of cardiac fibrosis associated with fibroblast activation and proliferation.

  4. Histone Deacetylase Inhibitors Preserve Function in Aging Axons

    PubMed Central

    Baltan, Selva

    2012-01-01

    Aging increases the vulnerability of aging white matter to ischemic injury. Histone deacetylase (HDAC) inhibitors preserve young adult white matter structure and function during ischemia by conserving ATP and reducing excitotoxicity. In isolated optic nerve from 12 month old mice, deprived of oxygen and glucose, we show that pan- and Class I specific HDAC inhibitors promote functional recovery of axons. This protection correlates with preservation of axonal mitochondria. The cellular expression of HDAC 3, in the central nervous system (CNS) and HDAC 2 in optic nerve considerably changed with age expanding to more cytoplasmic domains from nuclear compartments suggesting that changes in glial cell protein acetylation may confer protection to aging axons. Our results indicate manipulation of HDAC activities in glial cells may have a universal potential for stroke therapy across age groups. PMID:23050648

  5. Processing and membrane topology of the spike proteins G1 and G2 of Uukuniemi virus.

    PubMed Central

    Andersson, A M; Melin, L; Persson, R; Raschperger, E; Wikström, L; Pettersson, R F

    1997-01-01

    The membrane glycoproteins G1 and G2 of the members of the Bunyaviridae family are synthesized as a precursor from a single open reading frame. Here, we have analyzed the processing and membrane insertion of G1 and G2 of a member of the Phlebovirus genus, Uukuniemi virus. By expressing C-terminally truncated forms of the p10 precursor containing the whole of G1 and decreasing portions of G2, we found that processing in BHK21 cells occurred with an efficiency of about 50% if G1 was followed by 50 residues of G2, while complete processing occurred if 98, 150, or 200 residues of G2 were present. Surprisingly, processing of all truncated G2 forms was less efficient in HeLa cells. Proteinase K treatment of microsomes isolated from infected cells indicated that the C terminus of G1 is exposed on the cytoplasmic face. Using G1 tail peptide antisera, the tail was likewise found by immunofluorescence to be exposed on the cytoplasmic face in streptolysin O-permeabilized cells. By introducing stop codons at various positions of the G1 tail and at the natural cleavage site between G1 and G2 and expressing these mutants in BHK cells, we found that no further processing of the G1 C terminus occurred following cleavage of G2 by the signal peptidase. This was also supported by the finding that an antiserum raised against a peptide corresponding to the region immediately upstream from the G2 signal sequence reacted in immunoblotting with G1 from virions. Finally, we show that both G1 and G2 are palmitylated. Taken together, these results show that processing of p10 of Uukuniemi virus occurs cotranslationally at only one site, i.e., downstream of the internal G2 signal sequence. G1 and G2 are inserted as type I proteins into the lipid bilayer, leaving the G1 tail exposed on the cytoplasmic face of the membrane. Since the G2 tail is only 5 residues long, the G1 tail is likely to be responsible for the interaction with the nucleoproteins during the budding process, in addition to

  6. Histone deacetylase inhibitor (HDACI) mechanisms of action: emerging insights

    PubMed Central

    Bose, Prithviraj; Dai, Yun; Grant, Steven

    2014-01-01

    Initially regarded as “epigenetic modifiers” acting predominantly through chromatin remodeling via histone acetylation, HDACIs, alternatively referred to as lysine deacetylase or simply deacetylase inhibitors, have since been recognized to exert multiple cytotoxic actions in cancer cells, often through acetylation of non-histone proteins. Some well-recognized mechanisms of HDACI lethality include, in addition to relaxation of DNA and de-repression of gene transcription, interference with chaperone protein function, free radical generation, induction of DNA damage, up-regulation of endogenous inhibitors of cell cycle progression, e.g., p21, and promotion of apoptosis. Intriguingly, this class of agents is relatively selective for transformed cells, at least in pre-clinical studies. In recent years, additional mechanisms of action of these agents have been uncovered. For example, HDACIs interfere with multiple DNA repair processes, as well as disrupt cell cycle checkpoints, critical to the maintenance of genomic integrity in the face of diverse genotoxic insults. Despite their pre-clinical potential, the clinical use of HDACIs remains restricted to certain subsets of T-cell lymphoma. Currently, it appears likely that the ultimate role of these agents will lie in rational combinations, only a few of which have been pursued in the clinic to date. This review focuses on relatively recently identified mechanisms of action of HDACIs, with particular emphasis on those that relate to the DNA damage response (DDR), and discuss synergistic strategies combining HDACIs with several novel targeted agents that disrupt the DDR or antagonize anti-apoptotic proteins that could have implications for the future use of HDACIs in patients with cancer. PMID:24769080

  7. Role of HLA-G1 in trophoblast cell proliferation, adhesion and invasion

    SciTech Connect

    Jiang, Feng; Zhao, Hongxi; Wang, Li; Guo, Xinyu; Wang, Xiaohong; Yin, Guowu; Hu, Yunsheng; Li, Yi; Yao, Yuanqing

    2015-02-27

    Trophoblast cells are important in embryo implantation and fetomaternal tolerance. HLA-G is specifically expressed at the maternal–fetal interface and is a regulator in pregnancy. The aim of the present study was to detect the effect of HLA-G1 on trophoblast cell proliferation, adhesion, and invasion. Human trophoblast cell lines (JAR and HTR-8/SVneo cells) were infected with HLA-G1-expressing lentivirus. After infection, HLA-G1 expression of the cells was detected by western blotting. Cell proliferation was detected by the BrdU assay. The cell cycle and apoptosis of JAR and HTR-8/SVneo cells was measured by flow cytometry (FCM). The invasion of the cells under different conditions was detected by the transwell invasion chamber assay. HLA-G1 didn't show any significant influence on the proliferation, apoptosis, adhesion, and invasion of trophocytes in normal culture conditions. However, HLA-G1 inhibited JAR and HTR-8/SVneo cells invasion induced by hepatocyte growth factor (HGF) under normal oxygen conditions. In conditions of hypoxia, HLA-G1 couldn't inhibit the induction of cell invasion by HGF. HLA-G1 is not an independent factor for regulating the trophocytes. It may play an indirect role in embryo implantation and formation of the placenta. - Highlights: • HLA-G1 could not influence trophocytes under normal conditions. • HLA-G1 inhibited cell invasion induced by HGF under normal oxygen condition. • HLA-G1 could not influence cell invasion under hypoxia conditions.

  8. Msa1 and Msa2 Modulate G1-Specific Transcription to Promote G1 Arrest and the Transition to Quiescence in Budding Yeast

    PubMed Central

    Miles, Shawna; Croxford, Matthew W.; Abeysinghe, Amali P.; Breeden, Linda L.

    2016-01-01

    Yeast that naturally exhaust their glucose source can enter a quiescent state that is characterized by reduced cell size, and high cell density, stress tolerance and longevity. The transition to quiescence involves highly asymmetric cell divisions, dramatic reprogramming of transcription and global changes in chromatin structure and chromosome topology. Cells enter quiescence from G1 and we find that there is a positive correlation between the length of G1 and the yield of quiescent cells. The Swi4 and Swi6 transcription factors, which form the SBF transcription complex and promote the G1 to S transition in cycling cells, are also critical for the transition to quiescence. Swi6 forms a second complex with Mbp1 (MBF), which is not required for quiescence. These are the functional analogues of the E2F complexes of higher eukaryotes. Loss of the RB analogue, Whi5, and the related protein Srl3/Whi7, delays G1 arrest, but it also delays recovery from quiescence. Two MBF- and SBF-Associated proteins have been identified that have little effect on SBF or MBF activity in cycling cells. We show that these two related proteins, Msa1 and Msa2, are specifically required for the transition to quiescence. Like the E2F complexes that are quiescence-specific, Msa1 and Msa2 are required to repress the transcription of many SBF target genes, including SWI4, the CLN2 cyclin and histones, specifically after glucose is exhausted from the media. They also activate transcription of many MBF target genes. msa1msa2 cells fail to G1 arrest and rapidly lose viability upon glucose exhaustion. msa1msa2 mutants that survive this transition are very large, but they attain the same thermo-tolerance and longevity of wild type quiescent cells. This indicates that Msa1 and Msa2 are required for successful transition to quiescence, but not for the maintenance of that state. PMID:27272642

  9. Msa1 and Msa2 Modulate G1-Specific Transcription to Promote G1 Arrest and the Transition to Quiescence in Budding Yeast.

    PubMed

    Miles, Shawna; Croxford, Matthew W; Abeysinghe, Amali P; Breeden, Linda L

    2016-06-01

    Yeast that naturally exhaust their glucose source can enter a quiescent state that is characterized by reduced cell size, and high cell density, stress tolerance and longevity. The transition to quiescence involves highly asymmetric cell divisions, dramatic reprogramming of transcription and global changes in chromatin structure and chromosome topology. Cells enter quiescence from G1 and we find that there is a positive correlation between the length of G1 and the yield of quiescent cells. The Swi4 and Swi6 transcription factors, which form the SBF transcription complex and promote the G1 to S transition in cycling cells, are also critical for the transition to quiescence. Swi6 forms a second complex with Mbp1 (MBF), which is not required for quiescence. These are the functional analogues of the E2F complexes of higher eukaryotes. Loss of the RB analogue, Whi5, and the related protein Srl3/Whi7, delays G1 arrest, but it also delays recovery from quiescence. Two MBF- and SBF-Associated proteins have been identified that have little effect on SBF or MBF activity in cycling cells. We show that these two related proteins, Msa1 and Msa2, are specifically required for the transition to quiescence. Like the E2F complexes that are quiescence-specific, Msa1 and Msa2 are required to repress the transcription of many SBF target genes, including SWI4, the CLN2 cyclin and histones, specifically after glucose is exhausted from the media. They also activate transcription of many MBF target genes. msa1msa2 cells fail to G1 arrest and rapidly lose viability upon glucose exhaustion. msa1msa2 mutants that survive this transition are very large, but they attain the same thermo-tolerance and longevity of wild type quiescent cells. This indicates that Msa1 and Msa2 are required for successful transition to quiescence, but not for the maintenance of that state. PMID:27272642

  10. Role of Androgen Receptor in Progression of LNCaP Prostate Cancer Cells from G1 to S Phase

    PubMed Central

    Murthy, Shalini; Wu, Min; Bai, V. Uma; Hou, Zizheng; Menon, Mani; Barrack, Evelyn R.; Kim, Sahn-Ho; Reddy, G. Prem-Veer

    2013-01-01

    Background The androgen receptor (AR) plays a critical role in the proliferation of prostate cancer cells. However, its mechanism of action in proliferation remains unknown. An understanding of the mechanism of AR action in proliferation may lead to the development of effective strategies for the treatment of prostate cancer. Methodology/Principal Findings In this study we report that pulse treatment of synchronized LNCaP cells with Casodex, an AR-antagonist, for 4 hours in mid-G1 phase was sufficient to prevent cells from entering S phase. Since the assembly of pre-replication complex (pre-RC) in G1 is required for the progression of cells from G1 to S phase, the effect of Casodex during mid-G1 suggested that the role of AR in proliferation might be to regulate the assembly of pre-RC. To test this possibility, we investigated the interaction between AR and Cdc6, an essential component of pre-RC in LNCaP cells. AR co-localized and co-immunoprecipitated with Cdc6, and Casodex treatment disrupted this interaction. AR-immunoprecipitate (AR-IP) also contained cyclin E and cyclin A, which play a critical role in pre-RC assembly and cell cycle entry into S phase, and DNA polymerase-α, PCNA, and ribonucleotide reductase, which are essential for the initiation of DNA synthesis. In addition, in cells in S phase, AR co-sedimented with components of the DNA replication machinery of cells that entered S phase. Conclusions/Significance Together, these observations suggest a novel role of AR as a component of the pre-RC to exert control over progression of LNCaP cells from G1 to S phase through a mechanism that is independent of its role as a transcription factor. PMID:23437213

  11. Phylogenetic inference of the porcine Rotavirus A origin of the human G1 VP7 gene.

    PubMed

    Do, Loan Phuong; Nakagomi, Toyoko; Otaki, Hiroki; Agbemabiese, Chantal Ama; Nakagomi, Osamu; Tsunemitsu, Hiroshi

    2016-06-01

    Rotavirus A (RVA) is an important cause of acute gastroenteritis in children worldwide. The most common VP7 genotype of human RVA is G1, but G1 is rarely detected in porcine strains. To understand the evolutionary relationships between human and porcine G1 VP7 genes, we sequenced the VP7 genes of three Japanese G1 porcine strains; the first two (PRV2, S80B) were isolated in 1980 and the third (Kyusyu-14) was isolated in 2001. Then, we performed phylogenetic and in-silico structural analyses. All three VP7 sequences clustered into lineage VI, and the mean nucleotide sequence identity between any pair of porcine G1 VP7 sequences belonging to lineage VI was 91.9%. In contrast, the mean nucleotide sequence identity between any pair of human G1 VP7 sequences belonging to lineages I-V was 95.5%. While the mean nucleotide sequence identity between any pair of porcine lineage VI strain and human lineage I-V strain was 85.4%, the VP7 genes of PRV2 and a rare porcine-like human G1P[6] strain (AU19) were 98% identical, strengthening the porcine RVA origin of AU19. The phylogenetic tree suggests that human G1 VP7 genes originated from porcine G1 VP7 genes. The time of their most recent common ancestor was estimated to be 1948, and human and porcine RVA strains evolved along independent pathways. In-silico structural analyses identified 7 amino acid residues within the known neutralisation epitopes that show differences in electric charges and shape between different porcine and human G1 strains. When compared with much divergent porcine G1 VP7 lineages, monophyletic, less divergent human G1 VP7 lineages support the hypothesis that all human G1 VP7 genes included in this study originated from a rare event of a porcine RVA transmitting to humans that was followed by successful adaptation to the human host. By contrast, AU19 represents interspecies transmission that terminated in dead-end infection. PMID:26961591

  12. Mitotic UV irradiation induces a DNA replication-licensing defect that potentiates G1 arrest response.

    PubMed

    Morino, Masayuki; Nukina, Kohei; Sakaguchi, Hiroki; Maeda, Takeshi; Takahara, Michiyo; Shiomi, Yasushi; Nishitani, Hideo

    2015-01-01

    Cdt1 begins to accumulate in M phase and has a key role in establishing replication licensing at the end of mitosis or in early G1 phase. Treatments that damage the DNA of cells, such as UV irradiation, induce Cdt1 degradation through PCNA-dependent CRL4-Cdt2 ubiquitin ligase. How Cdt1 degradation is linked to cell cycle progression, however, remains unclear. In G1 phase, when licensing is established, UV irradiation leads to Cdt1 degradation, but has little effect on the licensing state. In M phase, however, UV irradiation does not induce Cdt1 degradation. When mitotic UV-irradiated cells were released into G1 phase, Cdt1 was degraded before licensing was established. Thus, these cells exhibited both defective licensing and G1 cell cycle arrest. The frequency of G1 arrest increased in cells expressing extra copies of Cdt2, and thus in cells in which Cdt1 degradation was enhanced, whereas the frequency of G1 arrest was reduced in cell expressing an extra copy of Cdt1. The G1 arrest response of cells irradiated in mitosis was important for cell survival by preventing the induction of apoptosis. Based on these observations, we propose that mammalian cells have a DNA replication-licensing checkpoint response to DNA damage induced during mitosis.

  13. Fluorimetric measurements and chromatin condensation patterns of nuclei from 3T3 cells throughout G1.

    PubMed

    Moser, G C; Fallon, R J; Meiss, H K

    1981-02-01

    Using two cytological methods based on nuclear morphology, quinacrine dihydrochloride (QDH) staining and premature chromosome condensation (PCC), it has been possible to identify cell cycle positions within G1 of growing and arrested 3T3 cells. The fluorescent intensity of QDH-stained interphase cells appears to decrease as the cells pass from mitosis to S phase. Likewise, the length and thickness of prematurely condensed chromatids can be related to the cells; position within the G1 period. Data are presented that deal with three interrelated topics: 1) We determined by fluorometric measurements of nuclei from 3T3 cells that the visual observation of the decrease in QDH fluorescence during G1 reflects an actual decrease in total fluorescence and not a dispersion of the fluorescent chromatin in a larger nuclear area. 2) We correlated the results obtained by QDH staining with those of PCC on the same cell samples blocked in G1 by different conditions. Serum-starved and contact-inhibited cell nuclei had the highest intensity, hydroxyurea-treated ones had the lowest intensity, while that of isoleucine-deprived cells was in between. The same relative order of G1 positions was obtained based on PCC morphology. Thus, both methods monitor the state of chromatin condensation and can be used to identify cell cycle position within G1. 3) We showed with both methods that the states of chromatin resulting from the various G1 blocking conditions differ from each other.

  14. Quarter variation and correlations of colostrum albumin, immunoglobulin G1 and G2 in dairy cows.

    PubMed

    Samarütel, Jaak; Baumrucker, Craig R; Gross, Josef J; Dechow, Chad D; Bruckmaier, Rupert M

    2016-05-01

    A high variation in immunoglobulin G1 (IgG1) concentration in first milked quarter colostrum has been reported, but BSA quarter colostrum variation is not known. The occurrence of serum albumin in milk has been attributed to increased blood-milk barrier penetration. Reports of serum albumin binding to the Fc Receptor of the neonate, the receptor thought to be responsible for IgG1 transcytosis, suggested that a correlation with the appearance of IgG1 in colostrum of dairy cows was likely. The objective of the study was to establish the quarter colostrum concentration and mass of immunoglobulins and serum albumin. First colostrum was quarter collected within 4 h of parturition from healthy udders of 31 multiparous dairy cows. Individual quarter colostrum weight was determined and a sample of each was frozen for subsequent analysis. Concentrations of immunoglobulin G1, G2, and BSA were measured by ELISA and total mass of components was calculated. In addition, colostrum was also analysed for L-lactate dehydrogenase activity. Analysis of concentration and mass of BSA, immunoglobulin G1, G2 established that the quarter variations were different by cow, quarter and quarter within cow. Partial correlations corrected for colostrum weight indicated that BSA and IgG2 concentration and mass are closely correlated while that of BSA and IgG1 concentration and mass exhibited no correlation suggesting that BSA and IgG1 may have different transport mechanisms. Interestingly, immunoglobulin G1 and G2 concentration and mass exhibited strong correlations suggesting that also some unknown mechanism of immunoglobulin G2 appearance in colostrum is occurring. Finally, no measured protein exhibited any correlation with the activity of lactate dehydrogenase in colostrum.

  15. Selective Histone Deacetylase 6 inhibition Prolongs Survival in a Lethal Two-hit Model

    PubMed Central

    Cheng, Xin; Liu, Zhengcai; Liu, Baoling; Zhao, Ting; Li, Yongqing; Alam, Hasan B.

    2015-01-01

    Introduction Hemorrhagic shock (HS) followed by a subsequent insult (“second hit”) often initiates an exaggerated systemic inflammatory response and multiple organ failure. We have previously demonstrated that valproic acid, a pan histone deacetylase (HDAC) inhibitor, could improve survival in a rodent “two-hit” model. In present study, our goal was to determine whether selective inhibition of histone deacetylase 6 with Tubstatin A (Tub-A) could prolong survival in a 2-hit model where HS was followed by sepsis from cecal ligation and puncture (CLP). Methods C57Bl/6J mice were subjected to sublethal HS (30% blood loss) and then randomly divided into 2 groups (n=13/group): Tub-A group (treatment) and vehicle group (control). The Tub-A group was given an intraperitoneal injection of Tub-A (70mg/kg) dissolved in dimethyl sulfoxide (DMSO). The vehicle group was injected with 1 μl/g DMSO. After 24 h, all mice were subjected CLP followed immediately by another dose of Tub-A or DMSO. Survival was monitored for 10 days. In a parallel study, peritoneal irrigation fluid and liver tissue from Tub-A or DMSO treated mice were collected 3h after CLP. Enzyme-linked immunosorbent assay was performed to quantify activity of the myeloperoxidase (MPO) and concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin -6 (IL-6) in the peritoneal irrigation fluid. RNA was isolated from the liver tissue and real-time PCR was performed to measure relative mRNA levels of TNF-α and IL-6. Results Treatment with Tub-A significantly improved survival compared to the control (69.2% vs. 15.4%). In addition, Tub-A significantly suppressed MPO activity (169.9 ± 8.4 ng/ml vs. 70.4 ± 17.4ng/ml; p < 0.01), and reduced levels of cytokines TNF-α and IL-6 in the peritoneal fluid (TNF-α: 105.7 ± 4.7 pg/ml vs. 7.4 ± 2.4 pg/ml; IL-6: 907.4 ± 2.3 pg/ml vs. 483.6 ± 1.6 pg/ml; p < 0.01) compared to vehicle control. Gene expression measured by real-time PCR confirmed that Tub

  16. Transfection-mediated cell synchronization: acceleration of G1-S phase transition by gamma irradiation.

    PubMed

    Jung, E J; Flemington, E K

    2001-11-01

    We have previously provided evidence that the uptake of DNA into cells is cell cycle specific following transfection. We show here that, immediately after transfection, successfully transfected cells are greatly enriched for cells in early G1 or G0 phase and that, upon removal of the DNA precipitates, cells progress through G1 and enter S phase in a synchronous fashion. We also demonstrate that this approach can be utilized in meaningful cell-cycle experiments, and we show that gamma irradiation accelerates the G1-S phase transition in a cell line with a functionally inactive p53 protein. PMID:11730009

  17. Design, synthesis, 3D pharmacophore, QSAR, and docking studies of carboxylic acid derivatives as Histone Deacetylase inhibitors and cytotoxic agents.

    PubMed

    Abdel-Atty, Mona M; Farag, Nahla A; Kassab, Shaymaa E; Serya, Rabah A T; Abouzid, Khaled A M

    2014-12-01

    In this study, five series of (E)-6-(4-substituted phenyl)-4-oxohex-5-enoic acids IIb-f (E), (E)-3-(4-(substituted)-phenyl)acrylic acids IIIa-g (E), 4-(4-(substituted)phenylamino)-4-oxobutanoic acids VIa,b,e, 5-(4-(substituted)phenylamino)-5-oxopentanoic acids VIIa,f and 2-[(4-(substituted)phenyl) carbamoyl]benzoic acids VIIIa,e were designed and synthesized. Selected compounds were screened in vitro for their cytotoxic effect on 60 human NCI tumor cell lines. Compound IIf (E) displayed significant inhibitory activity against NCI Non-Small Cell Lung A549/ATCC Cancer cell line (68% inhibition) and NCI-H460 Cancer cell line (66% inhibition). Moreover, the final compounds were evaluated in vitro for their cytotoxic activity on HepG2 Cancer cell line in which histone deacetylase (HDAC) is overexpressed. Compounds IIc (E), IIf (E), IIIb (E), and IIIg (E) exhibited the highest cytotoxic activity against HepG2 human cancer cell lines with IC50 ranging from 2.27 to 10.71μM. In addition, selected compounds were tested on histone deacetylase isoforms (HDAC1-11). Molecular docking simulation was also carried out for HDLP enzyme to investigate their HDAC binding affinity. In addition, generation of 3D-pharmacophore model and quantitative structure activity relationship (QSAR) models were combined to explore the structural requirements controlling the observed cytotoxic properties.

  18. Inhibition of histone deacetylase in cancer cells slows down replication forks, activates dormant origins and induces DNA damage

    PubMed Central

    Conti, Chiara; Leo, Elisabetta; Eichler, Gabriel S.; Sordet, Olivier; Martin, Melvenia M.; Fan, Angela; Aladjem, Mirit I.; Pommier, Yves

    2010-01-01

    Protein acetylation is a reversible process regulated by histone deacetylases (HDACs) that is often altered in human cancers. SAHA (suberoylanilide hydroxamic acid) is the first histone deacetylase inhibitor (HDACi) to be approved for clinical use as an anticancer agent. Given that histone acetylation is a key determinant of chromatin structure, we investigated how SAHA may affect DNA replication and integrity to gain deeper insights into the basis for its anticancer activity. Nuclear replication factories were visualized with confocal immunofluorescence microscopy and with single-replicon analyses conducted by genome-wide molecular combing after pulse labeling with two thymidine-analogues. Additionally, nascent strand real-time polymerase chain reaction (RT-PCR) in the human β-globin locus was used to assess the effects of SAHA on replication fork origin firing. We found that pharmacological concentrations of SAHA induce replication-mediated DNA damage, on the basis of single-cell and single-DNA molecule analyses. Molecular combing indicated slowdown in replication speed along with activation of dormant replication origins in response to SAHA. Similar results were obtained using siRNA-mediated depletion of HDAC3 expression, implicating this HDAC member as a likely target in the SAHA response. Activation of dormant origins was confirmed by molecular analyses of the β-globin locus control region. Our findings indicate that SAHA produces profound alterations in DNA replication that cause DNA damage, establishing a critical link between robust chromatin acetylation and DNA replication in human cancer cells. PMID:20460513

  19. A phosphorylation switch regulates the transcriptional activation of cell cycle regulator p21 by histone deacetylase inhibitors.

    PubMed

    Simboeck, Elisabeth; Sawicka, Anna; Zupkovitz, Gordin; Senese, Silvia; Winter, Stefan; Dequiedt, Franck; Ogris, Egon; Di Croce, Luciano; Chiocca, Susanna; Seiser, Christian

    2010-12-24

    Histone deacetylase inhibitors induce cell cycle arrest and apoptosis in tumor cells and are, therefore, promising anti-cancer drugs. The cyclin-dependent kinase inhibitor p21 is activated in histone deacetylase (HDAC) inhibitor-treated tumor cells, and its growth-inhibitory function contributes to the anti-tumorigenic effect of HDAC inhibitors. We show here that induction of p21 by trichostatin A involves MAP kinase signaling. Activation of the MAP kinase signaling pathway by growth factors or stress signals results in histone H3 serine 10 phosphorylation at the p21 promoter and is crucial for acetylation of the neighboring lysine 14 and recruitment of activated RNA polymerase II in response to trichostatin A treatment. In non-induced cells, the protein phosphatase PP2A is associated with the p21 gene and counteracts its activation. Induction of p21 is linked to simultaneous acetylation and phosphorylation of histone H3. The dual modification mark H3S10phK14ac at the activated p21 promoter is recognized by the phospho-binding protein 14-3-3ζ, which protects the phosphoacetylation mark from being processed by PP2A. Taken together we have revealed a cross-talk of reversible phosphorylation and acetylation signals that controls the activation of p21 by HDAC inhibitors and identify the phosphatase PP2A as chromatin-associated transcriptional repressor in mammalian cells.

  20. Bacillus amyloliquefaciens G1: A Potential Antagonistic Bacterium against Eel-Pathogenic Aeromonas hydrophila

    PubMed Central

    Cao, Haipeng; He, Shan; Wei, Ruopeng; Diong, Marek; Lu, Liqun

    2011-01-01

    Recent studies have revealed that the use of probiotics is an alternative to control marine aeromonas. However, few probiotics are available against Aeromonas hydrophila infections in eels. In the present study, a potential antagonistic strain G1 against the eel-pathogenic A. hydrophila was isolated from sediment underlying brackish water. Its extracellular products with antibacterial activities were shown to be stable under wide range of pH, temperature, and proteinase K. It was initially identified as Bacillus amyloliquefaciens using API identification kits and confirmed to be B. amyloliquefaciens strain (GenBank accession number DQ422953) by phylogenetic analysis. In addition, it was shown to be safe for mammalians, had a wide anti-A. hydrophila spectrum, and exhibited significant effects on inhibiting the growth of the eel-pathogenic A. hydrophila both in vitro and in vivo. To the best of our knowledge, this is the first report on a promising antagonistic Bacillus amyloliquefaciens strain from brackish water sediment against eel-pathogenic A. hydrophila. PMID:21754944

  1. Moments of the Spin Structure Functions g1p and g1d for 0.05 < Q2 < 3.0 GeV2

    SciTech Connect

    Prok, Yelena; Bosted, Peter; Burkert, Volker; Deur, Alexandre; Dharmawardane, Kahanawita; Dodge, Gail; Griffioen, Keith; Kuhn, Sebastian; Minehart, Ralph; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Anghinolfi, Marco; Asryan, G.; Audit, Gerard; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Beard, Kevin; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Boyarinov, Sergey; Bonner, Billy; Bouchigny, Sylvain; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Cazes, Antoine; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crede, Volker; Cummings, John; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Dhuga, Kalvir; Dickson, Richard; Djalali, Chaden; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Feldman, Gerald; Fersch, Robert; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Golovach, Evgeny; Gothe, Ralf; Guidal, Michel; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hardie, John; Hassall, Neil; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Huertas, Marco; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keith, Christopher; Kellie, James; Khandaker, Mahbubul; Kim, Kui; Kim, Kyungmo; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klusman, Mike; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, Dave; Lima, Ana; Livingston, Kenneth; Lu, Haiyun; Lukashin, K.; MacCormick, Marion; Marchand, Claude; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Morand, Ludyvine; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; O'Rielly, Grant; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Anefalos Pereira, S.; Philips, Sasha; Pierce, J.; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Popa, Iulian; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Procureur, Sebastien; Protopopescu, Dan; Qin, Liming; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rowntree, David; Rubin, Philip; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Seely, Mikell; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shaw, Jeffrey; Shvedunov, Nikolay; Skabelin, Alexander; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Suleiman, Riad; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; V

    2009-02-01

    The spin structure functions $g_1$ for the proton and the deuteron have been measured over a wide kinematic range in $x$ and \\Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH$_3$ and ND$_3$ targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for $0.05 < Q^2 < 5 $\\ GeV$^2$ and $W < 3$ GeV. The first moments of $g_1$ for the proton and deuteron are presented -- both have a negative slope at low \\Q2, as predicted by the extended Gerasimov-Drell-Hearn sum rule. The first result for the generalized forward spin polarizability of the proton $\\gamma_0^p$ is also reported, and shows evidence of scaling above $Q^2$ = 1.5 GeV$^2$. Although the first moments of $g_1$ are consistent with Chiral Perturbation Theory (\\ChPT) calculations up to approximately $Q^2 = 0.06$ GeV$^2$, a significant discrepancy is observed between the $\\gamma_0^p$ data and \\ChPT\\ for $\\gamma_0^p$,even at the lowest \\Q2.

  2. Androgen receptor regulates Cdc6 in synchronized LNCaP cells progressing from G1 to S phase.

    PubMed

    Bai, V Uma; Cifuentes, Eugenia; Menon, Mani; Barrack, Evelyn R; Reddy, G Prem-Veer

    2005-08-01

    We have shown previously that androgen receptor (AR) activity is required for the progression of cells from G(1) to S phase. In an attempt to elucidate the mechanism of androgen- and androgen-receptor-mediated proliferation of prostate cancer cells, we studied the effect of anti-androgen bicalutamide (Casodex) on the expression of cell-cycle regulatory genes in synchronized LNCaP cells progressing from G(1) to S phase. LNCaP cells were synchronized by isoleucine-deprivation. Expression of cell-cycle regulatory genes in S phase control cells versus Casodex-treated cells that fail to enter S phase was studied using a microarray containing cDNA probes for 111 cell-cycle specific genes. RT-PCR and Western-blots were used to validate microarray data. Casodex blocked synchronized LNCaP cells from entering S phase. Microarrays revealed downregulation of eight genes in cells prevented from entering into S phase by Casodex. Of these eight genes, only Cdc6, cyclin A, and cyclin B were downregulated at both the mRNA and protein level in Casodex treated cells as compared to control cells. The mRNA and protein levels of Cdc6 increased as synchronized LNCaP cells progressed from G(1) to S phase, and were attenuated in Casodex-treated cells failed to enter S phase. Cyclins A and B were detected when cells entered S phase, but not when they were in G(1) phase. Like Cdc6, the levels of both cyclins A and B were attenuated in Casodex-treated cells. AR may play an important role in the onset of DNA synthesis in prostate cancer cells by regulating the expression and stability of Cdc6, which is critically required for the assembly of the pre-replication complex(pre-RC).

  3. IgG1 variations in the colostrum of Holstein dairy cows.

    PubMed

    Le Cozler, Y; Guatteo, R; Le Dréan, E; Turban, H; Leboeuf, F; Pecceu, K; Guinard-Flament, J

    2016-02-01

    High-immune quality colostrum (IgG1 concentration ⩾50 g/l) is crucial for the health and development of the young calf. Studies on colostrum quality tend to focus on external factors such as breed, parity or dry period length, but few have focused on within-cow variations. Here we ran experiments to gain a deeper insight into within-cow variation in IgG1 concentrations in dairy cow colostrum. Trials were performed in an experimental farm, located in the Western part of France. Colostrum from each quarter and a composite sample (mix of four quarters) were concomitantly collected on 77 Holstein dairy cows just after calving to assess the influence of sample type on IgG1 concentrations. Variation in IgG1 concentrations during the first milking was studied on samples from nine cows collected every minute from the start of milking. Repeatability of colostral IgG1 concentration was estimated from 2009 and 2010 data on 16 healthy cows. IgG1 concentrations were tested using a radial immunodiffusion method. Sensitivity and specificity were similar regardless of sample type tested (individual quarter or composite milk). Mean average IgG1 concentration was 54.1 g/l in composite colostrum, and was significantly higher in hind quarter teats (56.2 g/l) than front quarter teats (53.1 g/l). Average IgG1 concentration did not change significantly during colostrum milking, and the variations observed (15% or less) were likely due to the laboratory method (CV 15%). IgG1 concentrations in dam colostrum increased slightly from 2009 to 2010 due to BW and parity effects. In 56% of cases, colostrum quality could have been assessed on either individual or composite colostrum samples collected at any time during the first milking without affecting the reliability of the measurement. However, in other cases, differences were significant enough to mean that estimates of average IgG1 concentration in colostrum from any one quarter would not be reliable. It is concluded that colostrum quality

  4. Commercial geophysical well logs from the USW G-1 drill hole, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Muller, D.C.; Kibler, J.E.

    1983-01-01

    Drill hole USW G-1 was drilled at Yucca Mountain, Nevada Test Site, Nevada, as part of the ongoing exploration program for the Nevada Nuclear Waste Storage Investigations. Contract geophysical well logs run at USW G-1 show only limited stratigraphic correlations, but correlate reasonably well with the welding of the ash-flow and ash-fall tuffs. Rocks in the upper part of the section have highly variable physical properties, but are more uniform and predictably lower in the section.

  5. Effects of Bordetella pertussis components on IgE and IgG1 responses.

    PubMed

    Sekiya, K

    1983-01-01

    The effect of dermonecrotic toxin (DNT), fimbrial hemagglutinin (FHA), K-agglutinogen, lipopolysaccharide (LPS), and pertussigen from Bordetella pertussis on the production of IgE and IgG1 antibodies to hen egg albumin (Ea) was investigated in C57BL/6 mice. The IgE antibody contents were determined by passive cutaneous anaphylaxis (PCA) in the skin of Lewis rats, while the IgG1 antibody contents were determined by PCA reactions on the skin of mice using sera that had been heated for 3 hr at 56 C to destroy the IgE antibodies. Among the B. pertussis components tested, pertussigen was the most effective adjuvant for increasing the IgE and IgG1 antibodies to Ea. LPS also moderately increased both types of antibodies, and FHA slightly increased the IgG1 titers. When LPS was given 5 days before Ea, it suppressed both IgE and IgG1 titers while FHA had only slight adjuvant action on both type of antibodies. When each of the components was tested for its ability to modify the adjuvant action of pertussigen, it was found that only DNT interfered significantly with the adjuvanticity of pertussigen when given on the day of immunization with Ea. When the components were given 5 days before Ea, DNT produced significant suppression of only the IgG1 response. LPS, FHA, and K-agglutinogen did not significantly affect the adjuvant action of pertussigen. PMID:6321910

  6. GPER agonist G-1 decreases adrenocortical carcinoma (ACC) cell growth in vitro and in vivo.

    PubMed

    Chimento, Adele; Sirianni, Rosa; Casaburi, Ivan; Zolea, Fabiana; Rizza, Pietro; Avena, Paola; Malivindi, Rocco; De Luca, Arianna; Campana, Carmela; Martire, Emilia; Domanico, Francesco; Fallo, Francesco; Carpinelli, Giulia; Cerquetti, Lidia; Amendola, Donatella; Stigliano, Antonio; Pezzi, Vincenzo

    2015-08-01

    We have previously demonstrated that estrogen receptor (ER) alpha (ESR1) increases proliferation of adrenocortical carcinoma (ACC) through both an estrogen-dependent and -independent (induced by IGF-II/IGF1R pathways) manner. Then, the use of tamoxifen, a selective estrogen receptor modulator (SERM), appears effective in reducing ACC growth in vitro and in vivo. However, tamoxifen not only exerts antiestrogenic activity, but also acts as full agonist on the G protein-coupled estrogen receptor (GPER). Aim of this study was to investigate the effect of a non-steroidal GPER agonist G-1 in modulating ACC cell growth. We found that G-1 is able to exert a growth inhibitory effect on H295R cells both in vitro and, as xenograft model, in vivo. Treatment of H295R cells with G-1 induced cell cycle arrest, DNA damage and cell death by the activation of the intrinsic apoptotic mechanism. These events required sustained extracellular regulated kinase (ERK) 1/2 activation. Silencing of GPER by a specific shRNA partially reversed G-1-mediated cell growth inhibition without affecting ERK activation. These data suggest the existence of G-1 activated but GPER-independent effects that remain to be clarified. In conclusion, this study provides a rational to further study G-1 mechanism of action in order to include this drug as a treatment option to the limited therapy of ACC.

  7. GPER agonist G-1 decreases adrenocortical carcinoma (ACC) cell growth in vitro and in vivo

    PubMed Central

    Zolea, Fabiana; Rizza, Pietro; Avena, Paola; Malivindi, Rocco; De Luca, Arianna; Campana, Carmela; Martire, Emilia; Domanico, Francesco; Fallo, Francesco; Carpinelli, Giulia; Cerquetti, Lidia; Amendola, Donatella; Stigliano, Antonio; Pezzi, Vincenzo

    2015-01-01

    We have previously demonstrated that estrogen receptor (ER) alpha (ESR1) increases proliferation of adrenocortical carcinoma (ACC) through both an estrogen-dependent and -independent (induced by IGF-II/IGF1R pathways) manner. Then, the use of tamoxifen, a selective estrogen receptor modulator (SERM), appears effective in reducing ACC growth in vitro and in vivo. However, tamoxifen not only exerts antiestrogenic activity, but also acts as full agonist on the G protein-coupled estrogen receptor (GPER). Aim of this study was to investigate the effect of a non-steroidal GPER agonist G-1 in modulating ACC cell growth. We found that G-1 is able to exert a growth inhibitory effect on H295R cells both in vitro and, as xenograft model, in vivo. Treatment of H295R cells with G-1 induced cell cycle arrest, DNA damage and cell death by the activation of the intrinsic apoptotic mechanism. These events required sustained extracellular regulated kinase (ERK) 1/2 activation. Silencing of GPER by a specific shRNA partially reversed G-1-mediated cell growth inhibition without affecting ERK activation. These data suggest the existence of G-1 activated but GPER-independent effects that remain to be clarified. In conclusion, this study provides a rational to further study G-1 mechanism of action in order to include this drug as a treatment option to the limited therapy of ACC. PMID:26131713

  8. GPER agonist G-1 decreases adrenocortical carcinoma (ACC) cell growth in vitro and in vivo.

    PubMed

    Chimento, Adele; Sirianni, Rosa; Casaburi, Ivan; Zolea, Fabiana; Rizza, Pietro; Avena, Paola; Malivindi, Rocco; De Luca, Arianna; Campana, Carmela; Martire, Emilia; Domanico, Francesco; Fallo, Francesco; Carpinelli, Giulia; Cerquetti, Lidia; Amendola, Donatella; Stigliano, Antonio; Pezzi, Vincenzo

    2015-08-01

    We have previously demonstrated that estrogen receptor (ER) alpha (ESR1) increases proliferation of adrenocortical carcinoma (ACC) through both an estrogen-dependent and -independent (induced by IGF-II/IGF1R pathways) manner. Then, the use of tamoxifen, a selective estrogen receptor modulator (SERM), appears effective in reducing ACC growth in vitro and in vivo. However, tamoxifen not only exerts antiestrogenic activity, but also acts as full agonist on the G protein-coupled estrogen receptor (GPER). Aim of this study was to investigate the effect of a non-steroidal GPER agonist G-1 in modulating ACC cell growth. We found that G-1 is able to exert a growth inhibitory effect on H295R cells both in vitro and, as xenograft model, in vivo. Treatment of H295R cells with G-1 induced cell cycle arrest, DNA damage and cell death by the activation of the intrinsic apoptotic mechanism. These events required sustained extracellular regulated kinase (ERK) 1/2 activation. Silencing of GPER by a specific shRNA partially reversed G-1-mediated cell growth inhibition without affecting ERK activation. These data suggest the existence of G-1 activated but GPER-independent effects that remain to be clarified. In conclusion, this study provides a rational to further study G-1 mechanism of action in order to include this drug as a treatment option to the limited therapy of ACC. PMID:26131713

  9. Evaluation of the hydrometer for testing immunoglobulin G1 concentrations in Holstein colostrum.

    PubMed

    Pritchett, L C; Gay, C C; Hancock, D D; Besser, T E

    1994-06-01

    Hydrometer measurement in globulin and IgG1 concentration measured by the radial immunodiffusion technique were compared for 915 samples of first milking colostrum from Holstein cows. Least squares analysis of the relationship between hydrometer measurement and IgG1 concentration was improved by log transformation of IgG1 concentration and resulted in a significant linear relationship between hydrometer measurement and log10 IgG1 concentration; r2 = .469. At 50 mg of globulin/ml of colostrum, the recommended hydrometer cutoff point for colostrum selection, the sensitivity of the hydrometer as a test of IgG1 concentration in Holstein colostrum was 26%, and the negative predictive value was 67%. The negative predictive value and sensitivity of the hydrometer as a test of IgG1 in Holstein colostrum was improved, and the cost of misclassification of colostrum was minimized, when the cutoff point for colostrum selection was increased above the recommended 50 mg/ml.

  10. IgG1 Fc N-glycan galactosylation as a biomarker for immune activation

    PubMed Central

    de Jong, Sanne E.; Selman, Maurice H. J.; Adegnika, Ayola A.; Amoah, Abena S.; van Riet, Elly; Kruize, Yvonne C. M.; Raynes, John G.; Rodriguez, Alejandro; Boakye, Daniel; von Mutius, Erika; Knulst, André C.; Genuneit, Jon; Cooper, Philip J.; Hokke, Cornelis H.; Wuhrer, Manfred; Yazdanbakhsh, Maria

    2016-01-01

    Immunoglobulin G (IgG) Fc N-glycosylation affects antibody-mediated effector functions and varies with inflammation rooted in both communicable and non-communicable diseases. Worldwide, communicable and non-communicable diseases tend to segregate geographically. Therefore, we studied whether IgG Fc N-glycosylation varies in populations with different environmental exposures in different parts of the world. IgG Fc N-glycosylation was analysed in serum/plasma of 700 school-age children from different communities of Gabon, Ghana, Ecuador, the Netherlands and Germany. IgG1 galactosylation levels were generally higher in more affluent countries and in more urban communities. High IgG1 galactosylation levels correlated with low total IgE levels, low C-reactive protein levels and low prevalence of parasitic infections. Linear mixed modelling showed that only positivity for parasitic infections was a significant predictor of reduced IgG1 galactosylation levels. That IgG1 galactosylation is a predictor of immune activation is supported by the observation that asthmatic children seemed to have reduced IgG1 galactosylation levels as well. This indicates that IgG1 galactosylation levels could be used as a biomarker for immune activation of populations, providing a valuable tool for studies examining the epidemiological transition from communicable to non-communicable diseases. PMID:27306703

  11. Evaluation of the hydrometer for testing immunoglobulin G1 concentrations in Holstein colostrum.

    PubMed

    Pritchett, L C; Gay, C C; Hancock, D D; Besser, T E

    1994-06-01

    Hydrometer measurement in globulin and IgG1 concentration measured by the radial immunodiffusion technique were compared for 915 samples of first milking colostrum from Holstein cows. Least squares analysis of the relationship between hydrometer measurement and IgG1 concentration was improved by log transformation of IgG1 concentration and resulted in a significant linear relationship between hydrometer measurement and log10 IgG1 concentration; r2 = .469. At 50 mg of globulin/ml of colostrum, the recommended hydrometer cutoff point for colostrum selection, the sensitivity of the hydrometer as a test of IgG1 concentration in Holstein colostrum was 26%, and the negative predictive value was 67%. The negative predictive value and sensitivity of the hydrometer as a test of IgG1 in Holstein colostrum was improved, and the cost of misclassification of colostrum was minimized, when the cutoff point for colostrum selection was increased above the recommended 50 mg/ml. PMID:8083433

  12. Design, synthesis, and antitumor evaluation of histone deacetylase inhibitors with l-phenylglycine scaffold

    PubMed Central

    Zhang, Yingjie; Li, Xiaoguang; Hou, Jinning; Huang, Yongxue; Xu, Wenfang

    2015-01-01

    In our previous research, a novel series of histone deacetylase (HDAC) inhibitors with l-phenylglycine scaffold were designed and synthesized, among which amides D3 and D7 and ureido D18 were far superior to the positive control (suberoylanilide hydroxamic acid [SAHA]) in HDAC inhibition, but were only comparable to SAHA in antiproliferation on tumor cell lines. Herein, further structural derivation of lead compounds D3, D7, and D18 was carried out to improve their cellular activities. Most of our newly synthesized compounds exhibited more potent HDAC inhibitory activities than the positive control SAHA, and several derivatives were even better than their parent compounds. However, compared with SAHA and our lead compounds, only secondary amine series compounds exhibited improved antiproliferative activities, likely due to their appropriate topological polar surface area values and cell permeabilities. In a human histiocytic lymphoma (U937) xenograft model, the most potent secondary amine 9d exhibited similar in vivo antitumor activity to that of SAHA. PMID:26504374

  13. Histone deacetylase inhibitor significantly improved the cloning efficiency of porcine somatic cell nuclear transfer embryos.

    PubMed

    Huang, Yongye; Tang, Xiaochun; Xie, Wanhua; Zhou, Yan; Li, Dong; Yao, Chaogang; Zhou, Yang; Zhu, Jianguo; Lai, Liangxue; Ouyang, Hongsheng; Pang, Daxin

    2011-12-01

    Valproic acid (VPA), a histone deacetylase inbibitor, has been shown to generate inducible pluripotent stem (iPS) cells from mouse and human fibroblasts with a significant higher efficiency. Because successful cloning by somatic cell nuclear transfer (SCNT) undergoes a full reprogramming process in which the epigenetic state of a differentiated donor nuclear is converted into an embryonic totipotent state, we speculated that VPA would be useful in promoting cloning efficiency. Therefore, in the present study, we examined whether VPA can promote the developmental competence of SCNT embryos by improving the reprogramming state of donor nucleus. Here we report that 1 mM VPA for 14 to 16 h following activation significantly increased the rate of blastocyst formation of porcine SCNT embryos constructed from Landrace fetal fibroblast cells compared to the control (31.8 vs. 11.4%). However, we found that the acetylation level of Histone H3 lysine 14 and Histone H4 lysine 5 and expression level of Oct4, Sox2, and Klf4 was not significantly changed between VPA-treated and -untreated groups at the blastocyst stage. The SCNT embryos were transferred to 38 surrogates, and the cloning efficiency in the treated group was significantly improved compared with the control group. Taken together, we have demonstrated that VPA can improve both in vitro and in vivo development competence of porcine SCNT embryos.

  14. Histone deacetylase inhibition impairs normal intestinal cell proliferation and promotes specific gene expression.

    PubMed

    Roostaee, Alireza; Guezguez, Amel; Beauséjour, Marco; Simoneau, Aline; Vachon, Pierre H; Levy, Emile; Beaulieu, Jean-François

    2015-11-01

    Mechanisms that maintain proliferation and delay cell differentiation in the intestinal crypt are not yet fully understood. We have previously shown the implication of histone methylation in the regulation of enterocytic differentiation. In this study, we investigated the role of histone deacetylation as an important epigenetic mechanism that controls proliferation and differentiation of intestinal cells using the histone deacetylase inhibitor suberanilohydroxamic acid (SAHA) on the proliferation and differentiation of human and mouse intestinal cells. Treatment of newly confluent Caco-2/15 cells with SAHA resulted in growth arrest, increased histone acetylation and up-regulation of the expression of intestine-specific genes such as those encoding sucrase-isomaltase, villin and the ion exchanger SLC26A3. Although SAHA has been recently used in clinical trials for cancer treatment, its effect on normal intestinal cells has not been documented. Analyses of small and large intestines of mice treated with SAHA revealed a repression of crypt cell proliferation and a higher expression of sucrase-isomaltase in both segments compared to control mice. Expression of SLC26A3 was also significantly up-regulated in the colons of mice after SAHA administration. Finally, SAHA was also found to strongly inhibit normal human intestinal crypt cell proliferation in vitro. These results demonstrate the important implication of epigenetic mechanisms such as histone acetylation/deacetylation in the regulation of normal intestinal cell fate and proliferation.

  15. Sulforaphane inhibits histone deacetylase in vivo and suppresses tumorigenesis in Apc-minus mice.

    PubMed

    Myzak, Melinda C; Dashwood, W Mohaiza; Orner, Gayle A; Ho, Emily; Dashwood, Roderick H

    2006-03-01

    Sulforaphane (SFN) is an isothiocyanate from broccoli that induces phase 2 detoxification enzymes. We recently reported that SFN acts as a histone deacetylase (HDAC) inhibitor in human colon cancer cells in vitro, and the present study sought to extend these findings in vivo. In mice treated with a single oral dose of 10 mumol SFN, there was significant inhibition of HDAC activity in the colonic mucosa after 6 h, and immunoblots revealed a concomitant increase in acetylated histones H3 and H4, which returned to control levels by 48 h. Longer-term treatment with SFN in the diet resulted in levels of acetylated histones and p21(WAF1) in the ileum, colon, prostate, and peripheral blood mononuclear cells that were elevated compared with controls. Consistent with these findings, SFN suppressed tumor development in Apc(min) mice, and there was an increase in acetylated histones in the polyps, including acetylated histones specifically associated with the promoter region of the P21 and bax genes. These results provide the first evidence for HDAC inhibition by SFN in vivo and imply that such a mechanism might contribute to the cancer chemoprotective and therapeutic effects of SFN, alone or in combination with other HDAC inhibitors currently undergoing clinical trials.

  16. Polycomb- and REST-associated histone deacetylases are independent pathways toward a mature neuronal phenotype

    PubMed Central

    McGann, James C; Oyer, Jon A; Garg, Saurabh; Yao, Huilan; Liu, Jun; Feng, Xin; Liao, Lujian; Yates, John R; Mandel, Gail

    2014-01-01

    The bivalent hypothesis posits that genes encoding developmental regulators required for early lineage decisions are poised in stem/progenitor cells by the balance between a repressor histone modification (H3K27me3), mediated by the Polycomb Repressor Complex 2 (PRC2), and an activator modification (H3K4me3). In this study, we test whether this mechanism applies equally to genes that are not required until terminal differentiation. We focus on the RE1 Silencing Transcription Factor (REST) because it is expressed highly in stem cells and is an established global repressor of terminal neuronal genes. Elucidation of the REST complex, and comparison of chromatin marks and gene expression levels in control and REST-deficient stem cells, shows that REST target genes are poised by a mechanism independent of Polycomb, even at promoters which bear the H3K27me3 mark. Specifically, genes under REST control are actively repressed in stem cells by a balance of the H3K4me3 mark and a repressor complex that relies on histone deacetylase activity. Thus, chromatin distinctions between pro-neural and terminal neuronal genes are established at the embryonic stem cell stage by two parallel, but distinct, repressor pathways. DOI: http://dx.doi.org/10.7554/eLife.04235.001 PMID:25250711

  17. 26 CFR 6a.6652(g)-1 - Failure to make return or furnish statement required under section 6039C.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... required under section 6039C. 6a.6652(g)-1 Section 6a.6652(g)-1 Internal Revenue INTERNAL REVENUE SERVICE... OMNIBUS RECONCILIATION ACT OF 1980 § 6a.6652(g)-1 Failure to make return or furnish statement required... limitation under § 6a.6652(g)-1(b)(3) with respect to failure to meet the requirements of section 6039C(c),...

  18. IgG1 deficiency exacerbates experimental autoimmune myasthenia gravis in BALB/c mice.

    PubMed

    Huda, Ruksana; Strait, Richard T; Tüzün, Erdem; Finkelman, Fred D; Christadoss, Premkumar

    2015-04-15

    Myasthenia gravis is an autoimmune disease characterized by muscle weakness due to neuromuscular junction (NMJ) damage by anti-acetylcholine receptor (AChR) auto-antibodies and complement. In experimental autoimmune myasthenia gravis (EAMG), which is induced by immunization with Torpedo AChR in CFA, anti-AChR IgG2b and IgG1 are the predominant isotypes in the circulation. Complement activation by isotypes such as IgG2b plays a crucial role in EAMG pathogenesis; this suggested the possibility that IgG1, which does not activate complement through the classical pathway, may suppress EAMG. In this study, we show that AChR-immunized BALB/c mice genetically deficient for IgG1 produce higher levels of complement-activating isotypes of anti-AChR, especially IgG3 and IgG2a, and develop increased IgG3/IgG2a deposits at the NMJ, as compared to wild type (WT) BALB/c mice. Consistent with this, AChR-immunized IgG1(-/-) BALB/c mice lose muscle strength and muscle AChR to a greater extent than AChR-immunized WT mice. These observations demonstrate that IgG1 deficiency leads to increased severity of EAMG associated with an increase in complement activating IgG isotypes. Further studies are needed to dissect the specific role or mechanism of IgG1 in limiting EAMG and that of EAMG exacerbating role of complement activating IgG3 and IgG2a in IgG1 deficiency. PMID:25867470

  19. IgG1 deficiency exacerbates experimental autoimmune myasthenia gravis in BALB/c mice.

    PubMed

    Huda, Ruksana; Strait, Richard T; Tüzün, Erdem; Finkelman, Fred D; Christadoss, Premkumar

    2015-04-15

    Myasthenia gravis is an autoimmune disease characterized by muscle weakness due to neuromuscular junction (NMJ) damage by anti-acetylcholine receptor (AChR) auto-antibodies and complement. In experimental autoimmune myasthenia gravis (EAMG), which is induced by immunization with Torpedo AChR in CFA, anti-AChR IgG2b and IgG1 are the predominant isotypes in the circulation. Complement activation by isotypes such as IgG2b plays a crucial role in EAMG pathogenesis; this suggested the possibility that IgG1, which does not activate complement through the classical pathway, may suppress EAMG. In this study, we show that AChR-immunized BALB/c mice genetically deficient for IgG1 produce higher levels of complement-activating isotypes of anti-AChR, especially IgG3 and IgG2a, and develop increased IgG3/IgG2a deposits at the NMJ, as compared to wild type (WT) BALB/c mice. Consistent with this, AChR-immunized IgG1(-/-) BALB/c mice lose muscle strength and muscle AChR to a greater extent than AChR-immunized WT mice. These observations demonstrate that IgG1 deficiency leads to increased severity of EAMG associated with an increase in complement activating IgG isotypes. Further studies are needed to dissect the specific role or mechanism of IgG1 in limiting EAMG and that of EAMG exacerbating role of complement activating IgG3 and IgG2a in IgG1 deficiency.

  20. Selective Subnormal IgG1 in 54 Adult Index Patients with Frequent or Severe Bacterial Respiratory Tract Infections

    PubMed Central

    Barton, James C.; Bertoli, Luigi F.; Barton, J. Clayborn; Acton, Ronald T.

    2016-01-01

    We characterized 54 adult index patients with reports of frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG1. Mean age was 50 ± 13 (SD) y; 87.0% were women. Associated disorders included the following: autoimmune conditions 50.0%; hypothyroidism 24.1%; atopy 38.9%; and other allergy 31.5%. In 35.5%, proportions of protective S. pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination (PPPV). Blood lymphocyte subset levels were within reference limits in most patients. Regressions on IgG1 and IgG3 revealed no significant association with age, sex, autoimmune conditions, hypothyroidism, atopy, other allergy, corticosteroid therapy, or lymphocyte subsets. Regression on IgG2 revealed significant associations with PPPV response (negative) and CD19+ lymphocytes (positive). Regression on IgG4 revealed significant positive associations with episodic corticosteroid use and IgA. Regression on IgA revealed positive associations with IgG2 and IgG4. Regression on IgM revealed negative associations with CD56+/CD16+ lymphocytes. Regressions on categories of infection revealed a negative association of urinary tract infections and IgG1. HLA-A⁎03, HLA-B⁎55 and HLA-A⁎24, HLA-B⁎35 haplotype frequencies were greater in 38 patients than 751 controls. We conclude that nonprotective S. pneumoniae IgG levels and atopy contribute to increased susceptibility to respiratory tract infections in patients with selective subnormal IgG1. PMID:27123464

  1. Echinococcus ortleppi (G5) and Echinococcus granulosus sensu stricto (G1) loads in cattle from Southern Brazil.

    PubMed

    Balbinotti, Helier; Santos, Guilherme B; Badaraco, Jeferson; Arend, Ana C; Graichen, Daniel Ângelo S; Haag, Karen L; Zaha, Arnaldo

    2012-09-10

    Echinococcus granulosus sensu stricto (G1) and Echinococcus ortleppi (G5) are haplotypes of the parasite formerly known as Echinococcus granulosus sensu lato, which in its larval stage causes cystic hydatid disease, endemic in Southern Brazil. Epidemiological and molecular knowledge about the haplotypes occurring in a region is essential to control the spread of the disease. The aim of this work was to analyze the haplotype frequency and fertility of hydatid cysts in cattle from the state of Rio Grande do Sul. Cysts were collected and classified according to their fertility status. DNA was extracted from protoscoleces and germinal layers and then used as template for the amplification of the cytochrome c oxidase subunit 1 gene by PCR. Amplicons were purified and sequenced, and the sequences were analyzed for haplotype identification. A total of 638 fertile cysts collected in the last ten years were genotyped. On average, G1 (56.6%) was more frequent than G5 (43.4%). In lungs, the G5 haplotype exhibited a higher parasite load (52.8%), whereas in the liver, G1 was more frequent (90.4%). The analysis revealed an increase in the frequency of G5 haplotype cysts during the period of sampling, and an increase in the abundance of fertile cysts has also been observed in the last several years. Most infertile cysts were genotyped as G1. The possible factors involved in the increase in the proportion of E. ortleppi (G5) and the consequences of this increase are discussed. This study suggests that the proportion of E. ortleppi (G5) loads in cattle may be increasing overtime.

  2. Histone Deacetylase 3 orchestrates commensal bacteria-dependent intestinal homeostasis

    PubMed Central

    Alenghat, Theresa; Osborne, Lisa C.; Saenz, Steven A.; Kobuley, Dmytro; Ziegler, Carly G. K.; Mullican, Shannon E.; Choi, Inchan; Grunberg, Stephanie; Sinha, Rohini; Wynosky-Dolfi, Meghan; Snyder, Annelise; Giacomin, Paul R.; Joyce, Karen L.; Hoang, Tram B.; Bewtra, Meenakshi; Brodsky, Igor E.; Sonnenberg, Gregory F.; Bushman, Frederic D.; Won, Kyoung-Jae; Lazar, Mitchell A.; Artis, David

    2014-01-01

    The development and severity of inflammatory bowel diseases (IBD) and other chronic inflammatory conditions can be influenced by host genetic and environmental factors, including signals derived from commensal bacteria1–6. However, the mechanisms that integrate these diverse cues remain undefined. Here we demonstrate that mice with an intestinal epithelial cell-specific deletion of the epigenome-modifying enzyme histone deacetylase 3 (HDAC3ΔIEC mice) exhibited extensive dysregulation of IEC-intrinsic gene expression, including decreased basal expression of genes associated with antimicrobial defense. Critically, conventionally-housed HDAC3ΔIEC mice demonstrated loss of Paneth cells, impaired IEC function and alterations in the composition of intestinal commensal bacteria. In addition, HDAC3ΔIEC mice exhibited significantly increased susceptibility to intestinal damage and inflammation, indicating that epithelial expression of HDAC3 plays a central role in maintaining intestinal homeostasis. Rederivation of HDAC3ΔIEC mice into germ-free conditions revealed that dysregulated IEC gene expression, Paneth cell homeostasis, and intestinal barrier function were largely restored in the absence of commensal bacteria. While the specific mechanisms through which IEC-intrinsic HDAC3 expression regulates these complex phenotypes remain to be elucidated, these data indicate that HDAC3 is a critical factor that integrates commensal bacteria-derived signals to calibrate epithelial cell responses required to establish normal host-commensal relationships and maintain intestinal homeostasis. PMID:24185009

  3. Histone deacetylase 6 inhibition enhances oncolytic viral replication in glioma

    PubMed Central

    Nakashima, Hiroshi; Kaufmann, Johanna K.; Wang, Pin-Yi; Nguyen, Tran; Speranza, Maria-Carmela; Kasai, Kazue; Okemoto, Kazuo; Otsuki, Akihiro; Nakano, Ichiro; Fernandez, Soledad; Goins, William F.; Grandi, Paola; Glorioso, Joseph C.; Lawler, Sean; Cripe, Timothy P.; Chiocca, E. Antonio

    2015-01-01

    Oncolytic viral (OV) therapy, which uses genetically engineered tumor-targeting viruses, is being increasingly used in cancer clinical trials due to the direct cytolytic effects of this treatment that appear to provoke a robust immune response against the tumor. As OVs enter tumor cells, intrinsic host defenses have the potential to hinder viral replication and spread within the tumor mass. In this report, we show that histone deacetylase 6 (HDAC6) in tumor cells appears to alter the trafficking of post-entry OVs from the nucleus toward lysosomes. In glioma cell lines and glioma-stem–like cells, HDAC6 inhibition (HDAC6i) by either pharmacologic or genetic means substantially increased replication of oncolytic herpes simplex virus type 1 (oHSV). Moreover, HDAC6i increased shuttling of post-entry oHSV to the nucleus. In addition, electron microscopic analysis revealed that post-entry oHSVs are preferentially taken up into glioma cells through the endosomal pathway rather than via fusion at the cell surface. Together, these findings illustrate a mechanism of glioma cell defense against an incoming infection by oHSV and identify possible approaches to enhance oHSV replication and subsequent lysis of tumor cells. PMID:26524593

  4. Histone deacetylase 3 coordinates commensal-bacteria-dependent intestinal homeostasis.

    PubMed

    Alenghat, Theresa; Osborne, Lisa C; Saenz, Steven A; Kobuley, Dmytro; Ziegler, Carly G K; Mullican, Shannon E; Choi, Inchan; Grunberg, Stephanie; Sinha, Rohini; Wynosky-Dolfi, Meghan; Snyder, Annelise; Giacomin, Paul R; Joyce, Karen L; Hoang, Tram B; Bewtra, Meenakshi; Brodsky, Igor E; Sonnenberg, Gregory F; Bushman, Frederic D; Won, Kyoung-Jae; Lazar, Mitchell A; Artis, David

    2013-12-01

    The development and severity of inflammatory bowel diseases and other chronic inflammatory conditions can be influenced by host genetic and environmental factors, including signals derived from commensal bacteria. However, the mechanisms that integrate these diverse cues remain undefined. Here we demonstrate that mice with an intestinal epithelial cell (IEC)-specific deletion of the epigenome-modifying enzyme histone deacetylase 3 (HDAC3(ΔIEC) mice) exhibited extensive dysregulation of IEC-intrinsic gene expression, including decreased basal expression of genes associated with antimicrobial defence. Critically, conventionally housed HDAC3(ΔIEC) mice demonstrated loss of Paneth cells, impaired IEC function and alterations in the composition of intestinal commensal bacteria. In addition, HDAC3(ΔIEC) mice showed significantly increased susceptibility to intestinal damage and inflammation, indicating that epithelial expression of HDAC3 has a central role in maintaining intestinal homeostasis. Re-derivation of HDAC3(ΔIEC) mice into germ-free conditions revealed that dysregulated IEC gene expression, Paneth cell homeostasis and intestinal barrier function were largely restored in the absence of commensal bacteria. Although the specific mechanisms through which IEC-intrinsic HDAC3 expression regulates these complex phenotypes remain to be determined, these data indicate that HDAC3 is a critical factor that integrates commensal-bacteria-derived signals to calibrate epithelial cell responses required to establish normal host-commensal relationships and maintain intestinal homeostasis.

  5. Dietary sulforaphane, a histone deacetylase inhibitor for cancer prevention.

    PubMed

    Ho, Emily; Clarke, John D; Dashwood, Roderick H

    2009-12-01

    The reversible acetylation of histones is an important mechanism of gene regulation. During prostate cancer progression, specific modifications in acetylation patterns on histones are apparent. Targeting the epigenome, including the use of histone deacetylase (HDAC) inhibitors, is a novel strategy for cancer chemoprevention. Recently, drugs classified as HDAC inhibitors have shown promise in cancer clinical trials. We have previously found that sulforaphane (SFN), a compound found in cruciferous vegetables, inhibits HDAC activity in human colorectal and prostate cancer cells. Based on the similarity of SFN metabolites and other phytochemicals to known HDAC inhibitors, we previously demonstrated that sulforaphane acted as an HDAC inhibitor in the prostate, causing enhanced histone acetylation, derepression of P21 and Bax, and induction of cell cycle arrest/apoptosis, leading to cancer prevention. The ability of SFN to target aberrant acetylation patterns, in addition to effects on phase 2 enzymes, may make it an effective chemoprevention agent. These studies are important because of the potential to qualify or change recommendations for high-risk prostate cancer patients and thereby increase their survival through simple dietary choices incorporating easily accessible foods into their diets. These studies also will provide a strong scientific foundation for future large-scale human clinical intervention studies.

  6. Histone deacetylase inhibitor panobinostat induces calcineurin degradation in multiple myeloma

    PubMed Central

    Ohta, Eri; Takeda, Shu; Sunamura, Satoko; Ishibashi, Mariko; Tamura, Hideto; Wang, Yan-hua; Deguchi, Atsuko; Tanaka, Junji; Maru, Yoshiro; Motoji, Toshiko

    2016-01-01

    Multiple myeloma (MM) is a relapsed and refractory disease, one that highlights the need for developing new molecular therapies for overcoming of drug resistance. Addition of panobinostat, a histone deacetylase (HDAC) inhibitor, to bortezomib and dexamethasone improved progression-free survival (PFS) in relapsed and refractory MM patients. Here, we demonstrate how calcineurin, when inhibited by immunosuppressive drugs like FK506, is involved in myeloma cell growth and targeted by panobinostat. mRNA expression of PPP3CA, a catalytic subunit of calcineurin, was high in advanced patients. Panobinostat degraded PPP3CA, a degradation that should have been induced by inhibition of the chaperone function of heat shock protein 90 (HSP90). Cotreatment with HDAC inhibitors and FK506 led to an enhanced antimyeloma effect with a greater PPP3CA reduction compared with HDAC inhibitors alone both in vitro and in vivo. In addition, this combination treatment efficiently blocked osteoclast formation, which results in osteolytic lesions. The poor response and short PFS duration observed in the bortezomib-containing therapies of patients with high PPP3CA suggested its relevance to bortezomib resistance. Moreover, bortezomib and HDAC inhibitors synergistically suppressed MM cell viability through PPP3CA inhibition. Our findings underscore the usefulness of calcineurin-targeted therapy in MM patients, including patients who are resistant to bortezomib. PMID:27699258

  7. Insights into neuroepigenetics through human histone deacetylase PET imaging.

    PubMed

    Wey, Hsiao-Ying; Gilbert, Tonya M; Zürcher, Nicole R; She, Angela; Bhanot, Anisha; Taillon, Brendan D; Schroeder, Fredrick A; Wang, Changing; Haggarty, Stephen J; Hooker, Jacob M

    2016-08-10

    Epigenetic dysfunction is implicated in many neurological and psychiatric diseases, including Alzheimer's disease and schizophrenia. Consequently, histone deacetylases (HDACs) are being aggressively pursued as therapeutic targets. However, a fundamental knowledge gap exists regarding the expression and distribution of HDACs in healthy individuals for comparison to disease states. Here, we report the first-in-human evaluation of neuroepigenetic regulation in vivo. Using positron emission tomography with [(11)C]Martinostat, an imaging probe selective for class I HDACs (isoforms 1, 2, and 3), we found that HDAC expression is higher in cortical gray matter than in white matter, with conserved regional distribution patterns within and between healthy individuals. Among gray matter regions, HDAC expression was lowest in the hippocampus and amygdala. Through biochemical profiling of postmortem human brain tissue, we confirmed that [(11)C]Martinostat selectively binds HDAC isoforms 1, 2, and 3, the HDAC subtypes most implicated in regulating neuroplasticity and cognitive function. In human stem cell-derived neural progenitor cells, pharmacologic-level doses of Martinostat induced changes in genes closely associated with synaptic plasticity, including BDNF (brain-derived neurotrophic factor) and SYP (synaptophysin), as well as genes implicated in neurodegeneration, including GRN (progranulin), at the transcript level, in concert with increased acetylation at both histone H3 lysine 9 and histone H4 lysine 12. This study quantifies HDAC expression in the living human brain and provides the foundation for gaining unprecedented in vivo epigenetic information in health and disease. PMID:27510902

  8. Histone deacetylase inhibitors induce autophagy through FOXO1-dependent pathways.

    PubMed

    Zhang, Jianbin; Ng, Shukie; Wang, Jigang; Zhou, Jing; Tan, Shi-Hao; Yang, Naidi; Lin, Qingsong; Xia, Dajing; Shen, Han-Ming

    2015-04-01

    Autophagy is a catabolic process in response to starvation or other stress conditions to sustain cellular homeostasis. At present, histone deacetylase inhibitors (HDACIs) are known to induce autophagy in cells through inhibition of mechanistic target of rapamycin (MTOR) pathway. FOXO1, an important transcription factor regulated by AKT, is also known to play a role in autophagy induction. At present, the role of FOXO1 in the HDACIs-induced autophagy has not been reported. In this study, we first observed that HDACIs increased the expression of FOXO1 at the mRNA and protein level. Second, we found that FOXO1 transcriptional activity was enhanced by HDACIs, as evidenced by increased FOXO1 nuclear accumulation and transcriptional activity. Third, suppression of FOXO1 function by siRNA knockdown or by a chemical inhibitor markedly blocked HDACIs-induced autophagy. Moreover, we found that FOXO1-mediated autophagy is achieved via its transcriptional activation, leading to a dual effect on autophagy induction: (i) enhanced expression of autophagy-related (ATG) genes, and (ii) suppression of MTOR via transcription of the SESN3 (sestrin 3) gene. Finally, we found that inhibition of autophagy markedly enhanced HDACIs-mediated cell death, indicating that autophagy serves as an important cell survival mechanism. Taken together, our studies reveal a novel function of FOXO1 in HDACIs-mediated autophagy in human cancer cells and thus support the development of a novel therapeutic strategy by combining HDACIs and autophagy inhibitors in cancer therapy.

  9. Histone deacetylase inhibitor panobinostat induces calcineurin degradation in multiple myeloma

    PubMed Central

    Ohta, Eri; Takeda, Shu; Sunamura, Satoko; Ishibashi, Mariko; Tamura, Hideto; Wang, Yan-hua; Deguchi, Atsuko; Tanaka, Junji; Maru, Yoshiro; Motoji, Toshiko

    2016-01-01

    Multiple myeloma (MM) is a relapsed and refractory disease, one that highlights the need for developing new molecular therapies for overcoming of drug resistance. Addition of panobinostat, a histone deacetylase (HDAC) inhibitor, to bortezomib and dexamethasone improved progression-free survival (PFS) in relapsed and refractory MM patients. Here, we demonstrate how calcineurin, when inhibited by immunosuppressive drugs like FK506, is involved in myeloma cell growth and targeted by panobinostat. mRNA expression of PPP3CA, a catalytic subunit of calcineurin, was high in advanced patients. Panobinostat degraded PPP3CA, a degradation that should have been induced by inhibition of the chaperone function of heat shock protein 90 (HSP90). Cotreatment with HDAC inhibitors and FK506 led to an enhanced antimyeloma effect with a greater PPP3CA reduction compared with HDAC inhibitors alone both in vitro and in vivo. In addition, this combination treatment efficiently blocked osteoclast formation, which results in osteolytic lesions. The poor response and short PFS duration observed in the bortezomib-containing therapies of patients with high PPP3CA suggested its relevance to bortezomib resistance. Moreover, bortezomib and HDAC inhibitors synergistically suppressed MM cell viability through PPP3CA inhibition. Our findings underscore the usefulness of calcineurin-targeted therapy in MM patients, including patients who are resistant to bortezomib.

  10. Histone deacetylase-mediated morphological transition in Candida albicans.

    PubMed

    Kim, Jueun; Lee, Ji-Eun; Lee, Jung-Shin

    2015-12-01

    Candida albicans is the most common opportunistic fungal pathogen, which switches its morphology from single-cell yeast to filament through the various signaling pathways responding to diverse environmental cues. Various transcriptional factors such as Nrg1, Efg1, Brg1, Ssn6, and Tup1 are the key components of these signaling pathways. Since C. albicans can regulate its transcriptional gene expressions using common eukaryotic regulatory systems, its morphological transition by these signaling pathways could be linked to the epigenetic regulation by chromatin structure modifiers. Histone proteins, which are critical components of eukaryotic chromatin structure, can regulate the eukaryotic chromatin structure through their own modifications such as acetylation, methylation, phosphorylation and ubiquitylation. Recent studies revealed that various histone modifications, especially histone acetylation and deacetylation, participate in morphological transition of C. albicans collaborating with well-known transcription factors in the signaling pathways. Here, we review recent studies about chromatin-mediated morphological transition of C. albicans focusing on the interaction between transcription factors in the signaling pathways and histone deacetylases.

  11. Production of chitin deacetylase by Aspergillus flavus in submerged conditions.

    PubMed

    Narayanan, Karthik; Parameswaran, Binod; Pandey, Ashok

    2016-07-01

    Chitosan is a biopolymer obtained by deacetylation of chitin and has been proven to have various applications in industry and biomedicine. Deacetylation of chitin using the enzyme chitin deacetylase (CDA) is favorable in comparison to the hazardous chemical method involving strong alkali and high temperature. A fungal strain producing CDA was isolated from environmental samples collected from coastal regions of South Kerala, India. It was identified as Aspergillus flavus by morphological characteristics and ITS DNA analysis. Nutritional requirement for maximum production of CDA under submerged condition was optimized using statistical methods including Plackett-Burman and response surface methodology central composite design. A 5.98-fold enhancement in CDA production was attained in shake flasks when the fermentation process parameters were used at their optimum levels. The highest CDA activity was 57.69 ± 1.68 U under optimized bioprocess conditions that included 30 g L(-1) glucose, 40 g L(-1) yeast extract, 15 g L(-1) peptone, and 7 g L(-1) MgCl2 at initial media pH of 7 and incubation temperature of 32°C after 48 hr of incubation, while the unoptimized basal medium yielded 9.64 ± 2.04 U. PMID:26474347

  12. Histone deacetylases inhibitors effects on Cryptococcus neoformans major virulence phenotypes

    PubMed Central

    Brandão, Fabiana AS; Derengowski, Lorena S; Albuquerque, Patrícia; Nicola, André M; Silva-Pereira, Ildinete; Poças-Fonseca, Marcio J

    2015-01-01

    Cryptococcus neoformans undergoes phenotypical changes during host infection in order to promote persistence and survival. Studies have demonstrated that such adaptations require alterations in gene transcription networks by distinct mechanisms. Drugs such as the histone deacetylases inhibitors (HDACi) Sodium Butyrate (NaBut) and Trichostatin A (TSA) can alter the chromatin conformation and have been used to modulate epigenetic states in the treatment of diseases such as cancer. In this work, we have studied the effect of NaBut and TSA on the expression of C. neoformans major virulence phenotypes and on the survival rate of an animal model infected with drugs-treated yeasts. Both drugs affected fungal growth at 37°C more intensely than at 30°C; nonetheless, drugs did not affect cell viability at the concentrations we studied. HDACi also provoked the reduction of the fungal capsule expansion. Phospholipases enzyme activity decreased; mating process and melanin synthesis were also affected by both inhibitors. NaBut led to an increase in the population of cells in G2/M. Treated yeast cells, which were washed in order to remove the drugs from the culture medium prior to the inoculation in the Galleria mellonela infection model, did not cause significant difference at the host survival curve when compared to non-treated cells. Overall, NaBut effects on the impairment of C. neoformans main virulence factors were more intense and stable than the TSA effects. PMID:26103530

  13. Histone deacetylase inhibitors promote the tumoricidal effect of HAMLET.

    PubMed

    Brest, Patrick; Gustafsson, Mattias; Mossberg, Ann-Kristin; Gustafsson, Lotta; Duringer, Caroline; Hamiche, Ali; Svanborg, Catharina

    2007-12-01

    Histone deacetylase inhibitors (HDIs) and HAMLET (human alpha-lactalbumin made lethal to tumor cells) interact with histones, modify the structure of chromatin, and trigger tumor cell death. This study investigated how the combination of HDIs and HAMLET influences cell viability, histone acetylation, and DNA integrity. The pretreatment of tumor cells with HDIs was shown to enhance the lethal effect of HAMLET and the histone hyperacetylation response to HDIs increased even further after HAMLET treatment. HDIs and HAMLET were shown to target different histone domains as HAMLET bound tailless core histones, whereas HDIs modify the acetylation of the histone tail. DNA damage in response to HAMLET was increased by HDIs. The DNA repair response (p21WAFI expression) was induced by both agonists but abolished when the two agonists were combined. The results suggest that the synergy of HDIs and HAMLET is based on different but converging death pathways, both involving chromatin alterations. We speculate that HAMLET and HDIs might be combined to promote tumor cell death in vivo.

  14. Human arylacetamide deacetylase hydrolyzes ketoconazole to trigger hepatocellular toxicity.

    PubMed

    Fukami, Tatsuki; Iida, Azumi; Konishi, Keigo; Nakajima, Miki

    2016-09-15

    Ketoconazole (KC), an antifungal agent, rarely causes severe liver injury when orally administered. It has been reported that KC is mainly hydrolyzed to N-deacetyl ketoconazole (DAK), followed by the N-hydroxylation of DAK by flavin-containing monooxygenase (FMO). Although the metabolism of KC has been considered to be associated with hepatotoxicity, the responsible enzyme(s) remain unknown. The purpose of this study was to identify the responsible enzyme(s) for KC hydrolysis in humans and to clarify their relevance to KC-induced toxicity. Kinetic analysis and inhibition studies using human liver microsomes (HLM) and recombinant enzymes revealed that human arylacetamide deacetylase (AADAC) is responsible for KC hydrolysis to form DAK, and confirmed that FMO3 is the enzyme responsible for DAK N-hydroxylation. In HLM, the clearance of KC hydrolysis occurred to the same extent as DAK N-hydroxylation, which indicates that both processes are not rate-limiting pathways. Cytotoxicity of KC and DAK was evaluated using HepaRG cells and human primary hepatocytes. Treatment of HepaRG cells with DAK for 24h showed cytotoxicity in a dose-dependent manner, whereas treatment with KC did not show due to the low expression of AADAC. Overexpression of AADAC in HepaRG cells with an adenovirus expression system elicited the cytotoxicity of KC. Cytotoxicity of KC in human primary hepatocytes was attenuated by diisopropylfluorophosphate, an AADAC inhibitor. In conclusion, the present study demonstrated that human AADAC hydrolyzes KC to trigger hepatocellular toxicity.

  15. Targeting histone deacetylase inhibitors for anti-malarial therapy.

    PubMed

    Andrews, Katherine T; Tran, Thanh N; Wheatley, Nicole C; Fairlie, David P

    2009-01-01

    It is now clear that histone acetylation plays key roles in regulating gene transcription in both eukaryotes and prokaryotes, the acetylated form inducing gene expression while deacetylation silences genes. Recent studies have identified roles for histone acetyltransferases (HATs) and/or histone deacetylases (HDACs) in a number of parasites including Entamoeba histolytica, Toxoplasma gondii, Schistosoma mansoni, Cryptosporidium sp., Leishmania donovani, Neospora caninum, and Plasmodium falciparum. Here we survey fairly limited efforts to date in profiling antimalarial activities of HDAC inhibitors, showing that such compounds are potent inhibitors of the growth of P. falciparum in vitro and in vivo. Most of the compounds evaluated so far have borne a zinc-binding hydroxamate group that tends to be metabolized in vivo, and thus new zinc-binding groups need to be incorporated into second generation inhibitors in order to mask the catalytic zinc in the active site of HDACs. Also the development of compounds that are selective for parasitic HDACs over mammalian HDACs is still in relative infancy and it will take some time to derive antiparasitic HDAC inhibitor compounds with minimal toxicity for the host and acceptable pharmacokinetic and pharmacodynamic profiles for human treatment. Nevertheless, results to date suggest that HDAC inhibitor development represents a promising new approach to the potential treatment of parasitic infections, including those induced by malaria protozoa, and may offer new therapeutic targets within increasingly drug-resistant malarial parasites. PMID:19355992

  16. Histone deacetylase inhibitor romidepsin inhibits de novo HIV-1 infections.

    PubMed

    Jønsson, Kasper L; Tolstrup, Martin; Vad-Nielsen, Johan; Kjær, Kathrine; Laustsen, Anders; Andersen, Morten N; Rasmussen, Thomas A; Søgaard, Ole S; Østergaard, Lars; Denton, Paul W; Jakobsen, Martin R

    2015-07-01

    Adjunct therapy with the histone deacetylase inhibitor (HDACi) romidepsin increases plasma viremia in HIV patients on combination antiretroviral therapy (cART). However, a potential concern is that reversing HIV latency with an HDACi may reactivate the virus in anatomical compartments with suboptimal cART concentrations, leading to de novo infection of susceptible cells in these sites. We tested physiologically relevant romidepsin concentrations known to reactivate latent HIV in order to definitively address this concern. We found that romidepsin significantly inhibited HIV infection in peripheral blood mononuclear cells and CD4(+) T cells but not in monocyte-derived macrophages. In addition, romidepsin impaired HIV spreading in CD4(+) T cell cultures. When we evaluated the impact of romidepsin on quantitative viral outgrowth assays with primary resting CD4(+) T cells, we found that resting CD4(+) T cells exposed to romidepsin exhibited reduced proliferation and viability. This significantly lowered assay sensitivity when measuring the efficacy of romidepsin as an HIV latency reversal agent. Altogether, our data indicate that romidepsin-based HIV eradication strategies are unlikely to reseed a latent T cell reservoir, even under suboptimal cART conditions, because romidepsin profoundly restricts de novo HIV infections.

  17. Histone deacetylase 6 inhibition enhances oncolytic viral replication in glioma.

    PubMed

    Nakashima, Hiroshi; Kaufmann, Johanna K; Wang, Pin-Yi; Nguyen, Tran; Speranza, Maria-Carmela; Kasai, Kazue; Okemoto, Kazuo; Otsuki, Akihiro; Nakano, Ichiro; Fernandez, Soledad; Goins, William F; Grandi, Paola; Glorioso, Joseph C; Lawler, Sean; Cripe, Timothy P; Chiocca, E Antonio

    2015-11-01

    Oncolytic viral (OV) therapy, which uses genetically engineered tumor-targeting viruses, is being increasingly used in cancer clinical trials due to the direct cytolytic effects of this treatment that appear to provoke a robust immune response against the tumor. As OVs enter tumor cells, intrinsic host defenses have the potential to hinder viral replication and spread within the tumor mass. In this report, we show that histone deacetylase 6 (HDAC6) in tumor cells appears to alter the trafficking of post-entry OVs from the nucleus toward lysosomes. In glioma cell lines and glioma-stem-like cells, HDAC6 inhibition (HDAC6i) by either pharmacologic or genetic means substantially increased replication of oncolytic herpes simplex virus type 1 (oHSV). Moreover, HDAC6i increased shuttling of post-entry oHSV to the nucleus. In addition, electron microscopic analysis revealed that post-entry oHSVs are preferentially taken up into glioma cells through the endosomal pathway rather than via fusion at the cell surface. Together, these findings illustrate a mechanism of glioma cell defense against an incoming infection by oHSV and identify possible approaches to enhance oHSV replication and subsequent lysis of tumor cells. PMID:26524593

  18. Histone Deacetylase Inhibition Restores Retinal Pigment Epithelium Function in Hyperglycemia

    PubMed Central

    Desjardins, Danielle; Liu, Yueying; Crosson, Craig E.; Ablonczy, Zsolt

    2016-01-01

    In diabetic individuals, macular edema is a major cause of vision loss. This condition is refractory to insulin therapy and has been attributed to metabolic memory. The retinal pigment epithelium (RPE) is central to maintaining fluid balance in the retina, and this function is compromised by the activation of advanced glycation end-product receptors (RAGE). Here we provide evidence that acute administration of the RAGE agonist, glycated-albumin (gAlb) or vascular endothelial growth factor (VEGF), increased histone deacetylase (HDAC) activity in RPE cells. The administration of the class I/II HDAC inhibitor, trichostatin-A (TSA), suppressed gAlb-induced reductions in RPE transepithelial resistance (in vitro) and fluid transport (in vivo). Systemic TSA also restored normal RPE fluid transport in rats with subchronic hyperglycemia. Both gAlb and VEGF increased HDAC activity and reduced acetyl-α-tubulin levels. Tubastatin-A, a relatively specific antagonist of HDAC6, inhibited gAlb-induced changes in RPE cell resistance. These data are consistent with the idea that RPE dysfunction following exposure to gAlb, VEGF, or hyperglycemia is associated with increased HDAC6 activity and decreased acetyl-α-tubulin. Therefore, we propose inhibiting HDAC6 in the RPE as a potential therapy for preserving normal fluid homeostasis in the hyperglycemic retina. PMID:27617745

  19. Histone deacetylase 4 possesses intrinsic nuclear import and export signals.

    PubMed

    Wang, A H; Yang, X J

    2001-09-01

    Nucleocytoplasmic trafficking of histone deacetylase 4 (HDAC4) plays an important role in regulating its function, and binding of 14-3-3 proteins is necessary for its cytoplasmic retention. Here, we report the identification of nuclear import and export sequences of HDAC4. While its N-terminal 118 residues modulate the nuclear localization, residues 244 to 279 constitute an authentic, strong nuclear localization signal. Mutational analysis of this signal revealed that three arginine-lysine clusters are necessary for its nuclear import activity. As for nuclear export, leucine-rich sequences located in the middle part of HDAC4 do not function as nuclear export signals. By contrast, a hydrophobic motif (MXXLXVXV) located at the C-terminal end serves as a nuclear export signal that is necessary for cytoplasmic retention of HDAC4. This motif is required for CRM1-mediated nuclear export of HDAC4. Furthermore, binding of 14-3-3 proteins promotes cytoplasmic localization of HDAC4 by both inhibiting its nuclear import and stimulating its nuclear export. Unlike wild-type HDAC4, a point mutant with abrogated MEF2-binding ability remains cytoplasmic upon exogenous expression of MEF2C, supporting the notion that direct MEF2 binding targets HDAC4 to the nucleus. Therefore, HDAC4 possesses intrinsic nuclear import and export signals for its dynamic nucleocytoplasmic shuttling, and association with 14-3-3 and MEF2 proteins affects such shuttling and thus directs HDAC4 to the cytoplasm and the nucleus, respectively.

  20. Class IIa Histone Deacetylases Are Conserved Regulators of Circadian Function*

    PubMed Central

    Fogg, Paul C. M.; O'Neill, John S.; Dobrzycki, Tomasz; Calvert, Shaun; Lord, Emma C.; McIntosh, Rebecca L. L.; Elliott, Christopher J. H.; Sweeney, Sean T.; Hastings, Michael H.; Chawla, Sangeeta

    2014-01-01

    Class IIa histone deacetylases (HDACs) regulate the activity of many transcription factors to influence liver gluconeogenesis and the development of specialized cells, including muscle, neurons, and lymphocytes. Here, we describe a conserved role for class IIa HDACs in sustaining robust circadian behavioral rhythms in Drosophila and cellular rhythms in mammalian cells. In mouse fibroblasts, overexpression of HDAC5 severely disrupts transcriptional rhythms of core clock genes. HDAC5 overexpression decreases BMAL1 acetylation on Lys-537 and pharmacological inhibition of class IIa HDACs increases BMAL1 acetylation. Furthermore, we observe cyclical nucleocytoplasmic shuttling of HDAC5 in mouse fibroblasts that is characteristically circadian. Mutation of the Drosophila homolog HDAC4 impairs locomotor activity rhythms of flies and decreases period mRNA levels. RNAi-mediated knockdown of HDAC4 in Drosophila clock cells also dampens circadian function. Given that the localization of class IIa HDACs is signal-regulated and influenced by Ca2+ and cAMP signals, our findings offer a mechanism by which extracellular stimuli that generate these signals can feed into the molecular clock machinery. PMID:25271152

  1. Histone deacetylases (HDACs): characterization of the classical HDAC family.

    PubMed Central

    de Ruijter, Annemieke J M; van Gennip, Albert H; Caron, Huib N; Kemp, Stephan; van Kuilenburg, André B P

    2003-01-01

    Transcriptional regulation in eukaryotes occurs within a chromatin setting, and is strongly influenced by the post-translational modification of histones, the building blocks of chromatin, such as methylation, phosphorylation and acetylation. Acetylation is probably the best understood of these modifications: hyperacetylation leads to an increase in the expression of particular genes, and hypoacetylation has the opposite effect. Many studies have identified several large, multisubunit enzyme complexes that are responsible for the targeted deacetylation of histones. The aim of this review is to give a comprehensive overview of the structure, function and tissue distribution of members of the classical histone deacetylase (HDAC) family, in order to gain insight into the regulation of gene expression through HDAC activity. SAGE (serial analysis of gene expression) data show that HDACs are generally expressed in almost all tissues investigated. Surprisingly, no major differences were observed between the expression pattern in normal and malignant tissues. However, significant variation in HDAC expression was observed within tissue types. HDAC inhibitors have been shown to induce specific changes in gene expression and to influence a variety of other processes, including growth arrest, differentiation, cytotoxicity and induction of apoptosis. This challenging field has generated many fascinating results which will ultimately lead to a better understanding of the mechanism of gene transcription as a whole. PMID:12429021

  2. Histone Deacetylase Inhibition Restores Retinal Pigment Epithelium Function in Hyperglycemia.

    PubMed

    Desjardins, Danielle; Liu, Yueying; Crosson, Craig E; Ablonczy, Zsolt

    2016-01-01

    In diabetic individuals, macular edema is a major cause of vision loss. This condition is refractory to insulin therapy and has been attributed to metabolic memory. The retinal pigment epithelium (RPE) is central to maintaining fluid balance in the retina, and this function is compromised by the activation of advanced glycation end-product receptors (RAGE). Here we provide evidence that acute administration of the RAGE agonist, glycated-albumin (gAlb) or vascular endothelial growth factor (VEGF), increased histone deacetylase (HDAC) activity in RPE cells. The administration of the class I/II HDAC inhibitor, trichostatin-A (TSA), suppressed gAlb-induced reductions in RPE transepithelial resistance (in vitro) and fluid transport (in vivo). Systemic TSA also restored normal RPE fluid transport in rats with subchronic hyperglycemia. Both gAlb and VEGF increased HDAC activity and reduced acetyl-α-tubulin levels. Tubastatin-A, a relatively specific antagonist of HDAC6, inhibited gAlb-induced changes in RPE cell resistance. These data are consistent with the idea that RPE dysfunction following exposure to gAlb, VEGF, or hyperglycemia is associated with increased HDAC6 activity and decreased acetyl-α-tubulin. Therefore, we propose inhibiting HDAC6 in the RPE as a potential therapy for preserving normal fluid homeostasis in the hyperglycemic retina. PMID:27617745

  3. Metabolism as a key to histone deacetylase inhibition

    PubMed Central

    Rajendran, Praveen; Williams, David E.; Ho, Emily; Dashwood, Roderick H.

    2012-01-01

    There is growing interest in the epigenetic mechanisms that are dysregulated in cancer and other human pathologies. Under this broad umbrella, modulators of histone deacetylase (HDAC) activity have gained interest as both cancer chemopreventive and therapeutic agents. Of the first generation, FDA-approved HDAC inhibitors to have progressed to clinical trials, vorinostat represents a “direct acting” compound with structural features suitable for docking into the HDAC pocket, whereas romidepsin can be considered a prodrug that undergoes reductive metabolism to generate the active intermediate (a zinc-binding thiol). It is now evident that other agents, including those in the human diet, can be converted by metabolism to intermediates that affect HDAC activity. Examples are cited of short-chain fatty acids, seleno-α-keto acids, small molecule thiols, mercapturic acid metabolites, indoles, and polyphenols. The findings are discussed in the context of putative endogenous HDAC inhibitors generated by intermediary metabolism (e.g. pyruvate), the yin–yang of HDAC inhibition versus HDAC activation, and the screening assays that might be most appropriate for discovery of novel HDAC inhibitors in the future. PMID:21599534

  4. [Induction of premature senescence program by an inhibitor of histone deacetylase sodium butyrate in normal and transformed rat fibroblasts].

    PubMed

    Zubova, Iu G; Bykova, T V; Zubova, S G; Abramova, M V; Aksenov, N D; Pospelov, V A; Pospelova, T V

    2005-01-01

    We investigated a possibility to induce the premature cell senescence in rat embryo fibroblasts and E1A + cHa-ras transformants. We found that after the treatment with sodium butyrate, an inhibitor of histone deacetylases, both normal and transformed cells completely stopped to proliferate and accumulated at G1/S and G2/M phases of the cell cycle. The cloning efficiency data show that the cell cycle arrest induced by sodium butyrate is irreversible and correlates with the accumulation of active phosphorylated form of stress kinase p38, and with the expression of marker of senescence--beta-galactosidase activity (SA beta-Gal). The program resembling the premature senescence after sodium butyrate treatment is supposed to develop both in normal and transformed cells. The irreversible block of proliferation in E1A + cHa-ras transformants may be regarded as an example of activation of anticancer program like that of premature senescence in the tumor rodent cells. PMID:16706193

  5. RESEARCH PAPER: Old stellar population synthesis: new age and mass estimates for Mayall II = G1

    NASA Astrophysics Data System (ADS)

    Ma, Jun; de Grijs, Richard; Fan, Zhou; Rey, Soo-Chang; Wu, Zhen-Yu; Zhou, Xu; Wu, Jiang-Hua; Jiang, Zhao-Ji; Chen, Jian-Sheng; Lee, Kyungsook; Sohn, Sangmo Tony

    2009-06-01

    Mayall II = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- and near-ultraviolet GALEX photometry, broad-band UBVRI, and infrared JHKS 2MASS data, we construct the most extensive spectral energy distribution of G1 to date, spanning the wavelength range from 1538 to 20 000 Å. A quantitative comparison with a variety of simple stellar population (SSP) models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ~1.7 Gyr after the Big Bang. Irrespective of the SSP model or stellar initial mass function adopted, the resulting mass estimates (of order 107 Modot) indicate that G1 is one of the most massive GCs in the Local Group. However, we speculate that the cluster's exceptionally high mass suggests that it may not be a genuine GC. Our results also suggest that G1 may contain, on average, (1.65±0.63) × 102 Lodot far-ultraviolet-bright, hot, extreme horizontal-branch stars, depending on the adopted SSP model. In addition, we demonstrate that extensive multi-passband photometry coupled with SSP analysis enables one to obtain age estimates for old SSPs that have similar accuracies as those from integrated spectroscopy or resolved stellar photometry, provided that some of the free parameters can be constrained independently.

  6. Laparoscopic and endoscopic cooperative surgery for duodenal neuroendocrine tumor (NET) G1: Report of a case

    PubMed Central

    Tsushimi, Takaaki; Mori, Hirohito; Harada, Takasuke; Nagase, Takashi; Iked, Yoshitaka; Ohnishi, Hiromo

    2014-01-01

    INTRODUCTION We report a case of duodenal neuroendocrine tumor (NET) G1 resected by laparoscopic and endoscopic cooperative surgery (LECS) technique. PRESENTATION OF CASE A 58-year-old woman underwent esophagastroduodenoscopy, revealing an 8-mm, gently rising tumor distal to the pylorus, on the anterior wall of the duodenal bulb. Endoscopic ultrasonography suggested the tumor might invade the submucosal layer. The tumor was pathologically diagnosed as a G1 duodenal NET, by biopsy. Endoscopic submucosal dissection was attempted, but was unsuccessful because of the difficulty of endoscopically performing an inversion operation in the narrow working space. The case was further complicated by the patient's duodenal ulcer scar. We performed a full-thickness local excision using laparoscopic and endoscopic cooperative surgery. The tumor was confirmed and endoscopically marked along the resection line. After full-thickness excision, using endoscopy and laparoscopy, interrupted full-thickness closure was performed laparoscopically. DISCUSSION Endoscopic treatment is generally recommended for G1 NETs <10 mm in diameter and extending only to the submucosal layer. However, some cases are difficult to resect endoscopically because the wall of duodenum is thinner than that of stomach, and endoscope maneuverability is limited within the narrow working space. LECS is appropriate for early duodenal G1 NETs because they are less invasive and resection of the lesion area is possible. CONCLUSION We demonstrated that LECS is a safe and feasible procedure for duodenal G1 NETs in the anterior wall of the first portion of the duodenum. PMID:25460463

  7. A Dynamical Framework for the All-or-None G1/S Transition.

    PubMed

    Barr, Alexis R; Heldt, Frank S; Zhang, Tongli; Bakal, Chris; Novák, Béla

    2016-01-27

    The transition from G1 into DNA replication (S phase) is an emergent behavior resulting from dynamic and complex interactions between cyclin-dependent kinases (Cdks), Cdk inhibitors (CKIs), and the anaphase-promoting complex/cyclosome (APC/C). Understanding the cellular decision to commit to S phase requires a quantitative description of these interactions. We apply quantitative imaging of single human cells to track the expression of G1/S regulators and use these data to parametrize a stochastic mathematical model of the G1/S transition. We show that a rapid, proteolytic, double-negative feedback loop between Cdk2:Cyclin and the Cdk inhibitor p27(Kip1) drives a switch-like entry into S phase. Furthermore, our model predicts that increasing Emi1 levels throughout S phase are critical in maintaining irreversibility of the G1/S transition, which we validate using Emi1 knockdown and live imaging of G1/S reporters. This work provides insight into the general design principles of the signaling networks governing the temporally abrupt transitions between cell-cycle phases. PMID:27136687

  8. A Dynamical Framework for the All-or-None G1/S Transition

    PubMed Central

    Barr, Alexis R.; Heldt, Frank S.; Zhang, Tongli; Bakal, Chris; Novák, Béla

    2016-01-01

    Summary The transition from G1 into DNA replication (S phase) is an emergent behavior resulting from dynamic and complex interactions between cyclin-dependent kinases (Cdks), Cdk inhibitors (CKIs), and the anaphase-promoting complex/cyclosome (APC/C). Understanding the cellular decision to commit to S phase requires a quantitative description of these interactions. We apply quantitative imaging of single human cells to track the expression of G1/S regulators and use these data to parametrize a stochastic mathematical model of the G1/S transition. We show that a rapid, proteolytic, double-negative feedback loop between Cdk2:Cyclin and the Cdk inhibitor p27Kip1 drives a switch-like entry into S phase. Furthermore, our model predicts that increasing Emi1 levels throughout S phase are critical in maintaining irreversibility of the G1/S transition, which we validate using Emi1 knockdown and live imaging of G1/S reporters. This work provides insight into the general design principles of the signaling networks governing the temporally abrupt transitions between cell-cycle phases. PMID:27136687

  9. A comparative genomic analysis of the alkalitolerant soil bacterium Bacillus lehensis G1.

    PubMed

    Noor, Yusuf Muhammad; Samsulrizal, Nurul Hidayah; Jema'on, Noor Azah; Low, Kheng Oon; Ramli, Aizi Nor Mazila; Alias, Noor Izawati; Damis, Siti Intan Rosdianah; Fuzi, Siti Fatimah Zaharah Mohd; Isa, Mohd Noor Mat; Murad, Abdul Munir Abdul; Raih, Mohd Firdaus Mohd; Bakar, Farah Diba Abu; Najimudin, Nazalan; Mahadi, Nor Muhammad; Illias, Rosli Md

    2014-07-25

    Bacillus lehensis G1 is a Gram-positive, moderately alkalitolerant bacterium isolated from soil samples. B. lehensis produces cyclodextrin glucanotransferase (CGTase), an enzyme that has enabled the extensive use of cyclodextrin in foodstuffs, chemicals, and pharmaceuticals. The genome sequence of B. lehensis G1 consists of a single circular 3.99 Mb chromosome containing 4017 protein-coding sequences (CDSs), of which 2818 (70.15%) have assigned biological roles, 936 (23.30%) have conserved domains with unknown functions, and 263 (6.55%) have no match with any protein database. Bacillus clausii KSM-K16 was established as the closest relative to B. lehensis G1 based on gene content similarity and 16S rRNA phylogenetic analysis. A total of 2820 proteins from B. lehensis G1 were found to have orthologues in B. clausii, including sodium-proton antiporters, transport proteins, and proteins involved in ATP synthesis. A comparative analysis of these proteins and those in B. clausii and other alkaliphilic Bacillus species was carried out to investigate their contributions towards the alkalitolerance of the microorganism. The similarities and differences in alkalitolerance-related genes among alkalitolerant/alkaliphilic Bacillus species highlight the complex mechanism of pH homeostasis. The B. lehensis G1 genome was also mined for proteins and enzymes with potential viability for industrial and commercial purposes. PMID:24811681

  10. Quantification and Gene Expression Analysis of Histone Deacetylases in Common Bean during Rust Fungal Inoculation.

    PubMed

    Melmaiee, Kalpalatha; Kalavacharla, Venu Kal; Brown, Adrianne; Todd, Antonette; Thurston, Yaqoob; Elavarthi, Sathya

    2015-01-01

    Histone deacetylases (HDACs) play an important role in plant growth, development, and defense processes and are one of the primary causes of epigenetic modifications in a genome. There was only one study reported on epigenetic modifications of the important legume crop, common bean, and its interaction with the fungal rust pathogen Uromyces appendiculatus prior to this project. We measured the total active HDACs levels in leaf tissues and observed expression patterns for the selected HDAC genes at 0, 12, and 84 hours after inoculation in mock inoculated and inoculated plants. Colorimetric analysis showed that the total amount of HDACs present in the leaf tissue decreased at 12 hours in inoculated plants compared to mock inoculated control plants. Gene expression analyses indicated that the expression pattern of gene PvSRT1 is similar to the trend of total active HDACs in this time course experiment. Gene PvHDA6 showed increased expression in the inoculated plants during the time points measured. This is one of the first attempts to study expression levels of HDACs in economically important legumes in the context of plant pathogen interactions. Findings from our study will be helpful to understand trends of total active HDACs and expression patterns of these genes under study during biotic stress.

  11. Regulation of mammalian epithelial differentiation and intestine development by class I histone deacetylases.

    PubMed

    Tou, Liqiang; Liu, Qiang; Shivdasani, Ramesh A

    2004-04-01

    The biochemical mechanisms underlying epigenetic control of gene expression are increasingly well known. In contrast, the contributions of individual modifications toward activation of lineage-specific genes during vertebrate development are poorly understood. Class II histone deacetylases (HDACs), which show restricted tissue distribution, regulate muscle-specific gene expression, in part through interactions with myogenic transcription factors. We have combined gene expression profiling with manipulation of fetal mouse intestinal tissue to define roles for other regulatory factors. We found that in the developing mouse intestine class I HDACs are confined to the prospective epithelium and that their levels decline coincidently with activation of differentiation genes, suggesting a functional relationship between these events. Overexpression of wild-type but not of mutant HDACs 1 and 2 in fetal intestine explants reverses expression of certain maturation markers. HDAC inhibitors, including the selective class I antagonist valproic acid, activate the same genes prematurely and accelerate cytodifferentiation. Chromatin immunoprecipitation of freshly isolated organs reveals early HDAC2 occupancy at differentiation gene promoters and corresponding histone hypoacetylation that reverses as HDAC levels fall. Thus, modulation of endogenous class I HDAC levels represents a previously unappreciated mechanism to enable onset of tissue-restricted gene expression in a developing mammalian organ.

  12. Histone deacetylase 8 regulates cortactin deacetylation and contraction in smooth muscle tissues.

    PubMed

    Li, Jia; Chen, Shu; Cleary, Rachel A; Wang, Ruping; Gannon, Olivia J; Seto, Edward; Tang, Dale D

    2014-08-01

    Histone deacetylases (HDACs) are a family of enzymes that mediate nucleosomal histone deacetylation and gene expression. Some members of the HDAC family have also been implicated in nonhistone protein deacetylation, which modulates cell-cycle control, differentiation, and cell migration. However, the role of HDACs in smooth muscle contraction is largely unknown. Here, HDAC8 was localized both in the cytoplasm and the nucleus of mouse and human smooth muscle cells. Knockdown of HDAC8 by lentivirus-encoding HDAC8 shRNA inhibited force development in response to acetylcholine. Treatment of smooth muscle tissues with HDAC8 inhibitor XXIV (OSU-HDAC-44) induced relaxation of precontracted smooth muscle tissues. In addition, cortactin is an actin-regulatory protein that undergoes deacetylation during migration of NIH 3T3 cells. In this study, acetylcholine stimulation induced cortactin deacetylation in mouse and human smooth muscle tissues, as evidenced by immunoblot analysis using antibody against acetylated lysine. Knockdown of HDAC8 by RNAi or treatment with the inhibitor attenuated cortactin deacetylation and actin polymerization without affecting myosin activation. Furthermore, expression of a charge-neutralizing cortactin mutant inhibited contraction and actin dynamics during contractile activation. These results suggest a novel mechanism for the regulation of smooth muscle contraction. In response to contractile stimulation, HDAC8 may mediate cortactin deacetylation, which subsequently promotes actin filament polymerization and smooth muscle contraction.

  13. Unliganded thyroid hormone receptor regulates metamorphic timing via the recruitment of histone deacetylase complexes.

    PubMed

    Shi, Yun-Bo

    2013-01-01

    Anuran metamorphosis involves a complex series of tissue transformations that change an aquatic tadpole to a terrestrial frog and resembles the postembryonic perinatal period in mammals. Thyroid hormone (TH) plays a causative role in amphibian metamorphosis and its effect is mediated by TH receptors (TRs). Molecular analyses during Xenopus development have shown that unliganded TR recruits histone deacetylase (HDAC)-containing N-CoR/SMRT complexes and causes histone deacetylation at target genes while liganded TR leads to increased histone acetylations and altered histone methylations at target genes. Transgenic studies involving mutant TR-cofactors have shown that corepressor recruitment by unliganded TR is required to ensure proper timing of the onset of metamorphosis while coactivator levels influence the rate of metamorphic progression. In addition, a number of factors that can influence cellular free TH levels appear to contribute the timing of metamorphic transformations of different organs by regulating the levels of unliganded vs. liganded TR in an organ-specific manner. Thus, the recruitment of HDAC-containing corepressor complexes by unliganded TR likely controls both the timing of the initiation of metamorphosis and the temporal regulation of organ-specific transformations. Similar mechanisms likely mediate TR function in mammals as the maturation of many organs during postembryonic development is dependent upon TH and resembles organ metamorphosis in amphibians.

  14. Histone acetyltransferases and histone deacetylases in B- and T-cell development, physiology and malignancy

    PubMed Central

    Haery, Leila; Thompson, Ryan C.; Gilmore, Thomas D.

    2015-01-01

    The development of B and T cells from hematopoietic precursors and the regulation of the functions of these immune cells are complex processes that involve highly regulated signaling pathways and transcriptional control. The signaling pathways and gene expression patterns that give rise to these developmental processes are coordinated, in part, by two opposing classes of broad-based enzymatic regulators: histone acetyltransferases (HATs) and histone deacetylases (HDACs). HATs and HDACs can modulate gene transcription by altering histone acetylation to modify chromatin structure, and by regulating the activity of non-histone substrates, including an array of immune-cell transcription factors. In addition to their role in normal B and T cells, dysregulation of HAT and HDAC activity is associated with a variety of B- and T-cell malignancies. In this review, we describe the roles of HATs and HDACs in normal B- and T-cell physiology, describe mutations and dysregulation of HATs and HDACs that are implicated lymphoma and leukemia, and discuss HAT and HDAC inhibitors that have been explored as treatment options for leukemias and lymphomas. PMID:26124919

  15. Retinoic Acid and Histone Deacetylases Regulate Epigenetic Changes in Embryonic Stem Cells*

    PubMed Central

    Urvalek, Alison M.; Gudas, Lorraine J.

    2014-01-01

    All-trans-retinoic acid (RA) is a vitamin A metabolite that plays major roles in regulating stem cell differentiation and development. RA is the ligand of the retinoic acid receptor (RAR) family of transcription factors, which interact with retinoic acid response elements (RAREs) within target gene proximal promoters and enhancers. Although RA-mediated gene activation is well understood, less is known about the mechanisms for repression at RA-regulated genes. Using chromatin immunoprecipitation experiments, we show that in embryonic stem cells in the absence of RA, histone deacetylases (HDACs) differentially bind to various RAREs in proximal promoters or enhancer regions of RA-regulated genes; HDAC1, HDAC2, and HDAC3 bind at RAREs in the Hoxa1 and Cyp26a1 gene regulatory regions, whereas only HDAC1 binds at the RARβ2 RARE. shRNA knockdown of HDAC1, HDAC2, or HDAC3 differentially increases the deposition of the histone 3 lysine 27 acetylation (H3K27ac) epigenetic mark associated with increases in these three transcripts. Importantly, RA treatment differentially mediates the removal of HDACs from the Hoxa1, Cyp26a1, and RARβ2 genes and promotes the deposition of the H3K27ac mark at these genes. Overall, we show that HDACs differentially bind to RA-regulated genes to control key epigenetic marks involved in stem cell differentiation. PMID:24821725

  16. Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

    SciTech Connect

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena . E-mail: elena.menegola@unimi.it

    2007-04-15

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor {alpha} = 0.51 and maximum velocity by a factor {beta} = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations.

  17. Clinical use and applications of histone deacetylase inhibitors in multiple myeloma

    PubMed Central

    Tandon, Nidhi; Ramakrishnan, Vijay; Kumar, Shaji K

    2016-01-01

    The incorporation of various novel therapies has resulted in a significant survival benefit in newly diagnosed and relapsed patients with multiple myeloma (MM) over the past decade. Despite these advances, resistance to therapy leads to eventual relapse and fatal outcomes in the vast majority of patients. Hence, there is an unmet need for new safe and efficacious therapies for continued improvement in outcomes. Given the role of epigenetic aberrations in the pathogenesis and progression of MM and the success of histone deacetylase inhibitors (HDACi) in other malignancies, many HDACi have been tried in MM. Various preclinical studies helped us to understand the antimyeloma activity of different HDACi in MM as a single agent or in combination with conventional, novel, and immune therapies. The early clinical trials of HDACi depicted only modest single-agent activity, but recent studies have revealed encouraging clinical response rates in combination with other antimyeloma agents, especially proteasome inhibitors. This led to the approval of the combination of panobinostat and bortezomib for the treatment of relapsed/refractory MM patients with two prior lines of treatment by the US Food and Drug Administration. However, it remains yet to be defined how we can incorporate HDACi in the current therapeutic paradigms for MM that will help to achieve longer disease control and significant survival benefits. In addition, isoform-selective and/or class-selective HDAC inhibition to reduce unfavorable side effects needs further evaluation. PMID:27226735

  18. MicroRNA-381 Regulates Chondrocyte Hypertrophy by Inhibiting Histone Deacetylase 4 Expression.

    PubMed

    Chen, Weishen; Sheng, Puyi; Huang, Zhiyu; Meng, Fangang; Kang, Yan; Huang, Guangxin; Zhang, Zhiqi; Liao, Weiming; Zhang, Ziji

    2016-01-01

    Chondrocyte hypertrophy, regulated by Runt-related transcription factor 2 (RUNX2) and matrix metalloproteinase 13 (MMP13), is a crucial step in cartilage degeneration and osteoarthritis (OA) pathogenesis. We previously demonstrated that microRNA-381 (miR-381) promotes MMP13 expression during chondrogenesis and contributes to cartilage degeneration; however, the mechanism underlying this process remained unclear. In this study, we observed divergent expression of miR-381 and histone deacetylase 4 (HDAC4), an enzyme that directly inhibits RUNX2 and MMP13 expression, during late-stage chondrogenesis of ATDC5 cells, as well as in prehypertrophic and hypertrophic chondrocytes during long bone development in E16.5 mouse embryos. We therefore investigated whether this miRNA regulates HDAC4 expression during chondrogenesis. Notably, overexpression of miR-381 inhibited HDAC4 expression but promoted RUNX2 expression. Moreover, transfection of SW1353 cells with an miR-381 mimic suppressed the activity of a reporter construct containing the 3'-untranslated region (3'-UTR) of HDAC4. Conversely, treatment with a miR-381 inhibitor yielded increased HDAC4 expression and decreased RUNX2 expression. Lastly, knockdown of HDAC4 expression resulted in increased RUNX2 and MMP13 expression in SW1353 cells. Collectively, our results indicate that miR-381 epigenetically regulates MMP13 and RUNX2 expression via targeting of HDAC4, thereby suggesting the possibilities of inhibiting miR-381 to control chondrocyte hypertrophy and cartilage degeneration. PMID:27563877

  19. Histone Deacetylase 4 promotes cholestatic liver injury in the absence of Prohibitin-1

    PubMed Central

    Barbier-Torres, Lucía; Beraza, Naiara; Fernández-Tussy, Pablo; Lopitz-Otsoa, Fernando; Fernández-Ramos, David; Zubiete-Franco, Imanol; Varela-Rey, Marta; Delgado, Teresa C; Gutiérrez, Virginia; Anguita, Juan; Pares, Albert; Banales, Jesús M; Villa, Erica; Caballería, Juan; Alvarez, Luis; Lu, Shelly C; Mato, Jose M; Martínez-Chantar, María Luz

    2015-01-01

    Prohibitin 1 (PHB1) is an evolutionary conserved pleiotropic protein that participates in diverse processes depending on its subcellular localization and interactome. Recent data have indicated a diverse role for PHB1 in the pathogenesis of obesity, cancer and inflammatory bowel disease, among others. Data presented here suggest that PHB1 is also linked to cholestatic liver disease. PHB1 expression is markedly reduced in patients with primary billiary cirrhosis and biliary atresia and Alagille syndrome, two major pediatric cholestatic conditions. In the experimental model of bile duct ligation, silencing of PHB1 induced liver fibrosis, reduced animal survival and induced bile duct proliferation. Importantly, the modulatory effect of PHB1 is not dependent on its known mitochondrial function. Importantly, d PHB1 interacts with Histone Deacetylase 4 (HDAC4) in the presence of bile acids. Hence, PHB1 depletion leads to increased nuclear HDAC4 content and its associated epigenetic changes. Remarkably, HDAC4 silencing and the administration of the HDAC inhibitor parthenolide during obstructive cholestasis in vivo promote genomic reprogramming leading to the regression of the fibrotic phenotype in the liver-specific Phb1 KO mice. Conclusion Our data identify PHB1 as an important mediator of cholestatic liver injury regulating the activity of HDAC4, which controls specific epigenetic marks. These results identify potential novel strategies to treat liver injury and fibrosis, particularly as a consequence of chronic cholestasis. PMID:26109312

  20. PVP and G1.5 PAMAM dendrimer co-mediated synthesis of silver nanoparticles

    SciTech Connect

    Li Guoping; Luo Yunjun . E-mail: yjluo@bit.edu.cn; Tan Huimin

    2005-04-15

    PVP and G1.5 PAMAM dendrimer co-mediated silver nanoparticles of smaller than 5nm in diameter were prepared using H{sub 2} as reducing agent. With the TEM micrograph, it was found that the molar ratios of PVP and G1.5 PAMAM dendrimer have significant effect in the morphology and size distribution of silver nanoparticles. The reaction rate (fitting a first-order equation) was strongly influenced by the molar ratios of PVP and G1.5 PAMAM dendrimer and the reaction temperature. From the UV-Vis spectra of an aqueous solution of silver nanoparticles, they could be stored for at least 2 months without coagulation at room temperature.

  1. Acute appendicitis with a neuroendocrine tumor G1 (carcinoid): pitfalls of conservative treatment.

    PubMed

    Watanabe, Hiroyuki A; Fujimoto, Taketoshi; Kato, Yo; Sasaki, Mayumi; Ikusue, Toshikazu

    2016-08-01

    A man in his early thirties presented to our clinic with right lower abdominal pain. Computed tomography (CT) and ultrasonography (US) revealed a swollen appendix and an appendicolith. Abscess formation was not observed but ongoing appendiceal rupture was not ruled out. Three months after successful conservative therapy, the lumen of the apical portion was kept dilated and laparoscopic interval appendectomy was performed. No tumorous findings were observed macroscopically. However, histology revealed many tiny nests infiltrating the submucosa, muscular layer, and subserosa at the root of the appendix. An appendiceal neuroendocrine tumor G1 (NET G1; carcinoid) was diagnosed immunohistologically. Neither CT nor US visualized the tumor because of its non-tumor-forming but infiltrative growth. In conclusion, after successful conservative treatment, interval appendectomy should be considered to uncover a possible appendiceal NET G1 (carcinoid), particularly when dilatation of the distal lumen is kept under observation. PMID:27311320

  2. Detection of histidine oxidation in a monoclonal immunoglobulin gamma (IgG) 1 antibody.

    PubMed

    Amano, Masato; Kobayashi, Naoki; Yabuta, Masayuki; Uchiyama, Susumu; Fukui, Kiichi

    2014-08-01

    Although oxidation of methionine and tryptophan are known as popular chemical modifications that occur in monoclonal antibody (mAb) molecules, oxidation of other amino acids in mAbs has not been reported to date. In this study, oxidation of the histidine residue in a human immunoglobulin gamma (IgG) 1 molecule was discovered for the first time by mass spectrometry. The oxidation of a specific histidine located at the CH2 domain of IgG1 occurred under light stress, but it was not observed under heat stress. With the forced degradation study using several reactive oxygen species, the singlet oxygen was attributed to a reactive source of the histidine oxidation. The reaction mechanism of the histidine oxidation was proposed on the basis of the mass spectrometric analysis of IgG1 oxidized in deuterium oxide and hydrogen heavy oxide. PMID:24940720

  3. PelA Deacetylase Activity Is Required for Pel Polysaccharide Synthesis in Pseudomonas aeruginosa

    PubMed Central

    Colvin, Kelly M.; Alnabelseya, Noor; Baker, Perrin; Whitney, John C.

    2013-01-01

    The Pel polysaccharide serves as an intercellular adhesin for the formation and maintenance of biofilms in the opportunistic pathogen Pseudomonas aeruginosa. Pel biosynthesis requires the products of a seven-gene operon, pelA-pelG, all of which are necessary for Pel-dependent biofilm formation and Pel-related phenotypes. One of the genes, pelA, encodes a protein with a predicted polysaccharide deacetylase domain. In this work, the role of the putative deacetylase domain in Pel production was examined. We first established that purified recombinant PelA hydrolyzed the pseudosubstrate p-nitrophenyl acetate in vitro, and site-specific mutations of predicted deacetylase active-site residues reduced activity greater than 10-fold. Additionally, these mutants were deficient in Pel-dependent biofilm formation and wrinkly colony morphology in vivo. Subcellular fractionation experiments demonstrate that PelA localizes to both the membrane and periplasmic fractions. Finally, antiserum against the Pel polysaccharide was generated, and PelA deacetylase mutants do not produce Pel-reactive material. Taken together, these results suggest that the deacetylase activity of PelA is important for the production of the Pel polysaccharide. PMID:23504011

  4. Doxazosin inhibits retinoblastoma protein phosphorylation and G(1)-->S transition in human coronary smooth muscle cells.

    PubMed

    Kintscher, U; Wakino, S; Kim, S; Jackson, S M; Fleck, E; Hsueh, W A; Law, R E

    2000-05-01

    Previous studies have demonstrated that the alpha(1)-adrenergic receptor antagonist doxazosin (Dox) inhibits multiple mitogenic signaling pathways in human vascular smooth muscle cells. This broad antiproliferative activity of Dox occurs through a novel mechanism unrelated to its blocking the alpha(1)-adrenergic receptor. Flow cytometry demonstrated that Dox prevents mitogen-induced G(1)-->S progression of human coronary artery smooth muscle cells (CASMCs) in a dose-dependent manner, with a maximal reduction of S-phase transition by 88+/-10.5% in 20 ng/mL platelet-derived growth factor and 1 micromol/L insulin (P+I)-stimulated cells (P<0.01 for 10 micromol/L Dox versus P+I alone) and 52+/-18.7% for 10% FBS-induced mitogenesis (P<0.05 for 10 micromol/L Dox versus 10% FBS alone). Inhibition of G(1) exit by Dox was accompanied by a significant blockade of retinoblastoma protein (Rb) phosphorylation. Hypophosphorylated Rb sequesters the E2F transcription factor, leading to G(1) arrest. Adenoviral overexpression of E2F-1 stimulated quiescent CASMCs to progress through G(1) and enter the S phase. E2F-mediated G(1) exit was not affected by Dox, suggesting that it targets events upstream from Rb hyperphosphorylation. Downregulation of the cyclin-dependent kinase inhibitory protein p27 is important for maximal activation of G(1) cyclin/cyclin-dependent kinase holoenzymes to overcome the cell cycle inhibitory activity of Rb. In Western blot analysis, p27 levels decreased after mitogenic stimulation (after P+I, 43+/-1.8% of quiescent cells [P<0.01 versus quiescent cells]; after 10% FBS, 55+/-7.7% of quiescent cells [P<0. 05 versus quiescent cells]), whereas the addition of Dox (10 micromol/L) markedly attenuated its downregulation (after P+I, 90+/-8.3% of quiescent cells [P<0.05 versus P+I alone]; after 10% FBS, 78+/-8.3% of quiescent cells [P<0.05 versus 10% FBS alone]). Furthermore, Dox inhibited cyclin A expression, an E2F regulated gene that is essential for cell cycle

  5. Identification and characterization of histone deacetylases in tomato (Solanum lycopersicum)

    PubMed Central

    Zhao, Linmao; Lu, Jingxia; Zhang, Jianxia; Wu, Pei-Ying; Yang, Songguang; Wu, Keqiang

    2015-01-01

    Histone acetylation and deacetylation at the N-terminus of histone tails play crucial roles in the regulation of eukaryotic gene activity. Histone acetylation and deacetylation are catalyzed by histone acetyltransferases and histone deacetylases (HDACs), respectively. A growing number of studies have demonstrated the importance of histone deacetylation/acetylation on genome stability, transcriptional regulation, development and response to stress in Arabidopsis. However, the biological functions of HDACs in tomato have not been investigated previously. Fifteen HDACs identified from tomato (Solanum lycopersicum) can be grouped into RPD3/HDA1, SIR2 and HD2 families based on phylogenetic analysis. Meanwhile, 10 members of the RPD3/HDA1 family can be further subdivided into four groups, namely Class I, Class II, Class III, and Class IV. High similarities of protein sequences and conserved domains were identified among SlHDACs and their homologs in Arabidopsis. Most SlHDACs were expressed in all tissues examined with different transcript abundance. Transient expression in Arabidopsis protoplasts showed that SlHDA8, SlHDA1, SlHDA5, SlSRT1 and members of the HD2 family were localized to the nucleus, whereas SlHDA3 and SlHDA4 were localized in both the cytoplasm and nucleus. The difference in the expression patterns and subcellular localization of SlHDACs suggest that they may play distinct functions in tomato. Furthermore, we found that three members of the RPD3/HDA1 family, SlHDA1, SIHDA3 and SlHDA4, interacted with TAG1 (TOMATO AGAMOUS1) and TM29 (TOMATO MADS BOX29), two MADS-box proteins associated with tomato reproductive development, indicating that these HDACs may be involved in gene regulation in reproductive development. PMID:25610445

  6. HDACiDB: a database for histone deacetylase inhibitors

    PubMed Central

    Murugan, Kasi; Sangeetha, Shanmugasamy; Ranjitha, Shanmugasamy; Vimala, Antony; Al-Sohaibani, Saleh; Rameshkumar, Gopal

    2015-01-01

    An histone deacetylase (HDAC) inhibitor database (HDACiDB) was constructed to enable rapid access to data relevant to the development of epigenetic modulators (HDAC inhibitors [HDACi]), helping bring precision cancer medicine a step closer. Thousands of HDACi targeting HDACs are in various stages of development and are being tested in clinical trials as monotherapy and in combination with other cancer agents. Despite the abundance of HDACi, information resources are limited. Tools for in silico experiments on specific HDACi prediction, for designing and analyzing the generated data, as well as custom-made specific tools and interactive databases, are needed. We have developed an HDACiDB that is a composite collection of HDACi and currently comprises 1,445 chemical compounds, including 419 natural and 1,026 synthetic ones having the potential to inhibit histone deacetylation. Most importantly, it will allow application of Lipinski’s rule of five drug-likeness and other physicochemical property-based screening of the inhibitors. It also provides easy access to information on their source of origin, molecular properties, drug likeness, as well as bioavailability with relevant references cited. Being the first comprehensive database on HDACi that contains all known natural and synthetic HDACi, the HDACiDB may help to improve our knowledge concerning the mechanisms of actions of available HDACi and enable us to selectively target individual HDAC isoforms and establish a new paradigm for intelligent epigenetic cancer drug design. The database is freely available on the http://hdacidb.bioinfo.au-kbc.org.in/hdacidb/website. PMID:25945037

  7. Histone Deacetylases in Bone Development and Skeletal Disorders

    PubMed Central

    Bradley, Elizabeth W.; Carpio, Lomeli R.; van Wijnen, Andre J.; McGee-Lawrence, Meghan E.; Westendorf, Jennifer J.

    2015-01-01

    Histone deacetylases (Hdacs) are conserved enzymes that remove acetyl groups from lysine side chains in histones and other proteins. Eleven of the 18 Hdacs encoded by the human and mouse genomes depend on Zn2+ for enzymatic activity, while the other 7, the sirtuins (Sirts), require NAD2+. Collectively, Hdacs and Sirts regulate numerous cellular and mitochondrial processes including gene transcription, DNA repair, protein stability, cytoskeletal dynamics, and signaling pathways to affect both development and aging. Of clinical relevance, Hdacs inhibitors are United States Food and Drug Administration-approved cancer therapeutics and are candidate therapies for other common diseases including arthritis, diabetes, epilepsy, heart disease, HIV infection, neurodegeneration, and numerous aging-related disorders. Hdacs and Sirts influence skeletal development, maintenance of mineral density and bone strength by affecting intramembranous and endochondral ossification, as well as bone resorption. With few exceptions, inhibition of Hdac or Sirt activity though either loss-of-function mutations or prolonged chemical inhibition has negative and/or toxic effects on skeletal development and bone mineral density. Specifically, Hdac/Sirt suppression causes abnormalities in physiological development such as craniofacial dimorphisms, short stature, and bone fragility that are associated with several human syndromes or diseases. In contrast, activation of Sirts may protect the skeleton from aging and immobilization-related bone loss. This knowledge may prolong healthspan and prevent adverse events caused by epigenetic therapies that are entering the clinical realm at an unprecedented rate. In this review, we summarize the general properties of Hdacs/Sirts and the research that has revealed their essential functions in bone forming cells (e.g., osteoblasts and chondrocytes) and bone resorbing osteoclasts. Finally, we offer predictions on future research in this area and the utility of

  8. Histone Deacetylase Expression in White Matter Oligodendrocytes after Stroke

    PubMed Central

    Kassis, Haifa; Chopp, Michael; Liu, Xian Shuang; Shehadah, Amjad; Roberts, Cynthia; Zhang, Zheng Gang

    2015-01-01

    Histone deacetylases (HDACs) constitute a super-family of enzymes grouped into four major classes (Class I–IV) that deacetylate histone tails leading to chromatin condensation and gene repression. Whether stroke-induced oligodendrogenesis is related to the expression of individual HDACs in the oligodendrocyte lineage has not been investigated. We found that 2 days after stroke, oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes (OLGs) were substantially reduced in the peri-infarct corpus callosum, whereas at 7 days after stroke, a robust increase in OPCs and OLGs was observed. Ischemic brains isolated from rats sacrificed 7 days after stroke were used to test levels of individual members of Class I (1 and 2) and Class II (4 and 5) HDACs in white matter oligodendrocytes during stroke-induced oligodendrogenesis. Double immunohistochemistry analysis revealed that stroke substantially increased the number of NG2+ OPCs with nuclear HDAC1 and HDAC2 immunoreactivity and cytoplasmic HDAC4 which were associated with augmentation of proliferating OPCs, as determined by BrdU and Ki67 double reactive cells after stroke. A decrease in HDAC1 and an increase in HDAC2 immunoreactivity were detected in mature adenomatous polyposis coli (APC) positive OLGs, which paralleled an increase in newly generated BrdU positive OLGs in the peri-infarct corpus callosum. Concurrently, stroke substantially decreased the acetylation levels of histones H3 and H4 in both OPCs and OLGs. Taken together, these findings demonstrate that stroke induces distinct profiles of Class I and Class II HDACs in white matter OPCs and OLGs, suggesting that the individual members of Class I and II HDACs play divergent roles in the regulation of OPC proliferation and differentiation during brain repair after stroke. PMID:24657831

  9. Electrocardiographic effects of class 1 selective histone deacetylase inhibitor romidepsin.

    PubMed

    Sager, Philip T; Balser, Barbara; Wolfson, Julie; Nichols, Jean; Pilot, Richard; Jones, Suzanne; Burris, Howard A

    2015-08-01

    Romidepsin is a histone deacetylase inhibitor approved by the FDA for the treatment of patients with cutaneous or peripheral T-cell lymphoma who have received prior systemic therapy. The objective of this analysis was to evaluate the potential QTc effects of romidepsin. Patients with advanced malignancy received 4-h infusions of 14 mg/m(2) romidepsin on days 1, 8, and 15 of a 28-day cycle. In cycle 2, a subset of patients received 1-h infusions of 8-12 mg/m(2) romidepsin. Patients were administered antiemetics before each romidepsin dose and electrolyte supplementation as needed. Electrocardiogram readings were performed prior to antiemetic administration, prior to romidepsin administration, and at specified time points over the subsequent 24 h. Romidepsin exposure and heart rate were also assessed. In the electrocardiogram-evaluable population, 26 patients received romidepsin at 14 mg/m(2) over 4 h. The maximum mean increases from the preantiemetic baseline for QTcF and heart rate were 10.1 msec (upper 90% CI, 14.5 msec) and 18.2 beats per minute, respectively. No patient in this study had an absolute QTcF value >450 msec and only one patient had an increase from the preantiemetic baseline of >60 msec. There was a mild reduction in the PR interval and no meaningful changes in the QRS interval. Despite the use of QT-prolonging antiemetics, treatment with romidepsin did not markedly prolong the QTc interval through 24 h. Increases in calculated QTc may have been exaggerated as a consequence of transient increases in heart rate.

  10. Histone Deacetylases in Bone Development and Skeletal Disorders.

    PubMed

    Bradley, Elizabeth W; Carpio, Lomeli R; van Wijnen, Andre J; McGee-Lawrence, Meghan E; Westendorf, Jennifer J

    2015-10-01

    Histone deacetylases (Hdacs) are conserved enzymes that remove acetyl groups from lysine side chains in histones and other proteins. Eleven of the 18 Hdacs encoded by the human and mouse genomes depend on Zn(2+) for enzymatic activity, while the other 7, the sirtuins (Sirts), require NAD2(+). Collectively, Hdacs and Sirts regulate numerous cellular and mitochondrial processes including gene transcription, DNA repair, protein stability, cytoskeletal dynamics, and signaling pathways to affect both development and aging. Of clinical relevance, Hdacs inhibitors are United States Food and Drug Administration-approved cancer therapeutics and are candidate therapies for other common diseases including arthritis, diabetes, epilepsy, heart disease, HIV infection, neurodegeneration, and numerous aging-related disorders. Hdacs and Sirts influence skeletal development, maintenance of mineral density and bone strength by affecting intramembranous and endochondral ossification, as well as bone resorption. With few exceptions, inhibition of Hdac or Sirt activity though either loss-of-function mutations or prolonged chemical inhibition has negative and/or toxic effects on skeletal development and bone mineral density. Specifically, Hdac/Sirt suppression causes abnormalities in physiological development such as craniofacial dimorphisms, short stature, and bone fragility that are associated with several human syndromes or diseases. In contrast, activation of Sirts may protect the skeleton from aging and immobilization-related bone loss. This knowledge may prolong healthspan and prevent adverse events caused by epigenetic therapies that are entering the clinical realm at an unprecedented rate. In this review, we summarize the general properties of Hdacs/Sirts and the research that has revealed their essential functions in bone forming cells (e.g., osteoblasts and chondrocytes) and bone resorbing osteoclasts. Finally, we offer predictions on future research in this area and the

  11. Class I Lysine Deacetylases Facilitate Glucocorticoid-induced Transcription*

    PubMed Central

    Kadiyala, Vineela; Patrick, Nina M.; Mathieu, Wana; Jaime-Frias, Rosa; Pookhao, Naruekamol; An, Lingling; Smith, Catharine L.

    2013-01-01

    Nuclear receptors use lysine acetyltransferases and lysine deacetylases (KDACs) in regulating transcription through histone acetylation. Lysine acetyltransferases interact with steroid receptors upon binding of an agonist and are recruited to target genes. KDACs have been shown to interact with steroid receptors upon binding to an antagonist. We have shown previously that KDAC inhibitors (KDACis) potently repress the mouse mammary tumor virus promoter through transcriptional mechanisms and impair the ability of the glucocorticoid receptor (GR) to activate it, suggesting that KDACs can play a positive role in GR transactivation. In the current study, we extended this analysis to the entire GR transcriptome and found that the KDACi valproic acid impairs the ability of agonist-bound GR to activate about 50% of its target genes. This inhibition is largely due to impaired transcription rather than defective GR processing and was also observed using a structurally distinct KDACi. Depletion of KDAC1 expression mimicked the effects of KDACi in over half of the genes found to be impaired in GR transactivation. Simultaneous depletion of KDACs 1 and 2 caused full or partial impairment of several more GR target genes. Altogether we found that Class I KDAC activity facilitates GR-mediated activation at a sizable fraction of GR-activated target genes and that KDAC1 alone or in coordination with KDAC2 is required for efficient GR transactivation at many of these target genes. Finally, our work demonstrates that KDACi exposure has a significant impact on GR signaling and thus has ramifications for the clinical use of these drugs. PMID:23946490

  12. Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

    PubMed

    Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

    2016-09-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and

  13. Interaction of KIR genes and G1M immunoglobulin allotypes confer susceptibility to type 2 diabetes in Puerto Rican Americans.

    PubMed

    Zuniga, Joaquin; Romero, Viviana; Azocar, Jose; Stern, Joel N H; Clavijo, Olga; Almeciga, Ingrid; Encinales, Liliana; Avendano, Angel; Fridkis-Hareli, Masha; Pandey, Janardan P; Yunis, Edmond J

    2006-11-01

    The susceptibility to type 2 diabetes (T2D) involves genetic factors. We studied the distribution of KIR and MHC class I ligands phenotype and genotype frequencies, as well as immunoglobulin KM and GM allotype frequencies in a group of patients (N = 95) with T2D and ethnically matched healthy controls (N = 74) with Puerto Rican ethnic background. We found a slight increase of the 2DL3/2DL3 homozygous genotype in T2D. Moreover, the association between 2DL3/2DL3 genotype was significant in the presence of 2DS4 (pC = 0.01). Also, we observed an epistatic effect of the interaction of 2DL3/2DL3, 2DS4 with allele z of G1M in T2D (pC = 0.004, OR = 3.60, 95% CI, 1.62-8.10). This genetic interaction between KIR and G1M allotypes, associated with T2D, was also significant by multiple logistic regression analysis (p < 0.0001, OR = 4.90, 95% CI, 2.12-11.3). We did not detect population stratification using unlinked short tandem repeat (STR) markers, demonstrating that the patients and controls were ethnically matched. Hence, we have demonstrated in this study an epistatic interaction between KIR genes and the G1M allotype that influences the susceptibility to T2D in Puerto Rican Americans. Our findings are important for understanding the autoimmune or innate immune inflammatory-mediated mechanisms involved in the pathogenesis of T2D.

  14. MicroRNA-22 Inhibits Histone Deacetylase 4 to Promote T Helper-17 Cell-Dependent Emphysema

    PubMed Central

    Lu, Wen; You, Ran; Yuan, Xiaoyi; Yang, Tianshu; Samuel, Errol L. G.; Marcano, Daniela C.; Sikkema, William K. A.; Tour, James M.; Rodriguez, Antony; Kheradmand, Farrah; Corry, David B.

    2015-01-01

    Smoking-related emphysema is a chronic inflammatory disease driven by T helper 17 (TH17) cells through molecular mechanisms that remain obscure. Here we have explored the role of microRNA-22 (miR-22) in emphysema. MiR-22 was upregulated in lung myeloid dendritic cells (mDCs) of smokers with emphysema and antigen-presenting cells (APCs) of mice exposed to smoke or nanoparticulate carbon black (nCB) through a mechanism involving NF-κB. MiR-22-deficient mice, but not wild-type, showed attenuated TH17 responses and failed to develop emphysema after exposure to either smoke or nCB. We further show that miR-22 controls APC activation and TH17 responses through activation of AP-1 transcription factor complexes and histone deacetylase (HDAC) 4. Thus, miR-22 is a critical regulator of both emphysema and TH17 responses. PMID:26437241

  15. Inhibition of class IIb histone deacetylase significantly improves cloning efficiency in mice.

    PubMed

    Ono, Tetsuo; Li, Chong; Mizutani, Eiji; Terashita, Yukari; Yamagata, Kazuo; Wakayama, Teruhiko

    2010-12-01

    Since the first mouse clone was produced by somatic cell nuclear transfer, the success rate of cloning in mice has been extremely low. Some histone deacetylase inhibitors, such as trichostatin A and scriptaid, have improved the full-term development of mouse clones significantly, but the mechanisms allowing for this are unclear. Here, we found that two other specific inhibitors, suberoylanilide hydroxamic acid and oxamflatin, could also reduce the rate of apoptosis in blastocysts, improve the full-term development of cloned mice, and increase establishment of nuclear transfer-generated embryonic stem cell lines significantly without leading to obvious abnormalities. However, another inhibitor, valproic acid, could not improve cloning efficiency. Suberoylanilide hydroxamic acid, oxamflatin, trichostatin A, and scriptaid are inhibitors for classes I and IIa/b histone deacetylase, whereas valproic acid is an inhibitor for classes I and IIa, suggesting that inhibiting class IIb histone deacetylase is an important step for reprogramming mouse cloning efficiency.

  16. Structure determination of BA0150, a putative polysaccharide deacetylase from Bacillus anthracis.

    PubMed

    Strunk, Robert J; Piemonte, Katrina M; Petersen, Natasha M; Koutsioulis, Dimitris; Bouriotis, Vassilis; Perry, Kay; Cole, Kathryn E

    2014-02-01

    Polysaccharide deacetylases are bacterial enzymes that catalyze the deacetylation of acetylated sugars on the membranes of Gram-positive bacteria, allowing them to be unrecognized by host immune systems. Inhibition of these enzymes would disrupt such pathogenic defensive mechanisms and therefore offers a promising route for the development of novel antibiotic therapeutics. Here, the first X-ray crystal structure of BA0150, a putative polysaccharide deacetylase from Bacillus anthracis, is reported to 2.0 Å resolution. The overall structure maintains the conserved (α/β)8 fold that is characteristic of this family of enzymes. The lack of a catalytic metal ion and a distinctive metal-binding site, however, suggest that this enzyme is not a functional polysaccharide deacetylase.

  17. 17 CFR 240.12g-1 - Exemption from section 12(g).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... pursuant to section 12(g)(1) if on the last day of its most recent fiscal year the issuer had total assets... quoted in an automated inter-dealer quotation system. (Secs. 6, 7, 8, 10, 19(a), 48 Stat. 78, 79, 81,...

  18. 26 CFR 301.6501(g)-1 - Certain income tax returns of corporations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Certain income tax returns of corporations. 301... and Collection § 301.6501(g)-1 Certain income tax returns of corporations. (a) Trusts or partnerships... and additions to the tax, additional amounts and assessable penalties allowed by chapter 68 of...

  19. 26 CFR 301.6501(g)-1 - Certain income tax returns of corporations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 18 2011-04-01 2011-04-01 false Certain income tax returns of corporations. 301... and Collection § 301.6501(g)-1 Certain income tax returns of corporations. (a) Trusts or partnerships... and additions to the tax, additional amounts and assessable penalties allowed by chapter 68 of...

  20. Human IgG1 antibodies suppress angiogenesis in a target-independent manner

    PubMed Central

    Bogdanovich, Sasha; Kim, Younghee; Mizutani, Takeshi; Yasuma, Reo; Tudisco, Laura; Cicatiello, Valeria; Bastos-Carvalho, Ana; Kerur, Nagaraj; Hirano, Yoshio; Baffi, Judit Z; Tarallo, Valeria; Li, Shengjian; Yasuma, Tetsuhiro; Arpitha, Parthasarathy; Fowler, Benjamin J; Wright, Charles B; Apicella, Ivana; Greco, Adelaide; Brunetti, Arturo; Ruvo, Menotti; Sandomenico, Annamaria; Nozaki, Miho; Ijima, Ryo; Kaneko, Hiroki; Ogura, Yuichiro; Terasaki, Hiroko; Ambati, Balamurali K; Leusen, Jeanette HW; Langdon, Wallace Y; Clark, Michael R; Armour, Kathryn L; Bruhns, Pierre; Verbeek, J Sjef; Gelfand, Bradley D; De Falco, Sandro; Ambati, Jayakrishna

    2016-01-01

    Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world’s population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type and FcγR humanized mice. This anti-angiogenic effect was abolished by Fcgr1 ablation or knockdown, Fc cleavage, IgG-Fc inhibition, disruption of Fc-FcγR interaction, or elimination of FcRγ-initated signaling. Furthermore, bevacizumab’s Fc region potentiated its anti-angiogenic activity in humanized VEGFA mice. Finally, mice deficient in FcγRI exhibited increased developmental and pathological angiogenesis. These findings reveal an unexpected anti-angiogenic function for FcγRI and a potentially concerning off-target effect of hIgG1 therapies. PMID:26918197

  1. 17 CFR 275.202(a)(11)(G)-1 - Family offices.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Family offices. 275.202(a)(11... COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT ADVISERS ACT OF 1940 § 275.202(a)(11)(G)-1 Family offices. (a) Exclusion. A family office, as defined in this section, shall not be considered to be...

  2. 17 CFR 275.202(a)(11)(G)-1 - Family offices.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Family offices. 275.202(a)(11... COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT ADVISERS ACT OF 1940 § 275.202(a)(11)(G)-1 Family offices. (a) Exclusion. A family office, as defined in this section, shall not be considered to be...

  3. 17 CFR 275.202(a)(11)(G)-1 - Family offices.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Family offices. 275.202(a)(11... COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT ADVISERS ACT OF 1940 § 275.202(a)(11)(G)-1 Family offices. (a) Exclusion. A family office, as defined in this section, shall not be considered to be...

  4. An Overview of Observations Made from the G-1 Aircraft during TexAQS 2000

    NASA Astrophysics Data System (ADS)

    Kleinman, L. I.; Daum, P. H.; Brechtel, F.; Buzorius, G.; Lee, Y.; Nunnermacker, L. J.; Springston, S. R.; Weinstein-Lloyd, J.; Zheng, J.

    2002-12-01

    As part of the Texas Air Quality Study, the DOE G-1 aircraft conducted 18 research flights in and around the Houston metropolitan area between August 19 and September 12, 2000. Overall objectives were to characterize emissions and their relation to the production of O3 and particulate matter. Chemical parameters measured on the G-1 included the concentrations of O3, NO, NO2, NOy, CO, speciated VOCs, HCHO, SO2, H2O2, organic peroxides, and aerosol anions and cations. Particle size distributions were obtained over the range 5nm to 15 um. This presentation is an overview of the G-1 data set and secondary quantities such as the production rate of O3 which can be calculated using trace gas observations from the G-1. In order to put into perspective the extraordinarily high concentrations of reactive VOCs and concomitantly high O3 production rates observed in Houston, we will rely on similar aircraft measurements from Nashville, New York City, Phoenix, and Philadelphia.

  5. H, G1, G2 photometric phase function extended to low-accuracy data

    NASA Astrophysics Data System (ADS)

    Penttilä, A.; Shevchenko, V. G.; Wilkman, O.; Muinonen, K.

    2016-04-01

    We introduce a constrained nonlinear least-squares algorithm to be used in estimating the parameters in the H, G1, G2 phase function. As the algorithm works directly in the magnitude space, it will surpass the possible bias problem that may be present in the existing H ,G1 ,G2 fit procedure when applied to low-accuracy observations with large magnitude variations. With constraints on the photometric phase-curve shape parameters G1 and G2, it guarantees a physically reasonable phase-curve estimate. With a new data set of 93 asteroids, we re-assess the two-parameter version of the H ,G1 ,G2 function. Finally, we introduce a one-parameter version of the phase function that can give a suggestion of the asteroids taxonomic group based only on its phase curve. A statistical model selection procedure is presented that can automatically select between the different versions of the photometric phase functions. An online tool that implements these algorithms is introduced.

  6. 26 CFR 301.6501(g)-1 - Certain income tax returns of corporations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 18 2012-04-01 2012-04-01 false Certain income tax returns of corporations. 301... and Collection § 301.6501(g)-1 Certain income tax returns of corporations. (a) Trusts or partnerships... and additions to the tax, additional amounts and assessable penalties allowed by chapter 68 of...

  7. 26 CFR 301.6501(g)-1 - Certain income tax returns of corporations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 18 2014-04-01 2014-04-01 false Certain income tax returns of corporations. 301... and Collection § 301.6501(g)-1 Certain income tax returns of corporations. (a) Trusts or partnerships... and additions to the tax, additional amounts and assessable penalties allowed by chapter 68 of...

  8. 26 CFR 301.6501(g)-1 - Certain income tax returns of corporations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 18 2013-04-01 2013-04-01 false Certain income tax returns of corporations. 301... and Collection § 301.6501(g)-1 Certain income tax returns of corporations. (a) Trusts or partnerships... and additions to the tax, additional amounts and assessable penalties allowed by chapter 68 of...

  9. Overview of Shipyard coast line with Piers G1, G2, G3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of Shipyard coast line with Piers G-1, G-2, G-3, G-4, and G-5 in view, view facing east-southeast - U.S. Naval Base, Pearl Harbor, Pier & Quay Walls, Entrance to Dry Dock No. 2 & Repair Wharfs, east & west sides of Dry Dock No. 2 & west side of Dry Dock No. 3, Pearl City, Honolulu County, HI

  10. Learning Progression of Ecological System Reasoning for Lower Elementary (G1-4) Students

    ERIC Educational Resources Information Center

    Hokayem, Hayat Al

    2012-01-01

    In this study, I utilized a learning progression framework to investigate lower elementary students (G1-4) systemic reasoning in ecology and I related students reasoning to their sources of knowledge. I used semi-structured interviews with 44 students from first through fourth grade, four teachers, and eight parents. The results revealed that a…

  11. Cyclic Equibiaxial Tensile Strain Alters Gene Expression of Chondrocytes via Histone Deacetylase 4 Shuttling

    PubMed Central

    Chen, Chongwei; Wei, Xiaochun; Lv, Zhi; Sun, Xiaojuan; Wang, Shaowei; Zhang, Yang; Jiao, Qiang; Wang, Xiaohu; Li, Yongping; Wei, Lei

    2016-01-01

    Objectives This paper aims to investigate whether equibiaxial tensile strain alters chondrocyte gene expression via controlling subcellular localization of histone deacetylase 4 (HDAC4). Materials and Methods Murine chondrocytes transfected with GFP-HDAC4 were subjected to 3 h cyclic equibiaxial tensile strain (CTS, 6% strain at 0.25 Hz) by a Flexcell® FX-5000™ Tension System. Fluorescence microscope and western blot were used to observe subcellular location of HDAC4. The gene expression was analyzed by real-time RT-PCR. The concentration of Glycosaminoglycans in culture medium was quantified by bimethylmethylene blue dye; Collagen II protein was evaluated by western blot. Cells phenotype was identified by immunohistochemistry. Cell viability was evaluated by live-dead cell detect kit. Okadaic acid, an inhibitor of HDAC4 nuclear relocation, was used to further validate whether HDAC4 nuclear relocation plays a role in gene expression in response to tension stimulation. Results 87.5% of HDAC4 was located in the cytoplasm in chondrocytes under no loading condition, but it was relocated to the nucleus after CTS. RT-PCR analysis showed that levels of mRNA for aggrecan, collagen II, LK1 and SOX9 were all increased in chondrocytes subjected to CTS as compared to no loading control chondrocytes; in contrast, the levels of type X collagen, MMP-13, IHH and Runx2 gene expression were decreased in the chondrocytes subjected to CTS as compared to control chondrocytes. Meanwhile, CTS contributed to elevation of glycosaminoglycans and collagen II protein, but did not change collagen I production. When Okadaic acid blocked HDAC4 relocation from the cytoplasm to nucleus, the changes of the chondrocytes induced by CTS were abrogated. There was no chondrocyte dead detected in this study in response to CTS. Conclusions CTS is able to induce HDAC4 relocation from cytoplasm to nucleus. Thus, CTS alters chondrocytes gene expression in association with the relocation of HDAC4 induced

  12. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner

    PubMed Central

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M. G. R.; Sainis, Krishna B.; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis. PMID:27148868

  13. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner.

    PubMed

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M G R; Sainis, Krishna B; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis. PMID:27148868

  14. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner.

    PubMed

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M G R; Sainis, Krishna B; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis.

  15. Role of histone deacetylase activity in the developing lateral line neuromast of zebrafish larvae.

    PubMed

    He, Yingzi; Mei, Honglin; Yu, Huiqian; Sun, Shan; Ni, Wenli; Li, Huawei

    2014-01-01

    Histone deacetylases are involved in many biological processes and have roles in regulating cell behaviors such as cell cycle entry, cell proliferation and apoptosis. However, the effect of histone deacetylases on the development of hair cells (HCs) has not been fully elucidated. In this study, we examined the influence of histone deacetylases on the early development of neuromasts in the lateral line of zebrafish. Hair cell development was evaluated by fluorescent immunostaining in the absence or presence of histone deacetylase inhibitors. Our results suggested that pharmacological inhibition of histone deacetylases with inhibitors, including trichostatin A, valproic acid and MS-275, reduced the numbers of both HCs and supporting cells in neuromasts. We also found that the treatment of zebrafish larvae with inhibitors caused accumulation of histone acetylation and suppressed proliferation of neuromast cells. Real-time PCR results showed that the expression of both p21 and p27 mRNA was increased following trichostatin A treatment and the increase in p53 mRNA was modest under the same conditions. However, the expression of p53 mRNA was significantly increased by treatment with a high concentration of trichostatin A. A high concentration of trichostatin A also led to increased cell death in neuromasts as detected in a TUNEL assay. Moreover, the nuclei of most of these pyknotic cells were immunohistochemically positive for cleaved caspase-3. These results suggest that histone deacetylase activity is involved in lateral line development in the zebrafish and might have a role in neuromast formation by altering cell proliferation through the expression of cell cycle regulatory proteins. PMID:24810423

  16. Differential expression of histone deacetylase and acetyltransferase genes in gastric cancer and their modulation by trichostatin A.

    PubMed

    Wisnieski, Fernanda; Calcagno, Danielle Queiroz; Leal, Mariana Ferreira; Chen, Elizabeth Suchi; Gigek, Carolina Oliveira; Santos, Leonardo Caires; Pontes, Thaís Brilhante; Rasmussen, Lucas Trevizani; Payão, Spencer Luiz Marques; Assumpção, Paulo Pimentel; Lourenço, Laércio Gomes; Demachki, Sâmia; Artigiani, Ricardo; Burbano, Rommel Rodríguez; Smith, Marília Cardoso

    2014-07-01

    Gastric cancer is still the second leading cause of cancer-related death worldwide, even though its incidence and mortality have declined over the recent few decades. Epigenetic control using histone deacetylase inhibitors, such as trichostatin A (TSA), is a promising cancer therapy. This study aimed to assess the messenger RNA (mRNA) levels of three histone deacetylases (HDAC1, HDAC2, and HDAC3), two histone acetyltransferases (GCN5 and PCAF), and two possible targets of these histone modifiers (MYC and CDKN1A) in 50 matched pairs of gastric tumors and corresponding adjacent nontumors samples from patients with gastric adenocarcinoma, as well as their correlations and their possible associations with clinicopathological features. Additionally, we evaluated whether these genes are sensitive to TSA in gastric cancer cell lines. Our results demonstrated downregulation of HDAC1, PCAF, and CDKN1A in gastric tumors compared with adjacent nontumors (P < 0.05). On the other hand, upregulation of HDAC2, GCN5, and MYC was observed in gastric tumors compared with adjacent nontumors (P < 0.05). The mRNA level of MYC was correlated to HDAC3 and GCN5 (P < 0.05), whereas CDKN1A was correlated to HDAC1 and GCN5 (P < 0.05 and P < 0.01, respectively). In addition, the reduced expression of PCAF was associated with intestinal-type gastric cancer (P = 0.03) and TNM stages I/II (P = 0.01). The increased expression of GCN5 was associated with advanced stage gastric cancer (P = 0.02) and tumor invasion (P = 0.03). The gastric cell lines treated with TSA showed different patterns of histone deacetylase and acetyltransferase mRNA expression, downregulation of MYC, and upregulation of CDKN1A. Our findings suggest that alteration of histone modifier genes play an important role in gastric carcinogenesis, contributing to MYC and CDKN1A deregulation. In addition, all genes studied here are modulated by TSA, although this modulation appears to be dependent of the genetic background of the cell

  17. Overexpression of a glycosyltransferase gene SrUGT74G1 from Stevia improved growth and yield of transgenic Arabidopsis by catechin accumulation.

    PubMed

    Guleria, Praveen; Yadav, Sudesh Kumar

    2014-03-01

    Steviol glycoside and gibberellin biosynthetic routes are known as divergent branches of a common origin in Stevia. A UDP-glycosyltransferase encoded by SrUGT74G1 catalyses the conversion of steviolbioside into stevioside in Stevia rebaudiana leaves. In the present study, transgenic Arabidopsis thaliana overexpressing SrUGT74G1 cDNA from Stevia were developed to check the probability of stevioside biosynthesis in them. However, stevioside accumulation was not evident in transgenics. Also, the transgenic Arabidopsis showed no change in GA3 content on SrUGT74G1 overexpression. Surprisingly, significant accumulation of catechin was noticed in transgenics. The transgenics showed a considerable increase in shoot length, root length and rosette area. An increase in free radical scavenging activity of transgenics was noticed. Moreover, the seed yield of transgenics was also increased by 6-15% than control. Additionally, variation in trichome branching pattern on leaf surface of transgenics was observed. The trichome branching pattern was also validated by exogenous catechin exposure (10, 50, 100 ng ml(-1)) to control plants. Hence, present study reports the probable role of SrUGT74G1 from Stevia in catechin accumulation of transgenic Arabidopsis thaliana. Thus, detailed study in present perspective has revealed the role of Stevia SrUGT74G1 gene in trichome branching pattern, improved vegetative growth, scavenging potential and seed yield by catechin accumulation in transgenic Arabidopsis.

  18. Class I and IIa histone deacetylases have opposite effects on sclerostin gene regulation.

    PubMed

    Baertschi, Stefan; Baur, Nina; Lueders-Lefevre, Valerie; Voshol, Johannes; Keller, Hansjoerg

    2014-09-01

    Adult bone mass is controlled by the bone formation repressor sclerostin (SOST). Previously, we have shown that intermittent parathyroid hormone (PTH) bone anabolic therapy involves SOST expression reduction by inhibiting myocyte enhancer factor 2 (MEF2), which activates a distant bone enhancer. Here, we extended our SOST gene regulation studies by analyzing a role of class I and IIa histone deacetylases (HDACs), which are known regulators of MEF2s. Expression analysis using quantitative PCR (qPCR) showed high expression of HDACs 1 and 2, lower amounts of HDACs 3, 5, and 7, low amounts of HDAC4, and no expression of HDACs 8 and 9 in constitutively SOST-expressing UMR106 osteocytic cells. PTH-induced Sost suppression was associated with specific rapid nuclear accumulation of HDAC5 and co-localization with MEF2s in nuclear speckles requiring serine residues 259 and 498, whose phosphorylations control nucleocytoplasmic shuttling. Increasing nuclear levels of HDAC5 in UMR106 by blocking nuclear export with leptomycin B (LepB) or overexpression in transient transfection assays inhibited endogenous Sost transcription and reporter gene expression, respectively. This repressor effect of HDAC5 did not require catalytic activity using specific HDAC inhibitors. In contrast, inhibition of class I HDAC activities and expression using RNA interference suppressed constitutive Sost expression in UMR106 cells. An unbiased comprehensive search for involved HDAC targets using an acetylome analysis revealed several non-histone proteins as candidates. These findings suggest that PTH-mediated Sost repression involves nuclear accumulation of HDAC inhibiting the MEF2-dependent Sost bone enhancer, and class I HDACs are required for constitutive Sost expression in osteocytes.

  19. Histone deacetylase enzyme silencing using shRNAs enhances radiosensitivity of SW579 thyroid cancer cells

    PubMed Central

    Wang, Ye; Jin, Tao; Dai, Xueming; Yan, Dongwang; Peng, Zhihai

    2016-01-01

    The aim of the present study was to screen the enzymes that are associated with the radiosensitivity of SW579 thyroid cancer cells, and investigate whether radiation, combined with specific RNA interference on the screened enzymes, enhances radiosensitivity of SW579 thyroid cancer cells. Quantitative polymerase chain reaction (qPCR) was used to analyze epigenetic enzyme expression changes before and after radiotherapy, and four enzymes, histone deacetylase 1 (HDAC1), HDAC2, HDAC4 and HDAC6 were screened. Western blot analysis was performed to analyze the change in HDAC1, HDAC2, HDAC4 and HDAC6 protein expression following radiotherapy. Short hairpin RNA (ShRNA)-HDAC1, shRNA-HDAC2, shRNA-HDAC4 and shRNA-HDAC6 plasmids were constructed and SW579 cells were transfected with corresponding shRNA-HDACs. Reverse transcription-qPCR was used to detect whether downregulation of HDAC mRNAs had been effective. In addition, shRNA and shRNA negative control (NC) pools were established and transfected into the SW579 cells. The samples were divided into four groups; control, trichostatin A, shRNA pool and shRNA NC pool, to analyze the effective enhancement of specific shRNA on radiosensitivity in thyroid cancer cells. The morphological changes were observed in the SW579 cells, and the number of tumor cells decreased markedly in the shRNA pool group compared with that of the other three groups. Therefore, it was concluded that HDACs present a potential target for increasing the sensitivity of thyroid cancer cells to radiotherapy, and shRNA-HDAC interference combined with radiotherapy promotes the radiosensitivity of tumors. PMID:27600599

  20. Histone Deacetylase Inhibition Impairs Normal Intestinal Cell Proliferation and Promotes Specific Gene Expression

    PubMed Central

    Roostaee, Alireza; Guezguez, Amel; Beauséjour, Marco; Simoneau, Aline; Vachon, Pierre H.; Levy, Emile

    2015-01-01

    ABSTRACT Mechanisms that maintain proliferation and delay cell differentiation in the intestinal crypt are not yet fully understood. We have previously shown the implication of histone methylation in the regulation of enterocytic differentiation. In this study, we investigated the role of histone deacetylation as an important epigenetic mechanism that controls proliferation and differentiation of intestinal cells using the histone deacetylase inhibitor suberanilohydroxamic acid (SAHA) on the proliferation and differentiation of human and mouse intestinal cells. Treatment of newly confluent Caco‐2/15 cells with SAHA resulted in growth arrest, increased histone acetylation and up‐regulation of the expression of intestine‐specific genes such as those encoding sucrase‐isomaltase, villin and the ion exchanger SLC26A3. Although SAHA has been recently used in clinical trials for cancer treatment, its effect on normal intestinal cells has not been documented. Analyses of small and large intestines of mice treated with SAHA revealed a repression of crypt cell proliferation and a higher expression of sucrase‐isomaltase in both segments compared to control mice. Expression of SLC26A3 was also significantly up‐regulated in the colons of mice after SAHA administration. Finally, SAHA was also found to strongly inhibit normal human intestinal crypt cell proliferation in vitro. These results demonstrate the important implication of epigenetic mechanisms such as histone acetylation/deacetylation in the regulation of normal intestinal cell fate and proliferation. J. Cell. Biochem. 116: 2695–2708, 2015. © 2015 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals, Inc. PMID:26129821

  1. 26 CFR 1.1402(g)-1 - Treatment of certain remuneration erroneously reported as net earnings from self-employment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... reported as net earnings from self-employment. 1.1402(g)-1 Section 1.1402(g)-1 Internal Revenue INTERNAL...-Employment Income § 1.1402(g)-1 Treatment of certain remuneration erroneously reported as net earnings from... request, and should indicate clearly that it is a request that, pursuant to section 1402(g) of the...

  2. 26 CFR 1.904(g)-1T - Overall domestic loss and the overall domestic loss account (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... loss account (temporary). 1.904(g)-1T Section 1.904(g)-1T Internal Revenue INTERNAL REVENUE SERVICE... United States § 1.904(g)-1T Overall domestic loss and the overall domestic loss account (temporary). (a... accounts for purposes of section 904(g). Section 1.904(g)-2T provides rules for recapturing the balance...

  3. 17 CFR 240.17g-1 - Application for registration as a nationally recognized statistical rating organization.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... as a nationally recognized statistical rating organization. 240.17g-1 Section 240.17g-1 Commodity and... Statistical Rating Organizations § 240.17g-1 Application for registration as a nationally recognized statistical rating organization. (a) Initial application. A credit rating agency applying to the Commission...

  4. 17 CFR 270.17g-1 - Bonding of officers and employees of registered management investment companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... employees of registered management investment companies. 270.17g-1 Section 270.17g-1 Commodity and... ACT OF 1940 § 270.17g-1 Bonding of officers and employees of registered management investment companies. (a) Each registered management investment company shall provide and maintain a bond which...

  5. 17 CFR 240.17g-1 - Application for registration as a nationally recognized statistical rating organization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... as a nationally recognized statistical rating organization. 240.17g-1 Section 240.17g-1 Commodity and... Statistical Rating Organizations § 240.17g-1 Application for registration as a nationally recognized statistical rating organization. (a) Initial application. A credit rating agency applying to the Commission...

  6. 17 CFR 240.17g-1 - Application for registration as a nationally recognized statistical rating organization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... as a nationally recognized statistical rating organization. 240.17g-1 Section 240.17g-1 Commodity and... Statistical Rating Organizations § 240.17g-1 Application for registration as a nationally recognized statistical rating organization. (a) Initial application. A credit rating agency applying to the Commission...

  7. 17 CFR 240.17g-1 - Application for registration as a nationally recognized statistical rating organization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... as a nationally recognized statistical rating organization. 240.17g-1 Section 240.17g-1 Commodity and... Statistical Rating Organizations § 240.17g-1 Application for registration as a nationally recognized statistical rating organization. (a) Initial application. A credit rating agency applying to the Commission...

  8. 17 CFR 240.17g-1 - Application for registration as a nationally recognized statistical rating organization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... as a nationally recognized statistical rating organization. 240.17g-1 Section 240.17g-1 Commodity and... Statistical Rating Organizations § 240.17g-1 Application for registration as a nationally recognized statistical rating organization. (a) Initial application. A credit rating agency applying to the Commission...

  9. Global Structure of HIV-1 Neutralizing Antibody IgG1 b12 is Asymmetric

    SciTech Connect

    Ashish, F.; Solanki, A; Boone, C; Krueger, J

    2010-01-01

    Human antibody IgG1 b12 is one of the four antibodies known to neutralize a broad range of human immunodeficiency virus-1. The crystal structure of this antibody displayed an asymmetric disposition of the Fab arms relative to its Fc portion. Comparison of structures solved for other IgG1 antibodies led to a notion that crystal packing forces entrapped a 'snap-shot' of different conformations accessible to this antibody. To elucidate global structure of this unique antibody, we acquired small-angle X-ray scattering data from its dilute solution. Data analysis indicated that b12 adopts a bilobal globular structure in solution with a radius of gyration and a maximum linear dimension of {approx}54 and {approx}180 {angstrom}, respectively. Extreme similarity between its solution and crystal structure concludes that non-flexible, asymmetric shape is an inherent property of this rare antibody.

  10. Permanent draft genome sequence of the gliding predator Saprospira grandis strain Sa g1 (= HR1)

    SciTech Connect

    Mavromatis, K; Chertkov, Olga; Lapidus, Alla L.; Nolan, Matt; Lucas, Susan; Tice, Hope; Glavina Del Rio, Tijana; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; Bruce, David; Goodwin, Lynne A.; Pitluck, Sam; Huntemann, Marcel; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Goker, Markus; Detter, J. Chris; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Woyke, Tanja

    2012-01-01

    Saprospira grandis Gross et al. 1911 is a member of the Saprospiraceae, a family in the class 'Sphingobacteria' that remains poorly characterized at the genomic level. The species is known for preying on other marine bacteria via 'ixotrophy'. S. grandis strain Sa g1 was isolated from decaying crab carapace in France and was selected for genome sequencing because of its isolated location in the tree of life. Only one type strain genome has been published so far from the Saprospiraceae, while the sequence of strain Sa g1 represents the second genome to be published from a non-type strain of S. grandis. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 4,495,250 bp long Improved-High-Quality draft of the genome with its 3,536 protein-coding and 62 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  11. Implications of intermediate mass black hole in globular cluster G1 on dark matter detection.

    SciTech Connect

    Zaharijas, G.; High Energy Physics

    2008-07-01

    Recently there has been growing evidence in favor of the presence of an intermediate mass black hole in the globular cluster G1, in Andromeda Galaxy. Under the assumption that formation of this globular cluster occurred within a dark matter halo, we explore whether the presence of a black hole could result in an observable gamma ray signal due to dark matter annihilation in this globular cluster. Starting from an initial Navarro-Frenk-White matter profile, with density parameters consistent with G1 observations, we find that indeed, if the spike in the density has been formed and has survived until the present, the signal could be observed by GLAST and current atmospheric Cerenkov telescope detectors.

  12. Implications of the intermediate mass black hole in globular cluster G1 on dark matter detection

    SciTech Connect

    Zaharijas, Gabrijela

    2008-07-15

    Recently there has been growing evidence in favor of the presence of an intermediate mass black hole in the globular cluster G1, in Andromeda Galaxy. Under the assumption that formation of this globular cluster occurred within a dark matter halo, we explore whether the presence of a black hole could result in an observable gamma ray signal due to dark matter annihilation in this globular cluster. Starting from an initial Navarro-Frenk-White matter profile, with density parameters consistent with G1 observations, we find that indeed, if the spike in the density has been formed and has survived until the present, the signal could be observed by GLAST and current atmospheric Cerenkov telescope detectors.

  13. Echinococcus ortleppi and E. granulosus G1, G2 and G3 genotypes in Italian bovines.

    PubMed

    Casulli, Adriano; Manfredi, Maria Teresa; La Rosa, Giuseppe; Cerbo, Anna Rita Di; Genchi, Claudio; Pozio, Edoardo

    2008-08-01

    To increase the knowledge on Echinococcus genotypes infesting cattle and water buffaloes (Bubalus bubalis) born and bred in Italy, the germinal layer of hydatid cysts was collected from the liver and the lungs of 80 animals slaughtered in 2007. Two mitochondrial genes (the cytochrome c oxidase subunit I and the NADH subunit I) were tested by PCR. Four genotypes were identified: G1 (sheep strain), G2 (Tasmanian sheep strain), G3 (buffalo strain), and G5 (cattle strain). Fertile cysts were detected only in the lungs of 4.5% of the total G1 lung cysts, of 9.4% of the total G3 lung cysts, and in the only G5 infected animal. This is the first report of Echinococcus ortleppi (genotype G5) in Italy.

  14. Aircraft measurements of aerosol properties during GoAmazon - G1 and HALO inter-comparison

    NASA Astrophysics Data System (ADS)

    Mei, F.; Cecchini, M. A.; Wang, J.; Tomlinson, J. M.; Comstock, J. M.; Hubbe, J. M.; Pekour, M. S.; Machado, L.; Wendisch, M.; Longo, K.; Martin, S. T.; Schmid, B.; Weinzierl, B.; Krüger, M. L.; Zöger, M.

    2015-12-01

    Currently, the indirect effects of atmospheric aerosols remain the most uncertain components in forcing of climate change over the industrial period (IPCC, 2013). This large uncertainty is partially a result of our incomplete understanding of the ability of particles to form cloud droplets under atmospherically relevant supersaturations. One objective of the US Department of Energy (DOE) Green Ocean Amazon Project (GoAmazon2014/5) is to understand the influence of the emission from Manaus, a tropical megacity, on aerosol size, concentration, and chemical composition, and their impact on cloud condensation nuclei (CCN) spectrum. The GoAmazon2014/5 study was an international campaign with the collaboration efforts from US, Brazil and Germany. During the intensive operation period, in the dry season (Sep. 1st - Oct. 10th, 2014), aerosol concentration, size distributions, and CCN spectra, both under pristine conditions and inside the Manaus plume, were characterized in-situ from the DOE Gulfstream-1 (G-1) research aircraft and German HALO aircraft during 4 coordinated flights on Sep. 9th, Sep. 16th, Sep 21st and Oct. 1st, 2014. During those four flights, aerosol number concentrations and CCN concentrations at two supersaturations (0.25% and 0.5%) were measured by condensation particle counters (CPCs) and a DMT dual column CCN counter onboard both G-1 and HALO. Aerosol size distribution was also measured by a Fast Integrated Mobility Spectrometer (FIMS) aboard the G-1 and is compared with the size distribution from Ultra High Sensitivity Aerosol Spectrometer - Airborne (UHSAS-A, DMT), which were deployed both on the G-1 and the HALO. Good agreement between the aerosol properties measured from the two aircraft has been achieved. The vertical profiles of aerosol size distribution and CCN spectrum will be discussed.

  15. On the first G 1 stiff fluid spike solution in General Relativity

    NASA Astrophysics Data System (ADS)

    Coley, A. A.; Gregoris, D.; Lim, W. C.

    2016-11-01

    Using the Geroch transformation we obtain the first example of an exact stiff fluid spike solution to the Einstein field equations in a closed form exhibiting a spacelike G 1 group of symmetries (i.e., with a single isometry). This new solution is of Petrov type I and exhibits a spike crossing which persists to the past, which allows us to better understand spike crossings in the context of structure formation.

  16. Nonuniform Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Green, David A.; Hwang, Una; Petre, Robert; Krishnamurthy, Kalyani; Willett, Rebecca

    2014-08-01

    We report measurements of the X-ray expansion of the youngest Galactic supernova remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The measured rates strongly deviate from uniform expansion, decreasing radially by about 60% along the X-ray bright SE-NW axis from 0.84% ± 0.06% yr-1 to 0.52% ± 0.03% yr-1. This corresponds to undecelerated ages of 120-190 yr, confirming the young age of G1.9+0.3 and implying a significant deceleration of the blast wave. The synchrotron-dominated X-ray emission brightens at a rate of 1.9% ± 0.4% yr-1. We identify bright outer and inner rims with the blast wave and reverse shock, respectively. Sharp density gradients in either the ejecta or ambient medium are required to produce the sudden deceleration of the reverse shock or the blast wave implied by the large spread in expansion ages. The blast wave could have been decelerated recently by an encounter with a modest density discontinuity in the ambient medium, such as may be found at a wind termination shock, requiring strong mass loss in the progenitor. Alternatively, the reverse shock might have encountered an order-of-magnitude density discontinuity within the ejecta, such as may be found in pulsating delayed-detonation Type Ia models. We demonstrate that the blast wave is much more decelerated than the reverse shock in these models for remnants at ages similar to G1.9+0.3. Similar effects may also be produced by dense shells possibly associated with high-velocity features in Type Ia spectra. Accounting for the asymmetry of G1.9+0.3 will require more realistic three-dimensional Type Ia models.

  17. NONUNIFORM EXPANSION OF THE YOUNGEST GALACTIC SUPERNOVA REMNANT G1.9+0.3

    SciTech Connect

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Green, David A.; Hwang, Una; Petre, Robert; Willett, Rebecca

    2014-08-01

    We report measurements of the X-ray expansion of the youngest Galactic supernova remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The measured rates strongly deviate from uniform expansion, decreasing radially by about 60% along the X-ray bright SE-NW axis from 0.84% ± 0.06% yr{sup –1} to 0.52% ± 0.03% yr{sup –1}. This corresponds to undecelerated ages of 120-190 yr, confirming the young age of G1.9+0.3 and implying a significant deceleration of the blast wave. The synchrotron-dominated X-ray emission brightens at a rate of 1.9% ± 0.4% yr{sup –1}. We identify bright outer and inner rims with the blast wave and reverse shock, respectively. Sharp density gradients in either the ejecta or ambient medium are required to produce the sudden deceleration of the reverse shock or the blast wave implied by the large spread in expansion ages. The blast wave could have been decelerated recently by an encounter with a modest density discontinuity in the ambient medium, such as may be found at a wind termination shock, requiring strong mass loss in the progenitor. Alternatively, the reverse shock might have encountered an order-of-magnitude density discontinuity within the ejecta, such as may be found in pulsating delayed-detonation Type Ia models. We demonstrate that the blast wave is much more decelerated than the reverse shock in these models for remnants at ages similar to G1.9+0.3. Similar effects may also be produced by dense shells possibly associated with high-velocity features in Type Ia spectra. Accounting for the asymmetry of G1.9+0.3 will require more realistic three-dimensional Type Ia models.

  18. A novel anticancer agent, decursin, induces G1 arrest and apoptosis in human prostate carcinoma cells.

    PubMed

    Yim, Dongsool; Singh, Rana P; Agarwal, Chapla; Lee, Sookyeon; Chi, Hyungjoon; Agarwal, Rajesh

    2005-02-01

    We isolated a coumarin compound decursin (C(19)H(20)O(5); molecular weight 328) from Korean angelica (Angelica gigas) root and characterized it by spectroscopy. Here, for the first time, we observed that decursin (25-100 micromol/L) treatment for 24 to 96 hours strongly inhibits growth and induces death in human prostate carcinoma DU145, PC-3, and LNCaP cells. Furthermore, we observed that decursinol [where (CH(3))(2)-C=CH-COO- side chain of decursin is substituted with -OH] has much lower effects compared with decursin, suggesting a possible structure-activity relationship. Decursin-induced growth inhibition was associated with a strong G(1) arrest (P < 0.001) in DU145 and LNCaP cells, and G(1), S as well as G(2)-M arrests depending upon doses and treatment times in PC-3 cells. Comparatively, decursin was nontoxic to human prostate epithelial PWR-1E cells and showed only moderate growth inhibition and G(1) arrest. Consistent with G(1) arrest in DU145 cells, decursin strongly increased protein levels of Cip1/p21 but showed a moderate increase in Kip1/p27 with a decrease in cyclin-dependent kinases (CDK); CDK2, CDK4, CDK6, and cyclin D1, and inhibited CDK2, CDK4, CDK6, cyclin D1, and cyclin E kinase activity, and increased binding of CDK inhibitor (CDKI) with CDK. Decursin-caused cell death was associated with an increase in apoptosis (P < 0.05-0.001) and cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase; however, pretreatment with all-caspases inhibitor (z-VAD-fmk) only partially reversed decursin-induced apoptosis, suggesting the involvement of both caspase-dependent and caspase-independent pathways. These findings suggest the novel anticancer efficacy of decursin mediated via induction of cell cycle arrest and apoptosis selectively in human prostate carcinoma cells.

  19. MicroRNA-224 Induces G1/S Checkpoint Release in Liver Cancer

    PubMed Central

    An, Fangmei; Olaru, Alexandru V.; Mezey, Esteban; Xie, Qing; Li, Ling; Piontek, Klaus B.; Selaru, Florin M.

    2015-01-01

    Profound changes in microRNA (miR) expression levels are frequently found in liver cancers compared to the normal liver. In this study, we evaluate the expression of miR-224 in human HCC and CCA, as well as its downstream targets and affected pathways. We show that miR-224 is upregulated in a large cohort of human CCA, similar to its upregulation in human HCC. For the purpose of studying the roles of miR-224 in HCC and CCA, we enforced miR-224 expression in cells. mRNA arrays followed by Ingenuity Pathway Analysis (IPA)-identified putative molecules and pathways downstream of miR-224. Phenotypically, we report that enforced expression of miR-224 increases the growth rate of normal cholangiocytes, CCA cell lines, and HCC cell lines. In addition, we identified, in an unbiased fashion, that one of the major biologic processes affected by miR-224 is Gap1 (G1) to Synthesis (S) transition checkpoint release. We next identified p21, p15, and CCNE1 as downstream targets of miR-224 and confirmed the coordinated downregulation results in the increased phosphorylation of Retinoblastoma (Rb) with resulting G1/S checkpoint release. Our data suggest that miR-224 is a master regulator of cell cycle progression, and that its overexpression results in G1/S checkpoint release followed by accelerated cell growth. PMID:26343737

  20. Fate of aflatoxins B1 and G 1 residues during biscuit processing.

    PubMed

    Amra, H A; Mahmoud, S A; Taha, A H; El-Azab, M A

    1996-09-01

    Effect of biscuit processing on the destruction of aflatoxins B1 and G1 with and/or without some commonly leavening agents used namely sodium bicarbonate, ammonium bicarbonate and sodium bisulfite and sodium chloride.It was found that mixing step reduced the concentration of aflatoxins B1 and G1 by 80.7% and 82.7%, while the effect of baking step being 28.9% and 21.5%. The effect of mixing was found to be more pronounced than that baking step.The highest destruction effect on aflatoxin B1 was observed by adding a mixture composed of sodium and ammonium bicarbonate and sodium bisulfite followed by sodium chloride, sodium bisulfite, ammonium bicarbonate and/or sodium bicarbonate alone, where the reduction values of toxin after mixing were 93.4,91.9,91.7, 88.8 and 86.6% respectively, while the baking effect ranged 17.2 to 34.5% in the presence of different leaving agents added.Concerning aflatoxin G1; the highest destructive effect of toxin was adsorbed by adding a mixture of sodium and ammonium bicarbonate and sodium bisulfite followed by sodium bisulfite, sodium chloride, ammonium bicarbonate and/or sodium bicarbonate alone since the destruction values of such toxin after mixing were 96.2%, 92.8%, 92.6%, 89.0% and 87.7% respectively, while the baking effect ranged 20.9 to 34.5% in all leavening agents added.

  1. Tet1 is required for Rb phosphorylation during G1/S phase transition

    SciTech Connect

    Huang, Shengsong; Zhu, Ziqi; Wang, Yiqin; Wang, Yanru; Xu, Longxia; Chen, Xuemei; Xu, Qing; Zhang, Qimin; Zhao, Xin; Yu, Yi; Wu, Denglong

    2013-05-03

    Highlights: •Tet1 was required for NIT3T3 proliferation. •Tet1 depletion inhibited G1-S entry. •Cyclin D1 accumulation and Rb phosphorylation was blocked by Tet1 knockdown. -- Abstract: DNA methylation plays an important role in many biological processes, including regulation of gene expression, maintenance of chromatin conformation and genomic stability. TET-family proteins convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which indicates that these enzymes may participate in DNA demethylation. The function of TET1 has not yet been well characterized in somatic cells. Here, we show that depletion of Tet1 in NIH3T3 cells inhibits cell growth. Furthermore, Tet1 knockdown blocks cyclin D1 accumulation in G1 phase, inhibits Rb phosphorylation and consequently delays entrance to G1/S phase. Taken together, this study demonstrates that Tet1 is required for cell proliferation and that this process is mediated through the Rb pathway.

  2. SUMOylation of Rb enhances its binding with CDK2 and phosphorylation at early G1 phase.

    PubMed

    Meng, Fengxi; Qian, Jiang; Yue, Han; Li, Xiaofeng; Xue, Kang

    2016-07-01

    Retinoblastoma protein (Rb) is a prototypical tumor suppressor that is vital to the negative regulation of the cell cycle and tumor progression. Hypo-phosphorylated Rb is associated with G0/G1 arrest by suppressing E2F transcription factor activity, whereas Rb hyper-phosphorylation allows E2F release and cell cycle progression from G0/G1 to S phase. However, the factors that regulate cyclin-dependent protein kinase (CDK)-dependent hyper-phosphorylation of Rb during the cell cycle remain obscure. In this study, we show that throughout the cell cycle, Rb is specifically small ubiquitin-like modifier (SUMO)ylated at early G1 phase. SUMOylation of Rb stimulates its phosphorylation level by recruiting a SUMO-interaction motif (SIM)-containing kinase CDK2, leading to Rb hyper-phosphorylation and E2F-1 release. In contrast, a SUMO-deficient Rb mutant results in reduced SUMOylation and phosphorylation, weakened CDK2 binding, and attenuated E2F-1 sequestration. Furthermore, we reveal that Rb SUMOylation is required for cell proliferation. Therefore, our study describes a novel mechanism that regulates Rb phosphorylation during cell cycle progression. PMID:27163259

  3. SUMOylation of Rb enhances its binding with CDK2 and phosphorylation at early G1 phase

    PubMed Central

    Meng, Fengxi; Qian, Jiang; Yue, Han; Li, Xiaofeng; Xue, Kang

    2016-01-01

    ABSTRACT Retinoblastoma protein (Rb) is a prototypical tumor suppressor that is vital to the negative regulation of the cell cycle and tumor progression. Hypo-phosphorylated Rb is associated with G0/G1 arrest by suppressing E2F transcription factor activity, whereas Rb hyper-phosphorylation allows E2F release and cell cycle progression from G0/G1 to S phase. However, the factors that regulate cyclin-dependent protein kinase (CDK)-dependent hyper-phosphorylation of Rb during the cell cycle remain obscure. In this study, we show that throughout the cell cycle, Rb is specifically small ubiquitin-like modifier (SUMO)ylated at early G1 phase. SUMOylation of Rb stimulates its phosphorylation level by recruiting a SUMO-interaction motif (SIM)-containing kinase CDK2, leading to Rb hyper-phosphorylation and E2F-1 release. In contrast, a SUMO-deficient Rb mutant results in reduced SUMOylation and phosphorylation, weakened CDK2 binding, and attenuated E2F-1 sequestration. Furthermore, we reveal that Rb SUMOylation is required for cell proliferation. Therefore, our study describes a novel mechanism that regulates Rb phosphorylation during cell cycle progression. PMID:27163259

  4. The human G1m1 allotype associates with CD4+ T-cell responsiveness to a highly conserved IgG1 constant region peptide and confers an asparaginyl endopeptidase cleavage site

    PubMed Central

    Stickler, M M; Reddy, A; Xiong, J M; Hinton, P R; DuBridge, R; Harding, F A

    2011-01-01

    The human G1m1 allotype comprises two amino acids, D12 and L14, in the CH3 domain of IGHG1. Although the G1m1 allotype is prevalent in human populations, ∼40% of Caucasiods are homozygous for the nG1m1 allotype corresponding to E12 and M14. Peptides derived from the G1m1 region were tested for their ability to induce CD4+ T-cell proliferative responses in vitro. A peptide immediately downstream from the G1m1 sequence was recognized by CD4+ T cells in a large percentage of donors (peptide CH315−29). CD4+ T-cell proliferative responses to CH315−29 were found at an increased frequency in nG1m1 homozygous donors. Homozygous nG1m1 donors possessing the HLA-DRB1*07 allele displayed the highest magnitudes of proliferation. CD4+ T cells from donors homozygous for nG1m1 proliferated to G1m1-carrying Fc-fragment proteins, whereas CD4+ T cells from G1m1 homozygous donors did not. The G1m1 sequence creates an enzymatic cleavage site for asparaginyl endopeptidase in vitro. Proteolytic activity at D12 may allow the presentation of the CH315−29 peptide, which in turn may result in the establishment of tolerance to this peptide in G1m1-positive donors. Homozygous nG1m1 patients may be more likely to develop CD4+ T-cell-mediated immune responses to therapeutic antibodies carrying the G1m1 allotype. PMID:21326320

  5. An APC/C-Cdh1 Biosensor Reveals the Dynamics of Cdh1 Inactivation at the G1/S Transition

    PubMed Central

    Ondracka, Andrej; Robbins, Jonathan A.; Cross, Frederick R.

    2016-01-01

    B-type cyclin-dependent kinase activity must be turned off for mitotic exit and G1 stabilization. B-type cyclin degradation is mediated by the anaphase-promoting complex/cyclosome (APC/C); during and after mitotic exit, APC/C is dependent on Cdh1. Cdh1 is in turn phosphorylated and inactivated by cyclin-CDK at the Start transition of the new cell cycle. We developed a biosensor to assess the cell cycle dynamics of APC/C-Cdh1. Nuclear exit of the G1 transcriptional repressor Whi5 is a known marker of Start; APC/C-Cdh1 is inactivated 12 min after Whi5 nuclear exit with little measurable cell-to-cell timing variability. Multiple phosphorylation sites on Cdh1 act in a redundant manner to repress its activity. Reducing the number of phosphorylation sites on Cdh1 can to some extent be tolerated for cell viability, but it increases variability in timing of APC/C-Cdh1 inactivation. Mutants with minimal subsets of phosphorylation sites required for viability exhibit striking stochasticity in multiple responses including budding, nuclear division, and APC/C-Cdh1 activity itself. Multiple cyclin-CDK complexes, as well as the stoichiometric inhibitor Acm1, contribute to APC/C-Cdh1 inactivation; this redundant control is likely to promote rapid and reliable APC/C-Cdh1 inactivation immediately following the Start transition. PMID:27410035

  6. TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells

    PubMed Central

    Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob

    2015-01-01

    Genome integrity is critically dependent on timely DNA replication and accurate chromosome segregation. Replication stress delays replication into G2/M, which in turn impairs proper chromosome segregation and inflicts DNA damage on the daughter cells. Here we show that TopBP1 forms foci upon mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin recruitment of SLX4 and by facilitating unscheduled DNA synthesis. PMID:26283799

  7. TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells.

    PubMed

    Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob; Oestergaard, Vibe H; Lisby, Michael

    2015-08-17

    Genome integrity is critically dependent on timely DNA replication and accurate chromosome segregation. Replication stress delays replication into G2/M, which in turn impairs proper chromosome segregation and inflicts DNA damage on the daughter cells. Here we show that TopBP1 forms foci upon mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin recruitment of SLX4 and by facilitating unscheduled DNA synthesis.

  8. Cellular expression of human centromere protein C demonstrates a cyclic behavior with highest abundance in the G1 phase.

    PubMed Central

    Knehr, M; Poppe, M; Schroeter, D; Eickelbaum, W; Finze, E M; Kiesewetter, U L; Enulescu, M; Arand, M; Paweletz, N

    1996-01-01

    Centromere proteins are localized within the centromere-kinetochore complex, which can be proven by means of immunofluorescence microscopy and immunoelectron microscopy. In consequence, their putative functions seem to be related exclusively to mitosis, namely to the interaction of the chromosomal kinetochores with spindle microtubules. However, electron microscopy using immune sera enriched with specific antibodies against human centromere protein C (CENP-C) showed that it occurs not only in mitosis but during the whole cell cycle. Therefore, we investigated the cell cycle-specific expression of CENP-C systematically on protein and mRNA levels applying HeLa cells synchronized in all cell cycle phases. Immunoblotting confirmed protein expression during the whole cell cycle and revealed an increase of CENP-C from the S phase through the G2 phase and mitosis to highest abundance in the G1 phase. Since this was rather surprising, we verified it by quantifying phase-specific mRNA levels of CENP-C, paralleled by the amplification of suitable internal standards, using the polymerase chain reaction. The results were in excellent agreement with abundant protein amounts and confirmed the cyclic behavior of CENP-C during the cell cycle. In consequence, we postulate that in addition to its role in mitosis, CENP-C has a further role in the G1 phase that may be related to cell cycle control. Images Fig. 1 Fig. 2 Fig. 4 PMID:8816782

  9. An APC/C-Cdh1 Biosensor Reveals the Dynamics of Cdh1 Inactivation at the G1/S Transition.

    PubMed

    Ondracka, Andrej; Robbins, Jonathan A; Cross, Frederick R

    2016-01-01

    B-type cyclin-dependent kinase activity must be turned off for mitotic exit and G1 stabilization. B-type cyclin degradation is mediated by the anaphase-promoting complex/cyclosome (APC/C); during and after mitotic exit, APC/C is dependent on Cdh1. Cdh1 is in turn phosphorylated and inactivated by cyclin-CDK at the Start transition of the new cell cycle. We developed a biosensor to assess the cell cycle dynamics of APC/C-Cdh1. Nuclear exit of the G1 transcriptional repressor Whi5 is a known marker of Start; APC/C-Cdh1 is inactivated 12 min after Whi5 nuclear exit with little measurable cell-to-cell timing variability. Multiple phosphorylation sites on Cdh1 act in a redundant manner to repress its activity. Reducing the number of phosphorylation sites on Cdh1 can to some extent be tolerated for cell viability, but it increases variability in timing of APC/C-Cdh1 inactivation. Mutants with minimal subsets of phosphorylation sites required for viability exhibit striking stochasticity in multiple responses including budding, nuclear division, and APC/C-Cdh1 activity itself. Multiple cyclin-CDK complexes, as well as the stoichiometric inhibitor Acm1, contribute to APC/C-Cdh1 inactivation; this redundant control is likely to promote rapid and reliable APC/C-Cdh1 inactivation immediately following the Start transition.

  10. Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells

    PubMed Central

    Lee, Hyun Sook; Kim, Eun Ji

    2015-01-01

    BACKGROUND/OBJECTIVES Inonotus obliquus (I. obliquus, Chaga mushroom) has long been used as a folk medicine to treat cancer. In the present study, we examined whether or not ethanol extract of I. obliquus (EEIO) inhibits cell cycle progression in HT-29 human colon cancer cells, in addition to its mechanism of action. MATERIALS/METHODS To examine the effects of Inonotus obliquus on the cell cycle progression and the molecular mechanism in colon cancer cells, HT-29 human colon cancer cells were cultured in the presence of 2.5 - 10 µg/mL of EEIO, and analyzed the cell cycle arrest by flow cytometry and the cell cycle controlling protein expression by Western blotting. RESULTS Treatment cells with 2.5 - 10 µg/mL of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased the percentage of cells in G1 phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among I. obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO treatment on cell proliferation and cell cycle-related protein levels. CONCLUSIONS These results demonstrate that fraction 2 is the major fraction that induces G1 arrest and inhibits cell proliferation, suggesting I. obliquus could be used as a natural anti-cancer ingredient in the food and/or pharmaceutical industry. PMID:25861415

  11. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication.

    PubMed

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

  12. Involvement of miR-15a in G0/G1 Phase Cell Cycle Arrest Induced by Porcine Circovirus Type 2 Replication

    PubMed Central

    Quan, Rong; Wei, Li; Zhu, Shanshan; Wang, Jing; Cao, Yongchang; Xue, Chunyi; Yan, Xu; Liu, Jue

    2016-01-01

    Many viruses exploit the host cell division cycle to favour their own growth. Here we demonstrated that porcine circovirus type 2 (PCV2), which is a major causative agent of an emerging and important swine disease complex, PCV2-associated diseases, caused G0/G1 cell cycle arrest through degradation of cyclin D1 and E followed by reduction of retinoblastoma phosphorylation in synchronized PCV2-infected cells dependent upon virus replication. This induction of G0/G1 cell cycle arrest promoted PCV2 replication as evidenced by increased viral protein expression and progeny virus production in the synchronized PCV2-infected cells. To delineate a mechanism of miRNAs in regulating PCV2-induced G0/G1 cell cycle arrest, we determined expression levels of some relevant miRNAs and found that only miR-15a but not miR-16, miR-21, and miR-34a was significantly changed in the PCV2-infected cells. We further demonstrated that upregulation of miR-15a promoted PCV2-induced G0/G1 cell cycle arrest via mediating cyclins D1 and E degradation, in which involves PCV2 growth. These results reveal that G0/G1 cell cycle arrest induced by PCV2 may provide favourable conditions for viral protein expression and progeny production and that miR-15a is implicated in PCV2-induced cell cycle control, thereby contributing to efficient viral replication. PMID:27302568

  13. TM4SF5 accelerates G1/S phase progression via cytosolic p27Kip1 expression and RhoA activity.

    PubMed

    Kim, Hyeonjung; Kang, Minkyung; Lee, Sin-Ae; Kwak, Tae Kyoung; Jung, Oisun; Lee, Hyo Jeong; Kim, Sung-Hoon; Lee, Jung Weon

    2010-08-01

    Transmembrane 4 L six family member 5 (TM4SF5) causes epithelial-mesenchymal transition (EMT) for aberrant cell proliferation. However, the effects of TM4SF5 expression on cell cycle are unknown so far. In this study, using hepatocytes that either ectopically or endogenously express TM4SF5 and human hepatocarcinoma tissues, the role of TM4SF5 in G1/S phase progression was examined. We found that TM4SF5 expression accelerated G1/S phase progression with facilitated cyclin D1 and E expression and Rb phosphorylation. Furthermore, TM4SF5 enhanced trafficking of CDK4 and cyclin D1 into the nucleus and induced complex formation between them. However, TM4SF5-facilitated G1/S phase progression was blocked by silencing of p27Kip1 using siRNA or by infection of active RhoA. Pharmacological inhibition of ROCK accelerated the G1/S phase progression of control TM4SF5-unexpressing cells. Altogether, these observations suggest that TM4SF5 accelerates G1/S phase progression with facilitated CDK4/cyclin D1 entry into the nucleus, which might be supported by TM4SF5-mediated actin reorganization through cytosolic p27Kip1 expression and Rho GTPase activity.

  14. Characterization of recombinant β-fructofuranosidase from Bifidobacterium adolescentis G1

    PubMed Central

    2010-01-01

    Background We have previously reported on purification and characterization of β-fructofuranosidase (β-FFase) from Bifidobacterium adolescentis G1. This enzyme showed high activity of hydrolysis on fructo-oligosaccharides with a low degree of polymerization. Recently, genome sequences of B. longum NCC2705 and B. adolescentis ATCC 15703 were determined, and cscA gene in the both genome sequences encoding β-FFase was predicted. Here, cloning of cscA gene encoding putative β-FFase from B. adolescentis G1, its expression in E. coli and properties of the recombinant protein are described. Results Using the information of cscA gene from Bifidobacterium adolescentis ATCC 15703, cscA gene from B. adolescentis G1 was cloned and sequenced. The N-terminal amino acid sequence of purified β-FFase from B. adolescentis G1 was identical to the deduced amino acid sequences of cscA gene from B. adolescentis G1. To confirm the translated product of the cscA gene, the recombinant protein was expressed in Escherichia coli. Molecular mass of the purified recombinant enzyme was estimated to be about 66,000 by SDS-PAGE and 60,300 by MALDI TOF-MS. The optimum pH of the enzyme was 5.7 and the enzyme was stable at pH 5.0-8.6. The thermostability of the enzyme was up to 50°C. The Km (mM), Vmax (μmol/mg of protein/min), k0 (sec-1) and k0/Km(mM-1 sec-1) for 1-kestose, neokestose, nystose, fructosylnystose, sucrose and inulin were 1.7, 107, 107.5, 63.2, and 1.7, 142, 142.7, 83.9, and 3.9, 152, 152.8, 39.2, and 2.2, 75, 75.4, 34.3, and 38, 79, 79.4, 2.1, and 25.9, 77, 77.4, 3.0, respectively. The hydrolytic activity was strongly inhibited by AgNO3, SDS, and HgCl2. Conclusion The recombinant enzyme had similar specificity to the native enzyme, high affinity for 1-kestose, and low affinity for sucrose and inulin, although properties of the recombinant enzyme showed slight difference from those of the native one previously described. PMID:20380746

  15. Discovery of bicyclic pyrazoles as class III histone deacetylase SIRT1 and SIRT2 inhibitors.

    PubMed

    Therrien, Eric; Larouche, Guillaume; Nguyen, Natalie; Rahil, Jubrail; Lemieux, Anne-Marie; Li, Zuomei; Fournel, Marielle; Yan, Theresa P; Landry, Anne-Julie; Lefebvre, Sylvain; Wang, James J; MacBeth, Kyle; Heise, Carla; Nguyen, Aaron; Besterman, Jeffrey M; Déziel, Robert; Wahhab, Amal

    2015-06-15

    A series of bicyclic pyrazole carboxamides was synthesized and tested for inhibitory activity against the class III deacetylase sirtuin enzymes. Moderate to low micromolar inhibitory activities were obtained against SIRT1 and SIRT2. These bicyclic pyrazole compounds represent a new class of sirtuin inhibitors with a preference for SIRT1 over SIRT2. PMID:25971769

  16. A Role for Histone Deacetylases in the Cellular and Behavioral Mechanisms Underlying Learning and Memory

    ERIC Educational Resources Information Center

    Mahgoub, Melissa; Monteggia, Lisa M.

    2014-01-01

    Histone deacetylases (HDACs) are a family of chromatin remodeling enzymes that restrict access of transcription factors to the DNA, thereby repressing gene expression. In contrast, histone acetyltransferases (HATs) relax the chromatin structure allowing for an active chromatin state and promoting gene transcription. Accumulating data have…

  17. Optimization of a series of potent and selective ketone histone deacetylase inhibitors.

    PubMed

    Pescatore, Giovanna; Kinzel, Olaf; Attenni, Barbara; Cecchetti, Ottavia; Fiore, Fabrizio; Fonsi, Massimiliano; Rowley, Michael; Schultz-Fademrecht, Carsten; Serafini, Sergio; Steinkühler, Christian; Jones, Philip

    2008-10-15

    Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in the clinic. Herein we describe the optimization of a series of ketone small molecule HDAC inhibitors leading to potent and selective class I HDAC inhibitors with good dog PK.

  18. Proteomic Investigations of Lysine Acetylation Identify Diverse Substrates of Mitochondrial Deacetylase Sirt3

    PubMed Central

    Weinert, Brian T.; Kumar, Amit; Kim, Hyun-Seok; Deng, Chu-Xia; Choudhary, Chunaram

    2012-01-01

    Lysine acetylation is a posttranslational modification that is dynamically regulated by the activity of acetyltransferases and deacetylases. The human and mouse genomes encode 18 different lysine deacetylases (KDACs) which are key regulators of many cellular processes. Identifying substrates of KDACs and pinpointing the regulated acetylation sites on target proteins may provide important information about the molecular basis of their functions. Here we apply quantitative proteomics to identify endogenous substrates of the mitochondrial deacetylase Sirtuin 3 (Sirt3) by comparing site-specific acetylation in wild-type murine embryonic fibroblasts to Sirt3 knockout cells. We confirm Sirt3-regulated acetylation of several mitochondrial proteins in human cells by comparing acetylation in U2OS cells overexpressing Sirt3 to U2OS cells in which Sirt3 expression was reduced by shRNA. Our data demonstrate that ablation of Sirt3 significantly increases acetylation at dozens of sites on mitochondrial proteins. Substrates of Sirt3 are implicated in various metabolic pathways, including fatty acid metabolism and the tricarboxylic acid cycle. These results imply broader regulatory roles of Sirt3 in the mitochondria by modulating acetylation on diverse substrates. The experimental strategy described here is generic and can be applied to identify endogenous substrates of other lysine deacetylases. PMID:23236377

  19. A phosphorescent rhenium(I) histone deacetylase inhibitor: mitochondrial targeting and paraptosis induction.

    PubMed

    Ye, Rui-Rong; Tan, Cai-Ping; Lin, Yan-Nan; Ji, Liang-Nian; Mao, Zong-Wan

    2015-05-14

    In this report, we designed a histone deacetylase-targeted phosphorescent Re(I) complex ReLMito. Colocalization studies suggested that ReLMito could specially localize to mitochondria. We also demonstrated that ReLMito could induce paraptosis in cancer cells. These features endowed the complex with potential to induce and monitor mitochondrial morphological changes during the paraptosis simultaneously.

  20. Dysregulated Class I histone deacetylases are indicators of poor prognosis in multiple myeloma

    PubMed Central

    Mithraprabhu, Sridurga; Kalff, Anna; Chow, Annie; Khong, Tiffany; Spencer, Andrew

    2014-01-01

    Histone deacetylases (HDAC) control gene expression through their ability to acetylate proteins, thereby influencing a diverse range of cellular functions. Class I HDAC (HDAC1–3 and 8) and HDAC6 are predominantly upregulated in malignancies and their altered expression in some cancers has a significant prognostic implication. The expression and prognostic consequence of dysregulated Class I HDAC and HDAC6, key players in multiple myeloma (MM), are unknown. This study hypothesized that HDAC are dysregulated in MM and patients with high expression have significantly poorer prognostic outcomes. Quantitative PCR for 11 HDAC (Class I, II, and IV) was performed in genetically heterogeneous human myeloma cell lines (HMCL) and primary MM and compared to normal plasma cells (PC). In HMCL, HDAC1–3 and 8 (Class I), and HDAC5 and HDAC10 (Class II) were significantly upregulated compared to normal PC. In primary MM, the median expression level of all of the HDAC, except HDAC1 and HDAC11, were elevated when compared to normal PC. Patients with higher levels of HDAC1–3, HDAC4, HDAC6, and HDAC11 transcripts demonstrated a significantly shorter progression-free survival (PFS). Immunohistochemical staining for HDAC1 and HDAC6 on bone marrow trephines from a uniformly treated cohort of transplant eligible MM patients revealed that HDAC1 protein was detectable in most patients and that higher levels of MM cell HDAC1 protein expression (≥90 % versus ≤20 % MM cell positivity) correlated with both shorter PFS (P = 0 .07) and shorter overall survival (P = 0 .003). Conversely, while the majority of patients expressed HDAC6, there was no correlation between HDAC6 levels and patient outcome. Together, these results indicate that overexpression of Class I HDAC, particularly HDAC1, is associated with poor prognosis in MM. PMID:25482492

  1. Analysis of the genomic response of human prostate cancer cells to histone deacetylase inhibitors

    PubMed Central

    Kortenhorst, Madeleine SQ; Wissing, Michel D; Rodriguez, Ronald; Kachhap, Sushant K; Jans, Judith JM; Van der Groep, Petra; Verheul, Henk MW; Gupta, Anuj; Aiyetan, Paul O; van der Wall, Elsken; Carducci, Michael A; Van Diest, Paul J; Marchionni, Luigi

    2013-01-01

    Histone deacetylases (HDACs) have emerged as important targets for cancer treatment. HDAC-inhibitors (HDACis) are well tolerated in patients and have been approved for the treatment of patients with cutaneous T-cell lymphoma (CTCL). To improve the clinical benefit of HDACis in solid tumors, combination strategies with HDACis could be employed. In this study, we applied Analysis of Functional Annotation (AFA) to provide a comprehensive list of genes and pathways affected upon HDACi-treatment in prostate cancer cells. This approach provides an unbiased and objective approach to high throughput data mining. By performing AFA on gene expression data from prostate cancer cell lines DU-145 (an HDACi-sensitive cell line) and PC3 (a relatively HDACi-resistant cell line) treated with HDACis valproic acid or vorinostat, we identified biological processes that are affected by HDACis and are therefore potential treatment targets for combination therapy. Our analysis revealed that HDAC-inhibition resulted among others in upregulation of major histocompatibility complex (MHC) genes and deregulation of the mitotic spindle checkpoint by downregulation of genes involved in mitosis. These findings were confirmed by AFA on publicly available data sets from HDACi-treated prostate cancer cells. In total, we analyzed 375 microarrays with HDACi treated and non-treated (control) prostate cancer cells. All results from this extensive analysis are provided as an online research source (available at the journal’s website and at http://luigimarchionni.org/HDACIs.html). By publishing this data, we aim to enhance our understanding of the cellular changes after HDAC-inhibition, and to identify novel potential combination strategies with HDACis for the treatment of prostate cancer patients. PMID:23880963

  2. Inhibition of histone deacetylases enhances DNA damage repair in SCNT embryos.

    PubMed

    Bohrer, Rodrigo Camponogara; Duggavathi, Raj; Bordignon, Vilceu

    2014-01-01

    Recent studies have shown that DNA damage affects embryo development and also somatic cell reprogramming into induced pluripotent stem (iPS) cells. It has been also shown that treatment with histone deacetylase inhibitors (HDACi) improves development of embryos produced by somatic cell nuclear transfer (SCNT) and enhances somatic cell reprogramming. There is evidence that increasing histone acetylation at the sites of DNA double-strand breaks (DSBs) is critical for DNA damage repair. Therefore, we hypothesized that HDACi treatment enhances cell programming and embryo development by facilitating DNA damage repair. To test this hypothesis, we first established a DNA damage model wherein exposure of nuclear donor cells to ultraviolet (UV) light prior to nuclear transfer reduced the development of SCNT embryos proportional to the length of UV exposure. Detection of phosphorylated histone H2A.x (H2AX139ph) foci confirmed that exposure of nuclear donor cells to UV light for 10 s was sufficient to increase DSBs in SCNT embryos. Treatment with HDACi during embryo culture increased development and reduced DSBs in SCNT embryos produced from UV-treated cells. Transcript abundance of genes involved in either the homologous recombination (HR) or nonhomologous end-joining (NHEJ) pathways for DSBs repair was reduced by HDACi treatment in developing embryos at day 5 after SCNT. Interestingly, expression of HR and NHEJ genes was similar between HDACi-treated and control SCNT embryos that developed to the blastocyst stage. This suggested that the increased number of embryos that could achieve the blastocyst stage in response to HDACi treatment have repaired DNA damage. These results demonstrate that DNA damage in nuclear donor cells is an important component affecting development of SCNT embryos, and that HDACi treatment after nuclear transfer enhances DSBs repair and development of SCNT embryos. PMID:24841373

  3. Radiosensitizing Effect of a Phenylbutyrate-Derived Histone Deacetylase Inhibitor in Hepatocellular Carcinoma

    SciTech Connect

    Lu, Yen-Shen; Chou, Chia-Hung; Tzen, Kai-Yuan; Gao, Ming; Cheng, Ann-Lii; Kulp, Samuel K.; Cheng, Jason Chia-Hsien

    2012-06-01

    Purpose: Radiotherapy is integrated into the multimodal treatment of localized hepatocellular carcinoma (HCC) refractory to conventional treatment. Tumor control remains unsatisfactory and the sublethal effect associates with secondary spread. The use of an effective molecularly targeted agent in combination with radiotherapy is a potential therapeutic approach. Our aim was to assess the effect of combining a phenylbutyrate-derived histone deacetylase (HDAC) inhibitor, AR-42, with radiotherapy in in vitro and in vivo models of human HCC. Methods and Materials: Human HCC cell lines (Huh-7 and PLC-5) were used to evaluate the in vitro synergism of combining AR-42 with irradiation. Flow cytometry analyzed the cell cycle changes, whereas Western blot investigated the protein expressions after the combined treatment. Severe combined immunodeficient (SCID) mice bearing ectopic and orthotopic HCC xenografts were treated with AR-42 and/or radiotherapy for the in vivo response. Results: AR-42 significantly enhanced radiation-induced cell death by the inhibition of the DNA end-binding activity of Ku70, a highly versatile regulatory protein for DNA repair, telomere maintenance, and apoptosis. In ectopic xenografts of Huh-7 and PLC-5, pretreatment with AR-42 significantly enhanced the tumor-suppressive effect of radiotherapy by 48% and 66%, respectively. A similar combinatorial effect of AR-42 (10 and 25 mg/kg) and radiotherapy was observed in Huh-7 orthotopic model of tumor growth by 52% and 82%, respectively. This tumor suppression was associated with inhibition of intratumoral Ku70 activity as well as reductions in markers of HDAC activity and proliferation, and increased apoptosis. Conclusion: AR-42 is a potent, orally bioavailable inhibitor of HDAC with therapeutic value as a radiosensitizer of HCC.

  4. MicroRNA-381 Regulates Chondrocyte Hypertrophy by Inhibiting Histone Deacetylase 4 Expression

    PubMed Central

    Chen, Weishen; Sheng, Puyi; Huang, Zhiyu; Meng, Fangang; Kang, Yan; Huang, Guangxin; Zhang, Zhiqi; Liao, Weiming; Zhang, Ziji

    2016-01-01

    Chondrocyte hypertrophy, regulated by Runt-related transcription factor 2 (RUNX2) and matrix metalloproteinase 13 (MMP13), is a crucial step in cartilage degeneration and osteoarthritis (OA) pathogenesis. We previously demonstrated that microRNA-381 (miR-381) promotes MMP13 expression during chondrogenesis and contributes to cartilage degeneration; however, the mechanism underlying this process remained unclear. In this study, we observed divergent expression of miR-381 and histone deacetylase 4 (HDAC4), an enzyme that directly inhibits RUNX2 and MMP13 expression, during late-stage chondrogenesis of ATDC5 cells, as well as in prehypertrophic and hypertrophic chondrocytes during long bone development in E16.5 mouse embryos. We therefore investigated whether this miRNA regulates HDAC4 expression during chondrogenesis. Notably, overexpression of miR-381 inhibited HDAC4 expression but promoted RUNX2 expression. Moreover, transfection of SW1353 cells with an miR-381 mimic suppressed the activity of a reporter construct containing the 3′-untranslated region (3′-UTR) of HDAC4. Conversely, treatment with a miR-381 inhibitor yielded increased HDAC4 expression and decreased RUNX2 expression. Lastly, knockdown of HDAC4 expression resulted in increased RUNX2 and MMP13 expression in SW1353 cells. Collectively, our results indicate that miR-381 epigenetically regulates MMP13 and RUNX2 expression via targeting of HDAC4, thereby suggesting the possibilities of inhibiting miR-381 to control chondrocyte hypertrophy and cartilage degeneration. PMID:27563877

  5. The histone deacetylase inhibitor, sodium butyrate, alleviates cognitive deficits in pre-motor stage PD.

    PubMed

    Rane, Pallavi; Shields, Jessica; Heffernan, Meghan; Guo, Yin; Akbarian, Schahram; King, Jean A

    2012-06-01

    Parkinson's disease (PD) patients often times experience impairment in their cognitive abilities early on in the progression of the disease. The reported deficits appear to mainly involve functions that are associated with frontal lobe and frontal-striatal pathways subserving attentional set-shifting, working memory and executive function. The current study explored executive function deficits in a rat model of PD in the pre-motor deficit stage. The rats were lesioned with 12 μg of 6-hydroxydonpamine (6-OHDA) in the striatum in a two step process (10 μg/μl followed by 2 μg/μl) 48 hours apart. Executive function was tested at 3 weeks post-surgery using a rat analogue of Wisconsin card sorting test called the Extra Dimensional/Intra Dimensional (ED/ID) set-shifting task. The results demonstrated that performance by the pre-motor rat model of PD was equivalent to that of the control groups in the simple and the compound discriminations as well as the intra-dimensional set-shifting. However the PD group exhibited attentional set-shifting deficits similar to those observed in PD patients. Additionally, sodium butyrate, a short chain fatty acid derivative and inhibitor of class I and II histone deacetylase (HDACi), was tested as a potential therapeutic agent to mitigate the pre-motor cognitive deficits in PD. The results indicated that the sodium butyrate treatment not only effectively alleviated the set-shifting deficits, but also improved the attentional set formation in the treated rats.

  6. Passive Smoking Impairs Histone Deacetylase-2 in Children With Severe Asthma

    PubMed Central

    Kobayashi, Yoshiki; Bossley, Cara; Gupta, Atul; Akashi, Kenichi; Tsartsali, Lemonia; Mercado, Nicolas; Barnes, Peter J.; Bush, Andrew

    2014-01-01

    Background: Parental smoking is known to worsen asthma symptoms in children and to make them refractory to asthma treatment, but the molecular mechanism is unclear. Oxidative stress from tobacco smoke has been reported to impair histone deacetylase-2 (HDAC2) via phosphoinositide-3-kinase (PI3K)/Akt activation and, thus, to reduce corticosteroid sensitivity. The aim of this study was to investigate passive smoking-dependent molecular abnormalities in alveolar macrophages (AMs) by comparing passive smoke-exposed children and non-passive smoke-exposed children with uncontrolled severe asthma. Methods: BAL fluid (BALF) was obtained from 19 children with uncontrolled severe asthma (10 non-passive smoking-exposed subjects and nine passive smoking-exposed subjects), and HDAC2 expression/activity, Akt/HDAC2 phosphorylation levels, and corticosteroid responsiveness in AMs were evaluated. Results: Parental smoking reduced HDAC2 protein expression by 54% and activity by 47%, with concomitant enhancement of phosphorylation of Akt1 and HDAC2. In addition, phosphorylation levels of Akt1 correlated positively with HDAC2 phosphorylation levels and negatively with HDAC2 activity. Furthermore, passive smoke exposure reduced the inhibitory effects of dexamethasone on tumor necrosis factor-α-induced CXCL8 release in AMs. There were relatively higher neutrophil counts and CXCL8 concentrations in BALF and lower Asthma Control Test scores compared with non-passive smoke-exposed children with uncontrolled severe asthma. Conclusions: Passive smoking impairs HDAC2 function via PI3K signaling activation, which could contribute to corticosteroid-insensitive inflammation in children with severe asthma. This novel mechanism will be a treatment target in children with severe asthma and stresses the need for a smoke-free environment for asthmatic children. PMID:24030221

  7. Downregulation of HMGA2 by the pan-deacetylase inhibitor panobinostat is dependent on hsa-let-7b expression in liver cancer cell lines

    SciTech Connect

    Di Fazio, Pietro; Montalbano, Roberta; Neureiter, Daniel; Alinger, Beate; Schmidt, Ansgar; Merkel, Anna Lena; Quint, Karl; Ocker, Matthias

    2012-09-10

    Inhibitors of protein deacetylases represent a novel therapeutic option for cancer diseases due to their effects on transcriptional regulation by interfering with histones acetylation and on several other cellular pathways. Recently, their ability to modulate several transcription factors and, interestingly, also co-factors, which actively participate in formation and modulation of transcription complexes was shown. We here investigate whether HMGA2 (High Mobility Group AT-2 hook), a nuclear non-histone transcriptional co-factor with known oncogenic properties, can be influenced by the novel pan-deacetylase inhibitor panobinostat (LBH589) in human hepatocellular carcinoma models. Panobinostat strongly downregulated HMGA2 in HepG2 and Hep3B cells; this effect was mediated by transcriptional upregulation and promotion of the maturation of the tumorsuppressor miRNA hsa-let-7b, which could inhibit HMGA2 expression via RNA interference pathways. siRNA knockdown of HMGA2 or transfection of hsa-let-7b mimicking oligonucleotides confirmed the role of HMGA2 in regulating cell proliferation and apoptosis in liver cancer cell lines. Co-incubation with panobinostat showed an additive effect on inhibition of cell proliferation using an impedance-based real-time cell analyzer. Treatment of HepG2 xenografts with panobinostat also led to a downregulation of HMGA2 in vivo. These findings show that pan-deacetylase inhibitors also modulate other signaling pathways and networks than histone modifications to influence cell fate. -- Highlights: Black-Right-Pointing-Pointer Panobinostat for the treatment of liver cancer. Black-Right-Pointing-Pointer Panobinostat meddles with miRNAs-dependent transcriptional and translational control. Black-Right-Pointing-Pointer Tumorsuppressor miRNA hsa-let-7b upregulation. Black-Right-Pointing-Pointer HMGA2 is downregulated via RNA interference pathways mediated by hsa-let-7b. Black-Right-Pointing-Pointer Panobinostat determines inhibition of

  8. The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukaemia cells

    PubMed Central

    Cellai, C; Balliu, M; Laurenzana, A; Guandalini, L; Matucci, R; Miniati, D; Torre, E; Nebbioso, A; Carafa, V; Altucci, L; Romanelli, M N; Paoletti, F

    2012-01-01

    Abstract Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn++-chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, which were first comparatively tested in promyelocytic NB4 cells. (S)-2 and partially 4– but not (R)-2 – caused G0/G1 cell-cycle arrest by up-regulating cyclin G2 and p21 expression and down-regulating cyclin D2 expression, and also apoptosis as assessed by cell morphology and cytofluorimetric assay, histone H2AX phosphorylation and PARP cleavage. Notably, these events were partly prevented by an anti-oxidant. Moreover, novel HDACi prompted p53 and α-tubulin acetylation and, consistently, inhibited HDAC1 and 6 activity. The rank order of potency was (S)-2 > 4 > (R)-2, reflecting that of other biological assays and addressing (S)-2 as the most effective compound capable of triggering apoptosis in various acute myeloid leukaemia (AML) cell lines and blasts from patients with different AML subtypes. Importantly, (S)-2 was safe in mice (up to 150 mg/kg/week) as determined by liver, spleen, kidney and bone marrow histopathology; and displayed negligible affinity for peripheral/central BDZ-receptors. Overall, the BDZ-hydroxamate (S)-2 showed to be a low-toxic HDACi with powerful anti-proliferative and pro-apototic activities towards different cultured and primary AML cells, and therefore of clinical interest to support conventional anti-leukaemic therapy. PMID:22004558

  9. Stabilization of IgG1 in spray-dried powders for inhalation.

    PubMed

    Schüle, S; Schulz-Fademrecht, T; Garidel, P; Bechtold-Peters, K; Frieb, W

    2008-08-01

    The protein stabilizing capabilities of spray-dried IgG1/mannitol formulations were evaluated. The storage stability was tested at different residual moisture levels prepared by vacuum-drying or equilibration prior to storage. Vacuum-drying at 32 degrees C/0.1mbar for 24h reduced the moisture level below 1%, constituting an optimal basis for improved storage stability. The crystalline IgG1/mannitol powders with a weight ratio of 20/80 up to 40/60 failed to prevent the antibody aggregation as assessed by size exclusion chromatography during storage. Ratios of 60/40 up to 80/20 IgG1/mannitol provided superior stability of the antibody and the powders could be produced with high yields. The lower the residual moisture, the better was the stabilizing capability. An amount of 20% mannitol provided the best stabilization. Storage stability of 60/40, 70/30, and 80/20 IgG1/mannitol formulations over one year was adequate at 2-8 degrees C and 25 degrees C. Closed storage (sealed in vials) at 40 degrees C/75% RH and open storage at 25 degrees C/60% RH revealed that the stability still required optimization. The lower the protein content, the better was the powder flowability. The aerodynamic properties of powders spray-dried with 10% solids content were inadequate, as the particle size ranged between 5.1 and 7.2 microm and the fine particle fraction accounted for only 4-11%. Reduction of the solids content to 2.5% did improve the aerodynamic properties as the mass mean aerodynamic diameter was reduced to 3.6 microm and the fine particle fraction was increased to about 14%. The reduction of the solids content did not influence the storage stability significantly. Also spray-drying at higher temperatures had no significant impact on the storage stability, despite a higher tendency to form amorphous systems. In order to improve the storage stability and to maintain the good flowability of 70/30 IgG1/mannitol powder or to keep the storage stability but to improve the flowability

  10. Contribution of variable domains to the stability of humanized IgG1 monoclonal antibodies.

    PubMed

    Ionescu, Roxana M; Vlasak, Josef; Price, Colleen; Kirchmeier, Marc

    2008-04-01

    Temperature-induced unfolding of three humanized IgG1 monoclonal antibodies and their Fab and Fc fragments was monitored by differential scanning calorimetry at neutral pH. With some exceptions, the thermogram of the intact antibody presents two peaks and the transition with the larger experimental enthalpy contains the contribution from the Fab fragments. Although the measured enthalpy was similar for all three Fab fragments studied, the apparent melting temperatures were found to vary significantly, even for Fab fragments originating from the same human germline. Therefore, we propose to use the measured enthalpy of unfolding as the key parameter to recognize the unfolding events in the melting profile of an intact IgG1 antibody. If the variable domain sequences, resulting from complementarity determining regions (CDRs) grafting and humanization, destabilize the Fab fragment with respect to the CH3 domain, the first transition represents the unfolding of the Fab fragment and the CH2 domain, while the second transition represents CH3 domain unfolding. Otherwise, the first transition represents CH2 domain unfolding, and the second transition represents the unfolding of the Fab fragment and the CH3 domain. In some cases, the DSC profile may present three transitions, with the Fab unfolding occurring at distinct temperatures compared to the melting of the CH2 and CH3 domains. If the DSC profile of a humanized IgG1 monoclonal antibody cannot be described by the model above, the result may be an indication of significant structural heterogeneity and/or of disruption of the Fab cooperative unfolding. Low stability or heterogeneity of the Fab fragment may prove problematic for long-term storage or consistency of production. Therefore, understanding the features of a DSC profile is important for clone selection and process maturation in the early stages of development of therapeutic monoclonal antibodies.

  11. JAZ mediates G1 cell cycle arrest by interacting with and inhibiting E2F1

    PubMed Central

    Yang, Mingli; Wu, Song; Jia, Jinghua

    2011-01-01

    We discovered and reported JAZ as a unique dsRNA binding zinc finger protein that functions as a direct, positive regulator of p53 transcriptional activity to mediate G1 cell cycle arrest in a mechanism involving upregulation of the p53 target gene, p21. We now find that JAZ can also negatively regulate the cell cycle in a novel, p53-independent mechanism resulting from the direct interaction with E2F1, a key intermediate in regulating cell proliferation and tumor suppression. JAZ associates with E2F1's central DNA binding/dimerization region and its C-terminal transactivation domain. Functionally, JAZ represses E2F1 transcriptional activity in association with repression of cyclin A expression and inhibition of G1/S transition. This mechanism involves JAZ-mediated inhibition of E2F1's specific DNA binding activity. JAZ directly binds E2F1 in vitro in a dsRNA-independent manner, and JAZ's dsRNA binding ZF domains, which are necessary for localizing JAZ to the nucleus, are required for repression of transcriptional activity in vivo. Importantly for specificity, siRNA-mediated “knockdown” of endogenous JAZ increases E2F transcriptional activity and releases cells from G1 arrest, indicating a necessary role for JAZ in this transition. Although JAZ can directly inhibit E2F1 activity independently of p53, if functional p53 is expressed, JAZ may exert a more potent inhibition of cell cycle following growth factor withdrawal. Therefore, JAZ plays a dual role in cell cycle regulation by both repressing E2F1 transcriptional activity and activating p53 to facilitate efficient growth arrest in response to cellular stress, which may potentially be exploited therapeutically for tumor growth inhibition. PMID:21715977

  12. Selenium Preconcentration in Geological Materials for Determination at sub-μ g\\ g-1 Concentration

    NASA Astrophysics Data System (ADS)

    Bedard, L. P.

    2004-05-01

    Selenium is important because it is a path finder element in economic geology. It has similar geochemical properties as sulfur, but slightly less mobile and less volatile in sulfides. Although its environmental cycle is better understood, its geological cycle is almost unknown. In geological samples, Se concentration ranges 0,02-1 μ g\\ g-1. Se has many spectral interefences in ICP-MS, rendering difficult to determine. INAA detection limit for geological samples is about 10 μ g\\ g-1. The analytical difficulties are one of the main reason why the geological cycle of Se is so poorly known. The preconcentration of Se with Thiol Cotton Fiber (TCF) followed by atomic absorption (AA) has been modified to be used with INAA. The modified technique involves sample dissolution (HF-HNO3) and evaporation to dryness at low temperature (55-60 oC) to keep Se in solution. Se is converted to SeIV by adding 5-6 mol l-1 HCl and heating covered in a boiling bath (95-100oC). Sample is diluted with deionized water to obtain 0,3 - 1 mol l-1 HCl and then collected on TCF. TCF is put in a polyethylene vial for irradiation in the SLOWPOKE II reactor for 10 seconds at a neutron flux of 1015 m-2 s-1. The 162 KeV peak of 77Se (half-life 17,36 sec) is read for 20 seconds after a decay of 7 seconds. Results for certified reference materials show the TCF preconcentration technique followed by INAA provides results comparable with AA with a detection limit of approximately 0,05 μ g\\ g-1. Moreover INAA provides many advantages such as eliminating the desorption step and is less time consuming than AA.

  13. Phospholipid hydroperoxide glutathione peroxidase induces a delay in G1 of the cell cycle.

    PubMed

    Wang, Hong P; Schafer, Freya Q; Goswami, Prabhat C; Oberley, Larry W; Buettner, Garry R

    2003-06-01

    Phospholipid hydroperoxide glutathione peroxidase (PhGPx) is an antioxidant enzyme that reduces cellular phospholipid hydroperoxides (PLOOHs) to alcohols. Cellular peroxide tone has been implicated in cell growth and differentiation. By reducing the PLOOH level in the cell membrane, PhGPx regulates the peroxide tone and thereby might be involved in cell growth. We hypothesized that overexpression of PhGPx in human breast cancer cells would decrease their growth rate. We stably transfected MCF-7 cells (Wt) with L-PhGPx and measured cell doubling time, plating efficiency, and cell cycle phase transit times. P-4 cells (8-fold increase in PhGPx activity) showed a 2-fold increase in doubling time; doubling time increased directly with PhGPx activity (r = 0.95). The higher the PhGPx activity, the lower the plating efficiency (r = -0.86). The profile of other antioxidant enzymes was unchanged. Overexpression of PhGPx lowered the steady-state level of PLOOH (by > 60%). Results from bromodeoxyuridine pulse-chase experiments and flow cytometry indicate that PhGPx induced a delay in MCF-7 proliferation that was primarily due to a slower progression from G1 to S. These results support the hypothesis that PhGPx plays a regulatory role in the progression of MCF-7 cells from G1 to S possibly by regulating the steady-state levels of PLOOH. These data suggest that PhGPx can lower the peroxide tone, which might change the cellular redox environment resulting in a delay in G1 transit. Thus, PhGPx could be an important factor in cell growth. PMID:12868489

  14. AAF G1 and Millimeter Wavelength ARM Radar Observations and Analysis from the ACAPEX Field Campaign

    NASA Astrophysics Data System (ADS)

    Matthews, A. A.; Hardin, J. C.; Comstock, J. M.; Bharadwaj, N.; Mei, F.

    2015-12-01

    From late January to early March of 2015, the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) deployed a variety of instruments to study atmospheric rivers as they made landfall on the western United States. These atmospheric rivers are an important source of rainfall for the drought-ridden regions of California, so it is important to understand the cloud characteristics and processes that occur during the events. For this study, the KAZR zenith pointing millimeter wavelength radar aboard the Ron Brown research vessel as well as two cloud probes, namely the Two-Dimensional Stereo Probe (2DS) and High Volume Precipitation Spectrometer-3 (HVPS3), flown on the ARM Aerial Facility Gulfstream-1 (AAF G1) aircraft were used to analyze the clouds associated with the atmospheric rivers. PyDisdrometer, an open-source software, is used to calculate radar reflectivity values based on the drop size distributions observed by the cloud probes so that the aircraft data may be directly compared to the KAZR data. This research will focus on two flight days. First, a coordinated flight flown on February 5, where the G1 flew a spiral pattern over the Ron Brown while the KAZR was running will be used to examine the clouds over the ocean. This will also allow for a direct comparison between the calculated radar reflectivity from the cloud probes and the KAZR measured reflectivity. The second case was chosen to be the atmospheric river landfall event on February 6. This case will be analyzed over the ocean using the KAZR, then over the shoreline, Sacramento, and the inland mountains using the cloud probe data, as well as other instrumentations onboard the G1, such as those that measure cloud thickness and liquid water content. In this way, the changes that occur to the clouds as they move from open-ocean to land may be examined in greater detail.

  15. Optimal management for infinite capacity N-policy M/G/1 queue with a removable service station

    NASA Astrophysics Data System (ADS)

    Chang, Y. C.; Pearn, W. L.

    2011-07-01

    In this article, we consider an infinite capacity N-policy M/G/1 queueing system with a single removable server. Poisson arrivals and general distribution service times are assumed. The server is controllable that may be turned on at arrival epochs or off at service completion epochs. We apply a differential technique to study system sensitivity, which examines the effect of different system input parameters on the system. A cost model for infinite capacity queueing system under steady-state condition is developed, to determine the optimal management policy at minimum cost. Analytical results for sensitivity analysis are derived. We also provide extensive numerical computations to illustrate the analytical sensitivity properties obtained. Finally, an application example is presented to demonstrate how the model could be used in real applications to obtain the optimal management policy.

  16. Some alkali and titania analyses of tektites before and after G-1 precision monitoring

    USGS Publications Warehouse

    Tatlock, D.B.

    1966-01-01

    A comparison of 55 older analyses of Australasian tektites with 110 modern precisely monitored analyses suggests that more than half of the older alkali and titania determinations are decidedly inaccurate and misleading. Deviations of the older analyses from the restricted values of the modern analyses are comparable to the imprecisions shown by early analyses of G-1 granite and W-1 diabase. This suggests that a high percentage of older alkali and titania analyses, such as those of Washington's tables, are of questionable quality. ?? 1966.

  17. THE ABSENCE OF RADIO EMISSION FROM THE GLOBULAR CLUSTER G1

    SciTech Connect

    Miller-Jones, J. C. A.; Wrobel, J. M.; Sivakoff, G. R.; Heinke, C. O.; Miller, R. E.; Plotkin, R. M.; Di Stefano, R.; Greene, J. E.; Ho, L. C.; Joseph, T. D.; Maccarone, T. J.; Kong, A. K. H.

    2012-08-10

    The detections of both X-ray and radio emission from the cluster G1 in M31 have provided strong support for existing dynamical evidence for an intermediate-mass black hole (IMBH) of mass (1.8 {+-} 0.5) Multiplication-Sign 10{sup 4} M{sub Sun} at the cluster center. However, given the relatively low significance and astrometric accuracy of the radio detection, and the non-simultaneity of the X-ray and radio measurements, this identification required further confirmation. Here we present deep, high angular resolution, strictly simultaneous X-ray and radio observations of G1. While the X-ray emission (L{sub X} = 1.74{sup +0.53}{sub -0.44} Multiplication-Sign 10{sup 36} (d/750 kpc){sup 2} erg s{sup -1} in the 0.5-10 keV band) remained fully consistent with previous observations, we detected no radio emission from the cluster center down to a 3{sigma} upper limit of 4.7 {mu}Jy beam{sup -1}. Our favored explanation for the previous radio detection is flaring activity from a black hole low-mass X-ray binary (LMXB). We performed a new regression of the 'Fundamental Plane' of black hole activity, valid for determining black hole mass from radio and X-ray observations of sub-Eddington black holes, finding log M{sub BH} = (1.638 {+-} 0.070)log L{sub R} - (1.136 {+-} 0.077)log L{sub X} - (6.863 {+-} 0.790), with an empirically determined uncertainty of 0.44 dex. This constrains the mass of the X-ray source in G1, if a black hole, to be <9.7 Multiplication-Sign 10{sup 3} M{sub Sun} at 95% confidence, suggesting that it is a persistent LMXB. This annuls what was previously the most convincing evidence from radiation for an IMBH in the Local Group, though the evidence for an IMBH in G1 from velocity dispersion measurements remains unaffected by these results.

  18. Asymmetric expansion of the youngest Galactic supernova remnant G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.

    2016-06-01

    The youngest Galactic supernova remnant (SNR) G1.9+0.3, produced by a (probable) Type Ia SN that exploded around CE 1900, is strongly asymmetric at radio wavelengths, with a single bright maximum in its shell, but exhibits a bilaterally symmetric morphology in X-rays. It has been difficult to understand the origin of these contrasting morphologies. We present the results of expansion measurements of G1.9+0.3 that illuminate the origin of the radio asymmetry. These measurements are based on a comparison of our 2015 400-ks Chandra observation with earlier Chandra observations, including a 1-Ms observation in 2011. The mean expansion rate from 2011 to 2015 is 0.58% per yr, in agreement with previous measurements. We also confirm that the expansion decreases radially away from the remnant's center along the major E-W axis, from 0.77% per yr to 0.53% per yr. Large variations in expansion are also present along the minor N-S axis, but expansion there is strongly asymmetric and varies on small spatial scales. We use the “Demons” method to study the complex motions within G1.9+0.3. This method provides a nonparametric way for measuring these motions globally. We find motions varying by a factor of 5, from 0.09" to 0.44" per year. The slowest shocks are in the north, at the outer boundary of the bright radio emission, with speeds there as low as 3,600 km/s (for an assumed distance of 8.5 kpc), much less than the average shock speed of 12,000 km/s. Such strong deceleration of the northern blast wave most likely arises from the collision of SN ejecta with a much denser than average ambient medium there. The presence of this asymmetric ambient medium naturally explains the radio asymmetry. The SN ejecta have also been strongly decelerated in the N, but they expand faster than the blast wave. In several locations, significant morphological changes and strongly nonradial motions are apparent. The spatially-integrated X-ray flux continues to increase with time. As with Kepler

  19. Nonuniform Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.; Borkowski, Kazimierz J.; Green, David; Hwang, Una; Petre, Robert

    2014-08-01

    G1.9+0.3 is the youngest known Galactic supernova remnant (SNR), about 100 yr old from global expansion measurements, and most likely the result of an asymmetric Type Ia supernova explosion. We smoothed a Chandra image from a 1 Ms observation in 2011 and fit the resulting model to unsmoothed images from 2007 and 2009, allowing for expansion and image shifts. The measured expansion rates strongly deviate from uniform expansion, increasing inward by about 60% along the X-ray bright SE-NW axis, from 0.52% +- 0.03% per yr to 0.84% +- 0.06% per yr. This corresponds to undecelerated ages of 120 - 190 yr, confirming the young age of G1.9 +0.3, and implying a significant (deceleration parameter m < 0.6) deceleration of the blast wave. The spatially-integrated X-ray flux, strongly dominated by synchrotron emission, increases at a rate of 1.9% +- 0.7% per year, in agreement with previous measurements. G1.9+0.3 is the only Galactic SNR brightening at X-ray and radio wavelengths. We identify the inner rims with the reverse shock and more slowly-expanding rims farther out with the blast wave. The large spread in expansion ages between the reverse shock and the blast wave requires abrupt density gradients in either the ejecta or the ambient medium, to suddenly decelerate the reverse shock or the blast wave. The blast wave could have been decelerated recently by an encounter with a modest (factor of several) density discontinuity in the ambient medium, such as found at a wind termination shock, implying a strong presupernova wind from the progenitor system. Alternatively, the reverse shock might have encountered a larger (factor of 10 or more) density discontinuity within the SN ejecta, such as found in pulsating delayed-detonation Type Ia SN models. Through 1D hydrodynamical simulations, we demonstrate that the blast wave is much more decelerated than the reverse shock in these models for remnants at ages similar to G1.9+0.3. The presence of strong density gradients in the outer

  20. Overexpression of c-Myc alters G(1)/S arrest following ionizing radiation.

    PubMed

    Sheen, Joon-Ho; Dickson, Robert B

    2002-03-01

    Study of the mechanism(s) of genomic instability induced by the c-myc proto-oncogene has the potential to shed new light on its well-known oncogenic activity. However, an underlying mechanism(s) for this phenotype is largely unknown. In the present study, we investigated the effects of c-Myc overexpression on the DNA damage-induced G(1)/S checkpoint, in order to obtain mechanistic insights into how deregulated c-Myc destabilizes the cellular genome. The DNA damage-induced checkpoints are among the primary safeguard mechanisms for genomic stability, and alterations of cell cycle checkpoints are known to be crucial for certain types of genomic instability, such as gene amplification. The effects of c-Myc overexpression were studied in human mammary epithelial cells (HMEC) as one approach to understanding the c-Myc-induced genomic instability in the context of mammary tumorigenesis. Initially, flow-cytometric analyses were used with two c-Myc-overexpressing, nontransformed immortal lines (184A1N4 and MCF10A) to determine whether c-Myc overexpression leads to alteration of cell cycle arrest following ionizing radiation (IR). Inappropriate entry into S phase was then confirmed with a bromodeoxyuridine incorporation assay measuring de novo DNA synthesis following IR. Direct involvement of c-Myc overexpression in alteration of the G(1)/S checkpoint was then confirmed by utilizing the MycER construct, a regulatable c-Myc. A transient excess of c-Myc activity, provided by the activated MycER, was similarly able to induce the inappropriate de novo DNA synthesis following IR. Significantly, the transient expression of full-length c-Myc in normal mortal HMECs also facilitated entry into S phase and the inappropriate de novo DNA synthesis following IR. Furthermore, irradiated, c-Myc-infected, normal HMECs developed a sub-G(1) population and a >4N population of cells. The c-Myc-induced alteration of the G(1)/S checkpoint was also compared to the effects of expression of MycS (N

  1. Matrine promotes G0/G1 arrest and down-regulates cyclin D1 expression in human rhabdomyosarcoma cells.

    PubMed

    Guo, L; Xue, T Y; Xu, W; Gao, J Z

    2013-09-01

    Matrine has a broad-spectrum of anti-cancer effects and is efficient in the inhibition of proliferation of hepatoma cells, leukemia cells and neuroblastoma cell. However, its efficacy and tentative mechanisms in rhabdomyosarcoma have not been addressed before. This study aimed to investigate the effects of Matrine on cell cycle and expression of cyclin D1 in human rhabdomyosarcoma cells (RD cell line). RD cell line was treated with different concentrations (0, 0.5, 1.0, and 1.5 mg/mL) of Matrine, and cell proliferation and cell cycle were evaluated using, respectively, MTT assay and flow cytometry. The effect of Matrine on cyclin D1 mRNA levels was measured by RT-PCR. There was a dose-dependent inhibition of proliferation in the matrine-treated group (inhibition of proliferation rate in control cells 12.70 ± 0.35%; Matrine-treated cells [0.5, 1.0, and 1.5 mg/mL]: 31.16 ± 0.11%, 42.96 ± 0.9%, and 57.26 ± 0.8%). The G0 / G1 ratio in study groups were, respectively, 58.44 ± 3.57%, 64.79 ± 2.03%, 69.97 ± 2.89% and 75.03 ± 1.23%.Cyclin D1 mRNA levels progressively diminished (control group ratio of cyclin D1 / β-actin: 0.59 ± 0.06; Matrine: 0.35 ± 0.05, 0.27 ± 0.02 and 0.04 ± 0.03). All aforementioned changes were significant (P<0.05). In conclusion, Matrine markedly suppresses cell proliferation in RD cells by decreasing expression of cyclin D1 mRNA and blocking the cell cycle at the G0 / G1 stage.

  2. Detection of IgG1 antibodies against Mycobacterium tuberculosis DosR and Rpf antigens in tuberculosis patients before and after chemotherapy.

    PubMed

    Mattos, Ana Márcia Menezes; Chaves, Alexandre Silva; Franken, Kees L M C; Figueiredo, Bárbara Bruna Muniz; Ferreira, Ana Paula; Ottenhoff, Tom H M; Teixeira, Henrique Couto

    2016-01-01

    Diagnosis of tuberculosis (TB) remains challenging. Serum IgG1 antibodies against Mycobacterium tuberculosis active growth phase antigens (ESAT-6/CFP-10, Rv0717 and Rv3353), DosR regulon-encoded proteins (Rv1733, Rv1737, Rv2628 and Rv2029), and resuscitation-promoting factors (Rv0867 and Rv2389) were evaluated in TB patients using ELISA. Active TB patients showed elevated levels of IgG1 antibodies against ESAT-6/CFP-10, Rv0717, Rv3353, Rv1733, Rv2628, Rv2029 and Rv0867 in comparison to healthy controls (p < 0.001). These levels remained high after the initiation of treatment, while responses to Rv0717 and Rv1733 peaked early during treatment. IgG1 responses to ESAT-6/CFP-10, Rv3353, Rv2628, Rv2029 and Rv0867 declined to control levels after the completion of 6 months chemotherapy. ROC analysis confirmed the good diagnostic performance of Rv0717, Rv1733, Rv3353, Rv2628, Rv2029 and Rv0867antigens. These data suggest that detecting IgG1 antibodies against M. tuberculosis antigens, including DosR and Rpf proteins, may represent an additional tool in the diagnosis of tuberculosis.

  3. The conserved histone deacetylase Rpd3 and the DNA binding regulator Ume6 repress BOI1's meiotic transcript isoform during vegetative growth in Saccharomyces cerevisiae.

    PubMed

    Liu, Yuchen; Stuparevic, Igor; Xie, Bingning; Becker, Emmanuelle; Law, Michael J; Primig, Michael

    2015-05-01

    BOI1 and BOI2 are paralogs important for the actin cytoskeleton and polar growth. BOI1 encodes a meiotic transcript isoform with an extended 5'-untranslated region predicted to impair protein translation. It is, however, unknown how the isoform is repressed during mitosis, and if Boi1 is present during sporulation. By interpreting microarray data from MATa cells, MATa/α cells, a starving MATα/α control, and a meiosis-impaired rrp6 mutant, we classified BOI1's extended isoform as early meiosis-specific. These results were confirmed by RNA-Sequencing, and extended by a 5'-RACE assay and Northern blotting, showing that meiotic cells induce the long isoform while the mitotic isoform remains detectable during meiosis. We provide evidence via motif predictions, an in vivo binding assay and genetic experiments that the Rpd3/Sin3/Ume6 histone deacetylase complex, which represses meiotic genes during mitosis, also prevents the induction of BOI1's 5'-extended isoform in mitosis by direct binding of Ume6 to its URS1 target. Finally, we find that Boi1 protein levels decline when cells switch from fermentation to respiration and sporulation. The histone deacetylase Rpd3 is conserved, and eukaryotic genes frequently encode transcripts with variable 5'-UTRs. Our findings are therefore relevant for regulatory mechanisms involved in the control of transcript isoforms in multi-cellular organisms.

  4. The transcription factor Swi4 is target for PKA regulation of cell size at the G1 to S transition in Saccharomyces cerevisiae

    PubMed Central

    Amigoni, Loredana; Colombo, Sonia; Belotti, Fiorella; Alberghina, Lilia; Martegani, Enzo

    2015-01-01

    To investigate the specific target of PKA in the regulation of cell cycle progression and cell size we developed a new approach using the yeast strain GG104 bearing a deletion in adenylate cyclase gene and permeable to cAMP ( cyr1Δ, pde2Δ, msn2Δ, msn4Δ). In this strain the PKA activity is absent and can be activated by addition of cAMP in the medium, without any other change of the growth conditions. In the present work we show that the activation of PKA by exogenous cAMP in the GG104 strain exponentially growing in glucose medium caused a marked increase of cell size and perturbation of cell cycle with a transient arrest of cells in G1, followed by an accumulation of cells in G2/M phase with a minimal change in the growth rate. Deletion of CLN1 gene, but not of CLN2, abolished the transient G1 phase arrest. Consistently we found that PKA activation caused a transcriptional repression of CLN1 gene. Transcription of CLN1 is controlled by SBF and MBF dual-regulated promoter. We found that also the deletion of SWI4 gene abolished the transient G1 arrest suggesting that Swi4 is a target responsible for PKA modulation of G1/S phase transition. We generated a SWI4 allele mutated in the consensus site for PKA (Swi4S159A) and we found that expression of Swi4S159A protein in the GG104-Swi4Δ strain did not restore the transient G1 arrest induced by PKA activation, suggesting that Swi4 phosphorylation by PKA regulates CLN1 gene expression and G1/S phase transition. PMID:26046481

  5. Nonuniform Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Green, David A.; Hwang, Una; Petre, Robert; Krishnamurthy, Kalyani; Willett, Rebecca

    2014-01-01

    We report measurements of the X-ray expansion of the youngest Galactic supernova remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The measured rates strongly deviate from uniform expansion, decreasing radially by about 60 along the X-ray bright SE-NW axis from 0.84 plus or minus 0.06% yr(exp -1) to 0.52% plus or minus 0.03 yr(exp -1). This corresponds to undecelerated ages of 120-190 yr, confirming the young age of G1.9+0.3 and implying a significant deceleration of the blast wave. The synchrotron-dominated X-ray emission brightens at a rate of 1.9% plus or minus 0.4% yr(exp -1). We identify bright outer and inner rims with the blast wave and reverse shock, respectively. Sharp density gradients in either the ejecta or ambient medium are required to produce the sudden deceleration of the reverse shock or the blast wave implied by the large spread in expansion ages. The blast wave could have been decelerated recently by an encounter with a modest density discontinuity in the ambient medium, such as may be found at a wind termination shock, requiring strong mass loss in the progenitor.

  6. Magnetic Shielding Accelerates the Proliferation of Human Neuroblastoma Cell by Promoting G1-Phase Progression

    PubMed Central

    Liu, Ying; Bartlett, Perry F.; He, Rong-qiao

    2013-01-01

    Organisms have been exposed to the geomagnetic field (GMF) throughout evolutionary history. Exposure to the hypomagnetic field (HMF) by deep magnetic shielding has recently been suggested to have a negative effect on the structure and function of the central nervous system, particularly during early development. Although changes in cell growth and differentiation have been observed in the HMF, the effects of the HMF on cell cycle progression still remain unclear. Here we show that continuous HMF exposure significantly increases the proliferation of human neuroblastoma (SH-SY5Y) cells. The acceleration of proliferation results from a forward shift of the cell cycle in G1-phase. The G2/M-phase progression is not affected in the HMF. Our data is the first to demonstrate that the HMF can stimulate the proliferation of SH-SY5Y cells by promoting cell cycle progression in the G1-phase. This provides a novel way to study the mechanism of cells in response to changes of environmental magnetic field including the GMF. PMID:23355897

  7. The extraction of the spin structure function, g2 (and g1) at low Bjorken x

    SciTech Connect

    Ndukum, Luwani Z.

    2015-08-01

    The Spin Asymmetries of the Nucleon Experiment (SANE) used the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory in Newport News, VA to investigate the spin structure of the proton. The experiment measured inclusive double polarization electron asymmetries using a polarized electron beam, scattered off a solid polarized ammonia target with target polarization aligned longitudinal and near transverse to the electron beam, allowing the extraction of the spin asymmetries A1 and A2, and spin structure functions g1 and g2. Polarized electrons of energies of 4.7 and 5.9 GeV were used. The scattered electrons were detected by a novel, non-magnetic array of detectors observing a four-momentum transfer range of 2.5 to 6.5 GeV*V. This document addresses the extraction of the spin asymmetries and spin structure functions, with a focus on spin structure function, g2 (and g1) at low Bjorken x. The spin structure functions were measured as a function of x and W in four Q square bins. A full understanding of the low x region is necessary to get clean results for SANE and extend our understanding of the kinematic region at low x.

  8. G1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus

    PubMed Central

    Deghelt, Michaël; Mullier, Caroline; Sternon, Jean-François; Francis, Nayla; Laloux, Géraldine; Dotreppe, Delphine; Van der Henst, Charles; Jacobs-Wagner, Christine; Letesson, Jean-Jacques; De Bolle, Xavier

    2014-01-01

    Several intracellular pathogens, such as Brucella abortus, display a biphasic infection process starting with a non-proliferative stage of unclear nature. Here, we study the cell cycle of B. abortus at the single-cell level, in culture and during infection of HeLa cells and macrophages. The localization of segregation and replication loci of the two bacterial chromosomes indicates that, immediately after being engulfed by host-cell endocytic vacuoles, most bacterial cells are newborn. These bacterial cells do not initiate DNA replication for the next 4 to 6 h, indicating a G1 arrest. Moreover, growth is completely stopped during that time, reflecting a global cell cycle block. Growth and DNA replication resume later, although bacteria still reside within endosomal-like compartments. We hypothesize that the predominance of G1-arrested bacteria in the infectious population, and the bacterial cell cycle arrest following internalization, may constitute a widespread strategy among intracellular pathogens to colonize new proliferation niches. PMID:25006695

  9. G-1-activated membrane estrogen receptors mediate increased contractility of the human myometrium.

    PubMed

    Maiti, K; Paul, J W; Read, M; Chan, E C; Riley, S C; Nahar, P; Smith, R

    2011-06-01

    Estrogens are key mediators of increased uterine contractility at labor. We sought to determine whether membrane-associated estrogen receptors, such as the recently described seven-transmembrane receptor G protein-coupled receptor 30 (GPR30), mediated some of this effect. Using human myometrium obtained at term cesarean section before or after the onset of labor, we demonstrated the presence of GPR30 mRNA and protein using quantitative RT-PCR and Western blotting. GPR30 receptor was localized to the cell membrane and often colocalized with calveolin-1. Using the specific estrogen membrane receptor agonist G-1 and myometrial explants, we showed that membrane receptor activation led to phosphorylation of MAPK and the actin-modifying small heat shock protein 27. Using myometrial strips incubated with G-1 or vehicle we demonstrated that estrogen membrane receptor activation increased the myometrial contractile response to oxytocin. These data suggest that activation of the plasma membrane estrogen receptor GPR30 likely participates in the physiology of the human myometrium during pregnancy and identifies it as a potential target to modify uterine activity. PMID:21427217

  10. Engineering upper hinge improves stability and effector function of a human IgG1.

    PubMed

    Yan, Boxu; Boyd, Daniel; Kaschak, Timothy; Tsukuda, Joni; Shen, Amy; Lin, Yuwen; Chung, Shan; Gupta, Priyanka; Kamath, Amrita; Wong, Anne; Vernes, Jean-Michel; Meng, Gloria Y; Totpal, Klara; Schaefer, Gabriele; Jiang, Guoying; Nogal, Bartek; Emery, Craig; Vanderlaan, Martin; Carter, Paul; Harris, Reed; Amanullah, Ashraf

    2012-02-17

    Upper hinge is vulnerable to radical attacks that result in breakage of the heavy-light chain linkage and cleavage of the hinge of an IgG1. To further explore mechanisms responsible for the radical induced hinge degradation, nine mutants were designed to determine the roles that the upper hinge Asp and His play in the radical reactions. The observation that none of these substitutions could inhibit the breakage of the heavy-light chain linkage suggests that the breakage may result from electron transfer from Cys(231) directly to the heavy-light chain linkage upon radical attacks, and implies a pathway separate from His(229)-mediated hinge cleavage. On the other hand, the substitution of His(229) with Tyr showed promising advantages over the native antibody and other substitutions in improving the stability and function of the IgG1. This substitution inhibited the hinge cleavage by 98% and suggests that the redox active nature of Tyr did not enable it to replicate the ability of His to facilitate radical induced degradation. We propose that the lower redox potential of Tyr, a residue that may be the ultimate sink for oxidizing equivalents in proteins, is responsible for the inhibition. More importantly, the substitution increased the antibody's binding to FcγRIII receptors by 2-3-fold, and improved ADCC activity by 2-fold, while maintaining a similar pharmacokinetic profile with respect to the wild type. Implications of these observations for antibody engineering and development are discussed.

  11. Magnetic shielding accelerates the proliferation of human neuroblastoma cell by promoting G1-phase progression.

    PubMed

    Mo, Wei-chuan; Zhang, Zi-jian; Liu, Ying; Bartlett, Perry F; He, Rong-qiao

    2013-01-01

    Organisms have been exposed to the geomagnetic field (GMF) throughout evolutionary history. Exposure to the hypomagnetic field (HMF) by deep magnetic shielding has recently been suggested to have a negative effect on the structure and function of the central nervous system, particularly during early development. Although changes in cell growth and differentiation have been observed in the HMF, the effects of the HMF on cell cycle progression still remain unclear. Here we show that continuous HMF exposure significantly increases the proliferation of human neuroblastoma (SH-SY5Y) cells. The acceleration of proliferation results from a forward shift of the cell cycle in G1-phase. The G2/M-phase progression is not affected in the HMF. Our data is the first to demonstrate that the HMF can stimulate the proliferation of SH-SY5Y cells by promoting cell cycle progression in the G1-phase. This provides a novel way to study the mechanism of cells in response to changes of environmental magnetic field including the GMF. PMID:23355897

  12. Serum Immunoglobulin G4 and Immunoglobulin G1 for Distinguishing Immunoglobulin G4-Associated Cholangitis From Primary Sclerosing Cholangitis

    PubMed Central

    Boonstra, Kirsten; Culver, Emma L; de Buy Wenniger, Lucas Maillette; van Heerde, Marianne J; van Erpecum, Karel J; Poen, Alexander C; van Nieuwkerk, Karin MJ; Spanier, BW Marcel; Witteman, Ben JM; Tuynman, Hans ARE; van Geloven, Nan; van Buuren, Henk; Chapman, Roger W; Barnes, Eleanor; Beuers, Ulrich; Ponsioen, Cyriel Y

    2014-01-01

    The recent addition of immunoglobulin (Ig)G4-associated cholangitis (IAC), also called IgG4-related sclerosing cholangitis (IRSC), to the spectrum of chronic cholangiopathies has created the clinical need for reliable methods to discriminate between IAC and the more common cholestatic entities, primary (PSC) and secondary sclerosing cholangitis. The current American Association for the Study of Liver Diseases practice guidelines for PSC advise on the measurement of specific Ig (sIg)G4 in PSC patients, but interpretation of elevated sIgG4 levels remains unclear. We aimed to provide an algorithm to distinguish IAC from PSC using sIgG analyses. We measured total IgG and IgG subclasses in serum samples of IAC (n = 73) and PSC (n = 310) patients, as well as in serum samples of disease controls (primary biliary cirrhosis; n = 22). sIgG4 levels were elevated above the upper limit of normal (ULN = >1.4 g/L) in 45 PSC patients (15%; 95% confidence interval [CI]: 11-19). The highest specificity and positive predictive value (PPV; 100%) for IAC were reached when applying the 4× ULN (sIgG4 > 5.6 g/L) cutoff with a sensitivity of 42% (95% CI: 31-55). However, in patients with a sIgG4 between 1× and 2× ULN (n = 38/45), the PPV of sIgG4 for IAC was only 28%. In this subgroup, the sIgG4/sIgG1 ratio cutoff of 0.24 yielded a sensitivity of 80% (95% CI: 51-95), a specificity of 74% (95% CI: 57-86), a PPV of 55% (95% CI: 33-75), and a negative predictive value of 90% (95% CI: 73-97). Conclusion: Elevated sIgG4 (>1.4 g/L) occurred in 15% of patients with PSC. In patients with a sIgG4 >1.4 and <2.8 g/L, incorporating the IgG4/IgG1 ratio with a cutoff at 0.24 in the diagnostic algorithm significantly improved PPV and specificity. We propose a new diagnostic algorithm based on IgG4/IgG1 ratio that may be used in clinical practice to distinguish PSC from IAC. (Hepatology 2014;59:1954–1963) PMID:24375491

  13. Dectin-1 agonist selectively induces IgG1 class switching by LPS-activated mouse B cells.

    PubMed

    Seo, Beom-Seok; Park, Ha-Yan; Yoon, Hee-Kyung; Yoo, Yung-Choon; Lee, Junglim; Park, Seok-Rae

    2016-10-01

    Heat-killed Saccharomyces cerevisiae (HKSC) is an agonist for Dectin-1, a major fungal cell wall β-glucan receptor. We previously reported that HKSC selectively enhances IgG1 production by LPS-activated mouse B cells. To determine if this IgG1 selectivity is caused by selective IgG1 class switching, we performed RT-PCRs for measuring germline transcripts (GLTs), flow cytometric analyses for detecting Ig-expressing cells, and ELISPOT assays for measuring the number of Ig-secreting cells in HKSC/LPS-stimulated mouse B cell cultures. HKSC selectively enhanced expression of GLTγ1, the number of IgG1-expressing cells, and the number of IgG1-secreting B cells in the presence of LPS stimulation. In addition, HKSC induced the expression of CD69, an activation marker for B lymphocytes, and the expression of surface Dectin-1. Two Dectin-1 antagonists, laminarin and a neutralizing Dectin-1 antibody, selectively diminished HKSC-reinforced IgG1 production by LPS-stimulated B cells. Furthermore, depleted zymosan (dzn), a Dectin-1 agonist with increased selectivity, also selectively enhanced GLTγ1 transcription. The Dectin-1 antagonists blocked dzn-induced IgG1 production by LPS-activated B cells. Collectively, these results suggest that Dectin-1 agonists selectively induce IgG1 class switching by direct stimulation of Dectin-1 on LPS-activated B cells resulting in selective production of IgG1. PMID:27568820

  14. Dectin-1 agonist selectively induces IgG1 class switching by LPS-activated mouse B cells.

    PubMed

    Seo, Beom-Seok; Park, Ha-Yan; Yoon, Hee-Kyung; Yoo, Yung-Choon; Lee, Junglim; Park, Seok-Rae

    2016-10-01

    Heat-killed Saccharomyces cerevisiae (HKSC) is an agonist for Dectin-1, a major fungal cell wall β-glucan receptor. We previously reported that HKSC selectively enhances IgG1 production by LPS-activated mouse B cells. To determine if this IgG1 selectivity is caused by selective IgG1 class switching, we performed RT-PCRs for measuring germline transcripts (GLTs), flow cytometric analyses for detecting Ig-expressing cells, and ELISPOT assays for measuring the number of Ig-secreting cells in HKSC/LPS-stimulated mouse B cell cultures. HKSC selectively enhanced expression of GLTγ1, the number of IgG1-expressing cells, and the number of IgG1-secreting B cells in the presence of LPS stimulation. In addition, HKSC induced the expression of CD69, an activation marker for B lymphocytes, and the expression of surface Dectin-1. Two Dectin-1 antagonists, laminarin and a neutralizing Dectin-1 antibody, selectively diminished HKSC-reinforced IgG1 production by LPS-stimulated B cells. Furthermore, depleted zymosan (dzn), a Dectin-1 agonist with increased selectivity, also selectively enhanced GLTγ1 transcription. The Dectin-1 antagonists blocked dzn-induced IgG1 production by LPS-activated B cells. Collectively, these results suggest that Dectin-1 agonists selectively induce IgG1 class switching by direct stimulation of Dectin-1 on LPS-activated B cells resulting in selective production of IgG1.

  15. Histone Deacetylase 3 Coordinates Deacetylase-independent Epigenetic Silencing of Transforming Growth Factor-β1 (TGF-β1) to Orchestrate Second Heart Field Development.

    PubMed

    Lewandowski, Sara L; Janardhan, Harish P; Trivedi, Chinmay M

    2015-11-01

    About two-thirds of human congenital heart disease involves second heart field-derived structures. Histone-modifying enzymes, histone deacetylases (HDACs), regulate the epigenome; however, their functions within the second heart field remain elusive. Here we demonstrate that histone deacetylase 3 (HDAC3) orchestrates epigenetic silencing of Tgf-β1, a causative factor in congenital heart disease pathogenesis, in a deacetylase-independent manner to regulate development of second heart field-derived structures. In murine embryos lacking HDAC3 in the second heart field, increased TGF-β1 bioavailability is associated with ascending aortic dilatation, outflow tract malrotation, overriding aorta, double outlet right ventricle, aberrant semilunar valve development, bicuspid aortic valve, ventricular septal defects, and embryonic lethality. Activation of TGF-β signaling causes aberrant endothelial-to-mesenchymal transition and altered extracellular matrix homeostasis in HDAC3-null outflow tracts and semilunar valves, and pharmacological inhibition of TGF-β rescues these defects. HDAC3 recruits components of the PRC2 complex, methyltransferase EZH2, EED, and SUZ12, to the NCOR complex to enrich trimethylation of Lys-27 on histone H3 at the Tgf-β1 regulatory region and thereby maintains epigenetic silencing of Tgf-β1 specifically within the second heart field-derived mesenchyme. Wild-type HDAC3 or catalytically inactive HDAC3 expression rescues aberrant endothelial-to-mesenchymal transition and epigenetic silencing of Tgf-β1 in HDAC3-null outflow tracts and semilunar valves. These findings reveal that epigenetic dysregulation within the second heart field is a predisposing factor for congenital heart disease.

  16. Asymmetric Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz J.; Green, David; Gwynne, Peter; Hwang, Una; Petre, Robert; Reynolds, Stephen P.; Willett, Rebecca

    2016-04-01

    The youngest Galactic supernova remnant (SNR) G1.9+0.3, produced by a (likely) Type Ia SN that exploded around CE 1900, is strongly asymmetric at radio wavelengths but exhibits a bilaterally symmetric morphology in X-rays. It has been difficult to understand the origin of these contrasting morphologies. We present results of X-ray expansion measurements of G1.9+0.3 that illuminate the origin of the radio asymmetry. These measurements are based on comparing recent (2015), 400 ks-long Chandra observations with earlier Chandra observations that include 1 Ms-long 2011 observations. The mean expansion rate from 2011 to 2015 is 0.58% yr-1, in agreement with previous measurements. We also confirm that expansion decreases radially away from the remnant's center along the major E-W axis, from 0.77% yr-1 to 0.53% yr-1. Large variations in expansion are also present along the minor N-S axis. Expansion of the faint S rim and the outermost faint N rim is comparable to the mean expansion. But the prominent X-ray rim in the N, coincident with the outer edge of the bright radio rim that marks the primary blast wave there, is expanding more slowly. Its expansion relative to the S rim is only 0.47% yr-1. At 8.5 kpc, this corresponds to a speed of about 5000 km/s, less than half of the overall blast wave speed of 12,000 km/s. Such strong deceleration of the northern blast wave most likely arises from the collision of SN ejecta with a much denser than average ambient medium there. The presence of the asymmetric ambient medium naturally explains the radio asymmetry. The SN ejecta have also been strongly decelerated in the N, but they expand faster than the blast wave. In several locations, significant morphological changes and strongly nonradial motions are apparent. The spatially-integrated X-ray flux continues to increase with time. As with Kepler's SN - the most recent historical SN in the Galaxy - the SN ejecta are likely colliding with the asymmetric circumstellar medium (CSM

  17. Birth of Archaeal Cells: Molecular Phylogenetic Analyses of G1P Dehydrogenase, G3P Dehydrogenases, and Glycerol Kinase Suggest Derived Features of Archaeal Membranes Having G1P Polar Lipids

    PubMed Central

    2016-01-01

    Bacteria and Eukarya have cell membranes with sn-glycerol-3-phosphate (G3P), whereas archaeal membranes contain sn-glycerol-1-phosphate (G1P). Determining the time at which cells with either G3P-lipid membranes or G1P-lipid membranes appeared is important for understanding the early evolution of terrestrial life. To clarify this issue, we reconstructed molecular phylogenetic trees of G1PDH (G1P dehydrogenase; EgsA/AraM) which is responsible for G1P synthesis and G3PDHs (G3P dehydrogenase; GpsA and GlpA/GlpD) and glycerol kinase (GlpK) which is responsible for G3P synthesis. Together with the distribution of these protein-encoding genes among archaeal and bacterial groups, our phylogenetic analyses suggested that GlpA/GlpD in the Commonote (the last universal common ancestor of all extant life with a cellular form, Commonote commonote) acquired EgsA (G1PDH) from the archaeal common ancestor (Commonote archaea) and acquired GpsA and GlpK from a bacterial common ancestor (Commonote bacteria). In our scenario based on this study, the Commonote probably possessed a G3P-lipid membrane synthesized enzymatically, after which the archaeal lineage acquired G1PDH followed by the replacement of a G3P-lipid membrane with a G1P-lipid membrane. PMID:27774041

  18. Echinococcus canadensis (G7) and Echinococcus granulosus sensu stricto (G1) in swine of southern Brazil.

    PubMed

    Monteiro, D U; Botton, S A; Tonin, A A; Azevedo, M I; Graichen, D A S; Noal, C B; de la Rue, M L

    2014-05-28

    The cystic echinococcosis (CE) is an important zoonotic disease caused by the parasite Echinococcus spp. In Brazil, this parasite is present in Rio Grande do Sul (RS) state, border with Argentina and Uruguay, causing several damages to human and animal health. This study aimed to identify Echinococcus spp. in hydatid cysts of swine and evaluate the similarity of the genotypes through the phylogenetic analysis. A total of 3,101,992 swine were slaughtered in the central/northern region of RS/Brazil, during 2008-2012. Five isolates were characterized as hydatid cyst by molecular analysis, based on the mitochondrial gene cytochrome c oxidase subunit I (cox-I). The genotypes E. granulosus sensu stricto (G1) (n=2) and E. canadensis (G7) (n=3) were identified in the hydatid cysts. The swine represents a potential intermediate host for different genotypes of Echinococcus spp., besides it can contribute to the perpetuation of the parasite's life cycle in rural areas.

  19. Cdi1, a human G1 and S phase protein phosphatase that associates with Cdk2.

    PubMed

    Gyuris, J; Golemis, E; Chertkov, H; Brent, R

    1993-11-19

    We used the interaction trap, a yeast genetic selection for interacting proteins, to isolate human cyclin-dependent kinase interactor 1 (Cdi1). In yeast, Cdi1 interacts with cyclin-dependent kinases, including human Cdc2, Cdk2, and Cdk3, but not with Ckd4. In HeLa cells, Cdi1 is expressed at the G1 to S transition, and the protein forms stable complexes with Cdk2. Cdi1 bears weak sequence similarity to known tyrosine and dual specificity phosphatases. In vitro, Cdi1 removes phosphate from tyrosine residues in model substrates, but a mutant protein that bears a lesion in the putative active site cysteine does not. Overexpression of wild-type Cdi1 delays progression through the cell cycle in yeast and HeLa cells; delay is dependent on Cdi1 phosphatase activity. These experiments identify Cdi1 as a novel type of protein phosphatase that forms complexes with cyclin-dependent kinases. PMID:8242750

  20. The impact of geoengineering on vegetation in experiment G1 of the GeoMIP

    NASA Astrophysics Data System (ADS)

    Glienke, Susanne; Irvine, Peter J.; Lawrence, Mark G.

    2015-10-01

    Solar Radiation Management (SRM) has been proposed as a mean to partly counteract global warming. The Geoengineering Model Intercomparison Project (GeoMIP) has simulated the climate consequences of a number of SRM techniques. Thus far, the effects on vegetation have not yet been thoroughly analyzed. Here the vegetation response to the idealized GeoMIP G1 experiment from eight fully coupled Earth system models (ESMs) is analyzed, in which a reduction of the solar constant counterbalances the radiative effects of quadrupled atmospheric CO2 concentrations (abrupt4 × CO2). For most models and regions, changes in net primary productivity (NPP) are dominated by the increase in CO2, via the CO2 fertilization effect. As SRM will reduce temperatures relative to abrupt4 × CO2, in high latitudes this will offset increases in NPP. In low latitudes, this cooling relative to the abrupt4 × CO2 simulation decreases plant respiration while having little effect on gross primary productivity, thus increasing NPP. In Central America and the Mediterranean, generally dry regions which are expected to experience increased water stress with global warming, NPP is highest in the G1 experiment for all models due to the easing of water limitations from increased water use efficiency at high-CO2 concentrations and the reduced evaporative demand in a geoengineered climate. The largest differences in the vegetation response are between models with and without a nitrogen cycle, with a much smaller CO2 fertilization effect for the former. These results suggest that until key vegetation processes are integrated into ESM predictions, the vegetation response to SRM will remain highly uncertain.

  1. Supernova Ejecta in the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Hwang, Una; Green, David A.; Petre, Robert; Krishnamurthy, Kalyani; Willett, Rebecca

    2013-01-01

    G1.9+0.3 is the youngest known Galactic supernova remnant (SNR), with an estimated supernova (SN) explosion date of approximately 1900, and most likely located near the Galactic Center. Only the outermost ejecta layers with free-expansion velocities (is) approximately greater than 18,000 km s-1 have been shocked so far in this dynamically young, likely Type Ia SNR. A long (980 ks) Chandra observation in 2011 allowed spatially-resolved spectroscopy of heavy-element ejecta. We denoised Chandra data with the spatio-spectral method of Krishnamurthy et al., and used a wavelet based technique to spatially localize thermal emission produced by intermediate-mass elements (IMEs: Si and S) and iron. The spatial distribution of both IMEs and Fe is extremely asymmetric, with the strongest ejecta emission in the northern rim. Fe K alpha emission is particularly prominent there, and fits with thermal models indicate strongly oversolar Fe abundances. In a localized, outlying region in the northern rim, IMEs are less abundant than Fe, indicating that undiluted Fe-group elements (including 56Ni) with velocities greater than 18,000 km s-1 were ejected by this SN. But in the inner west rim, we find Si- and S-rich ejecta without any traces of Fe, so high-velocity products of O-burning were also ejected. G1.9+0.3 appears similar to energetic Type Ia SNe such as SN 2010jn where iron-group elements at such high free-expansion velocities have been recently detected. The pronounced asymmetry in the ejecta distribution and abundance inhomogeneities are best explained by a strongly asymmetric SN explosion, similar to those produced in some recent 3D delayed-detonation Type Ia models.

  2. Production of α2,6-sialylated IgG1 in CHO cells

    PubMed Central

    Raymond, Céline; Robotham, Anna; Spearman, Maureen; Butler, Michael; Kelly, John; Durocher, Yves

    2015-01-01

    The presence of α2,6-sialic acids on the Fc N-glycan provides anti-inflammatory properties to the IgGs through a mechanism that remains unclear. Fc-sialylated IgGs are rare in humans as well as in industrial host cell lines such as Chinese hamster ovary (CHO) cells. Facilitated access to well-characterized α2,6-sialylated IgGs would help elucidate the mechanism of this intriguing IgG's effector function. This study presents a method for the efficient Fc glycan α2,6-sialylation of a wild-type and a F243A IgG1 mutant by transient co-expression with the human α2,6-sialyltransferase 1 (ST6) and β1,4-galactosyltransferase 1 (GT) in CHO cells. Overexpression of ST6 alone only had a moderate effect on the glycoprofiles, whereas GT alone greatly enhanced Fc-galactosylation, but not sialylation. Overexpression of both GT and ST6 was necessary to obtain a glycoprofile dominated by α2,6-sialylated glycans in both antibodies. The wild-type was composed of the G2FS(6)1 glycan (38%) with remaining unsialylated glycans, while the mutant glycoprofile was essentially composed of G2FS(6)1 (25%), G2FS(3,6)2 (16%) and G2FS(6,6)2 (37%). The α2,6-linked sialic acids represented over 85% of all sialic acids in both antibodies. We discuss how the limited sialylation level in the wild-type IgG1 expressed alone or with GT results from the glycan interaction with Fc's amino acid residues or from intrinsic galactosyl- and sialyl-transferases substrate specificities. PMID:25875452

  3. SUPERNOVA EJECTA IN THE YOUNGEST GALACTIC SUPERNOVA REMNANT G1.9+0.3

    SciTech Connect

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Hwang, Una; Green, David A.; Petre, Robert

    2013-07-01

    G1.9+0.3 is the youngest known Galactic supernova remnant (SNR), with an estimated supernova (SN) explosion date of {approx}1900, and most likely located near the Galactic center. Only the outermost ejecta layers with free-expansion velocities {approx}>18,000 km s{sup -1} have been shocked so far in this dynamically young, likely Type Ia SNR. A long (980 ks) Chandra observation in 2011 allowed spatially resolved spectroscopy of heavy-element ejecta. We denoised Chandra data with the spatio-spectral method of Krishnamurthy et al., and used a wavelet-based technique to spatially localize thermal emission produced by intermediate-mass elements (IMEs; Si and S) and iron. The spatial distribution of both IMEs and Fe is extremely asymmetric, with the strongest ejecta emission in the northern rim. Fe K{alpha} emission is particularly prominent there, and fits with thermal models indicate strongly oversolar Fe abundances. In a localized, outlying region in the northern rim, IMEs are less abundant than Fe, indicating that undiluted Fe-group elements (including {sup 56}Ni) with velocities >18,000 km s{sup -1} were ejected by this SN. However, in the inner west rim, we find Si- and S-rich ejecta without any traces of Fe, so high-velocity products of O-burning were also ejected. G1.9+0.3 appears similar to energetic Type Ia SNe such as SN 2010jn where iron-group elements at such high free-expansion velocities have been recently detected. The pronounced asymmetry in the ejecta distribution and abundance inhomogeneities are best explained by a strongly asymmetric SN explosion, similar to those produced in some recent three-dimensional delayed-detonation Type Ia models.

  4. D-type cyclins and G1 progression during liver development in the rat

    SciTech Connect

    Boylan, Joan M. . E-mail: Joan_Boylan@brown.edu; Gruppuso, Philip A. . E-mail: Philip_Gruppuso@brown.edu

    2005-05-13

    Initiation and progression through G1 requires the activity of signaling complexes containing cyclins (D- or E-type) and cyclin-dependent kinases (CDK4/6 and CDK2, respectively). We set out to identify the G1-phase cyclins and CDKs that are operative during late gestation liver development in the rat. This is a period during which hepatocytes show a high rate of proliferation that is, at least in part, independent of the mitogenic signaling pathways that are functional in mature hepatocytes. RNase protection assay and Western immunoblotting indicated that cyclin D1 is expressed at similar levels in fetal and adult liver. When cyclin D1 was induced after partial hepatectomy, its predominant CDK-binding partner was CDK4. In contrast, cyclins D2 and D3 predominated in fetal liver and were complexed with both CDK4 and CDK6. Little CDK6 protein was expressed in quiescent or regenerating adult liver. Cyclins E1 and E2 were both transcriptionally up-regulated in fetal liver. Activity of complexes containing cyclins E1 and E2 was higher in fetal liver, as was content of the cell cycle regulator, Rb. In fetal liver, Rb was highly phosphorylated at both cyclin D- and cyclin E-dependent sites. In conclusion, liver development is associated with a switch from cyclin D2/D3-containing complexes to cyclin D1:CDK4 complexes. We speculate that the switch in D-type cyclins may be associated with the dependence on mitogenic signaling that develops as hepatocytes mature.

  5. Nuclear vasohibin-2 promotes cell proliferation by inducing G0/G1 to S phase progression.

    PubMed

    Ge, Qianqian; Zhou, Jia; Tu, Min; Xue, Xiaofeng; Li, Zhanjun; Lu, Zipeng; Wei, Jishu; Song, Guoxin; Chen, Jianmin; Guo, Feng; Jiang, Kuirong; Miao, Yi; Gao, Wentao

    2015-09-01

    As a member of the vasohibin (VASH2) family, VASH2 is localized intracellularly as a nuclear and cytoplasmic type. Cytoplasmic VASH2 is associated with carcinoma angiogenesis and malignant transformation and promotes cancer growth. However, the function of nuclear VASH2 has yet to be investigated. The aim of the present study was to detect the nuclear VASH2 expression profile in human organs and tissues by protein microarray technique. To examine the function of nuclear VASH2, we analyzed the relationship between nuclear VASH2 and Ki-67, and stably constructed VASH2 overexpression and knockdown in LO2 and HepG2 cell lines, based on a previous study in hepatic cells. The study was conducted using bromodeoxyuridine, immunofluorescent staining, western blot analysis and flow cytometry. Nuclear VASH2 was highly expressed in actively dividing cells in normal and cancer tissues. There was a significant positive correlation between nuclear VASH2 and Ki-67, indicating that nuclear VASH2 positively correlated with cell proliferation in normal and cancer tissues. The bromodeoxyuridine (BrdU) proliferation test showed that nuclear VASH2 increased the S-phase population and promoted cell proliferation, while VASH2 knockdown reduced BrdU absorbance. Cell cycle analysis revealed that nuclear VASH2 overexpression increased the S-phase population in LO2 and HepG2 cells, while nuclear VASH2 knockdown reduced the S-phase population and increased the G0/G1 population. The findings of this study challenge the classic view of VASH2, which was previously reported as an angiogenesis factor. Furthermore, to the best of our knowledge, these results are the first clinical data indicating that nuclear VASH2, but not cytoplasmic VASH2, promotes cell proliferation by driving the cell cycle from the G0/G1 to S phase.

  6. A prominent lack of IgG1-Fc fucosylation of platelet alloantibodies in pregnancy.

    PubMed

    Kapur, Rick; Kustiawan, Iwan; Vestrheim, Anne; Koeleman, Carolien A M; Visser, Remco; Einarsdottir, Helga K; Porcelijn, Leendert; Jackson, Dave; Kumpel, Belinda; Deelder, André M; Blank, Dennis; Skogen, Björn; Killie, Mette Kjaer; Michaelsen, Terje E; de Haas, Masja; Rispens, Theo; van der Schoot, C Ellen; Wuhrer, Manfred; Vidarsson, Gestur

    2014-01-23

    Immunoglobulin G (IgG) formed during pregnancy against human platelet antigens (HPAs) of the fetus mediates fetal or neonatal alloimmune thrombocytopenia (FNAIT). Because antibody titer or isotype does not strictly correlate with disease severity, we investigated by mass spectrometry variations in the glycosylation at Asn297 in the IgG Fc because the composition of this glycan can be highly variable, affecting binding to phagocyte IgG-Fc receptors (FcγR). We found markedly decreased levels of core fucosylation of anti-HPA-1a-specific IgG1 from FNAIT patients (n = 48), but not in total serum IgG1. Antibodies with a low amount of fucose displayed higher binding affinity to FcγRIIIa and FcγRIIIb, but not to FcγRIIa, compared with antibodies with a high amount of Fc fucose. Consequently, these antibodies with a low amount of Fc fucose showed enhanced phagocytosis of platelets using FcγRIIIb(+) polymorphonuclear cells or FcγRIIIa(+) monocytes as effector cells, but not with FcγRIIIa(-) monocytes. In addition, the degree of anti-HPA-1a fucosylation correlated positively with the neonatal platelet counts in FNAIT, and negatively to the clinical disease severity. In contrast to the FNAIT patients, no changes in core fucosylation were observed for anti-HLA antibodies in refractory thrombocytopenia (post platelet transfusion), indicating that the level of fucosylation may be antigen dependent and/or related to the immune milieu defined by pregnancy.

  7. A prominent lack of IgG1-Fc fucosylation of platelet alloantibodies in pregnancy

    PubMed Central

    Kapur, Rick; Kustiawan, Iwan; Vestrheim, Anne; Koeleman, Carolien A. M.; Visser, Remco; Einarsdottir, Helga K.; Porcelijn, Leendert; Jackson, Dave; Kumpel, Belinda; Deelder, André M.; Blank, Dennis; Skogen, Björn; Killie, Mette Kjaer; Michaelsen, Terje E.; de Haas, Masja; Rispens, Theo; van der Schoot, C. Ellen; Wuhrer, Manfred

    2014-01-01

    Immunoglobulin G (IgG) formed during pregnancy against human platelet antigens (HPAs) of the fetus mediates fetal or neonatal alloimmune thrombocytopenia (FNAIT). Because antibody titer or isotype does not strictly correlate with disease severity, we investigated by mass spectrometry variations in the glycosylation at Asn297 in the IgG Fc because the composition of this glycan can be highly variable, affecting binding to phagocyte IgG-Fc receptors (FcγR). We found markedly decreased levels of core fucosylation of anti-HPA-1a–specific IgG1 from FNAIT patients (n = 48), but not in total serum IgG1. Antibodies with a low amount of fucose displayed higher binding affinity to FcγRIIIa and FcγRIIIb, but not to FcγRIIa, compared with antibodies with a high amount of Fc fucose. Consequently, these antibodies with a low amount of Fc fucose showed enhanced phagocytosis of platelets using FcγRIIIb+ polymorphonuclear cells or FcγRIIIa+ monocytes as effector cells, but not with FcγRIIIa– monocytes. In addition, the degree of anti-HPA-1a fucosylation correlated positively with the neonatal platelet counts in FNAIT, and negatively to the clinical disease severity. In contrast to the FNAIT patients, no changes in core fucosylation were observed for anti-HLA antibodies in refractory thrombocytopenia (post platelet transfusion), indicating that the level of fucosylation may be antigen dependent and/or related to the immune milieu defined by pregnancy. PMID:24243971

  8. Analysis of the NuRD subunits reveals a histone deacetylase core complex and a connection with DNA methylation

    PubMed Central

    Zhang, Yi; Ng, Huck-Hui; Erdjument-Bromage, Hediye; Tempst, Paul; Bird, Adrian; Reinberg, Danny

    1999-01-01

    ATP-dependent nucleosome remodeling and core histone acetylation and deacetylation represent mechanisms to alter nucleosome structure. NuRD is a multisubunit complex containing nucleosome remodeling and histone deacetylase activities. The histone deacetylases HDAC1 and HDAC2 and the histone binding proteins RbAp48 and RbAp46 form a core complex shared between NuRD and Sin3-histone deacetylase complexes. The histone deacetylase activity of the core complex is severely compromised. A novel polypeptide highly related to the metastasis-associated protein 1, MTA2, and the methyl-CpG-binding domain-containing protein, MBD3, were found to be subunits of the NuRD complex. MTA2 modulates the enzymatic activity of the histone deacetylase core complex. MBD3 mediates the association of MTA2 with the core histone deacetylase complex. MBD3 does not directly bind methylated DNA but is highly related to MBD2, a polypeptide that binds to methylated DNA and has been reported to possess demethylase activity. MBD2 interacts with the NuRD complex and directs the complex to methylated DNA. NuRD may provide a means of gene silencing by DNA methylation. PMID:10444591

  9. Increased proportion of responders to a murine anti-CD3 monoclonal antibody of the IgG1 class in patients with systemic lupus erythematosus (SLE).

    PubMed Central

    Blasini, A M; Stekman, I L; Leon-Ponte, M; Caldera, D; Rodriguez, M A

    1993-01-01

    A group of Venezuelan patients with SLE showed an increased proportion of responders to Leu-4, an anti-CD3 MoAb of the IgG1 class, compared with ethnically matched non-SLE patients and healthy controls. The rate of proliferative responses or IL-2 production induced by MoAb Leu-4, and the helper effect of macrophages from Leu-4 responders on T cells from a third-party donor were comparable in patients and controls. No significant differences in the binding of murine IgG1 molecules by macrophages from SLE patients and controls were observed. The proportion of monocytes/macrophages expressing Fc gamma RI was significantly higher in SLE patients. However, the expression of FcRII, the type capable of supporting Leu-4-mediated responses, and of Fc gamma RIII was comparable in monocytes from SLE patients and controls. Our results suggest that Venezuelan patients with SLE may have a genetic predisposition for the expression of the phenotypic variant of Fc gamma RII capable of binding murine IgG1 molecules. PMID:8252802

  10. Recruitment of trimeric proliferating cell nuclear antigen by G1-phase cyclin-dependent kinases following DNA damage with platinum-based antitumour agents

    PubMed Central

    He, G; Kuang, J; Koomen, J; Kobayashi, R; Khokhar, A R; Siddik, Z H

    2013-01-01

    Background: In cycling tumour cells, the binary cyclin-dependent kinase Cdk4/cyclin D or Cdk2/cyclin E complex is inhibited by p21 following DNA damage to induce G1 cell-cycle arrest. However, it is not known whether other proteins are also recruited within Cdk complexes, or their role, and this was investigated. Methods: Ovarian A2780 tumour cells were exposed to the platinum-based antitumour agent 1R,2R-diaminocyclohexane(trans-diacetato)(dichloro)platinum(IV) (DAP), which preferentially induces G1 arrest in a p21-dependent manner. The Cdk complexes were analysed by gel filtration chromatography, immunoblot and mass spectrometry. Results: The active forms of Cdk4 and Cdk2 complexes in control tumour cells have a molecular size of ∼140 kDa, which increased to ∼290 kDa when inhibited following G1 checkpoint activation by DAP. Proteomic analysis identified Cdk, cyclin, p21 and proliferating cell nuclear antigen (PCNA) in the inhibited complex, and biochemical studies provided unequivocal evidence that the increase in ∼150 kDa of the inhibited complex is consistent with p21-dependent recruitment of PCNA as a trimer, likely bound to three molecules of p21. Although p21 alone was sufficient to inhibit the Cdk complex, PCNA was critical for stabilising p21. Conclusion: G1 Cdk complexes inhibited by p21 also recruit PCNA, which inhibits degradation and, thereby, prolongs activity of p21 within the complex. PMID:24104967

  11. Banana Transcription Factor MaERF11 Recruits Histone Deacetylase MaHDA1 and Represses the Expression of MaACO1 and Expansins during Fruit Ripening.

    PubMed

    Han, Yan-Chao; Kuang, Jian-Fei; Chen, Jian-Ye; Liu, Xun-Cheng; Xiao, Yun-Yi; Fu, Chang-Chun; Wang, Jun-Ning; Wu, Ke-Qiang; Lu, Wang-Jin

    2016-06-01

    Phytohormone ethylene controls diverse developmental and physiological processes such as fruit ripening via modulation of ethylene signaling pathway. Our previous study identified that ETHYLENE RESPONSE FACTOR11 (MaERF11), a transcription factor in the ethylene signaling pathway, negatively regulates the ripening of banana, but the mechanism for the MaERF11-mediated transcriptional regulation remains largely unknown. Here we showed that MaERF11 has intrinsic transcriptional repression activity in planta. Electrophoretic mobility shift assay and chromatin immunoprecipitation analyses demonstrated that MaERF11 binds to promoters of three ripening-related Expansin genes, MaEXP2, MaEXP7 and MaEXP8, as well as an ethylene biosynthetic gene MaACO1, via the GCC-box motif. Furthermore, expression patterns of MaACO1, MaEXP2, MaEXP7, and MaEXP8 genes are correlated with the changes of histone H3 and H4 acetylation level during fruit ripening. Moreover, we found that MaERF11 physically interacts with a histone deacetylase, MaHDA1, which has histone deacetylase activity, and the interaction significantly strengthens the MaERF11-mediated transcriptional repression of MaACO1 and Expansins Taken together, these findings suggest that MaERF11 may recruit MaHDA1 to its target genes and repress their expression via histone deacetylation. PMID:27208241

  12. Histone deacetylase activity is necessary for left-right patterning during vertebrate development

    PubMed Central

    2011-01-01

    Background Consistent asymmetry of the left-right (LR) axis is a crucial aspect of vertebrate embryogenesis. Asymmetric gene expression of the TGFβ superfamily member Nodal related 1 (Nr1) in the left lateral mesoderm plate is a highly conserved step regulating the situs of the heart and viscera. In Xenopus, movement of maternal serotonin (5HT) through gap-junctional paths at cleavage stages dictates asymmetry upstream of Nr1. However, the mechanisms linking earlier biophysical asymmetries with this transcriptional control point are not known. Results To understand how an early physiological gradient is transduced into a late, stable pattern of Nr1 expression we investigated epigenetic regulation during LR patterning. Embryos injected with mRNA encoding a dominant-negative of Histone Deacetylase (HDAC) lacked Nr1 expression and exhibited randomized sidedness of the heart and viscera (heterotaxia) at stage 45. Timing analysis using pharmacological blockade of HDACs implicated cleavage stages as the active period. Inhibition during these early stages was correlated with an absence of Nr1 expression at stage 21, high levels of heterotaxia at stage 45, and the deposition of the epigenetic marker H3K4me2 on the Nr1 gene. To link the epigenetic machinery to the 5HT signaling pathway, we performed a high-throughput proteomic screen for novel cytoplasmic 5HT partners associated with the epigenetic machinery. The data identified the known HDAC partner protein Mad3 as a 5HT-binding regulator. While Mad3 overexpression led to an absence of Nr1 transcription and randomized the LR axis, a mutant form of Mad3 lacking 5HT binding sites was not able to induce heterotaxia, showing that Mad3's biological activity is dependent on 5HT binding. Conclusion HDAC activity is a new LR determinant controlling the epigenetic state of Nr1 from early developmental stages. The HDAC binding partner Mad3 may be a new serotonin-dependent regulator of asymmetry linking early physiological

  13. Histone deacetylases inhibitor trichostatin A modulates the extracellular release of APE1/Ref-1.

    PubMed

    Choi, Sunga; Lee, Yu Ran; Park, Myoung Soo; Joo, Hee Kyoung; Cho, Eun Jung; Kim, Hyo Shin; Kim, Cuk Seong; Park, Jin Bong; Irani, Kaikobad; Jeon, Byeong Hwa

    2013-06-01

    Apurinic/apyrimidinic endonuclease 1/Redox factor-1 (APE1/Ref-1) can be acetylated via post-translational modification. We investigated the effect of an inhibitor of histone deacetylases on the extracellular release of APE1/Ref-1 in HEK293 cells. Trichostatin A (TSA), an inhibitor of histone deacetylases, induced APE1/Ref-1 secretion without changing cell viability. In a fluorescence quantitative assay, the secreted APE1/Ref-1 was estimated to be about 10 ng/mL in response to TSA (1 μM). However, TSA did not induce the secretion of lysine-mutated APE1/Ref-1 (K6R/K7R). TSA also caused nuclear to cytoplasmic translocation of APE1/Ref-1. Taken together, these findings suggest that APE1/Ref-1 is a protein whose secretion is governed by lysine acetylation.

  14. Histone Deacetylases Inhibitors in the Treatment of Retinal Degenerative Diseases: Overview and Perspectives

    PubMed Central

    Dai, Xufeng; Du, Wei; Pang, Ji-jing

    2015-01-01

    Retinal degenerative diseases are one of the important refractory ophthalmic diseases, featured with apoptosis of photoreceptor cells. Histone acetylation and deacetylation can regulate chromosome assembly, gene transcription, and posttranslational modification, which are regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. The histone deacetylase inhibitors (HDACis) have the ability to cause hyperacetylation of histone and nonhistone proteins, resulting in a variety of effects on cell proliferation, differentiation, anti-inflammation, and anti-apoptosis. Several HDACis have been approved for clinical trials to treat cancer. Studies have shown that HDACis have neuroprotective effects in nervous system damage. In this paper, we will summarize the neuroprotective effects of common HDACis in retinal degenerative diseases and make a prospect to the applications of HDACis in the treatment of retinal degenerative diseases in the future. PMID:26137316

  15. Methyl effect in azumamides provides insight into histone deacetylase inhibition by macrocycles.

    PubMed

    Maolanon, Alex R; Villadsen, Jesper S; Christensen, Niels J; Hoeck, Casper; Friis, Tina; Harris, Pernille; Gotfredsen, Charlotte H; Fristrup, Peter; Olsen, Christian A

    2014-11-26

    Natural, nonribosomal cyclotetrapeptides have traditionally been a rich source of inspiration for design of potent histone deacetylase (HDAC) inhibitors. We recently disclosed the total synthesis and full HDAC profiling of the naturally occurring azumamides ( J. Med. Chem. 2013 , 56 , 6512 ). In this work, we investigate the structural requirements for potent HDAC inhibition by macrocyclic peptides using the azumamides along with a series of unnatural analogues obtained through chemical synthesis. By solving solution NMR structures of selected macrocycles and combining these findings with molecular modeling, we pinpoint crucial enzyme-ligand interactions required for potent inhibition of HDAC3. Docking of additional natural products confirmed these features to be generally important. Combined with the structural conservation across HDACs 1-3, this suggests that while cyclotetrapeptides have provided potent and class-selective HDAC inhibitors, it will be challenging to distinguish between the three major class I deacetylases using these chemotypes.

  16. Non-Peptide Macrocyclic Histone Deacetylase Inhibitors Derived from Tricyclic Ketolide Skeleton

    PubMed Central

    Mwakwari, Sandra C.; Guerrant, William; Patil, Vishal; Khan, Shabana I.; Tekwani, Babu L.; Gurard-Levin, Zachary A.; Mrksich, Milan; Oyelere, Adegboyega K.

    2010-01-01

    Inhibition of histone deacetylase (HDAC) function is a validated therapeutic strategy for cancer treatment. Of the several structurally distinct small molecule histone deacetylase inhibitors (HDACi) reported, macrocyclic depsipeptides possess the most complex cap-groups and have demonstrated excellent HDAC inhibition potency and isoform selectivity. Unfortunately, the development of macrocyclic depsipeptides has been hampered in part due to development problems characteristic of large peptides and the complex reaction schemes required for their synthesis. Herein we report that tricyclic ketolide TE-802 is an excellent mimetic for the peptide backbone of macrocyclic HDACi. Compounds derived from this template are particularly selective against HDAC 1 and 2 with nanomolar inhibitory activity. Interrogation of the association between a subset of these compounds and key HDAC isoforms, using AutoDock, enables a molecular description of the interaction between the HDAC enzyme's outer rim and the inhibitors’ macrocyclic cap group that are responsible for compound affinity and presumably isoform selectivity. PMID:20669972

  17. Structural Basis of Inhibition of the Human NAD+ -Dependent Deacetylase SIRT5 by Suramin

    SciTech Connect

    Schuetz,A.; Min, J.; Antoshenko, T.; Wang, C.; Allali-Hassani, A.; Dong, A.; Loppnau, P.; vedadi, M.; Bochkarev, A.; et al.

    2007-01-01

    Sirtuins are NAD+-dependent protein deacetylases and are emerging as molecular targets for the development of pharmaceuticals to treat human metabolic and neurological diseases and cancer. To date, several sirtuin inhibitors and activators have been identified, but the structural mechanisms of how these compounds modulate sirtuin activity have not yet been determined. We identified suramin as a compound that binds to human SIRT5 and showed that it inhibits SIRT5 NAD+-dependent deacetylase activity with an IC50 value of 22 {mu}M. To provide insights into how sirtuin function is altered by inhibitors, we determined two crystal structures of SIRT5, one in complex with ADP-ribose, the other bound to suramin. Our structural studies provide a view of a synthetic inhibitory compound in a sirtuin active site revealing that suramin binds into the NAD+, the product, and the substrate-binding site. Finally, our structures may enable the rational design of more potent inhibitors.

  18. Phosphorylation-triggered CUEDC2 degradation promotes UV-induced G1 arrest through APC/C(Cdh1) regulation.

    PubMed

    Zhang, Wei-Na; Zhou, Jie; Zhou, Tao; Li, Ai-Ling; Wang, Na; Xu, Jin-Jing; Chang, Yan; Man, Jiang-Hong; Pan, Xin; Li, Tao; Li, Wei-Hua; Mu, Rui; Liang, Bing; Chen, Liang; Jin, Bao-Feng; Xia, Qing; Gong, Wei-Li; Zhang, Xue-Min; Wang, Li; Li, Hui-Yan

    2013-07-01

    DNA damage triggers cell cycle arrest to provide a time window for DNA repair. Failure of arrest could lead to genomic instability and tumorigenesis. DNA damage-induced G1 arrest is generally achieved by the accumulation of Cyclin-dependent kinase inhibitor 1 (p21). However, p21 is degraded and does not play a role in UV-induced G1 arrest. The mechanism of UV-induced G1 arrest thus remains elusive. Here, we have identified a critical role for CUE domain-containing protein 2 (CUEDC2) in this process. CUEDC2 binds to and inhibits anaphase-promoting complex/cyclosome-Cdh1 (APC/C(Cdh1)), a critical ubiquitin ligase in G1 phase, thereby stabilizing Cyclin A and promoting G1-S transition. In response to UV irradiation, CUEDC2 undergoes ERK1/2-dependent phosphorylation and ubiquitin-dependent degradation, leading to APC/C(Cdh1)-mediated Cyclin A destruction, Cyclin-dependent kinase 2 inactivation, and G1 arrest. A nonphosphorylatable CUEDC2 mutant is resistant to UV-induced degradation. Expression of this stable mutant effectively overrides UV-induced G1-S block. These results establish CUEDC2 as an APC/C(Cdh1) inhibitor and indicate that regulated CUEDC2 degradation is critical for UV-induced G1 arrest.

  19. Antitumor Efficacy of Anti-GD2 IgG1 Is Enhanced by Fc Glyco-Engineering.

    PubMed

    Xu, Hong; Guo, Hongfen; Cheung, Irene Y; Cheung, Nai-Kong V

    2016-07-01

    The affinity of therapeutic antibodies for Fcγ receptors (FcγRs) strongly influences their antitumor potency. To generate antibodies with optimal binding and immunologic efficacy, we compared the affinities of different versions of an IgG1 Fc region that had an altered peptide backbone, altered glycans, or both. To produce IgG1 with glycans that lacked α1,6-fucose, we used CHO cells that were deficient in the enzyme UDP-N-acetylglucosamine: α-3-d-mannoside-β-1,2-N-acetylglucosaminyltransferase I (GnT1), encoded by the MGAT1 gene. Mature N-linked glycans require this enzyme, and without it, CHO cells synthesize antibodies carrying only Man5-GlcNAc2, which were more effective in antibody-dependent cell-mediated cytotoxicity (ADCC). Our engineered IgG1, hu3F8-IgG1, is specific for GD2, a neuroendocrine tumor ganglioside. Its peptide mutant is IgG1-DEL (S239D/I332E/A330L), both produced in wild-type CHO cells. When produced in GnT1-deficient CHO cells, we refer to them as IgG1n and IgG1n-DEL, respectively. Affinities for human FcγRs were measured using Biacore T-100 (on CD16 and CD32 polymorphic alleles), their immunologic properties compared for ADCC and complement-mediated cytotoxicity (CMC) in vitro, and pharmacokinetics and antitumor effects were compared in vivo in humanized mice. IgG1n and IgG1n-DEL contained only mannose and acetylglucosamine and had preferential affinity for activating CD16s, over inhibitory CD32B, receptors. In vivo, the antitumor effects of IgG1, IgG1-DEL, and IgG1n-DEL were similar but modest, whereas IgG1n was significantly more effective (P < 0.05). Thus, IgG1n antibodies produced in GnT1-deficient CHO cells may have potential as improved anticancer therapeutics. Cancer Immunol Res; 4(7); 631-8. ©2016 AACR. PMID:27197064

  20. Transcriptional induction of GRP78/BiP by histone deacetylase inhibitors and resistance to histone deacetylase inhibitor-induced apoptosis

    PubMed Central

    Baumeister, Peter; Dong, Dezheng; Fu, Yong; Lee, Amy S.

    2009-01-01

    Histone deacetylase (HDAC) inhibitors are emerging as effective therapies in the treatment of cancer, and the role of HDACs in the regulation of promoters is rapidly expanding. GRP78/BiP is a stress inducible endoplasmic reticulum (ER) chaperone with anti-apoptotic properties. We present here the mechanism for repression of the Grp78 promoter by histone deacetylase 1 (HDAC1). Our studies reveal that HDAC inhibitors specifically induce GRP78, and the induction level is amplified by ER stress. Through mutational analysis, we have identified the minimal Grp78 promoter and specific elements responsible for HDAC-mediated repression. We show the involvement of HDAC1 in the negative regulation of the Grp78 promoter not only by its induction in the presence of the HDAC inhibitors trichostatin A and MS-275, but also by exogenous overexpression and siRNA knockdown of specific HDACs. We present the results of chromatin immunoprecipitation analysis that reveals the binding of HDAC1 to the Grp78 promoter before but not after ER stress. Furthermore, overexpression of GRP78 confers resistance to HDAC inhibitor induced apoptosis in cancer cells and, conversely, suppression of GRP78 sensitizes them to HDAC inhibitor. These results define HDAC inhibitors as new agents that upregulate GRP78 without concomitantly inducing the ER or heat shock stress response, and suppression of GRP78 in tumors may provide a novel, adjunctive option to enhance anti-cancer therapies that utilize these compounds. PMID:19417144

  1. Thermodynamics of ligand binding to histone deacetylase like amidohydrolase from Bordetella/Alcaligenes.

    PubMed

    Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

    2014-03-01

    Thermodynamic studies on ligand-protein binding have become increasingly important in the process of drug design. In combination with structural data and molecular dynamics simulations, thermodynamic studies provide relevant information about the mode of interaction between compounds and their target proteins and therefore build a sound basis for further drug optimization. Using the example of histone deacetylases (HDACs), particularly the histone deacetylase like amidohydrolase (HDAH) from Bordetella/Alcaligenes, a novel sensitive competitive fluorescence resonance energy transfer-based binding assay was developed and the thermodynamics of interaction of both fluorescent ligands and inhibitors to histone deacetylase like amidohydrolase were investigated. The assay consumes only small amounts of valuable target proteins and is suitable for fast kinetic and mechanistic studies as well as high throughput screening applications. Binding affinity increased with increasing length of aliphatic spacers (n = 4-7) between the hydroxamate moiety and the dansyl head group of ligand probes. Van't Hoff plots revealed an optimum in enthalpy contribution to the free energy of binding for the dansyl-ligand with hexyl spacer. The selectivity in the series of dansyl-ligands against human class I HDAC1 but not class II HDACs 4 and 6 increased with the ratio of ΔH(0)/ΔG(0). The data clearly emphasize the importance of thermodynamic signatures as useful general guidance for the optimization of ligands or rational drug design.

  2. Evaluation of histone deacetylase inhibitors (HDACi) as therapeutic leads for human African trypanosomiasis (HAT).

    PubMed

    Carrillo, Angela K; Guiguemde, W Armand; Guy, R Kiplin

    2015-08-15

    Two of the histone deacetylases, TbDAC1 and TbDAC3, have been reported to be essential genes in trypanosomes. Therefore, we tested the activity of a panel of human histone deacetylase inhibitors (HDACi) for their ability to block proliferation of Trypanosoma brucei brucei. Among the HDACi's, the hydroxamic acid derivatives panobinostat and belinostat exhibited potency that appeared to make them viable candidates for development due to their reported pharmacokinetic characteristics. However, cellular pharmacodynamic analysis demonstrated that these drugs were unable to kill cultured parasites at exposures seen in patients at their tolerated doses and additionally failed to show any synergistic effects in combination with pentamidine, suramin, melarsoprol, or nifurtimox. Analysis of the potency of the entire HDACi panel revealed no correlations between potency against any human HDAC isoform and inhibition of T. brucei proliferation, suggesting that the trypanosome histone deacetylases possess a unique specificity. These studies confirmed that HDAC inhibitors have potential as leads against human African trypanosomiasis but that none of the current clinical candidates can be directly repurposed. Therefore, development of HDACi's with appropriate specificity and potency may be a viable route to a new class of anti-trypanosomal drugs.

  3. CHD4 Is a Peripheral Component of the Nucleosome Remodeling and Deacetylase Complex.

    PubMed

    Low, Jason K K; Webb, Sarah R; Silva, Ana P G; Saathoff, Hinnerk; Ryan, Daniel P; Torrado, Mario; Brofelth, Mattias; Parker, Benjamin L; Shepherd, Nicholas E; Mackay, Joel P

    2016-07-22

    Chromatin remodeling enzymes act to dynamically regulate gene accessibility. In many cases, these enzymes function as large multicomponent complexes that in general comprise a central ATP-dependent Snf2 family helicase that is decorated with a variable number of regulatory subunits. The nucleosome remodeling and deacetylase (NuRD) complex, which is essential for normal development in higher organisms, is one such macromolecular machine. The NuRD complex comprises ∼10 subunits, including the histone deacetylases 1 and 2 (HDAC1 and HDAC2), and is defined by the presence of a CHD family remodeling enzyme, most commonly CHD4 (chromodomain helicase DNA-binding protein 4). The existing paradigm holds that CHD4 acts as the central hub upon which the complex is built. We show here that this paradigm does not, in fact, hold and that CHD4 is a peripheral component of the NuRD complex. A complex lacking CHD4 that has HDAC activity can exist as a stable species. The addition of recombinant CHD4 to this nucleosome deacetylase complex reconstitutes a NuRD complex with nucleosome remodeling activity. These data contribute to our understanding of the architecture of the NuRD complex. PMID:27235397

  4. Histone deacetylase inhibitors disrupt the mitotic spindle assembly checkpoint by targeting histone and nonhistone proteins.

    PubMed

    Gabrielli, Brian; Brown, Mellissa

    2012-01-01

    Histone deacetylase inhibitors exhibit pleiotropic effects on cell functions, both in vivo and in vitro. One of the more dramatic effects of these drugs is their ability to disrupt normal mitotic division, which is a significant contributor to the anticancer properties of these drugs. The most important feature of the disrupted mitosis is that drug treatment overcomes the mitotic spindle assembly checkpoint and drives mitotic slippage, but in a manner that triggers apoptosis. The mechanism by which histone deacetylase inhibitors affect mitosis is now becoming clearer through the identification of a number of chromatin and nonchromatin protein targets that are critical to the regulation of normal mitotic progression and cell division. These proteins are directly regulated by acetylation and deacetylation, or in some cases indirectly through the acetylation of essential partner proteins. There appears to be little contribution from deacetylase inhibitor-induced transcriptional changes to the mitotic effects of these drugs. The overall mitotic phenotype of drug treatment appears to be the sum of these disrupted mechanisms. PMID:23088867

  5. CHD4 Is a Peripheral Component of the Nucleosome Remodeling and Deacetylase Complex.

    PubMed

    Low, Jason K K; Webb, Sarah R; Silva, Ana P G; Saathoff, Hinnerk; Ryan, Daniel P; Torrado, Mario; Brofelth, Mattias; Parker, Benjamin L; Shepherd, Nicholas E; Mackay, Joel P

    2016-07-22

    Chromatin remodeling enzymes act to dynamically regulate gene accessibility. In many cases, these enzymes function as large multicomponent complexes that in general comprise a central ATP-dependent Snf2 family helicase that is decorated with a variable number of regulatory subunits. The nucleosome remodeling and deacetylase (NuRD) complex, which is essential for normal development in higher organisms, is one such macromolecular machine. The NuRD complex comprises ∼10 subunits, including the histone deacetylases 1 and 2 (HDAC1 and HDAC2), and is defined by the presence of a CHD family remodeling enzyme, most commonly CHD4 (chromodomain helicase DNA-binding protein 4). The existing paradigm holds that CHD4 acts as the central hub upon which the complex is built. We show here that this paradigm does not, in fact, hold and that CHD4 is a peripheral component of the NuRD complex. A complex lacking CHD4 that has HDAC activity can exist as a stable species. The addition of recombinant CHD4 to this nucleosome deacetylase complex reconstitutes a NuRD complex with nucleosome remodeling activity. These data contribute to our understanding of the architecture of the NuRD complex.

  6. Epigenetic suppression of the antitumor cytotoxicity of NK cells by histone deacetylase inhibitor valproic acid

    PubMed Central

    Shi, Xiumin; Li, Min; Cui, Meizi; Niu, Chao; Xu, Jianting; Zhou, Lei; Li, Wei; Gao, Yushun; Kong, Weisheng; Cui, Jiuwei; Hu, Jifan; Jin, Haofan

    2016-01-01

    Natural killer (NK) cells play an essential role in the fight against tumor development. The therapeutic use of autologous NK cells has been exploited to treat human malignancies, yet only limited antitumor activity is observed in cancer patients. In this study, we sought to augment the antitumor activity of NK cells using epigenetic approaches. Four small molecules that have been known to promote epigenetic reprogramming were tested for their ability to enhance the activity of NK cells. Using a tumor cell lysis assay, we found that the DNA demethylating agent 5-azacytidine and vitamin C did not significantly affect the tumor killing ability of NK cells. The thyroid hormone triiodothyronine (T3) slightly increased the activity of NK cells. The histone deacetylase inhibitor valproic acid (VPA), however, inhibited NK cell lytic activity against leukemic cells in a dose-dependent manner. Pretreatment using VPA reduced IFNγ secretion, impaired CD107a degranulation, and induced apoptosis by activating the PD-1/PD-L1 pathway. VPA downregulated the expression of the activating receptor NKG2D (natural-killer group 2, member D) by inducing histone K9 hypermethylation and DNA methylation in the gene promoter. Histone deacetylase inhibitors have been developed as anticancer agents for use as monotherapies or in combination with other anticancer therapies. Our data suggest that the activity of histone deacetylase inhibitors on NK cell activity should be considered in drug development. PMID:27152238

  7. Deacetylase-Independent Function of HDAC3 in Transcription and Metabolism Requires Nuclear Receptor Corepressor

    PubMed Central

    Sun, Zheng; Feng, Dan; Fang, Bin; Mullican, Shannon E.; You, Seo-Hee; Lim, Hee-Woong; Everett, Logan J.; Nabel, Christopher S.; Li, Yun; Selvakumaran, Vignesh; Won, Kyoung-Jae; Lazar, Mitchell A.

    2013-01-01

    Histone deacetylases (HDACs) are believed to regulate gene transcription by catalyzing deacetylation reactions. HDAC3 depletion in mouse liver upregulates lipogenic genes and results in severe hepatosteatosis. Here we show that pharmacologic HDAC inhibition in primary hepatocytes causes histone hyperacetylation but does not upregulate expression of HDAC3 target genes. Meanwhile, deacetylase-dead HDAC3 mutants can rescue hepatosteatosis and repress lipogenic genes expression in HDAC3-depleted mouse liver, demonstrating that histone acetylation is insufficient to activate gene transcription. Mutations abolishing interactions with the nuclear receptor corepressor (NCOR or SMRT) render HDAC3 nonfunctional in vivo. Additionally, liver-specific knockout of NCOR, but not SMRT, causes metabolic and transcriptomal alterations resembling those of mice without hepatic HDAC3, demonstrating that interaction with NCOR is essential for deacetylase-independent function of HDAC3. These findings highlight non-enzymatic roles of a major HDAC in transcriptional regulation in vivo and warrant reconsideration of the mechanism of action of HDAC inhibitors. PMID:24268577

  8. Isolation, purification, and characterization of a thermostable xylanase from a novel strain, Paenibacillus campinasensis G1-1.

    PubMed

    Zheng, Hongchen; Liu, Yihan; Liu, Xiaoguang; Wang, Jianling; Han, Ying; Lu, Fuping

    2012-07-01

    High levels of xylanase activity (143.98 IU/ml) produced by the newly isolated Paenibacillus campinasensis G1-1 were detected when it was cultivated in a synthetic medium. A thermostable xylanase, designated XynG1-1, from P. campinasensis G1-1 was purified to homogeneity by Octyl-Sepharose hydrophobic-interaction chromatography, Sephadex G75 gel-filter chromatography, and Q-Sepharose ion-exchange chromatography, consecutively. By multistep purification, the specific activity of XynG1-1 was up to 1,865.5 IU/mg with a 9.1-fold purification. The molecular mass of purified XynG1-1 was about 41.3 kDa as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Sequence analysis revealed that XynG1-1 containing 377 amino acids encoded by 1,134 bp genomic sequences of P. campinasensis G1-1 shared 96% homology with XylX from Paenibacillus campinasensis BL11 and 77%~78% homology with xylanases from Bacillus sp. YA- 335 and Bacillus sp. 41M-1, respectively. The activity of XynG1-1 was stimulated by Ca2+, Ba2+, DTT, and beta- mercaptoethanol, but was inhibited by Ni2+, Fe2+, Fe3+, Zn2+, SDS, and EDTA. The purified XynG1-1 displayed a greater affinity for birchwood xylan, with an optimal temperature of 60 degrees C and an optimal pH of 7.5. The fact that XynG1-1 is cellulose-free, thermostable (stability at high temperature of 70 degrees C~80 degrees C), and active over a wide pH range (pH 5.0~9.0) suggests that the enzyme is potentially valuable for various industrial applications, especially for pulp bleaching pretreatment.

  9. Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA directed against malaria histone deacetylase

    SciTech Connect

    Sriwilaijaroen, N.; Boonma, S.; Attasart, P.; Pothikasikorn, J.; Panyim, S.; Noonpakdee, W.

    2009-04-03

    Acetylation and deacetylation of histones play important roles in transcription regulation, cell cycle progression and development events. The steady state status of histone acetylation is controlled by a dynamic equilibrium between competing histone acetylase and deacetylase (HDAC). We have used long PfHDAC-1 double-stranded (ds)RNA to interfere with its cognate mRNA expression and determined the effect on malaria parasite growth and development. Chloroquine- and pyrimethamine-resistant Plasmodium falciparum K1 strain was exposed to 1-25 {mu}g of dsRNA/ml of culture for 48 h and growth was determined by [{sup 3}H]-hypoxanthine incorporation and microscopic examination. Parasite culture treated with 10 {mu}g/ml pfHDAC-1 dsRNA exhibited 47% growth inhibition when compared with either untreated control or culture treated with an unrelated dsRNA. PfHDAC-1 dsRNA specifically blocked maturation of trophozoite to schizont stages and decreased PfHDAC-1 transcript 44% in treated trophozoites. These results indicate the potential of HDAC-1 as a target for development of novel antimalarials.

  10. Heavy-Element Ejecta in G1.9+0.3

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz J.; Reynolds, S. P.; Green, D.; Hwang, U.; Petre, R.; Krishnamurthy, K.; Willett, R.

    2013-04-01

    G1.9+0.3 is the youngest known Galactic supernova remnant (SNR), with an estimated supernova (SN) explosion date of about 1900, most likely located near the Galactic center. Only the outermost ejecta layers with free-expansion velocities in excess of 18,000 km/s have been shocked so far in this dynamically-young, likely Type Ia SNR. A long (980 ks) Chandra observation in 2011 allowed for spatially-resolved spectroscopy of heavy-element ejecta. We denoised Chandra data with the spatio-spectral method of Krishnamurthy, Raginsky, & Willett, and then used a wavelet-based technique to spatially localize thermal emission produced by intermediate-mass elements (IMEs: Si, S, Ar, and Ca) and by iron. The spatial distribution of both IMEs and Fe is extremely asymmetric and inhomogeneous, with the strongest ejecta emission in the northern limb. Fe K emission is particularly prominent there, and fits with a thermal plane-shock model indicate strongly oversolar Fe abundances. In a localized, outlying region in the northern shell, IMEs are at least 5 times less abundant than Fe (by mass), indicating that undiluted Fe-group elements (including radioactive Ni) with velocities > 18,000 km/s were ejected by this SN. More modest (up to a factor of 2) Fe overabundances with respect to IMEs are present in other locations within the northern limb. There are several thousandths of a solar mass of shocked Fe in G1.9+0.3. In several locations within the remnant, including the (inner) west limb, we also find Si- and S-rich ejecta without any traces of Fe, so high-velocity, presumably undiluted products of O-burning were also ejected by the SN. If the underlying continuum is thermal, with plasma temperatures of 3-4 keV, then it must be produced by lighter elements such as O that comprise the bulk of the shocked gas. We discuss these findings in the context of Type Ia SNe such as SN 2010jn where iron-group elements at such high free-expansion velocities have been recently detected. We also

  11. Growth stimulating effect on queen bee larvae of histone deacetylase inhibitors.

    PubMed

    Huang, Chung-Yang; Chi, Li-Ling; Huang, Wei-Jan; Chen, Yue-Wen; Chen, Wei-Jung; Kuo, Yu-Cheng; Yuan, Cheng Mike; Chen, Chia-Nan

    2012-06-20

    Royal jelly (RJ) is a widely used natural food. It is also a major source of nutrition for queen bees and plays a key role in their development. RJ is secreted from the hypopharyngeal and mandibular glands of young adult worker bees. The regulation of gene expression in these two glands may influence the development of queen bees by affecting the content of RJ. This study investigated the epigenetic effects in these two glands in young adult worker bees treated with histone deacetylase inhibitors (HDACis), a U.S. Food and Drug Administration-approved drug, suberoylanilide hydroxamic acid (SAHA), and NBM-HD-1, a novel compound synthesized in this laboratory. Western blot analyses indicated that the levels of acetyl-histone 3 and p21 protein expression in MCF-7 cells increased markedly after treatment with NBM-HD-1. The data proved that NBM-HD-1 was a novel and potent HDACi. Furthermore, a method of affecting epigenetic regulation of the mrjp family gene in the hypopharyngeal and mandibular glands of young adult worker bees was developed by feeding young adult worker bees HDACi. Epigenetic regulation produced several important biological effects. A marked change in the protein composition of the RJ secreted from these treated bees was found. Only the ratio of specific major royal jelly protein 3 (MRJP3) was significantly altered in the treated bees versus the untreated controls. Other MRJP family proteins did not change. This alteration in the ratio of royal jelly proteins resulted in a significant increase in the body size of queen bee larvae. The data seem to suggest that HDACis may play an important role in the epigenetic regulation of the hypopharyngeal and mandibular glands of young adult worker bees. They appear to change mrjp3 gene expression and alter the ratio of MRJP3 protein in RJ. This study presents the first evidence that HDACis are capable of regulating the ratio of MRJP3 proteins in RJ, which has the potential to change the body size of queen bees

  12. Emergence and Characterization of Unusual DS-1-Like G1P[8] Rotavirus Strains in Children with Diarrhea in Thailand

    PubMed Central

    Komoto, Satoshi; Tacharoenmuang, Ratana; Guntapong, Ratigorn; Ide, Tomihiko; Haga, Kei; Katayama, Kazuhiko; Kato, Takema; Ouchi, Yuya; Kurahashi, Hiroki; Tsuji, Takao; Sangkitporn, Somchai; Taniguchi, Koki

    2015-01-01

    The emergence and rapid spread of unusual DS-1-like G1P[8] rotaviruses in Japan have been recently reported. During rotavirus surveillance in Thailand, three DS-1-like G1P[8] strains (RVA/Human-wt/THA/PCB-180/2013/G1P[8], RVA/Human-wt/THA/SKT-109/2013/G1P[8], and RVA/Human-wt/THA/SSKT-41/2013/G1P[8]) were identified in stool specimens from hospitalized children with severe diarrhea. In this study, we sequenced and characterized the complete genomes of strains PCB-180, SKT-109, and SSKT-41. On whole genomic analysis, all three strains exhibited a unique genotype constellation including both genogroup 1 and 2 genes: G1-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. This novel genotype constellation is shared with Japanese DS-1-like G1P[8] strains. Phylogenetic analysis revealed that the G/P genes of strains PCB-180, SKT-109, and SSKT-41 appeared to have originated from human Wa-like G1P[8] strains. On the other hand, the non-G/P genes of the three strains were assumed to have originated from human DS-1-like strains. Thus, strains PCB-180, SKT-109, and SSKT-41 appeared to be derived through reassortment event(s) between Wa-like G1P[8] and DS-1-like human rotaviruses. Furthermore, strains PCB-180, SKT-109, and SSKT-41 were found to have the 11-segment genome almost indistinguishable from one another in their nucleotide sequences and phylogenetic lineages, indicating the derivation of the three strains from a common origin. Moreover, all the 11 genes of the three strains were closely related to those of Japanese DS-1-like G1P[8] strains. Therefore, DS-1-like G1P[8] strains that have emerged in Thailand and Japan were assumed to have originated from a recent common ancestor. To our knowledge, this is the first report on whole genome-based characterization of DS-1-like G1P[8] strains that have emerged in an area other than Japan. Our observations will provide important insights into the evolutionary dynamics of emerging DS-1-like G1P[8] rotaviruses. PMID:26540260

  13. Fangchinoline induces G1 arrest in breast cancer cells through cell-cycle regulation.

    PubMed

    Xing, Zhibo; Zhang, Youxue; Zhang, Xianyu; Yang, Yanmei; Ma, Yuyan; Pang, Da

    2013-12-01

    Fangchinoline, an alkaloid derived from the dry roots of Stephaniae tetrandrine S. Moore (Menispermaceae), has been shown to possess cytotoxic, anti-inflammatory, and antioxidant properties. In this study, we used Fangchinoline to inhibit breast cancer cell proliferation and to investigate its underlying molecular mechanisms. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were both used in this study. We found that Fangchinoline significantly decreased cell proliferation in a dose-dependent manner and induced G1-phase arrest in both cell lines. In addition, upon analysis of expression of cell cycle-related proteins, we found that Fangchinoline reduced expression of cyclin D1, cyclin D3, and cyclin E, and increased expression of the cyclin-dependent kinase (CDK) inhibitors, p21/WAF1, and p27/KIP1. Moreover, Fangchinoline also inhibited the kinase activities of CDK2, CDK4, and CDK6. These results suggest that Fangchinoline can inhibit human breast cancer cell proliferation and thus may have potential applications in cancer therapy. PMID:23401195

  14. 3D structural fluctuation of IgG1 antibody revealed by individual particle electron tomography

    DOE PAGES

    Zhang, Xing; Zhang, Lei; Tong, Huimin; Peng, Bo; Rames, Matthew J.; Zhang, Shengli; Ren, Gang

    2015-05-05

    Commonly used methods for determining protein structure, including X-ray crystallography and single-particle reconstruction, often provide a single and unique three-dimensional (3D) structure. However, in these methods, the protein dynamics and flexibility/fluctuation remain mostly unknown. Here, we utilized advances in electron tomography (ET) to study the antibody flexibility and fluctuation through structural determination of individual antibody particles rather than averaging multiple antibody particles together. Through individual-particle electron tomography (IPET) 3D reconstruction from negatively-stained ET images, we obtained 120 ab-initio 3D density maps at an intermediate resolution (~1–3 nm) from 120 individual IgG1 antibody particles. Using these maps as a constraint, wemore » derived 120 conformations of the antibody via structural flexible docking of the crystal structure to these maps by targeted molecular dynamics simulations. Statistical analysis of the various conformations disclosed the antibody 3D conformational flexibility through the distribution of its domain distances and orientations. This blueprint approach, if extended to other flexible proteins, may serve as a useful methodology towards understanding protein dynamics and functions.« less

  15. Long noncoding RNA linc00598 regulates CCND2 transcription and modulates the G1 checkpoint.

    PubMed

    Jeong, Oh-Seok; Chae, Yun-Cheol; Jung, Hyeonsoo; Park, Soon Cheol; Cho, Sung-Jin; Kook, Hyun; Seo, SangBeom

    2016-01-01

    Data derived from genomic and transcriptomic analyses have revealed that long noncoding RNAs (lncRNAs) have important roles in the transcriptional regulation of various genes. Recent studies have identified the mechanism underlying this function. To date, a variety of noncoding transcripts have been reported to function in conjunction with epigenetic regulator proteins. In this study, we investigated the function of linc00598, which is transcribed by a genomic sequence on chromosome 13, downstream of FoxO1 and upstream of COG6. Microarray analysis showed that linc00598 regulates the transcription of specific target genes, including those for cell cycle regulators. We discovered that linc00598 regulates CCND2 transcription through modulation of the transcriptional regulatory effect of FoxO1 on the CCND2 promoter. Moreover, we observed that knockdown of linc00598 induced G0/G1 cell cycle arrest and inhibited proliferation. These data indicate that linc00598 plays an important role in cell cycle regulation and proliferation through its ability to regulate the transcription of CCND2. PMID:27572135

  16. A gradient in the duration of the G1 phase in the murine neocortical proliferative epithelium

    NASA Technical Reports Server (NTRS)

    Miyama, S.; Takahashi, T.; Nowakowski, R. S.; Caviness, V. S. Jr

    1997-01-01

    Neuronogenesis in the neocortical pseudostratified ventricular epithelium (PVE) is initiated rostrolaterally and progresses caudo-medially as development progresses. Here we have measured the cytokinetic parameters and the fractional neuronal output parameter, Q, of laterally located early-maturing regions over the principal embryonic days (E12-E15) of neocortical neuronogenesis in the mouse. These measures are compared with ones previously made of a medial, late-maturing portion of the PVE. Laterally, as medially, the duration of the neuronogenetic interval is 6 days and comprises 11 integer cell cycles. Also, in both lateral and medial areas the length of G1 phase (TG1) increases nearly 4-fold and is the only cell cycle parameter to change. Q progresses essentially identically laterally and medially with respect to the succession of integer cell cycles. Most importantly, from E12 to E13 there is a steeply declining lateral to medial gradient in TG1. The gradient is due both to the lateral to medial graded stage of neuronogenesis and to the stepwise increase in TG1 with each integer cycle during the neuronogenetic interval. To our knowledge this gradient in TG1 of the cerebral PVE is the first cell biological gradient to be demonstrated experimentally in such an extensive proliferative epithelial sheet. We suggest that this gradient in TG1 is the cellular mechanism for positionally encoding a protomap of the neocortex within the PVE.

  17. Biosimilarity Assessments of Model IgG1-Fc Glycoforms Using a Machine Learning Approach.

    PubMed

    Kim, Jae Hyun; Joshi, Sangeeta B; Tolbert, Thomas J; Middaugh, C Russell; Volkin, David B; Smalter Hall, Aaron

    2016-02-01

    Biosimilarity assessments are performed to decide whether 2 preparations of complex biomolecules can be considered "highly similar." In this work, a machine learning approach is demonstrated as a mathematical tool for such assessments using a variety of analytical data sets. As proof-of-principle, physical stability data sets from 8 samples, 4 well-defined immunoglobulin G1-Fragment crystallizable glycoforms in 2 different formulations, were examined (see More et al., companion article in this issue). The data sets included triplicate measurements from 3 analytical methods across different pH and temperature conditions (2066 data features). Established machine learning techniques were used to determine whether the data sets contain sufficient discriminative power in this application. The support vector machine classifier identified the 8 distinct samples with high accuracy. For these data sets, there exists a minimum threshold in terms of information quality and volume to grant enough discriminative power. Generally, data from multiple analytical techniques, multiple pH conditions, and at least 200 representative features were required to achieve the highest discriminative accuracy. In addition to classification accuracy tests, various methods such as sample space visualization, similarity analysis based on Euclidean distance, and feature ranking by mutual information scores are demonstrated to display their effectiveness as modeling tools for biosimilarity assessments.

  18. Long noncoding RNA linc00598 regulates CCND2 transcription and modulates the G1 checkpoint

    PubMed Central

    Jeong, Oh-Seok; Chae, Yun-Cheol; Jung, Hyeonsoo; Park, Soon Cheol; Cho, Sung-Jin; Kook, Hyun; Seo, SangBeom

    2016-01-01

    Data derived from genomic and transcriptomic analyses have revealed that long noncoding RNAs (lncRNAs) have important roles in the transcriptional regulation of various genes. Recent studies have identified the mechanism underlying this function. To date, a variety of noncoding transcripts have been reported to function in conjunction with epigenetic regulator proteins. In this study, we investigated the function of linc00598, which is transcribed by a genomic sequence on chromosome 13, downstream of FoxO1 and upstream of COG6. Microarray analysis showed that linc00598 regulates the transcription of specific target genes, including those for cell cycle regulators. We discovered that linc00598 regulates CCND2 transcription through modulation of the transcriptional regulatory effect of FoxO1 on the CCND2 promoter. Moreover, we observed that knockdown of linc00598 induced G0/G1 cell cycle arrest and inhibited proliferation. These data indicate that linc00598 plays an important role in cell cycle regulation and proliferation through its ability to regulate the transcription of CCND2. PMID:27572135

  19. Screening of recombinant glycosyltransferases reveals the broad acceptor specificity of stevia UGT-76G1.

    PubMed

    Dewitte, Griet; Walmagh, Maarten; Diricks, Margo; Lepak, Alexander; Gutmann, Alexander; Nidetzky, Bernd; Desmet, Tom

    2016-09-10

    UDP-glycosyltransferases (UGTs) are a promising class of biocatalysts that offer a sustainable alternative for chemical glycosylation of natural products. In this study, we aimed to characterize plant-derived UGTs from the GT-1 family with an emphasis on their acceptor promiscuity and their potential application in glycosylation processes. Recombinant expression in E. coli provided sufficient amounts of enzyme for the in-depth characterization of the salicylic acid UGT from Capsella rubella (UGT-SACr) and the stevia UGT from Stevia rebaudiana (UGT-76G1Sr). The latter was found to have a remarkably broad specificity with activities on a wide diversity of structures, from aliphatic and branched alcohols, over small phenolics to larger flavonoids, terpenoids and even higher glycoside compounds. As an example for its industrial potential, the glycosylation of curcumin was thoroughly evaluated. Under optimized conditions, 96% of curcumin was converted within 24h into the corresponding curcumin β-glycosides. In addition, the reaction was performed in a coupled system with sucrose synthase from Glycine max, to enable the cost-efficient (re)generation of UDP-Glc from sucrose as abundant and renewable resource.

  20. Screening of recombinant glycosyltransferases reveals the broad acceptor specificity of stevia UGT-76G1.

    PubMed

    Dewitte, Griet; Walmagh, Maarten; Diricks, Margo; Lepak, Alexander; Gutmann, Alexander; Nidetzky, Bernd; Desmet, Tom

    2016-09-10

    UDP-glycosyltransferases (UGTs) are a promising class of biocatalysts that offer a sustainable alternative for chemical glycosylation of natural products. In this study, we aimed to characterize plant-derived UGTs from the GT-1 family with an emphasis on their acceptor promiscuity and their potential application in glycosylation processes. Recombinant expression in E. coli provided sufficient amounts of enzyme for the in-depth characterization of the salicylic acid UGT from Capsella rubella (UGT-SACr) and the stevia UGT from Stevia rebaudiana (UGT-76G1Sr). The latter was found to have a remarkably broad specificity with activities on a wide diversity of structures, from aliphatic and branched alcohols, over small phenolics to larger flavonoids, terpenoids and even higher glycoside compounds. As an example for its industrial potential, the glycosylation of curcumin was thoroughly evaluated. Under optimized conditions, 96% of curcumin was converted within 24h into the corresponding curcumin β-glycosides. In addition, the reaction was performed in a coupled system with sucrose synthase from Glycine max, to enable the cost-efficient (re)generation of UDP-Glc from sucrose as abundant and renewable resource. PMID:27378621

  1. 3D structural fluctuation of IgG1 antibody revealed by individual particle electron tomography

    SciTech Connect

    Zhang, Xing; Zhang, Lei; Tong, Huimin; Peng, Bo; Rames, Matthew J.; Zhang, Shengli; Ren, Gang

    2015-05-05

    Commonly used methods for determining protein structure, including X-ray crystallography and single-particle reconstruction, often provide a single and unique three-dimensional (3D) structure. However, in these methods, the protein dynamics and flexibility/fluctuation remain mostly unknown. Here, we utilized advances in electron tomography (ET) to study the antibody flexibility and fluctuation through structural determination of individual antibody particles rather than averaging multiple antibody particles together. Through individual-particle electron tomography (IPET) 3D reconstruction from negatively-stained ET images, we obtained 120 ab-initio 3D density maps at an intermediate resolution (~1–3 nm) from 120 individual IgG1 antibody particles. Using these maps as a constraint, we derived 120 conformations of the antibody via structural flexible docking of the crystal structure to these maps by targeted molecular dynamics simulations. Statistical analysis of the various conformations disclosed the antibody 3D conformational flexibility through the distribution of its domain distances and orientations. This blueprint approach, if extended to other flexible proteins, may serve as a useful methodology towards understanding protein dynamics and functions.

  2. c-myc can induce expression of G0/G1 transition genes.

    PubMed Central

    Schweinfest, C W; Fujiwara, S; Lau, L F; Papas, T S

    1988-01-01

    The human c-myc oncogene was linked to the heat shock-inducible Drosophila hsp70 promoter and used to stably transfect mouse BALB/c 3T3 cells. Heat shock of the transfectants at 42 degrees C followed by recovery at 37 degrees C resulted in the appearance of the human c-myc protein which was appropriately localized to the nuclear fraction. Two-dimensional analysis of the proteins of density-arrested cells which had been heat shock treated revealed the induction of eight protein species and the repression of five protein species. All of the induced and repressed proteins were nonabundant. cDNA clones corresponding to genes induced during the G0/G1 transition were used as probes to assay for c-myc inducibility of these genes. Two anonymous sequences previously identified as serum inducible (3CH77 and 3CH92) were induced when c-myc was expressed. In response to serum stimulation, 3CH77 and 3CH92 were expressed before c-myc mRNA levels increased. However, in response to specific induction of c-myc by heat shock of serum arrested cells, 3CH77 and 3CH92 mRNA levels increased after the rise in c-myc mRNA. Therefore, we hypothesize that abnormal expression of c-myc can induce genes involved in the proliferative response. Images PMID:3211137

  3. Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells

    PubMed Central

    Nagesh, Prashanth Thevkar

    2016-01-01

    ABSTRACT Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. IMPORTANCE Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal

  4. Whole genomic analysis of human G1P[8] rotavirus strains from different age groups in China.

    PubMed

    Shintani, Tsuzumi; Ghosh, Souvik; Wang, Yuan-Hong; Zhou, Xuan; Zhou, Dun-Jin; Kobayashi, Nobumichi

    2012-08-01

    G1P[8] rotaviruses are an important cause of diarrhea in humans in China. To date, there are no reports on the whole genomic analysis of the Chinese G1P[8] rotaviruses. To determine the origin and overall genetic makeup of the recent Chinese G1P[8] strains, the whole genomes of three strains, RVA/Human-wt/CHN/E1911/2009/G1P[8], RVA/Human-tc/CHN/R588/2005/G1P[8] and RVA/Human-tc/CHN/Y128/2004/G1P[8], detected in an infant, a child and an adult, respectively, were analyzed. Strains E1911, R588 and Y128 exhibited a typical Wa-like genotype constellation. Except for the NSP3 gene of E1911, the whole genomes of strains E1911, R588 and Y128 were found to be more closely related to those of the recent Wa-like common human strains from different countries than those of the prototype G1P[8] strain, or other old strains. On the other hand, the NSP3 gene of E1911 was genetically distinct from those of Y128, R588, or other Wa-like common human strains, and appeared to share a common origin with those of the porcine-like human G9 strains, providing evidence for intergenotype reassortment events. Comparisons of the amino acid residues defining the VP7 and VP4 antigenic domains revealed several mismatches between these Chinese G1P[8] strains and the G1 and P[8] strains contained in the currently licensed rotavirus vaccines Rotarix(TM )and RotaTeq(TM). PMID:23012626

  5. Histone deacetylase inhibitors reduce WB-F344 oval cell viability and migration capability by suppressing AKT/mTOR signaling in vitro.

    PubMed

    Zhang, Peng; Zhu, Xiaofeng; Wu, Ying; Hu, Ronglin; Li, Dongming; Du, Jun; Jiao, Xingyuan; He, Xiaoshun

    2016-01-15

    Histone deacetylase (HDAC) can blockDNA replication and transcription and altered HDAC expression was associated with tumorigenesis. This study investigated the effects of HDAC inhibitors on hepatic oval cells and aimed to delineate the underlying molecular events. Hepatic oval cells were treated with two different HDAC inhibitors, suberoylanilidehydroxamic acid (SAHA) and trichostatin-A (TSA). Cells were subjected to cell morphology, cell viability, cell cycle, and wound healing assays. The expression of proteins related to both apoptosis and the cell cycle, and proteins of the AKT/mammalian target of rapamycin (mTOR) signaling pathway were analyzed by Western blot. The data showed that HDAC inhibitors reduced oval cell viability and migration capability, and arrested oval cells at the G0/G1 and S phases of the cell cycle, in a dose- and time-dependent manner. HDAC inhibitors altered cell morphology and reduced oval cell viability, and downregulated the expression of PCNA, cyclinD1, c-Myc and Bmi1 proteins, while also suppressing AKT/mTOR and its downstream target activity. In conclusion, this study demonstrates that HDAC inhibitors affect oval cells by suppressing AKT/mTOR signaling. PMID:26558695

  6. Chidamide, a novel histone deacetylase inhibitor, inhibits the viability of MDS and AML cells by suppressing JAK2/STAT3 signaling.

    PubMed

    Zhao, Sida; Guo, Juan; Zhao, Youshan; Fei, Chengming; Zheng, Qingqing; Li, Xiao; Chang, Chunkang

    2016-01-01

    Many studies have indicated that histone deacetylase (HDAC) activity is always increased in a lot of human tumors, and inhibition of HDAC activity is a promising new strategy in the treatment of cancers. Chidamide, a novel HDAC inhibitor of the benzamide class, is currently under clinical trials. In this study, we aimed to investigate the antitumor activity of Chidamide on myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) cell lines and explore the possible mechanism. Chidamide exhibited efficient anti-proliferative activity on MDS and AML cells in a time- and dose-dependent manner, accompanied by cell cycle arrest at G0/G1 phase and cell apoptosis. Importantly, Chidamide possessed potent HDAC inhibition property, as evaluated by HDAC activity analysis and acetylation of histone H3 and H4. Moreover, Chidamide significantly increased the expression of Suppressors of cytokine signaling 3 (SOCS3), reduced the expression of Janus activated kinases 2 (JAK2) and Signal transducer and activator of transcription 3 (STAT3), and inhibited STAT3 downstream genes, including c-Myc, Bcl-xL, and Mcl-1, which are involved in cell cycle progression and anti-apoptosis. Therefore, we demonstrate that Chidamide exhibits potent inhibitory effect on cell viability of MDS and AML cells, and the possible mechanism may lie in the downregulation of JAK2/STAT3 signaling through SOCS3 upregulation. Our data provide rationale for clinical investigations of Chidamide in MDS and AML.

  7. Chidamide, a novel histone deacetylase inhibitor, inhibits the viability of MDS and AML cells by suppressing JAK2/STAT3 signaling

    PubMed Central

    Zhao, Sida; Guo, Juan; Zhao, Youshan; Fei, Chengming; Zheng, Qingqing; Li, Xiao; Chang, Chunkang

    2016-01-01

    Many studies have indicated that histone deacetylase (HDAC) activity is always increased in a lot of human tumors, and inhibition of HDAC activity is a promising new strategy in the treatment of cancers. Chidamide, a novel HDAC inhibitor of the benzamide class, is currently under clinical trials. In this study, we aimed to investigate the antitumor activity of Chidamide on myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) cell lines and explore the possible mechanism. Chidamide exhibited efficient anti-proliferative activity on MDS and AML cells in a time- and dose-dependent manner, accompanied by cell cycle arrest at G0/G1 phase and cell apoptosis. Importantly, Chidamide possessed potent HDAC inhibition property, as evaluated by HDAC activity analysis and acetylation of histone H3 and H4. Moreover, Chidamide significantly increased the expression of Suppressors of cytokine signaling 3 (SOCS3), reduced the expression of Janus activated kinases 2 (JAK2) and Signal transducer and activator of transcription 3 (STAT3), and inhibited STAT3 downstream genes, including c-Myc, Bcl-xL, and Mcl-1, which are involved in cell cycle progression and anti-apoptosis. Therefore, we demonstrate that Chidamide exhibits potent inhibitory effect on cell viability of MDS and AML cells, and the possible mechanism may lie in the downregulation of JAK2/STAT3 signaling through SOCS3 upregulation. Our data provide rationale for clinical investigations of Chidamide in MDS and AML. PMID:27508038

  8. 26 CFR 1.45G-1 - Railroad track maintenance credit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rules for computing the amount of the RTMC in the case of a controlled group, and for the allocation of the group credit among members of the controlled group. (b) Definitions. For purposes of section 45G... to the controlled group rules under section 45G(e)(2). (2) Eligible railroad track is railroad...

  9. PKCeta enhances cell cycle progression, the expression of G1 cyclins and p21 in MCF-7 cells.

    PubMed

    Fima, E; Shtutman, M; Libros, P; Missel, A; Shahaf, G; Kahana, G; Livneh, E

    2001-10-11

    Protein kinase C encodes a family of enzymes implicated in cellular differentiation, growth control and tumor promotion. However, not much is known with respect to the molecular mechanisms that link protein kinase C to cell cycle control. Here we report that the expression of PKCeta in MCF-7 cells, under the control of a tetracycline-responsive inducible promoter, enhanced cell growth and affected the cell cycle at several points. The induced expression of another PKC isoform, PKCdelta, in MCF-7 cells had opposite effects and inhibited their growth. PKCeta expression activated cellular pathways in these cells that resulted in the increased expression of the G1 phase cyclins, cyclin D and cyclin E. Expression of the cyclin-dependent kinase inhibitor p21(WAF1) was also specifically elevated in PKCeta expressing cells, but its overall effects were not inhibitory. Although, the protein levels of the cyclin-dependent kinase inhibitor p27(KIP1) were not altered by the induced expression of PKCeta, the cyclin E associated Cdk2 kinase activity was in correlation with the p27(KIP1) bound to the cyclin E complex and not by p21(WAF1) binding. PKCeta expression enhanced the removal of p27(KIP1) from this complex, and its re-association with the cyclin D/Cdk4 complex. Reduced binding of p27(KIP1) to the cyclin D/Cdk4 complex at early time points of the cell cycle also enhanced the activity of this complex, while at later time points the decrease in bound p21(WAF1) correlated with its increased activity in PKCeta-expressing cells. Thus, PKCeta induces altered expression of several cell cycle functions, which may contribute to its ability to affect cell growth.

  10. PKCeta enhances cell cycle progression, the expression of G1 cyclins and p21 in MCF-7 cells.

    PubMed

    Fima, E; Shtutman, M; Libros, P; Missel, A; Shahaf, G; Kahana, G; Livneh, E

    2001-10-11

    Protein kinase C encodes a family of enzymes implicated in cellular differentiation, growth control and tumor promotion. However, not much is known with respect to the molecular mechanisms that link protein kinase C to cell cycle control. Here we report that the expression of PKCeta in MCF-7 cells, under the control of a tetracycline-responsive inducible promoter, enhanced cell growth and affected the cell cycle at several points. The induced expression of another PKC isoform, PKCdelta, in MCF-7 cells had opposite effects and inhibited their growth. PKCeta expression activated cellular pathways in these cells that resulted in the increased expression of the G1 phase cyclins, cyclin D and cyclin E. Expression of the cyclin-dependent kinase inhibitor p21(WAF1) was also specifically elevated in PKCeta expressing cells, but its overall effects were not inhibitory. Although, the protein levels of the cyclin-dependent kinase inhibitor p27(KIP1) were not altered by the induced expression of PKCeta, the cyclin E associated Cdk2 kinase activity was in correlation with the p27(KIP1) bound to the cyclin E complex and not by p21(WAF1) binding. PKCeta expression enhanced the removal of p27(KIP1) from this complex, and its re-association with the cyclin D/Cdk4 complex. Reduced binding of p27(KIP1) to the cyclin D/Cdk4 complex at early time points of the cell cycle also enhanced the activity of this complex, while at later time points the decrease in bound p21(WAF1) correlated with its increased activity in PKCeta-expressing cells. Thus, PKCeta induces altered expression of several cell cycle functions, which may contribute to its ability to affect cell growth. PMID:11709714

  11. The G1/S Specific Cyclin D2 Is a Regulator of HIV-1 Restriction in Non-proliferating Cells

    PubMed Central

    Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M.; Ballana, Ester

    2016-01-01

    Macrophages are a heterogeneous cell population strongly influenced by differentiation stimuli that become susceptible to HIV-1 infection after inactivation of the restriction factor SAMHD1 by cyclin-dependent kinases (CDK). Here, we have used primary human monocyte-derived macrophages differentiated through different stimuli to evaluate macrophage heterogeneity on cell activation and proliferation and susceptibility to HIV-1 infection. Stimulation of monocytes with GM-CSF induces a non-proliferating macrophage population highly restrictive to HIV-1 infection, characterized by the upregulation of the G1/S-specific cyclin D2, known to control early steps of cell cycle progression. Knockdown of cyclin D2, enhances HIV-1 replication in GM-CSF macrophages through inactivation of SAMHD1 restriction factor by phosphorylation. Co-immunoprecipitation experiments show that cyclin D2 forms a complex with CDK4 and p21, a factor known to restrict HIV-1 replication by affecting the function of the downstream cascade that leads to SAMHD1 deactivation. Thus, we demonstrate that cyclin D2 acts as regulator of cell cycle proteins affecting SAMHD1-mediated HIV-1 restriction in non-proliferating macrophages. PMID:27541004

  12. Inhibition of G1P3 expression found in the differential display study on respiratory syncytial virus infection

    PubMed Central

    Zhao, Dongchi; Peng, Dan; Li, Lei; Zhang, Qiwei; Zhang, Chuyu

    2008-01-01

    Background Respiratory syncytial virus (RSV) is the leading viral pathogen associated with bronchiolitis and lower respiratory tract disease in infants and young children worldwide. The respiratory epithelium is the primary initiator of pulmonary inflammation in RSV infections, which cause significant perturbations of global gene expression controlling multiple cellular processes. In this study, differential display reverse transcription polymerase chain reaction amplification was performed to examine mRNA expression in a human alveolar cell line (SPC-A1) infected with RSV. Results Of the 2,500 interpretable bands on denaturing polyacrylamide gels, 40 (1.6%) cDNA bands were differentially regulated by RSV, in which 28 (70%) appeared to be upregulated and another 12 (30%) appeared to be downregulated. Forty of the expressed sequence tags (EST) were isolated, and 20 matched homologs in GenBank. RSV infection upregulated the mRNA expression of chemokines CC and CXC and interfered with type α/β interferon-inducible gene expression by upregulation of MG11 and downregulation of G1P3. Conclusion RSV replication could induce widespread changes in gene expression including both positive and negative regulation and play a different role in the down-regulation of IFN-α and up-regulation of IFN-γ inducible gene expression, which suggests that RSV interferes with the innate antiviral response of epithelial cells by multiple mechanisms. PMID:18838000

  13. The impact of geoengineering on vegetation in experiment G1 of the Geoengineering Model Intercomparison Project

    NASA Astrophysics Data System (ADS)

    Irvine, Peter; Glienke, Susanne; Lawrence, Mark

    2015-04-01

    Solar Radiation Management (SRM) has been proposed as a means to partly counteract global warming. The Geoengineering Model Intercomparison Project (GeoMIP) simulated the climate consequences of a number of SRM techniques, but the effects on vegetation have not yet been thoroughly studied. Here, the vegetation response to the idealized GeoMIP G1 experiment is analyzed, in which a reduction of the solar constant counterbalances the radiative effects of quadrupled atmospheric CO2 concentrations; the results from eight fully coupled earth system models (ESMs) are included. For most models and regions, changes in net primary productivity (NPP) are dominated by the increase in CO2, via the CO2 fertilization effect. As SRM will lower temperatures, in high latitudes this will reverse gains in NPP from the lifting of temperature limitations. In low latitudes this cooling relative to the 4xCO2 simulation decreases plant respiration whilst having little effect on gross primary productivity, increasing NPP. Despite reductions in precipitation in most regions in response to SRM, runoff and NPP increase in many regions including those previously highlighted as potentially being at risk of drought under SRM. This is due to simultaneous reductions in evaporation and increases in water use efficiency by plants due to higher CO2 concentrations. The relative differences between models in the vegetation response are substantially larger than the differences in their climate responses. The largest differences between models are for those with and without a nitrogen-cycle, with a much smaller CO2 fertilization effect for the former. These results suggest that until key vegetation processes are integrated into ESM predictions, the vegetation response to SRM will remain highly uncertain.

  14. Induction of G1 cell cycle arrest and apoptosis by berberine in bladder cancer cells.

    PubMed

    Yan, Keqiang; Zhang, Cheng; Feng, Jinbo; Hou, Lifang; Yan, Lei; Zhou, Zunlin; Liu, Zhaoxu; Liu, Cheng; Fan, Yidon; Zheng, Baozhong; Xu, Zhonghua

    2011-07-01

    Bladder cancer is the ninth most common type of cancer, and its surgery is always followed by chemotherapy to prevent recurrence. Berberine is non-toxic to normal cells but has anti-cancer effects in many cancer cell lines. This study was aimed to determine whether berberine inhibits the cell proliferation and induces cell cycle arrest and apoptosis in BIU-87 and T24 bladder cancer cell line. The superficial bladder cancer cell line BIU-87 and invasive T24 bladder cancer cells were treated with different concentrations of berberine. MTT assay was used to determine the effects of berberine on the viability of these cells. The cell cycle arrest was detected through propidium iodide (PI) staining. The induction of apoptosis was determined through Annexin V-conjugated Alexa Fluor 488 (Alexa488) staining. Berberine inhibited the viability of BIU-87 and T24 cells in a dose- and time-dependent manner. It also promoted cell cycle arrest at G0/G1 in a dose-dependent manner and induced apoptosis. We observed that H-Ras and c-fos mRNA and protein expressionswere dose-dependently and time-dependently decreased by berberine treatment. Also, we investigated the cleaved caspase-3 and caspase-9 protein expressions increased in a dose-dependent manner. Berberine inhibits the cell proliferation and induces cell cycle arrest and apoptosis in BIU-87, bladder cancer cell line and T24, invasive bladder cancer cell line. Berberine can inhibit the oncogentic H-Ras and c-fos in T24 cells, and can induce the activation of the caspase-3 and caspase-9 apoptosis. Therefore, berberine has the potential to be a novel chemotherapy drug to treat the bladder cancer by suppressing tumor growth.

  15. Nicotine overrides DNA damage-induced G1/S restriction in lung cells.

    PubMed

    Nishioka, Takashi; Yamamoto, Daisuke; Zhu, Tongbo; Guo, Jinjin; Kim, Sung-Hoon; Chen, Chang Yan

    2011-01-01

    As an addictive substance, nicotine has been suggested to facilitate pro-survival activities (such as anchorage-independent growth or angiogenesis) and the establishment of drug resistance to anticancer therapy. Tobacco smoking consists of a variety of carcinogens [such as benzopyrene (BP) and nitrosamine derivatives] that are able to cause DNA double strand breaks. However, the effect of nicotine on DNA damage-induced checkpoint response induced by genotoxins remains unknown. In this study, we investigated the events occurred during G(1) arrest induced by γ-radiation or BP in nicotine-treated murine or human lung epithelial cells. DNA synthesis was rapidly inhibited after exposure to γ-radiation or BP treatment, accompanied with the activation of DNA damage checkpoint. When these cells were co-treated with nicotine, the growth restriction was compromised, manifested by upregulation of cyclin D and A, and attenuation of Chk2 phosphorylation. Knockdown of cyclin D or Chk2 by the siRNAs blocked nicotine-mediated effect on DNA damage checkpoint activation. However, nicotine treatment appeared to play no role in nocodazole-induced mitotic checkpoint activation. Overall, our study presented a novel observation, in which nicotine is able to override DNA damage checkpoint activated by tobacco-related carcinogen BP or γ-irradiation. The results not only indicates the potentially important role of nicotine in facilitating the establishment of genetic instability to promote lung tumorigenesis, but also warrants a dismal prognosis for cancer patients who are smokers, heavily exposed second-hand smokers or nicotine users. PMID:21559516

  16. Downregulation of CREB Promotes Cell Proliferation by Mediating G1/S Phase Transition in Hodgkin Lymphoma.

    PubMed

    Lu, Fangjin; Zheng, Ying; Donkor, Paul Owusu; Zou, Peng; Mu, Ping

    2016-01-01

    The cyclic-AMP response element-binding protein (CREB), a well-known nuclear transcription factor, has been shown to play an essential role in many cellular processes, including differentiation, cell survival, and cell proliferation, by regulating the expression of downstream genes. Recently, increased expression of CREB was frequently found in various tumors, indicating that CREB is implicated in the process of tumorigenesis. However, the effects of CREB on Hodgkin lymphoma (HL) remain unknown. To clarify the role of CREB in HL, we performed knockdown experiments in HL. We found that downregulation of CREB by short hairpin RNA (shRNA) resulted in enhancement of cell proliferation and promotion of G1/S phase transition, and these effects can be rescued by expression of shRNA-resistant CREB. Meanwhile, the expression level of cell cycle-related proteins, such as cyclin D1, cyclin E1, cyclin-dependent kinase 2 (CDK2), and CDK4, was elevated in response to depletion of CREB. Furthermore, we performed chromatin immunoprecipitation (ChIP) assay and confirmed that CREB directly bound to the promoter regions of these genes, which consequently contributed to the regulation of cell cycle. Consistent with our results, a clinical database showed that high expression of CREB correlates with favorable prognosis in B-cell lymphoma patients, which is totally different from the function of CREB in other cancers such as colorectal cancer, acute myeloid leukemia, and some endocrine cancers. Taken together, all of these features of CREB in HL strongly support its role as a tumor suppressor gene that can decelerate cell proliferation by inhibiting the expression of several cell cycle-related genes. Our results provide new evidence for prognosis prediction of HL and a promising therapeutic strategy for HL patients. PMID:27458098

  17. Exploration of Novel Inhibitors for Class I Histone Deacetylase Isoforms by QSAR Modeling and Molecular Dynamics Simulation Assays

    PubMed Central

    Noor, Zainab; Afzal, Noreen; Rashid, Sajid

    2015-01-01

    Histone deacetylases (HDAC) are metal-dependent enzymes and considered as important targets for cell functioning. Particularly, higher expression of class I HDACs is common in the onset of multiple malignancies which results in deregulation of many target genes involved in cell growth, differentiation and survival. Although substantial attempts have been made to control the irregular functioning of HDACs by employing various inhibitors with high sensitivity towards transformed cells, limited success has been achieved in epigenetic cancer therapy. Here in this study, we used ligand-based pharmacophore and 2-dimensional quantitative structure activity relationship (QSAR) modeling approaches for targeting class I HDAC isoforms. Pharmacophore models were generated by taking into account the known IC50 values and experimental energy scores with extensive validations. The QSAR model having an external R2 value of 0.93 was employed for virtual screening of compound libraries. 10 potential lead compounds (C1-C10) were short-listed having strong binding affinities for HDACs, out of which 2 compounds (C8 and C9) were able to interact with all members of class I HDACs. The potential binding modes of HDAC2 and HDAC8 to C8 were explored through molecular dynamics simulations. Overall, bioactivity and ligand efficiency (binding energy/non-hydrogen atoms) profiles suggested that proposed hits may be more effective inhibitors for cancer therapy. PMID:26431201

  18. SCARECROW-LIKE15 interacts with HISTONE DEACETYLASE19 and is essential for repressing the seed maturation programme

    PubMed Central

    Gao, Ming-Jun; Li, Xiang; Huang, Jun; Gropp, Gordon M.; Gjetvaj, Branimir; Lindsay, Donna L.; Wei, Shu; Coutu, Cathy; Chen, Zhixiang; Wan, Xiao-Chun; Hannoufa, Abdelali; Lydiate, Derek J.; Gruber, Margaret Y.; Chen, Z. Jeffrey; Hegedus, Dwayne D.

    2015-01-01

    Epigenetic regulation of gene expression is critical for controlling embryonic properties during the embryo-to-seedling phase transition. Here we report that a HISTONE DEACETYLASE19 (HDA19)-associated regulator, SCARECROW-LIKE15 (SCL15), is essential for repressing the seed maturation programme in vegetative tissues. SCL15 is expressed in and GFP-tagged SCL15 predominantly localizes to, the vascular bundles particularly in the phloem companion cells and neighbouring specialized cells. Mutation of SCL15 leads to a global shift in gene expression in seedlings to a profile resembling late embryogenesis in seeds. In scl15 seedlings, many genes involved in seed maturation are markedly derepressed with concomitant accumulation of seed 12S globulin; this is correlated with elevated levels of histone acetylation at a subset of seed-specific loci. SCL15 physically interacts with HDA19 and direct targets of HDA19–SCL15 association are identified. These studies reveal that SCL15 acts as an HDA19-associated regulator to repress embryonic traits in seedlings. PMID:26129778

  19. The pan-deacetylase inhibitor panobinostat modulates the expression of epithelial-mesenchymal transition markers in hepatocellular carcinoma models

    PubMed Central

    DI FAZIO, PIETRO; MONTALBANO, ROBERTA; QUINT, KARL; ALINGER, BEATE; KEMMERLING, RALF; KIESSLICH, TOBIAS; OCKER, MATTHIAS; NEUREITER, DANIEL

    2013-01-01

    Deacetylase inhibitors (DACis) represent a novel therapeutic option for human cancers by classically affecting proliferation or apoptosis. Since transdifferentiation and dedifferentiation play a key role in carcinogenesis, we investigated the epigenetic influence on the molecular differentiation status in human hepatocellular carcinoma (HCC) models. Markers of differentiation, including cytokeratin (Ck) 7, Ck8, Ck18, Ck19, Ck20, vimentin, sonic hedgehog homolog (SHH), smoothened (Smo), patched (Ptc), glioma-associated oncogene homolog 1 (Gli1), CD133, octamer-binding transcription factor 4 (Oct4) and β-catenin, were examined in the human HCC cell lines HepG2 and Hep3B in vitro and in vivo (xenograft model) using quantitative real-time PCR and immunohistochemistry following treatment with the pan-DACi panobinostat (LBH589). Compared to untreated controls, treated HepG2 xenografts, and to a lesser extent cell lines, demonstrated a significant increase of differentiation markers Ck7 and Ck19 (classical cholangiocellular type) and Ck8 and Ck18 (classical HCC type), and a decreased level of dedifferentiation markers vimentin (mesenchymal) and SHH/Ptc (embryonic), paralleled with a more membranous expression of β-catenin. These findings were dose-dependently correlated with tumor size, necrosis rate, microvessel density and mitosis/Ki-67-associated proliferation rate. Our results demonstrate that the differentiation status of human HCC cells is influenced by the pan-DACi panobinostat, indicating that this treatment may influence the epithelial-mesenchymal transition (EMT) status related to metastasis and aggressiveness. PMID:23255907

  20. Exposure to histone deacetylase inhibitors during Pavlovian conditioning enhances subsequent cue-induced reinstatement of operant behavior.

    PubMed

    Ploense, Kyle L; Kerstetter, Kerry A; Wade, Matthew A; Woodward, Nicholas C; Maliniak, Dan; Reyes, Michael; Uchizono, Russell S; Bredy, Timothy W; Kippin, Tod E

    2013-06-01

    Histone deacetylase inhibitors (HDACIs) strengthen memory following fear conditioning and cocaine-induced conditioned place preference. Here, we examined the effects of two nonspecific HDACIs, valproic acid (VPA) and sodium butyrate (NaB), on appetitive learning measured by conditioned stimulus (CS)-induced reinstatement of operant responding. Rats were trained to lever press for food reinforcement and then injected with VPA (50-200 mg/kg, i.p.), NaB (250-1000 mg/kg, i.p.), or saline vehicle (1.0 ml/kg), 2 h before receiving pairings of noncontingent presentation of food pellets preceded by a tone+light cue CS. Rats next underwent extinction of operant responding followed by response-contingent re-exposure to the CS. Rats receiving VPA (100 mg/kg) or NaB (1000 mg/kg) before conditioning displayed significantly higher cue-induced reinstatement than did saline controls. Rats that received either vehicle or VPA (100 mg/kg) before a conditioning session with a randomized relation between presentation of food pellets and the CS failed to show subsequent cue-induced reinstatement with no difference between the two groups. These findings indicate that, under certain contexts, HDACIs strengthen memory formation by specifically increasing the associative strength of the CS, not through an increasing motivation to seek reinforcement.

  1. Histone deacetylases and the nuclear receptor corepressor regulate lytic-latent switch gene 50 in murine gammaherpesvirus 68-infected macrophages.

    PubMed

    Goodwin, Megan M; Molleston, Jerome M; Canny, Susan; Abou El Hassan, Mohamed; Willert, Erin K; Bremner, Rod; Virgin, Herbert W

    2010-11-01

    Gammaherpesviruses are important oncogenic pathogens that transit between lytic and latent life cycles. Silencing the lytic gene expression program enables the establishment of latency and a lifelong chronic infection of the host. In murine gammaherpesvirus 68 (MHV68, γHV68), essential lytic switch gene 50 controls the interchange between lytic and latent gene expression programs. However, negative regulators of gene 50 expression remain largely undefined. We report that the MHV68 lytic cycle is silenced in infected macrophages but not fibroblasts and that histone deacetylases (HDACs) mediate silencing. The HDAC inhibitor trichostatin A (TSA) acts on the gene 50 promoter to induce lytic replication of MHV68. HDAC3, HDAC4, and the nuclear receptor corepressor (NCoR) are required for efficient silencing of gene 50 expression. NCoR is critical for transcriptional repression of cellular genes by unliganded nuclear receptors. Retinoic acid, a known ligand for the NCoR complex, derepresses gene 50 expression and enhances MHV68 lytic replication. Moreover, HDAC3, HDAC4, and NCoR act on the gene 50 promoter and are recruited to this promoter in a retinoic acid-responsive manner. We provide the first example of NCoR-mediated, HDAC-dependent regulation of viral gene expression. PMID:20719946

  2. Histone Deacetylase (HDAC) Inhibitor Kinetic Rate Constants Correlate with Cellular Histone Acetylation but Not Transcription and Cell Viability

    PubMed Central

    Lauffer, Benjamin E. L.; Mintzer, Robert; Fong, Rina; Mukund, Susmith; Tam, Christine; Zilberleyb, Inna; Flicke, Birgit; Ritscher, Allegra; Fedorowicz, Grazyna; Vallero, Roxanne; Ortwine, Daniel F.; Gunzner, Janet; Modrusan, Zora; Neumann, Lars; Koth, Christopher M.; Lupardus, Patrick J.; Kaminker, Joshua S.; Heise, Christopher E.; Steiner, Pascal

    2013-01-01

    Histone deacetylases (HDACs) are critical in the control of gene expression, and dysregulation of their activity has been implicated in a broad range of diseases, including cancer, cardiovascular, and neurological diseases. HDAC inhibitors (HDACi) employing different zinc chelating functionalities such as hydroxamic acids and benzamides have shown promising results in cancer therapy. Although it has also been suggested that HDACi with increased isozyme selectivity and potency may broaden their clinical utility and minimize side effects, the translation of this idea to the clinic remains to be investigated. Moreover, a detailed understanding of how HDACi with different pharmacological properties affect biological functions in vitro and in vivo is still missing. Here, we show that a panel of benzamide-containing HDACi are slow tight-binding inhibitors with long residence times unlike the hydroxamate-containing HDACi vorinostat and trichostatin-A. Characterization of changes in H2BK5 and H4K14 acetylation following HDACi treatment in the neuroblastoma cell line SH-SY5Y revealed that the timing and magnitude of histone acetylation mirrored both the association and dissociation kinetic rates of the inhibitors. In contrast, cell viability and microarray gene expression analysis indicated that cell death induction and changes in transcriptional regulation do not correlate with the dissociation kinetic rates of the HDACi. Therefore, our study suggests that determining how the selective and kinetic inhibition properties of HDACi affect cell function will help to evaluate their therapeutic utility. PMID:23897821

  3. Histone Deacetylase Inhibitors Enhance CD4 T Cell Susceptibility to NK Cell Killing but Reduce NK Cell Function

    PubMed Central

    Pace, Matthew; Williams, James; Kurioka, Ayako; Gerry, Andrew B.; Jakobsen, Bent; Klenerman, Paul; Nwokolo, Nneka; Fox, Julie

    2016-01-01

    In the search for a cure for HIV-1 infection, histone deacetylase inhibitors (HDACi) are being investigated as activators of latently infected CD4 T cells to promote their targeting by cytotoxic T-lymphocytes (CTL). However, HDACi may also inhibit CTL function, suggesting different immunotherapy approaches may need to be explored. Here, we study the impact of different HDACi on both Natural Killer (NK) and CTL targeting of HIV-1 infected cells. We found HDACi down-regulated HLA class I expression independently of HIV-1 Nef which, without significantly compromising CTL function, led to enhanced targeting by NK cells. HDACi-treated HIV-1-infected CD4 T cells were also more effectively cleared than untreated controls during NK co-culture. However, HDACi impaired NK function, reducing degranulation and killing capacity. Depending on the HDACi and dose, this impairment could counteract the benefit gained by treating infected target cells. These data suggest that following HDACi-induced HLA class I down-regulation NK cells kill HIV-1-infected cells, although HDACi-mediated NK cell inhibition may negate this effect. Our data emphasize the importance of studying the effects of potential interventions on both targets and effectors. PMID:27529554

  4. Sodium butyrate stimulates expression of fibroblast growth factor 21 in liver by inhibition of histone deacetylase 3.

    PubMed

    Li, Huating; Gao, Zhanguo; Zhang, Jin; Ye, Xin; Xu, Aimin; Ye, Jianping; Jia, Weiping

    2012-04-01

    Fibroblast growth factor 21 (FGF21) stimulates fatty acid oxidation and ketone body production in animals. In this study, we investigated the role of FGF21 in the metabolic activity of sodium butyrate, a dietary histone deacetylase (HDAC) inhibitor. FGF21 expression was examined in serum and liver after injection of sodium butyrate into dietary obese C57BL/6J mice. The role of FGF21 was determined using antibody neutralization or knockout mice. FGF21 transcription was investigated in liver and HepG2 hepatocytes. Trichostatin A (TSA) was used in the control as an HDAC inhibitor. Butyrate was compared with bezafibrate and fenofibrate in the induction of FGF21 expression. Butyrate induced FGF21 in the serum, enhanced fatty acid oxidation in mice, and stimulated ketone body production in liver. The butyrate activity was significantly reduced by the FGF21 antibody or gene knockout. Butyrate induced FGF21 gene expression in liver and hepatocytes by inhibiting HDAC3, which suppresses peroxisome proliferator-activated receptor-α function. Butyrate enhanced bezafibrate activity in the induction of FGF21. TSA exhibited a similar set of activities to butyrate. FGF21 mediates the butyrate activity to increase fatty acid use and ketogenesis. Butyrate induces FGF21 transcription by inhibition of HDAC3.

  5. Intercellular transfer of P-glycoprotein in human blood-brain barrier endothelial cells is increased by histone deacetylase inhibitors

    PubMed Central

    Noack, Andreas; Noack, Sandra; Buettner, Manuela; Naim, Hassan Y.; Löscher, Wolfgang

    2016-01-01

    The blood–brain barrier (BBB) controls the entry of compounds into the brain, thereby regulating brain homeostasis. Efflux transporters such as P-glycoprotein (Pgp) significantly contribute to BBB function. Multiple signaling pathways modulate the expression and activity of Pgp in response to xenobiotics and disease. A non-genetic way of intercellular transfer of Pgp occurs in cancer cells, but whether this also occurs in non-cancer cells such as endothelial cells that form the BBB is not known. A human brain endothelial cell line (hCMEC/D3) was used to study whether cell-to-cell Pgp transfer occurs during co-culturing with Pgp-EGFP expressing hCMEC/D3 cells. The Pgp-EGFP fusion protein was transferred from donor to recipient cells by cell-to-cell contact and Pgp-EGFP enriched vesicles, which were exocytosed by donor cells and endocytosed by adherent recipient cells. Flow cytometry experiments with the Pgp substrate eFLUXX-ID Gold demonstrated that the transferred Pgp is functional in the recipient cells. Exposure of the donor cells with inhibitors of histone deacetylases (HDACs) resulted in an enhanced intercellular Pgp transfer. Non-genetic transfer of a resistance phenotype and its regulation by HDACs is a novel mechanism of altering BBB functionality. This mechanism may have important implications for understanding drug-induced alterations in Pgp expression and activity. PMID:27375084

  6. Exploration of Novel Inhibitors for Class I Histone Deacetylase Isoforms by QSAR Modeling and Molecular Dynamics Simulation Assays.

    PubMed

    Noor, Zainab; Afzal, Noreen; Rashid, Sajid

    2015-01-01

    Histone deacetylases (HDAC) are metal-dependent enzymes and considered as important targets for cell functioning. Particularly, higher expression of class I HDACs is common in the onset of multiple malignancies which results in deregulation of many target genes involved in cell growth, differentiation and survival. Although substantial attempts have been made to control the irregular functioning of HDACs by employing various inhibitors with high sensitivity towards transformed cells, limited success has been achieved in epigenetic cancer therapy. Here in this study, we used ligand-based pharmacophore and 2-dimensional quantitative structure activity relationship (QSAR) modeling approaches for targeting class I HDAC isoforms. Pharmacophore models were generated by taking into account the known IC50 values and experimental energy scores with extensive validations. The QSAR model having an external R2 value of 0.93 was employed for virtual screening of compound libraries. 10 potential lead compounds (C1-C10) were short-listed having strong binding affinities for HDACs, out of which 2 compounds (C8 and C9) were able to interact with all members of class I HDACs. The potential binding modes of HDAC2 and HDAC8 to C8 were explored through molecular dynamics simulations. Overall, bioactivity and ligand efficiency (binding energy/non-hydrogen atoms) profiles suggested that proposed hits may be more effective inhibitors for cancer therapy.

  7. Activity in mice of recombinant BCG-EgG1Y162 vaccine for Echinococcus granulosus infection.

    PubMed

    Ma, Xiumin; Zhao, Hui; Zhang, Fengbo; Zhu, Yuejie; Peng, Shanshan; Ma, Haimei; Cao, Chunbao; Xin, Yan; Yimiti, Delixiati; Wen, Hao; Ding, Jianbing

    2016-01-01

    Cystic hydatid disease is a zoonotic parasitic disease caused by Echinococcus granulosus which is distributed worldwide. The disease is difficult to treat with surgery removal is the only cure treatment. In the high endemic areas, vaccination of humans is believed a way to protect communities from the disease. In this study we vaccinated BALB/c mice with rBCG-EgG1Y162, and then detected the level of IgG and IgE specifically against the recombinant protein by ELISA, rBCG-EgG1Y162 induced strong and specific cellular and humoral immune responses. In vitro study showed that rBCG-EgG1Y162 vaccine not only promote splenocytes proliferation but also active T cell. In addition, the rBCG-EgG1Y162 induced a protection in the mice against secondary infection of Echinococcus granulosus.

  8. Activity in mice of recombinant BCG-EgG1Y162 vaccine for Echinococcus granulosus infection

    PubMed Central

    Ma, Xiumin; Zhao, Hui; Zhang, Fengbo; Zhu, Yuejie; Peng, Shanshan; Ma, Haimei; Cao, Chunbao; Xin, Yan; Yimiti, Delixiati; Wen, Hao; Ding, Jianbing

    2016-01-01

    Cystic hydatid disease is a zoonotic parasitic disease caused by Echinococcus granulosus which is distributed worldwide. The disease is difficult to treat with surgery removal is the only cure treatment. In the high endemic areas, vaccination of humans is believed a way to protect communities from the disease. In this study we vaccinated BALB/c mice with rBCG-EgG1Y162, and then detected the level of IgG and IgE specifically against the recombinant protein by ELISA, rBCG-EgG1Y162 induced strong and specific cellular and humoral immune responses. In vitro study showed that rBCG-EgG1Y162 vaccine not only promote splenocytes proliferation but also active T cell. In addition, the rBCG-EgG1Y162 induced a protection in the mice against secondary infection of Echinococcus granulosus. PMID:26266551

  9. Review of geochemical reference sample programs since G-1 and W-1: progress to date and remaining challenges

    USGS Publications Warehouse

    Kane, J.S.

    1991-01-01

    A brief history of programs to develop geochemical reference samples and certified reference samples for use in geochemical analysis is presented. While progress has been made since G-1 and W-1 were issued, many challenges remain. ?? 1991.

  10. Galactosylation of IgG1 modulates FcγRIIB-mediated inhibition of murine autoimmune hemolytic anemia.

    PubMed

    Yamada, Kazunori; Ito, Kiyoaki; Furukawa, Jun-Ichi; Nakata, Junichiro; Alvarez, Montserrat; Verbeek, J Sjef; Shinohara, Yasuro; Izui, Shozo

    2013-12-01

    Murine immune effector cells express three different stimulatory FcγRs (FcγRI, FcγRIII and FcγRIV) and one inhibitory receptor, FcγRIIB. Competitive engagement of stimulatory and inhibitory FcγRs has been shown to be critical for the development of immune complex-mediated inflammatory disorders. Because of the previous demonstration that FcγRIIB was unable to inhibit FcγRIII-mediated autoimmune hemolytic anemia induced by 105-2H IgG1 anti-RBC mAb, we reevaluated the regulatory role of FcγRIIB on the development of anemia using two additional IgG1 anti-RBC mAbs (34-3C and 3H5G1) and different 34-3C IgG subclass-switch variants. We were able to induce a more severe anemia in FcγRIIB-deficient mice than in FcγRIIB-sufficient mice after injection of 34-3C and 3H5G1 IgG1, but not 105-2H IgG1. Structural analysis of N-linked oligosaccharides attached to the CH2 domain revealed that 105-2H was poorly galactosylated as compared with the other mAbs, while the extent of sialylation was comparable between all mAbs. In addition, we observed that a more galactosylated 105-2H variant provoked more severe anemia in FcγRIIB-deficient mice than FcγRIIB-sufficient mice. In contrast, the development of anemia induced by three non-IgG1 subclass variants of the 34-3C mAb was not down-regulated by FcγRIIB, although they were more galactosylated than its IgG1 variant. These data indicate that FcγRIIB-mediated inhibition of autoimmune hemolytic anemia is restricted to the IgG1 subclass and that galactosylation, but not sialylation, of IgG1 (but not other IgG subclasses) is critical for the interaction with FcγR, thereby determining the pathogenic potential of IgG1 autoantibodies.

  11. Fc Engineering of Human IgG1 for Altered Binding to the Neonatal Fc Receptor Affects Fc Effector Functions.

    PubMed

    Grevys, Algirdas; Bern, Malin; Foss, Stian; Bratlie, Diane Bryant; Moen, Anders; Gunnarsen, Kristin Støen; Aase, Audun; Michaelsen, Terje Einar; Sandlie, Inger; Andersen, Jan Terje

    2015-06-01

    Engineering of the constant Fc part of monoclonal human IgG1 (hIgG1) Abs is an approach to improve effector functions and clinical efficacy of next-generation IgG1-based therapeutics. A main focus in such development is tailoring of in vivo half-life and transport properties by engineering the pH-dependent interaction between IgG and the neonatal Fc receptor (FcRn), as FcRn is the main homeostatic regulator of hIgG1 half-life. However, whether such engineering affects binding to other Fc-binding molecules, such as the classical FcγRs and complement factor C1q, has not been studied in detail. These effector molecules bind to IgG1 in the lower hinge-CH2 region, structurally distant from the binding site for FcRn at the CH2-CH3 elbow region. However, alterations of the structural composition of the Fc may have long-distance effects. Indeed, in this study we show that Fc engineering of hIgG1 for altered binding to FcRn also influences binding to both the classical FcγRs and complement factor C1q, which ultimately results in alterations of cellular mechanisms such as Ab-dependent cell-mediated cytotoxicity, Ab-dependent cellular phagocytosis, and Ab-dependent complement-mediated cell lysis. Thus, engineering of the FcRn-IgG1 interaction may greatly influence effector functions, which has implications for the therapeutic efficacy and use of Fc-engineered hIgG1 variants.

  12. Fc Engineering of Human IgG1 for Altered Binding to the Neonatal Fc Receptor Affects Fc Effector Functions

    PubMed Central

    Grevys, Algirdas; Bern, Malin; Foss, Stian; Bratlie, Diane Bryant; Moen, Anders; Gunnarsen, Kristin Støen; Aase, Audun; Michaelsen, Terje Einar; Sandlie, Inger

    2015-01-01

    Engineering of the constant Fc part of monoclonal human IgG1 (hIgG1) Abs is an approach to improve effector functions and clinical efficacy of next-generation IgG1-based therapeutics. A main focus in such development is tailoring of in vivo half-life and transport properties by engineering the pH-dependent interaction between IgG and the neonatal Fc receptor (FcRn), as FcRn is the main homeostatic regulator of hIgG1 half-life. However, whether such engineering affects binding to other Fc-binding molecules, such as the classical FcγRs and complement factor C1q, has not been studied in detail. These effector molecules bind to IgG1 in the lower hinge–CH2 region, structurally distant from the binding site for FcRn at the CH2–CH3 elbow region. However, alterations of the structural composition of the Fc may have long-distance effects. Indeed, in this study we show that Fc engineering of hIgG1 for altered binding to FcRn also influences binding to both the classical FcγRs and complement factor C1q, which ultimately results in alterations of cellular mechanisms such as Ab-dependent cell-mediated cytotoxicity, Ab-dependent cellular phagocytosis, and Ab-dependent complement-mediated cell lysis. Thus, engineering of the FcRn–IgG1 interaction may greatly influence effector functions, which has implications for the therapeutic efficacy and use of Fc-engineered hIgG1 variants. PMID:25904551

  13. Mutational analysis of a histone deacetylase in Drosophila melanogaster: missense mutations suppress gene silencing associated with position effect variegation.

    PubMed Central

    Mottus, R; Sobel, R E; Grigliatti, T A

    2000-01-01

    For many years it has been noted that there is a correlation between acetylation of histones and an increase in transcriptional activity. One prediction, based on this correlation, is that hypomorphic or null mutations in histone deacetylase genes should lead to increased levels of histone acetylation and result in increased levels of transcription. It was therefore surprising when it was reported, in both yeast and fruit flies, that mutations that reduced or eliminated a histone deacetylase resulted in transcriptional silencing of genes subject to telomeric and heterochromatic position effect variegation (PEV). Here we report the first mutational analysis of a histone deacetylase in a multicellular eukaryote by examining six new mutations in HDAC1 of Drosophila melanogaster. We observed a suite of phenotypes accompanying the mutations consistent with the notion that HDAC1 acts as a global transcriptional regulator. However, in contrast to recent findings, here we report that specific missense mutations in the structural gene of HDAC1 suppress the silencing of genes subject to PEV. We propose that the missense mutations reported here are acting as antimorphic mutations that "poison" the deacetylase complex and propose a model that accounts for the various phenotypes associated with lesions in the deacetylase locus. PMID:10655219

  14. DNA resection proteins Sgs1 and Exo1 are required for G1 checkpoint activation in budding yeast

    PubMed Central

    Balogun, Fiyinfolu O.; Truman, Andrew W.; Kron, Stephen J.

    2013-01-01

    Double-strand breaks (DSBs) in budding yeast trigger activation of DNA damage checkpoints, allowing repair to occur. Although resection is necessary for initiating damage-induced cell cycle arrest in G2, no role has been assigned to it in the activation of G1 checkpoint. Here we demonstrate for the first time that the resection proteins Sgs1 and Exo1 are required for efficient G1 checkpoint activation. We find in G1 arrested cells that histone H2A phosphorylation in response to ionizing radiation is independent of Sgs1 and Exo1. In contrast, these proteins are required for damage-induced recruitment of Rfa1 to the DSB sites, phosphorylation of the Rad53 effector kinase, cell cycle arrest and RNR3 expression. Checkpoint activation in G1 requires the catalytic activity of Sgs1, suggesting that it is DNA resection mediated by Sgs1 that stimulates the damage response pathway rather than protein-protein interactions with other DDR proteins. Together, these results implicate DNA resection, which is thought to be minimal in G1, as necessary for activation of the G1 checkpoint. PMID:23835406

  15. Characterization of a G1 inhibitor from old JB-1 ascites tumor fluid. Interaction with polyions and ion exchangers.

    PubMed

    Barfod, N M; Bichel, P

    1976-09-17

    In most experimental ascites tumors the growth rate decreases with increasing age and cell number. This decrease is caused by a prolongation of the cell cycle and an increasing accumulation of noncycling cells in resting (or quiescent) G1 and G2 compartments. In cell-free ascitic fluid from the JB-1 ascites tumor in the plateau phase of growth, low molecular weight substances have been found which reversibly and specifically arrest JB-1 cells in G1 and G2. In order to characterize the JB-1 G1 inhibitor we have investigated the effect of ion exchangers and polyions on the activity of this inhibitor assayed in vitro by means of a partially synchronized JB-1 cell population analyzed by flow microfluorometry. The results indicate that polyanions and cation exchangers (immobilized polyanions) bind and abolish the G1-inhibitory activity. From this it is suggested that the G1 inhibitor is of a basic or polycationic nature. Since anion exchangers (immobilized polycations) are without effect on this activity it was surprising to find that polycations also neutralize the activity. The results indicate that this occurs by blocking an anionic G2-inhibitor receptor on the cell, thus preventing the polycationic G1 inhibitor from being bound to this receptor.

  16. Canonical Wnt activity regulates trunk neural crest delamination linking BMP/noggin signaling with G1/S transition.

    PubMed

    Burstyn-Cohen, Tal; Stanleigh, Jonathan; Sela-Donenfeld, Dalit; Kalcheim, Chaya

    2004-11-01

    Delamination of premigratory neural crest cells depends on a balance between BMP/noggin and on successful G1/S transition. Here, we report that BMP regulates G1/S transition and consequent crest delamination through canonical Wnt signaling. Noggin overexpression inhibits G1/S transition and blocking G1/S abrogates BMP-induced delamination; moreover, transcription of Wnt1 is stimulated by BMP and by the developing somites, which concomitantly inhibit noggin production. Interfering with beta-catenin and LEF/TCF inhibits G1/S transition, neural crest delamination and transcription of various BMP-dependent genes, which include Cad6B, Pax3 and Msx1, but not that of Slug, Sox9 or FoxD3. Hence, we propose that developing somites inhibit noggin transcription in the dorsal tube, resulting in activation of BMP and consequent Wnt1 production. Canonical Wnt signaling in turn stimulates G1/S transition and generation of neural crest cell motility independently of its proposed role in earlier neural crest specification. PMID:15456730

  17. Netrin-G1 regulates fear-like and anxiety-like behaviors in dissociable neural circuits

    PubMed Central

    Zhang, Qi; Sano, Chie; Masuda, Akira; Ando, Reiko; Tanaka, Mika; Itohara, Shigeyoshi

    2016-01-01

    In vertebrate mammals, distributed neural circuits in the brain are involved in emotion-related behavior. Netrin-G1 is a glycosyl-phosphatidylinositol-anchored synaptic adhesion molecule whose deficiency results in impaired fear-like and anxiety-like behaviors under specific circumstances. To understand the cell type and circuit specificity of these responses, we generated netrin-G1 conditional knockout mice with loss of expression in cortical excitatory neurons, inhibitory neurons, or thalamic neurons. Genetic deletion of netrin-G1 in cortical excitatory neurons resulted in altered anxiety-like behavior, but intact fear-like behavior, whereas loss of netrin-G1 in inhibitory neurons resulted in attenuated fear-like behavior, but intact anxiety-like behavior. These data indicate a remarkable double dissociation of fear-like and anxiety-like behaviors involving netrin-G1 in excitatory and inhibitory neurons, respectively. Our findings support a crucial role for netrin-G1 in dissociable neural circuits for the modulation of emotion-related behaviors, and provide genetic models for investigating the mechanisms underlying the dissociation. The results also suggest the involvement of glycosyl-phosphatidylinositol-anchored synaptic adhesion molecules in the development and pathogenesis of emotion-related behavior. PMID:27345935

  18. Relative biological effectiveness of 6 MeV neutrons with respect to cell inactivation and disturbances of the G1 phase.

    PubMed

    Zölzer, F; Streffer, C

    2008-02-01

    The relative biological effectiveness (RBE) of neutrons and other types of densely ionizing radiation appears to be close to 1.0 for the induction of strand breaks, but considerably higher RBEs have been found for cellular end points such as colony-forming ability. This may be due to differences in the processing of strand breaks or to the involvement of other lesions whose yields are more dependent on radiation quality. Because cell cycle delays may be of great importance in the processing of DNA damage, we determined the RBE for disturbances of the G1 phase in four different cell types (Be11 melanoma, 4197 squamous cell carcinoma, EA14 glioma, GM6419 fibroblasts) and compared them with the RBE for cell inactivation. The method we used to determine the progress from G1 into S was as follows: Cells were serum-deprived for a number of days and then stimulated to grow with culture medium containing normal amounts of serum. Immediately before the change of medium, cells were exposed to graded doses of either 240 kV X rays or 6 MeV neutrons. At different times afterward, cells were labeled with BrdU and the numbers of active S-phase cells were assessed using two-parameter flow cytometry. For all four cell types, cells started to progress from G1 into S after a few hours. Radiation suppressed this process in all cases, but there were some interesting differences. For Be11 and 4197 cells, the most obvious effect was a delay in G1; the labeling index increased a few hours later in irradiated samples than in controls, and there was no significant effect on the maximum labeling index. For EA14 and GM6419 cells, although smaller doses were used because of greater radiosensitivity, a delay of the entry into S phase was again noticeable, but the most significant effect was a reduction in the maximum percentage of active S-phase cells after stimulation, indicating a permanent or long-term arrest in G1. The RBE for the G1 delay was the same for all four cell types, about 2

  19. Binding of fusion protein FLSC IgG1 to CCR5 is enhanced by CCR5 antagonist Maraviroc.

    PubMed

    Latinovic, Olga; Schneider, Kate; Szmacinski, Henryk; Lakowicz, Joseph R; Heredia, Alonso; Redfield, Robert R

    2014-12-01

    The CCR5 chemokine receptor is crucial for human immunodeficiency virus type 1 (HIV-1) infection, acting as the principal coreceptor for HIV-1 entry and transmission and is thus an attractive target for antiviral therapy. Studies have suggested that CCR5 surface density and its conformational changes subsequent to virion engagement are rate limiting for entry, and consequently, infection. Not all CCR5 antibodies inhibit HIV-1 infection, suggesting a need for more potent reagents. Here we evaluated full length single chain (FLSC) IgG1, a novel IgG-CD4-gp120(BAL) fusion protein with several characteristics that make it an attractive candidate for treatment of HIV-1 infections, including bivalency and a potentially increased serum half-life over FLSC, the parental molecule. FLSC IgG1 binds two domains on CCR5, the N-terminus and the second extracellular loop, lowering the levels of available CCR5 viral attachment sites. Furthermore, FLSC IgG1 synergizes with Maraviroc (MVC), the only licensed CCR5 antagonist. In this study, we used both microscopy and functional assays to address the mechanistic aspects of the interactions of FLSC IgG1 and MVC in the context of CCR5 conformational changes and viral infection. We used a novel stochastic optical reconstruction microscopy (STORM), based on high resolution localization of photoswitchable dyes to visualize direct contacts between FLSC IgG1 and CCR5. We compared viral entry inhibition by FLSC IgG1 with that of other CCR5 blockers and showed FLSC IgG1 to be the most potent. We also showed that lower CCR5 surface densities in HIV-1 infected primary cells result in lower FLSC IgG1 EC50 values. In addition, CCR5 binding by FLSC IgG1, but not CCR5 Ab 2D7, was significantly increased when cells were treated with MVC, suggesting MVC allosterically increases exposure of the FLSC IgG1 binding site. These data have implications for future antiviral therapy development.

  20. RABL6A promotes G1-S phase progression and pancreatic neuroendocrine tumor cell proliferation in an Rb1-dependent manner.

    PubMed

    Hagen, Jussara; Muniz, Viviane P; Falls, Kelly C; Reed, Sara M; Taghiyev, Agshin F; Quelle, Frederick W; Gourronc, Francoise A; Klingelhutz, Aloysius J; Major, Heather J; Askeland, Ryan W; Sherman, Scott K; O'Dorisio, Thomas M; Bellizzi, Andrew M; Howe, James R; Darbro, Benjamin W; Quelle, Dawn E

    2014-11-15

    Mechanisms of neuroendocrine tumor (NET) proliferation are poorly understood, and therapies that effectively control NET progression and metastatic disease are limited. We found amplification of a putative oncogene, RABL6A, in primary human pancreatic NETs (PNET) that correlated with high-level RABL6A protein expression. Consistent with those results, stable silencing of RABL6A in cultured BON-1 PNET cells revealed that it is essential for their proliferation and survival. Cells lacking RABL6A predominantly arrested in G1 phase with a moderate mitotic block. Pathway analysis of microarray data suggested activation of the p53 and retinoblastoma (Rb1) tumor-suppressor pathways in the arrested cells. Loss of p53 had no effect on the RABL6A knockdown phenotype, indicating that RABL6A functions independent of p53 in this setting. By comparison, Rb1 inactivation partially restored G1 to S phase progression in RABL6A-knockdown cells, although it was insufficient to override the mitotic arrest and cell death caused by RABL6A loss. Thus, RABL6A promotes G1 progression in PNET cells by inactivating Rb1, an established suppressor of PNET proliferation and development. This work identifies RABL6A as a novel negative regulator of Rb1 that is essential for PNET proliferation and survival. We suggest RABL6A is a new potential biomarker and target for anticancer therapy in PNET patients.

  1. Saccharomyces cerevisiae G1 cyclins are differentially involved in invasive and pseudohyphal growth independent of the filamentation mitogen-activated protein kinase pathway.

    PubMed Central

    Loeb, J D; Kerentseva, T A; Pan, T; Sepulveda-Becerra, M; Liu, H

    1999-01-01

    Several lines of evidence suggest that the morphogenetic transition from the yeast form to pseudohyphae in Saccharomyces cerevisiae may be regulated by the cyclin-dependent kinase (Cdk). To examine this hypothesis, we mutated all of the G1 cyclin genes in strains competent to form pseudohyphae. Interestingly, mutation of each G1 cyclin results in a different filamentation phenotype, varying from a significant defect in cln1/cln1 strains to enhancement of filament production in cln3/cln3 strains. cln1 cln2 double mutants are more defective in pseudohyphal development and haploid invasive growth than cln1 strains. FLO11 transcription, which correlates with the level of invasive growth, is low in cln1 cln2 mutants and high in grr1 cells (defective in proteolysis of Cln1,2), suggesting that Cln1,2/Cdks regulate the pseudohyphal transcriptional program. Epistasis analysis reveals that Cln1,2/Cdk and the filamentation MAP kinase pathway function in parallel in regulating filamentous and invasive growth. Cln1 and Cln2, but not Ste20 or Ste12, are responsible for most of the elevated FLO11 transcription in grr1 strains. Furthermore, phenotypic comparison of various filamentation mutants illustrates that cell elongation and invasion/cell-cell adhesion during filamentation are separable processes controlled by the pseudohyphal transcriptional program. Potential targets for G1 cyclin/Cdks during filamentous growth are discussed. PMID:10581264

  2. RABL6A promotes G1-S phase progression and pancreatic neuroendocrine tumor cell proliferation in an Rb1-dependent manner

    PubMed Central

    Hagen, Jussara; Muniz, Viviane P.; Falls, Kelly; Reed, Sara M.; Taghiyev, Agshin F.; Quelle, Frederick W.; Gourronc, Francoise; Klingelhutz, Aloysius J.; Major, Heather J.; Askeland, Ryan; Sherman, Scott K.; O'Dorisio, Thomas M.; Bellizzi, Andrew M.; Howe, James R.; Darbro, Benjamin W.; Quelle, Dawn E.

    2014-01-01

    Mechanisms of neuroendocrine tumor (NET) proliferation are poorly understood and therapies that effectively control NET progression and metastatic disease are limited. We found amplification of a putative oncogene, RABL6A, in primary human pancreatic NETs(PNETs) that correlated with high level RABL6A protein expression. Consistent with those results, stable silencing of RABL6A in cultured BON-1 PNET cells revealed that it is essential for their proliferation and survival. Cells lacking RABL6A predominantly arrested in G1 phase with a moderate mitotic block. Pathway analysis of microarray data suggested activation of the p53 and retinoblastoma (Rb1) tumor suppressor pathways in the arrested cells. Loss of p53 had no effect on the RABL6A knockdown phenotype, indicating RABL6A functions independent of p53 in this setting. By comparison, Rb1 inactivation partially restored G1 to S phase progression in RABL6A knockdown cells although it was insufficient to override the mitotic arrest and cell death caused by RABL6A loss. Thus, RABL6A promotes G1 progression in PNET cells by inactivating Rb1, an established suppressor of PNET proliferation and development. This work identifies RABL6A as a novel negative regulator of Rb1 that is essential for PNET proliferation and survival. We suggest RABL6A is a new potential biomarker and target for anticancer therapy in PNET patients. PMID:25273089

  3. Histone deacetylase-1 (HDAC1) is a molecular switch between neuronal survival and death.

    PubMed

    Bardai, Farah H; Price, Valerie; Zaayman, Marcus; Wang, Lulu; D'Mello, Santosh R

    2012-10-12

    Both neuroprotective and neurotoxic roles have previously been described for histone deacetylase-1 (HDAC1). Here we report that HDAC1 expression is elevated in vulnerable brain regions of two mouse models of neurodegeneration, the R6/2 model of Huntington disease and the Ca(2+)/calmodulin-dependent protein kinase (CaMK)/p25 double-transgenic model of tauopathic degeneration, suggesting a role in promoting neuronal death. Indeed, elevating HDAC1 expression by ectopic expression promotes the death of otherwise healthy cerebellar granule neurons and cortical neurons in culture. The neurotoxic effect of HDAC1 requires interaction and cooperation with HDAC3, which has previously been shown to selectively induce the death of neurons. HDAC1-HDAC3 interaction is greatly elevated under conditions of neurodegeneration both in vitro and in vivo. Furthermore, the knockdown of HDAC3 suppresses HDAC1-induced neurotoxicity, and the knockdown of HDAC1 suppresses HDAC3 neurotoxicity. As described previously for HDAC3, the neurotoxic effect of HDAC1 is inhibited by treatment with IGF-1, the expression of Akt, or the inhibition of glycogen synthase kinase 3β (GSK3β). In addition to HDAC3, HDAC1 has been shown to interact with histone deacetylase-related protein (HDRP), a truncated form of HDAC9, whose expression is down-regulated during neuronal death. In contrast to HDAC3, the interaction between HDRP and HDAC1 protects neurons from death, an effect involving acquisition of the deacetylase activity of HDAC1 by HDRP. We find that elevated HDRP inhibits HDAC1-HDAC3 interaction and prevents the neurotoxic effect of either of these two proteins. Together, our results suggest that HDAC1 is a molecular switch between neuronal survival and death. Its interaction with HDRP promotes neuronal survival, whereas interaction with HDAC3 results in neuronal death. PMID:22918830

  4. Substrate recognition of N,N'-diacetylchitobiose deacetylase from Pyrococcus horikoshii.

    PubMed

    Nakamura, Tsutomu; Yonezawa, Yasushige; Tsuchiya, Yuko; Niiyama, Mayumi; Ida, Kurumi; Oshima, Maki; Morita, Junji; Uegaki, Koichi

    2016-09-01

    Enzymes of carbohydrate esterase (CE) family 14 catalyze hydrolysis of N-acetyl groups at the non-reducing end of the N-acetylglucosamine (GlcNAc) residue of chitooligosaccharides or related compounds. N,N'-diacetylchitobiose deacetylase (Dac) belongs to the CE-14 family and plays a role in the chitinolytic pathway in archaea by deacetylating N,N'-diacetylchitobiose (GlcNAc2), which is the end product of chitinase. In this study, we revealed the structural basis of reaction specificity in CE-14 deacetylases by solving a crystal structure of Dac from Pyrococcus horikoshii (Ph-Dac) in complex with a novel reaction intermediate analog. We developed 2-deoxy-2-methylphosphoramido-d-glucose (MPG) as the analog of the tetrahedral oxyanion intermediate of the monosaccharide substrate GlcNAc. The crystal structure of Ph-Dac in complex with MPG demonstrated that Arg92, Asp115, and His152 side chains interact with hydroxyl groups of the glucose moiety of the non-reducing-end GlcNAc residue. The amino acid residues responsible for recognition of the MPG glucose moiety are spatially conserved in other CE-14 deacetylases. Molecular dynamics simulation of the structure of the Ph-Dac-GlcNAc2 complex indicated that the reducing GlcNAc residue is placed in a large intermolecular cleft and is not involved with specific interactions with the enzyme. This observation was consistent with results indicating that Ph-Dac displayed similar kinetic parameters for both GlcNAc and GlcNAc2. This study provides the structural basis of reaction-site specificity of Dac and related CE-14 enzymes.

  5. Substrate recognition of N,N'-diacetylchitobiose deacetylase from Pyrococcus horikoshii.

    PubMed

    Nakamura, Tsutomu; Yonezawa, Yasushige; Tsuchiya, Yuko; Niiyama, Mayumi; Ida, Kurumi; Oshima, Maki; Morita, Junji; Uegaki, Koichi

    2016-09-01

    Enzymes of carbohydrate esterase (CE) family 14 catalyze hydrolysis of N-acetyl groups at the non-reducing end of the N-acetylglucosamine (GlcNAc) residue of chitooligosaccharides or related compounds. N,N'-diacetylchitobiose deacetylase (Dac) belongs to the CE-14 family and plays a role in the chitinolytic pathway in archaea by deacetylating N,N'-diacetylchitobiose (GlcNAc2), which is the end product of chitinase. In this study, we revealed the structural basis of reaction specificity in CE-14 deacetylases by solving a crystal structure of Dac from Pyrococcus horikoshii (Ph-Dac) in complex with a novel reaction intermediate analog. We developed 2-deoxy-2-methylphosphoramido-d-glucose (MPG) as the analog of the tetrahedral oxyanion intermediate of the monosaccharide substrate GlcNAc. The crystal structure of Ph-Dac in complex with MPG demonstrated that Arg92, Asp115, and His152 side chains interact with hydroxyl groups of the glucose moiety of the non-reducing-end GlcNAc residue. The amino acid residues responsible for recognition of the MPG glucose moiety are spatially conserved in other CE-14 deacetylases. Molecular dynamics simulation of the structure of the Ph-Dac-GlcNAc2 complex indicated that the reducing GlcNAc residue is placed in a large intermolecular cleft and is not involved with specific interactions with the enzyme. This observation was consistent with results indicating that Ph-Dac displayed similar kinetic parameters for both GlcNAc and GlcNAc2. This study provides the structural basis of reaction-site specificity of Dac and related CE-14 enzymes. PMID:27456364

  6. Reduced vasorelaxation to estradiol and G-1 in aged female and adult male rats is associated with GPR30 downregulation.

    PubMed

    Lindsey, Sarah H; da Silva, Ariel S; Silva, Mauro S; Chappell, Mark C

    2013-07-01

    Previously, we reported that chronic activation of the estrogen receptor GPR30 by its selective agonist G-1 decreases blood pressure in ovariectomized hypertensive mRen2.Lewis (mRen2) rats but not intact male littermates. Furthermore, G-1 relaxes female mesenteric resistance arteries via both endothelium-dependent and -independent mechanisms. Because of the lack of a blood pressure-lowering effect by G-1 in males and the potential influence of aging on estrogen receptor expression, we hypothesized that GPR30-dependent vasodilation and receptor expression are altered in males and aged females. Thus, we assessed the response to 17β-estradiol or G-1 in mesenteric arteries obtained from 15-wk-old normotensive Lewis and hypertensive mRen2 females and males as well as 52-wk-old Lewis females. Vasodilation to 17β-estradiol (E₂) and G-1 was significantly attenuated in 15-wk-old Lewis and mRen2 males compared with age-matched females. Pretreatment of male vessels with the nitric oxide synthase inhibitor L-NAME had no significant effect on the estradiol or G-1 response. In aged females, E₂ and G-1 vasorelaxation was also significantly blunted; however, L-NAME essentially abolished the response. Associated with the reduced vascular responses, GPR30 expression in mesenteric arteries was approximately 50% lower in males and aged females compared with young females. We conclude that alterations in GPR30 expression and signaling may contribute to vascular dysfunction in aging females and a greater blood pressure in hypertensive males.

  7. Interleukin-1beta partially alleviates cyclosporin A-induced suppression of IgG1 isotype response to thyroglobulin in BALB/c mice in vivo.

    PubMed Central

    Dalai, S K; Miriyala, B; Kar, S K

    1998-01-01

    Cyclosporin A (CsA) at 120 mg/kg body weight when injected subcutaneously into BALB/c mice along with thyroglobulin emulsified in incomplete Freund's adjuvant (IFA) was found to suppress antigen-specific IgG titre by 86%. Isotyping revealed that both IgG1 and IgG2a titres were suppressed by 87% and 57%, respectively. But under identical conditions when complete Freund's adjuvant (CFA) was used, the suppression of antigen-specific IgG, IgG1 and IgG2a titres was 50%, 51% and 55%, respectively. Injection of anti-IL-1beta-neutralizing hamster monoclonal antibodies along with thyroglobulin and CsA emulsified in CFA increased the suppression of antigen-specific IgG titre. Under such conditions the IgG1 titre was suppressed more than the IgG2a titre. Recombinant human interleukin-1 receptor antagonist (rhuIL-1ra) also enhanced the suppression caused by CsA in the presence of CFA but control hamster immunoglobulin had no such effect. Recombinant human IL-1beta, when administered along with thyroglobulin and CsA emulsified in IFA, alleviated the suppression of antigen-specific IgG titre and the IgG1 titre was alleviated more than the IgG2a titre. Under identical conditions, rhuIL-1ra did not alleviate CsA-induced suppression. Lymphocytes from the lymph nodes of thyroglobulin-sensitized BALB/c mice when stimulated in vitro by thyroglobulin in the presence of CsA, secreted very little interferon-gamma (IFN-gamma) and IL-4, but on addition of an optimal dose of rhuIL-1beta, IFN-gamma and IL-4 secretion was partially restored. PMID:9767461

  8. Extremely low-frequency electromagnetic fields cause G1 phase arrest through the activation of the ATM-Chk2-p21 pathway.

    PubMed

    Huang, Chao-Ying; Chang, Cheng-Wei; Chen, Chaang-Ray; Chuang, Chun-Yu; Chiang, Chi-Shiun; Shu, Wun-Yi; Fan, Tai-Ching; Hsu, Ian C

    2014-01-01

    In daily life, humans are exposed to the extremely low-frequency electromagnetic fields (ELF-EMFs) generated by electric appliances, and public concern is increasing regarding the biological effects of such exposure. Numerous studies have yielded inconsistent results regarding the biological effects of ELF-EMF exposure. Here we show that ELF-EMFs activate the ATM-Chk2-p21 pathway in HaCaT cells, inhibiting cell proliferation. To present well-founded results, we comprehensively evaluated the biological effects of ELF-EMFs at the transcriptional, protein, and cellular levels. Human HaCaT cells from an immortalized epidermal keratinocyte cell line were exposed to a 1.5 mT, 60 Hz ELF-EMF for 144 h. The ELF-EMF could cause G1 arrest and decrease colony formation. Protein expression experiments revealed that ELF-EMFs induced the activation of the ATM/Chk2 signaling cascades. In addition, the p21 protein, a regulator of cell cycle progression at G1 and G2/M, exhibited a higher level of expression in exposed HaCaT cells compared with the expression of sham-exposed cells. The ELF-EMF-induced G1 arrest was diminished when the CHK2 gene expression (which encodes checkpoint kinase 2; Chk2) was suppressed by specific small interfering RNA (siRNA). These findings indicate that ELF-EMFs activate the ATM-Chk2-p21 pathway in HaCaT cells, resulting in cell cycle arrest at the G1 phase. Based on the precise control of the ELF-EMF exposure and rigorous sham-exposure experiments, all transcriptional, protein, and cellular level experiments consistently supported the conclusion. This is the first study to confirm that a specific pathway is triggered by ELF-EMF exposure.

  9. Topologically associating domains and their long-range contacts are established during early G1 coincident with the establishment of the replication-timing program.

    PubMed

    Dileep, Vishnu; Ay, Ferhat; Sima, Jiao; Vera, Daniel L; Noble, William S; Gilbert, David M

    2015-08-01

    Mammalian genomes are partitioned into domains that replicate in a defined temporal order. These domains can replicate at similar times in all cell types (constitutive) or at cell type-specific times (developmental). Genome-wide chromatin conformation capture (Hi-C) has revealed sub-megabase topologically associating domains (TADs), which are the structural counterparts of replication domains. Hi-C also segregates inter-TAD contacts into defined 3D spatial compartments that align precisely to genome-wide replication timing profiles. Determinants of the replication-timing program are re-established during early G1 phase of each cell cycle and lost in G2 phase, but it is not known when TAD structure and inter-TAD contacts are re-established after their elimination during mitosis. Here, we use multiplexed 4C-seq to study dynamic changes in chromatin organization during early G1. We find that both establishment of TADs and their compartmentalization occur during early G1, within the same time frame as establishment of the replication-timing program. Once established, this 3D organization is preserved either after withdrawal into quiescence or for the remainder of interphase including G2 phase, implying 3D structure is not sufficient to maintain replication timing. Finally, we find that developmental domains are less well compartmentalized than constitutive domains and display chromatin properties that distinguish them from early and late constitutive domains. Overall, this study uncovers a strong connection between chromatin re-organization during G1, establishment of replication timing, and its developmental control. PMID:25995270

  10. Focus on acetylation: the role of histone deacetylase inhibitors in cancer therapy and beyond.

    PubMed

    Konstantinopoulos, Panagiotis A; Karamouzis, Michalis V; Papavassiliou, Athanasios G

    2007-05-01

    Reversal of tumorigenic epigenetic alterations is an exciting strategy for anticancer drug development. Pharmacologic inhibition of histone deacetylases (HDACs) induces differentiation, proliferation arrest and apoptosis of cancer cells. In addition to their effects on histones, HDAC inhibitors increase the acetylation level of several non-histone proteins, such as transcription factors, cytoskeletal proteins and molecular chaperones, which are crucial in tumorigenesis. Most importantly, the therapeutic potential of HDAC inhibitors goes well beyond carcinogenesis and may include neurodegenerative and inflammatory disorders. This editorial discusses the implication of HDACs in carcinogenesis, the molecular basis of the selectivity of HDAC inhibitors and their possible therapeutic role in non-malignant pathologic conditions.

  11. Transcriptional activation of NAD{sup +}-dependent protein deacetylase SIRT1 by nuclear receptor TLX

    SciTech Connect

    Iwahara, Naotoshi; Hisahara, Shin; Hayashi, Takashi; Horio, Yoshiyuki

    2009-09-04

    An orphan nuclear receptor TLX is a transcriptional repressor that promotes the proliferation and self-renewal of neural precursor cells (NPCs). SIRT1, an NAD{sup +}-dependent protein deacetylase, is highly expressed in the NPCs and participates in neurogenesis. Here, we found that TLX colocalized with SIRT1 and knockdown of TLX by small interfering RNAs decreased SIRT1 levels in NPCs. TLX increased the SIRT1 expression by binding to the newly identified TLX-activating element in the SIRT1 gene promoter in HEK293 cells. Thus, TLX is an inducer of SIRT1 and may contribute to neurogenesis both as a transactivator and as a repressor.

  12. A Photoactivatable Platinum(IV) Complex Targeting Genomic DNA and Histone Deacetylases.

    PubMed

    Kasparkova, Jana; Kostrhunova, Hana; Novakova, Olga; Křikavová, Radka; Vančo, Ján; Trávníček, Zdeněk; Brabec, Viktor

    2015-11-23

    We report toxic effects of a photoactivatable platinum(IV) complex conjugated with suberoyl-bis-hydroxamic acid in tumor cells. The conjugate exerts, after photoactivation, two functions: activity as both a platinum(II) anticancer drug and histone deacetylase (HDAC) inhibitor in cancer cells. This approach relies on the use of a Pt(IV) pro-drug, acting by two independent mechanisms of biological action in a cooperative manner, which can be selectively photoactivated to a cytotoxic species in and around a tumor, thereby increasing selectivity towards cancer cells. These results suggest that this strategy is a valuable route to design new platinum agents with higher efficacy for photodynamic anticancer chemotherapy.

  13. Histone deacetylase inhibitors relieve morphine resistance in neuropathic pain after peripheral nerve injury.

    PubMed

    Uchida, Hitoshi; Matsushita, Yosuke; Araki, Kohei; Mukae, Takehiro; Ueda, Hiroshi

    2015-08-01

    Neuropathic pain is often insensitive to morphine. Our previous study has demonstrated that neuron-restrictive silencer factor represses mu opioid receptor (MOP) gene expression in the dorsal root ganglion (DRG) via histone hypoacetylation-mediated mechanisms after peripheral nerve injury, thereby causing loss of peripheral morphine analgesia. Here, we showed that histone deacetylase (HDAC) inhibitors, such as trichostatin A and valproic acid, restored peripheral and systemic morphine analgesia in neuropathic pain. Also, these agents blocked nerve injury-induced MOP down-regulation in the DRG. These results suggest that HDAC inhibitors could serve as adjuvant analgesics to morphine for the management of neuropathic pain.

  14. Non-isotopic dual parameter competition assay suitable for high-throughput screening of histone deacetylases.

    PubMed

    Riester, Daniel; Hildmann, Christian; Haus, Patricia; Galetovic, Antonia; Schober, Andreas; Schwienhorst, Andreas; Meyer-Almes, Franz-Josef

    2009-07-01

    Histone deacetylases reside among the most important and novel target classes in oncology. Selective lead structures are intensively developed to improve efficacy and reduce adverse effects. The common assays used so far to identify new lead structures suffer from many false positive hits due to auto-fluorescence of compounds or triggering undesired signal transduction pathways. These drawbacks are eliminated by the dual parameter competition assay reported in this study. The assay involves a new fluorescent inhibitor probe that shows an increase in both, fluorescence anisotropy and fluorescence lifetime upon binding to the enzyme. The assay is well suited for high-throughput screening.

  15. The Nucleosome Remodeling and Deacetylase (NuRD) Complex in Development and Disease

    PubMed Central

    Basta, Jeannine; Rauchman, Michael

    2014-01-01

    The Nucleosome Remodeling and Deacetylase (NuRD) complex is one of the major chromatin remodeling complexes found in cells. It plays an important role in regulating gene transcription, genome integrity and cell cycle progression. Through its impact on these basic cellular processes, increasing evidence indicates that alterations in the activity of this macromolecular complex can lead to developmental defects, oncogenesis and accelerated ageing. Recent genetic and biochemical studies have elucidated the mechanisms of NuRD action in modifying the chromatin landscape. These advances have the potential to lead to new therapeutic approaches to birth defects and cancer. PMID:24880148

  16. Isoform-specific toxicity of Mecp2 in postmitotic neurons: suppression of neurotoxicity by FoxG1.

    PubMed

    Dastidar, Somasish Ghosh; Bardai, Farah H; Ma, Chi; Price, Valerie; Rawat, Varun; Verma, Pragya; Narayanan, Vinodh; D'Mello, Santosh R

    2012-02-22

    The methyl-CpG binding protein 2 (MeCP2) is a widely expressed protein, the mutations of which cause Rett syndrome. The level of MeCP2 is highest in the brain where it is expressed selectively in mature neurons. Its functions in postmitotic neurons are not known. The MeCP2 gene is alternatively spliced to generate two proteins with different N termini, designated as MeCP2-e1 and MeCP2-e2. The physiological significance of these two isoforms has not been elucidated, and it is generally assumed they are functionally equivalent. We report that in cultured cerebellar granule neurons induced to die by low potassium treatment and in Aβ-treated cortical neurons, Mecp2-e2 expression is upregulated whereas expression of the Mecp2-e1 isoform is downregulated. Knockdown of Mecp2-e2 protects neurons from death, whereas knockdown of the e1 isoform has no effect. Forced expression of MeCP2-e2, but not MeCP2-e1, promotes apoptosis in otherwise healthy neurons. We find that MeCP2-e2 interacts with the forkhead protein FoxG1, mutations of which also cause Rett syndrome. FoxG1 has been shown to promote neuronal survival and its downregulation leads to neuronal death. We find that elevated FoxG1 expression inhibits MeCP2-e2 neurotoxicity. MeCP2-e2 neurotoxicity is also inhibited by IGF-1, which prevents the neuronal death-associated downregulation of FoxG1 expression, and by Akt, the activation of which is necessary for FoxG1-mediated neuroprotection. Finally, MeCP2-e2 neurotoxicity is enhanced if FoxG1 expression is suppressed or in neurons cultured from FoxG1-haplodeficient mice. Our results indicate that Mecp2-e2 promotes neuronal death and that this activity is normally inhibited by FoxG1. Reduced FoxG1 expression frees MecP2-e2 to promote neuronal death. PMID:22357867

  17. Copy Number Variation and Transposable Elements Feature in Recent, Ongoing Adaptation at the Cyp6g1 Locus

    PubMed Central

    Schmidt, Joshua M.; Good, Robert T.; Appleton, Belinda; Sherrard, Jayne; Raymant, Greta C.; Bogwitz, Michael R.; Martin, Jon; Daborn, Phillip J.; Goddard, Mike E.; Batterham, Philip; Robin, Charles

    2010-01-01

    The increased transcription of the Cyp6g1 gene of Drosophila melanogaster, and consequent resistance to insecticides such as DDT, is a widely cited example of adaptation mediated by cis-regulatory change. A fragment of an Accord transposable element inserted upstream of the Cyp6g1 gene is causally associated with resistance and has spread to high frequencies in populations around the world since the 1940s. Here we report the existence of a natural allelic series at this locus of D. melanogaster, involving copy number variation of Cyp6g1, and two additional transposable element insertions (a P and an HMS-Beagle). We provide evidence that this genetic variation underpins phenotypic variation, as the more derived the allele, the greater the level of DDT resistance. Tracking the spatial and temporal patterns of allele frequency changes indicates that the multiple steps of the allelic series are adaptive. Further, a DDT association study shows that the most resistant allele, Cyp6g1-[BP], is greatly enriched in the top 5% of the phenotypic distribution and accounts for ∼16% of the underlying phenotypic variation in resistance to DDT. In contrast, copy number variation for another candidate resistance gene, Cyp12d1, is not associated with resistance. Thus the Cyp6g1 locus is a major contributor to DDT resistance in field populations, and evolution at this locus features multiple adaptive steps occurring in rapid succession. PMID:20585622

  18. Molecular Dynamics Simulation of the Crystallizable Fragment of IgG1—Insights for the Design of Fcabs

    PubMed Central

    Lai, Balder; Hasenhindl, Christoph; Obinger, Christian; Oostenbrink, Chris

    2014-01-01

    An interesting format in the development of therapeutic monoclonal antibodies uses the crystallizable fragment of IgG1 as starting scaffold. Engineering of its structural loops allows generation of an antigen binding site. However, this might impair the molecule’s conformational stability, which can be overcome by introducing stabilizing point mutations in the CH3 domains. These point mutations often affect the stability and unfolding behavior of both the CH2 and CH3 domains. In order to understand this cross-talk, molecular dynamics simulations of the domains of the Fc fragment of human IgG1 are reported. The structure of human IgG1-Fc obtained from X-ray crystallography is used as a starting point for simulations of the wild-type protein at two different pH values. The stabilizing effect of a single point mutation in the CH3 domain as well as the impact of the hinge region and the glycan tree structure connected to the CH2 domains is investigated. Regions of high local flexibility were identified as potential sites for engineering antigen binding sites. Obtained data are discussed with respect to the available X-ray structure of IgG1-Fc, directed evolution approaches that screen for stability and use of the scaffold IgG1-Fc in the design of antigen binding Fc proteins. PMID:24451126

  19. Expanding the phenotype associated with FOXG1 mutations and in vivo FoxG1 chromatin-binding dynamics.

    PubMed

    De Filippis, R; Pancrazi, L; Bjørgo, K; Rosseto, A; Kleefstra, T; Grillo, E; Panighini, A; Cardarelli, F; Meloni, I; Ariani, F; Mencarelli, M A; Hayek, J; Renieri, A; Costa, M; Mari, F

    2012-10-01

    Mutations in the Forkhead box G1 (FOXG1) gene, a brain specific transcriptional factor, are responsible for the congenital variant of Rett syndrome. Until now FOXG1 point mutations have been reported in 12 Rett patients. Recently seven additional patients have been reported with a quite homogeneous severe phenotype designated as the FOXG1 syndrome. Here we describe two unrelated patients with a de novo FOXG1 point mutation, p.Gln46X and p.Tyr400X, respectively, having a milder phenotype and sharing a distinctive facial appearance. Although FoxG1 action depends critically on its binding to chromatin, very little is known about the dynamics of this process. Using fluorescence recovery after photobleaching, we showed that most of the GFP-FoxG1 fusion protein associates reversibly to chromatin whereas the remaining fraction is bound irreversibly. Furthermore, we showed that the two pathologic derivatives of FoxG1 described in this paper present a dramatic alteration in chromatin affinity and irreversibly bound fraction in comparison with Ser323fsX325 mutant (associated with a severe phenotype) and wild type Foxg1 protein. Our observations suggest that alterations in the kinetics of FoxG1 binding to chromatin might contribute to the pathological effects of FOXG1 mutations.

  20. The spin structure function g1p of the proton and a test of the Bjorken sum rule

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chang, W.-C.; Chiosso, M.; Choi, I.; Chung, S. U.; Cicuttin, A.; Crespo, M. L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dziewiecki, M.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse-Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; -Yu Hsieh, C.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jörg, P.; Joosten, R.; Kabuß, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G. K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pesek, M.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2016-02-01

    New results for the double spin asymmetry A1p and the proton longitudinal spin structure function g1p are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 target. The data were collected in 2011 and complement those recorded in 2007 at 160 GeV, in particular at lower values of x. They improve the statistical precision of g1p (x) by about a factor of two in the region x ≲ 0.02. A next-to-leading order QCD fit to the g1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1p. The uncertainty of ΔΣ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g1NS (x ,Q2) yields as ratio of the axial and vector coupling constants |gA /gV | = 1.22 ± 0.05 (stat.) ± 0.10 (syst.), which validates the sum rule to an accuracy of about 9%.

  1. Impacts, Effectiveness and Regional Inequalities of the GeoMIP G1 to G4 Solar Radiation Management Scenarios

    SciTech Connect

    Yu, Xiaoyong; Moore, John; Cui, Xuefeng; Rinke, Annette; Ji, Duoying; Kravitz, Benjamin S.; Yoon, Jin-Ho

    2015-06-01

    We evaluate the regional effectiveness of solar radiation management (SRM) to compensate for simultaneous changes in temperature and precipitation induced by increased greenhouse gas concentrations. We analyze results from multiple earth system models under four Geoengineering Model Intercomparison Project(GeoMIP) experiments with a modified form of the Residual Climate Response approach. Under the solar dimming geoengineering experiments G1(4xCO2) and G2(increasing CO2 by 1% per year), global average temperature is successfully restored to pre-industrial level over 50 years simulations. However, these two SRM experiments also produce a robust global precipitation decrease. The stratospheric aerosol GeoMIP geoengineering experiment, G4 has significantly greater regional inequality and lower effectiveness for compensating temperature change than G1 and G2. G4 also has significantly larger regional inequality for compensating precipitation change than G1and G2. However, there is no significant difference between precipitation change compensation effectiveness of G4 and G2, though there is much larger across model variability in G4 results. G3 has significant greater regional inequality for compensating temperature change than G1 and G2, and has significant lower effectiveness than G1. The effectiveness of four SRMs to compensate for temperature change is much higher than for precipitation. The large cross-model variation in adjustment percentage of compensated SAT and precipitation change by SRM to achieve optimal compensation effectiveness shed a light on the uncertainty accumulation effect in optimizing compensation effectiveness of SRM.

  2. Expression of the NS5 (VPg) Protein of Murine Norovirus Induces a G1/S Phase Arrest

    PubMed Central

    Davies, Colin; Ward, Vernon K.

    2016-01-01

    Murine norovirus-1 (MNV-1) is known to subvert host cell division inducing an accumulation of cells in the G0/G1 phase, creating conditions where viral replication is favored. This study identified that NS5 (VPg), is capable of inducing cell cycle arrest in the absence of viral replication or other viral proteins in an analogous manner to MNV-1 infection. NS5 expression induced an accumulation of cells in the G0/G1 phase in an asynchronous population by inhibiting progression at the G1/S restriction point. Furthermore, NS5 expression resulted in a down-regulation of cyclin A expression in asynchronous cells and inhibited cyclin A expression in cells progressing from G1 to S phase. The activity of NS5 on the host cell cycle occurs through an uncharacterized func