SUN2 Modulates HIV-1 Infection and Latency through Association with Lamin A/C To Maintain the Repressive Chromatin.

PubMed

Sun, Wei-Wei; Jiao, Shi; Sun, Li; Zhou, Zhaocai; Jin, Xia; Wang, Jian-Hua

2018-05-01

The postintegrational latency of HIV-1 is characterized by reversible silencing of long terminal repeat (LTR)-driven transcription of the HIV genome. It is known that the formation of repressive chromatin at the 5'-LTR of HIV-1 proviral DNA impedes viral transcription by blocking the recruitment of positive transcription factors. How the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. Elucidation of which chromatin reassembly factor mediates the reorganization of chromatin is likely to facilitate the understanding of the host's modulation of HIV-1 transcription and latency. Here we revealed that "Sad1 and UNC84 domain containing 2" (SUN2), an inner nuclear membrane protein, maintained the repressive chromatin and inhibited HIV LTR-driven transcription of proviral DNA through an association with lamin A/C. Specifically, lamin A/C tethered SUN2 to the nucleosomes 1 and 2 of the HIV-1 5'-LTR to block the initiation and elongation of HIV-1 transcription. SUN2 knockdown converted chromatin to an active form and thus enhanced the phosphorylation of RNA polymerase II and its recruitment to the 5'-LTR HIV-1 proviral DNA, leading to reactivation of HIV-1 from latency. Conversely, the exogenous factors such as tumor necrosis factor alpha (TNF-α) induced reactivation, and the replication of HIV-1 led to the disassociation between SUN2 and lamin A/C, suggesting that disruption of the association between SUN2 and lamin A/C to convert the repressive chromatin to the active form might be a prerequisite for the initiation of HIV-1 transcription and replication. Together, our findings indicate that SUN2 is a novel chromatin reassembly factor that helps to maintain chromatin in a repressive state and consequently inhibits HIV-1 transcription. IMPORTANCE Despite the successful use of scores of antiretroviral drugs, HIV latency poses a major impediment to virus eradication. Elucidation of the mechanism of latency facilitates the discovery of new therapeutic strategies. It has been known that the formation of repressive chromatin at the 5'-LTR of HIV-1 proviral DNA impedes viral transcription and maintains viral latency, but how the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. In this study, we performed in-depth virological and cell biological studies and discovered that an inner nuclear membrane protein, SUN2, is a novel chromatin reassembly factor that maintains repressive chromatin and thus modulates HIV-1 transcription and latency: therefore, targeting SUN2 may lead to new strategies for HIV cure. Copyright © 2018 Sun et al.

Herpes simplex virus latency-associated transcript sequence downstream of the promoter influences type-specific reactivation and viral neurotropism.

PubMed

Bertke, Andrea S; Patel, Amita; Krause, Philip R

2007-06-01

Herpes simplex virus (HSV) establishes latency in sensory nerve ganglia during acute infection and may later periodically reactivate to cause recurrent disease. HSV type 1 (HSV-1) reactivates more efficiently than HSV-2 from trigeminal ganglia while HSV-2 reactivates more efficiently than HSV-1 from lumbosacral dorsal root ganglia (DRG) to cause recurrent orofacial and genital herpes, respectively. In a previous study, a chimeric HSV-2 that expressed the latency-associated transcript (LAT) from HSV-1 reactivated similarly to wild-type HSV-1, suggesting that the LAT influences the type-specific reactivation phenotype of HSV-2. To further define the LAT region essential for type-specific reactivation, we constructed additional chimeric HSV-2 viruses by replacing the HSV-2 LAT promoter (HSV2-LAT-P1) or 2.5 kb of the HSV-2 LAT sequence (HSV2-LAT-S1) with the corresponding regions from HSV-1. HSV2-LAT-S1 was impaired for reactivation in the guinea pig genital model, while its rescuant and HSV2-LAT-P1 reactivated with a wild-type HSV-2 phenotype. Moreover, recurrences of HSV-2-LAT-S1 were frequently fatal, in contrast to the relatively mild recurrences of the other viruses. During recurrences, HSV2-LAT-S1 DNA increased more in the sacral cord compared to its rescuant or HSV-2. Thus, the LAT sequence region, not the LAT promoter region, provides essential elements for type-specific reactivation of HSV-2 and also plays a role in viral neurotropism. HSV-1 DNA, as quantified by real-time PCR, was more abundant in the lumbar spinal cord, while HSV-2 DNA was more abundant in the sacral spinal cord, which may provide insights into the mechanism for type-specific reactivation and different patterns of central nervous system infection of HSV-1 and HSV-2.

Herpes Simplex Virus Latency-Associated Transcript Sequence Downstream of the Promoter Influences Type-Specific Reactivation and Viral Neurotropism▿

PubMed Central

Bertke, Andrea S.; Patel, Amita; Krause, Philip R.

2007-01-01

Herpes simplex virus (HSV) establishes latency in sensory nerve ganglia during acute infection and may later periodically reactivate to cause recurrent disease. HSV type 1 (HSV-1) reactivates more efficiently than HSV-2 from trigeminal ganglia while HSV-2 reactivates more efficiently than HSV-1 from lumbosacral dorsal root ganglia (DRG) to cause recurrent orofacial and genital herpes, respectively. In a previous study, a chimeric HSV-2 that expressed the latency-associated transcript (LAT) from HSV-1 reactivated similarly to wild-type HSV-1, suggesting that the LAT influences the type-specific reactivation phenotype of HSV-2. To further define the LAT region essential for type-specific reactivation, we constructed additional chimeric HSV-2 viruses by replacing the HSV-2 LAT promoter (HSV2-LAT-P1) or 2.5 kb of the HSV-2 LAT sequence (HSV2-LAT-S1) with the corresponding regions from HSV-1. HSV2-LAT-S1 was impaired for reactivation in the guinea pig genital model, while its rescuant and HSV2-LAT-P1 reactivated with a wild-type HSV-2 phenotype. Moreover, recurrences of HSV-2-LAT-S1 were frequently fatal, in contrast to the relatively mild recurrences of the other viruses. During recurrences, HSV2-LAT-S1 DNA increased more in the sacral cord compared to its rescuant or HSV-2. Thus, the LAT sequence region, not the LAT promoter region, provides essential elements for type-specific reactivation of HSV-2 and also plays a role in viral neurotropism. HSV-1 DNA, as quantified by real-time PCR, was more abundant in the lumbar spinal cord, while HSV-2 DNA was more abundant in the sacral spinal cord, which may provide insights into the mechanism for type-specific reactivation and different patterns of central nervous system infection of HSV-1 and HSV-2. PMID:17409161

Cellular FLIP can substitute for the herpes simplex virus type 1 latency-associated transcript gene to support a wild-type virus reactivation phenotype in mice

PubMed Central

Jin, Ling; Carpenter, Dale; Moerdyk-Schauwecker, Megan; Vanarsdall, Adam L; Osorio, Nelson; Hsiang, Chinhui; Jones, Clinton; Wechsler, Steven L

2010-01-01

Latency-associated transcript (LAT) deletion mutants of herpes simplex virus type 1 (HSV-1) have reduced reactivation phenotypes. Thus, LAT plays an essential role in the latency-reactivation cycle of HSV-1. We have shown that LAT has antiapoptosis activity and demonstrated that the chimeric virus, dLAT-cpIAP, resulting from replacing LAT with the baculovirus antiapoptosis gene cpIAP, has a wild-type HSV-1 reactivation phenotype in mice and rabbits. Thus, LAT can be replaced by an alternative antiapoptosis gene, confirming that LAT’s antiapoptosis activity plays an important role in the mechanism by which LAT enhances the virus’ reactivation phenotype. However, because cpIAP interferes with both of the major apoptosis pathways, these studies did not address whether LAT’s proreactivation phenotype function was due to blocking the extrinsic (Fas-ligand–, caspase-8–, or caspase-10–dependent pathway) or the intrinsic (mitochondria-, caspase-9–dependent pathway) pathway, or whether both pathways must be blocked. Here we constructed an HSV-1 LAT(−) mutant that expresses cellular FLIP (cellular FLICE-like inhibitory protein) under control of the LAT promoter and in place of LAT nucleotides 76 to 1667. Mice were ocularly infected with this mutant, designated dLAT-FLIP, and the reactivation phenotype was determined using the trigeminal ganglia explant model. dLAT-FLIP had a reactivation phenotype similar to wild-type virus and significantly higher than the LAT(−) mutant dLAT2903. Thus, the LAT function responsible for enhancing the reactivation phenotype could be replaced with an antiapoptosis gene that primarily blocks the extrinsic signaling apoptosis pathway. PMID:18989818

Genome-wide Determinants of Proviral Targeting, Clonal Abundance and Expression in Natural HTLV-1 Infection

PubMed Central

Melamed, Anat; Laydon, Daniel J.; Gillet, Nicolas A.; Tanaka, Yuetsu; Taylor, Graham P.; Bangham, Charles R. M.

2013-01-01

The regulation of proviral latency is a central problem in retrovirology. We postulate that the genomic integration site of human T lymphotropic virus type 1 (HTLV-1) determines the pattern of expression of the provirus, which in turn determines the abundance and pathogenic potential of infected T cell clones in vivo. We recently developed a high-throughput method for the genome-wide amplification, identification and quantification of proviral integration sites. Here, we used this protocol to test two hypotheses. First, that binding sites for transcription factors and chromatin remodelling factors in the genome flanking the proviral integration site of HTLV-1 are associated with integration targeting, spontaneous proviral expression, and in vivo clonal abundance. Second, that the transcriptional orientation of the HTLV-1 provirus relative to that of the nearest host gene determines spontaneous proviral expression and in vivo clonal abundance. Integration targeting was strongly associated with the presence of a binding site for specific host transcription factors, especially STAT1 and p53. The presence of the chromatin remodelling factors BRG1 and INI1 and certain host transcription factors either upstream or downstream of the provirus was associated respectively with silencing or spontaneous expression of the provirus. Cells expressing HTLV-1 Tax protein were significantly more frequent in clones of low abundance in vivo. We conclude that transcriptional interference and chromatin remodelling are critical determinants of proviral latency in natural HTLV-1 infection. PMID:23555266

Transcription of the herpes simplex virus 1 genome during productive and quiescent infection of neuronal and nonneuronal cells.

PubMed

Harkness, Justine M; Kader, Muhamuda; DeLuca, Neal A

2014-06-01

Herpes simplex virus 1 (HSV-1) can undergo a productive infection in nonneuronal and neuronal cells such that the genes of the virus are transcribed in an ordered cascade. HSV-1 can also establish a more quiescent or latent infection in peripheral neurons, where gene expression is substantially reduced relative to that in productive infection. HSV mutants defective in multiple immediate early (IE) gene functions are highly defective for later gene expression and model some aspects of latency in vivo. We compared the expression of wild-type (wt) virus and IE gene mutants in nonneuronal cells (MRC5) and adult murine trigeminal ganglion (TG) neurons using the Illumina platform for cDNA sequencing (RNA-seq). RNA-seq analysis of wild-type virus revealed that expression of the genome mostly followed the previously established kinetics, validating the method, while highlighting variations in gene expression within individual kinetic classes. The accumulation of immediate early transcripts differed between MRC5 cells and neurons, with a greater abundance in neurons. Analysis of a mutant defective in all five IE genes (d109) showed dysregulated genome-wide low-level transcription that was more highly attenuated in MRC5 cells than in TG neurons. Furthermore, a subset of genes in d109 was more abundantly expressed over time in neurons. While the majority of the viral genome became relatively quiescent, the latency-associated transcript was specifically upregulated. Unexpectedly, other genes within repeat regions of the genome, as well as the unique genes just adjacent the repeat regions, also remained relatively active in neurons. The relative permissiveness of TG neurons to viral gene expression near the joint region is likely significant during the establishment and reactivation of latency. During productive infection, the genes of HSV-1 are transcribed in an ordered cascade. HSV can also establish a more quiescent or latent infection in peripheral neurons. HSV mutants defective in multiple immediate early (IE) genes establish a quiescent infection that models aspects of latency in vivo. We simultaneously quantified the expression of all the HSV genes in nonneuronal and neuronal cells by RNA-seq analysis. The results for productive infection shed further light on the nature of genes and promoters of different kinetic classes. In quiescent infection, there was greater transcription across the genome in neurons than in nonneuronal cells. In particular, the transcription of the latency-associated transcript (LAT), IE genes, and genes in the unique regions adjacent to the repeats persisted in neurons. The relative activity of this region of the genome in the absence of viral activators suggests a more dynamic state for quiescent genomes persisting in neurons. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

In vivo Knock-down of the HSV-1 Latency-Associated Transcript Reduces Reactivation from Latency.

PubMed

Watson, Zachary L; Washington, Shannan D; Phelan, Dane M; Lewin, Alfred S; Tuli, Sonal S; Schultz, Gregory S; Neumann, Donna M; Bloom, David C

2018-06-06

During Herpes Simplex Virus (HSV) latency, most viral genes are silenced with the exception of one region of the genome encoding the latency-associated transcript (LAT). This long non-coding RNA was originally described as having a role in enhancing HSV-1 reactivation. However, subsequent evidence showing that the LAT blocked apoptosis and promoted efficient establishment of latency suggested that its effects on reactivation were secondary to establishment. Here, we utilize an Adeno-associated Virus (AAV) vector to deliver a LAT-targeting hammerhead ribozyme to HSV-1-infected neurons of rabbits after the establishment of HSV-1 latency. The rabbits were then induced to reactivate latent HSV-1. Using this model, we show that decreasing LAT levels in neurons following the establishment of latency reduced the ability of the virus to reactivate. This demonstrates that the HSV-1 LAT RNA has a role in reactivation that is independent of its function in establishment of latency. In addition these results suggest the potential of AAV vectors expressing LAT-targeting ribozymes as a potential therapy for recurrent HSV disease such as herpes stromal keratitis, a leading cause of infectious blindness. Importance Herpes Simplex Virus (HSV) establishes a life long infection and remains dormant (latent) in our nerve cells. Occasionally HSV reactivates to cause disease, with HSV-1 typically causing cold sores whereas HSV-2 is the most common cause of genital herpes. The details of how HSV reactivates are largely unknown. Most of HSV's genes are silent during latency with the exception of RNAs made from the latency-associated transcript (LAT) region. While viruses that make less LAT do not reactivate efficiently, these viruses also do not establish latency as efficiently. Here we deliver a ribozyme that can degrade the LAT to the nerve cells of latently infected rabbits using a gene therapy vector. We show that this treatment blocks reactivation in the majority of the rabbits. This work shows that the LAT RNA is important for reactivation and the suggests the potential of this treatment as a therapy for treating HSV infections. Copyright © 2018 American Society for Microbiology.

Epstein-Barr virus growth/latency III program alters cellular microRNA expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron, Jennifer E.; Tulane Cancer Center, Tulane University Health Sciences Center, 1430 Tulane Avenue, SL79, New Orleans, LA 70112; Fewell, Claire

The Epstein-Barr virus (EBV) is associated with lymphoid and epithelial cancers. Initial EBV infection alters lymphocyte gene expression, inducing cellular proliferation and differentiation as the virus transitions through consecutive latency transcription programs. Cellular microRNAs (miRNAs) are important regulators of signaling pathways and are implicated in carcinogenesis. The extent to which EBV exploits cellular miRNAs is unknown. Using micro-array analysis and quantitative PCR, we demonstrate differential expression of cellular miRNAs in type III versus type I EBV latency including elevated expression of miR-21, miR-23a, miR-24, miR-27a, miR-34a, miR-146a and b, and miR-155. In contrast, miR-28 expression was found to be lowermore » in type III latency. The EBV-mediated regulation of cellular miRNAs may contribute to EBV signaling and associated cancers.« less

Increased neurovirulence and reactivation of the herpes simplex virus type 1 latency associated transcript (LAT) negative mutant dLAT2903 with a disrupted LAT miR-H2

PubMed Central

Jiang, Xianzhi; Brown, Don; Osorio, Nelson; Hsiang, Chinhui; BenMohamed, Lbachir; Wechsler, Steven L.

2015-01-01

At least six microRNAs (miRNAs) appear to be encoded by the latency associated transcript (LAT) of herpes simplex virus type 1 (HSV-1). The gene for ICP0, an important immediate early (IE) viral protein, is antisense to, and overlaps with, the region of LAT from which miRNA H2 (miR-H2) is derived. We recently reported that a mutant (McK-ΔH2) disrupted for miR-H2 on the wild type HSV-1 strain McKrae genomic background has increased ICP0 expression, increased neurovirulence, and slightly more rapid reactivation. We report here that HSV-1 mutants deleted for the LAT promoter nonetheless make significant amounts of miR-H2 during lytic tissue culture infection, presumably via readthrough transcription from an upstream promoter. To determine if miR-H2 might also play a role in the HSV-1 latency-reactivation cycle of a LAT negative mutant, we constructed dLAT-ΔH2, in which miR-H2 is disrupted in dLAT2903 without altering the predicted amino acid sequence of the overlapping ICP0 open reading frame. Similar to McK-ΔH2, dLAT-ΔH2 expressed more ICP0, was more neurovirulent, and had increased reactivation in the mouse TG explant induced reactivation model of HSV-1 compared to its parental virus. Interestingly, although the increased reactivation of McK-ΔH2 compared to its parental wt virus was subtle and only detected at very early times after explant TG induced reactivation, the increased reactivation of dLAT-ΔH2 compared to its dLAT2903 parental virus appeared more robust and was significantly increased even at late times after induction. These results confirm that miR-H2 plays a role in modulating the HSV-1 reactivation phenotype. PMID:26069184

Interactions between Herpesvirus Entry Mediator (TNFRSF14) and Latency-Associated Transcript during Herpes Simplex Virus 1 Latency

PubMed Central

Allen, Sariah J.; Rhode-Kurnow, Antje; Mott, Kevin R.; Jiang, Xianzhi; Carpenter, Dale; Rodriguez-Barbosa, J. Ignacio; Jones, Clinton; Wechsler, Steven L.; Ware, Carl F.

2014-01-01

Herpesvirus entry mediator (HVEM) is one of several cell surface proteins herpes simplex virus (HSV) uses for attachment/entry. HVEM regulates cellular immune responses and can also increase cell survival. Interestingly, latency-associated transcript (LAT), the only viral gene consistently expressed during neuronal latency, enhances latency and reactivation by promoting cell survival and by helping the virus evade the host immune response. However, the mechanisms of these LAT activities are not well understood. We show here for the first time that one mechanism by which LAT enhances latency and reactivation appears to be by upregulating HVEM expression. HSV-1 latency/reactivation was significantly reduced in Hvem−/− mice, indicating that HVEM plays a significant role in HSV-1 latency/reactivation. Furthermore, LAT upregulated HVEM expression during latency in vivo and also when expressed in vitro in the absence of other viral factors. This study suggests a mechanism whereby LAT upregulates HVEM expression potentially through binding of two LAT small noncoding RNAs to the HVEM promoter and that the increased HVEM then leads to downregulation of immune responses in the latent microenvironment and increased survival of latently infected cells. Thus, one of the mechanisms by which LAT enhances latency/reactivation appears to be through increasing expression of HVEM. PMID:24307582

A gene capable of blocking apoptosis can substitute for the herpes simplex virus type 1 latency-associated transcript gene and restore wild-type reactivation levels.

PubMed

Perng, Guey-Chuen; Maguen, Barak; Jin, Ling; Mott, Kevin R; Osorio, Nelson; Slanina, Susan M; Yukht, Ada; Ghiasi, Homayon; Nesburn, Anthony B; Inman, Melissa; Henderson, Gail; Jones, Clinton; Wechsler, Steven L

2002-02-01

After ocular herpes simplex virus type 1 (HSV-1) infection, the virus travels up axons and establishes a lifelong latent infection in neurons of the trigeminal ganglia. LAT (latency-associated transcript), the only known viral gene abundantly transcribed during HSV-1 neuronal latency, is required for high levels of reactivation. The LAT function responsible for this reactivation phenotype is not known. Recently, we showed that LAT can block programmed cell death (apoptosis) in neurons of the trigeminal ganglion in vivo and in tissue culture cells in vitro (G.-C. Perng et al., Science 287:1500-1503, 2000; M. Inman et al., J. Virol. 75:3636-3646, 2001). Consequently, we proposed that this antiapoptosis function may be a key to the mechanism by which LAT enhances reactivation. To study this further, we constructed a recombinant HSV-1 virus in which the HSV-1 LAT gene was replaced by an alternate antiapoptosis gene. We used the bovine herpes virus 1 (BHV-1) latency-related (LR) gene, which was previously shown to have antiapoptosis activity, for this purpose. The resulting chimeric virus, designated CJLAT, contains two complete copies of the BHV-1 LR gene (one in each viral long repeat) in place of the normal two copies of the HSV-1 LAT, on an otherwise wild-type HSV-1 strain McKrae genomic background. We report here that in both rabbits and mice reactivation of CJLAT was significantly greater than the LAT null mutant dLAT2903 (P < 0.0004 and P = 0.001, respectively) and was at least as efficient as wild-type McKrae. This strongly suggests that a BHV-1 LR gene function was able to efficiently substitute for an HSV-1 LAT gene function involved in reactivation. Although replication of CJLAT in rabbits and mice was similar to that of wild-type McKrae, CJLAT killed more mice during acute infection and caused more corneal scarring in latently infected rabbits. This suggested that the BHV-1 LR gene and the HSV-1 LAT gene are not functionally identical. However, LR and LAT both have antiapoptosis activity. These studies therefore strongly support the hypothesis that replacing LAT with an antiapoptosis gene restores the wild-type reactivation phenotype to a LAT null mutant of HSV-1 McKrae.

Herpes Simplex Virus 2 MicroRNA miR-H6 Is a Novel Latency-Associated Transcript-Associated MicroRNA, but Reduction of Its Expression Does Not Influence the Establishment of Viral Latency or the Recurrence Phenotype▿

PubMed Central

Tang, Shuang; Bertke, Andrea S.; Patel, Amita; Margolis, Todd P.; Krause, Philip R.

2011-01-01

The herpes simplex virus 2 (HSV-2) viral microRNA (miRNA) designated miR-H6 is located upstream of the latency-associated transcript (LAT) promoter region on the strand opposite the LAT. Deletion of the LAT promoter and part of LAT exon 1 abolished HSV-2 miR-H6 expression in acutely and latently infected guinea pig dorsal root ganglia (DRG), suggesting that this region is needed both for the expression of LAT-encoded miRNAs and for miR-H6 expression in vivo. Relative to cells infected with a viral rescuant, miR-H6 expression was significantly reduced in cells infected with a mutant HSV-2 virus, NotPolyA, with an insertion of a simian virus (SV40) polyadenylation signal sequence between the LAT promoter and miR-H6 sequences. In addition, expression of miR-H6, but not LAT or viral DNA, was significantly reduced in both mouse trigeminal ganglia (TG) and guinea pig DRG latently infected with the NotPolyA mutant. Guinea pigs infected with NotPolyA experienced reduced neurological complications of acute infection relative to those infected with the rescuant, but the recurrence phenotype of the NotPolyA mutant was similar to those of its rescuant and wild-type HSV-2, indicating that reduction of miR-H6 expression is not by itself able to alter the establishment of latency for the wild-type virus or the recurrence phenotype. Furthermore, the mutation in NotPolyA did not affect the propensity of wild-type HSV-2 to establish latency in neurons positive for subtype marker KH10. In contrast to published reports regarding its HSV-1 homolog, HSV-2 miR-H6 did not affect ICP4 expression in transfected or infected cells. We hypothesize that viral miRNAs associated with LAT expression are likely to work collectively, contributing to the phenotype attributed to the LAT. PMID:21325410

Latency of Epstein-Barr virus is stabilized by antisense-mediated control of the viral immediate-early gene BZLF-1.

PubMed

Prang, N; Wolf, H; Schwarzmann, F

1999-12-01

The ability of the Epstein-Barr virus (EBV) to avoid lytic replication and to establish a latent infection in B-lymphocytes is fundamental for its lifelong persistence and the pathogenesis of various EBV-associated diseases. The viral immediate-early gene BZLF-1 plays a key role for the induction of lytic replication and its activity is strictly regulated on different levels of gene expression. Recently, it was demonstrated that BZLF-1 is also controlled by a posttranscriptional mechanism. Transient synthesis of a mutated competitor RNA saturated this mechanism and caused both expression of the BZLF-1 protein and the induction of lytic viral replication. Using short overlapping fragments of the competitor, it is shown that this control acts on the unspliced primary transcript. RT-PCR demonstrated unspliced BZLF-1 RNA in latently infected B-lymphocytes in the absence of BZLF-1 protein. Due to the complementarity of the gene BZLF-1 and the latency-associated gene EBNA-1 on the opposite strand of the genome, we propose an antisense-mediated mechanism. RNase protection assays demonstrated transcripts in antisense orientation to the BZLF-1 transcript during latency, which comprise a comparable constellation to other herpesviruses. A combined RNAse protection/RT-PCR assay detected the double-stranded hybrid RNA, consisting of the unspliced BZLF-1 transcript and a noncoding intron of the EBNA-1 gene. Binding of BZLF-1 transcripts is suggested to be an important backup control mechanism in addition to transcriptional regulation, stabilizing latency and preventing inappropriate lytic viral replication in vivo. Copyright 1999 Wiley-Liss, Inc.

The molecular basis of herpes simplex virus latency

PubMed Central

Nicoll, Michael P; Proença, João T; Efstathiou, Stacey

2012-01-01

Herpes simplex virus type 1 is a neurotropic herpesvirus that establishes latency within sensory neurones. Following primary infection, the virus replicates productively within mucosal epithelial cells and enters sensory neurones via nerve termini. The virus is then transported to neuronal cell bodies where latency can be established. Periodically, the virus can reactivate to resume its normal lytic cycle gene expression programme and result in the generation of new virus progeny that are transported axonally back to the periphery. The ability to establish lifelong latency within the host and to periodically reactivate to facilitate dissemination is central to the survival strategy of this virus. Although incompletely understood, this review will focus on the mechanisms involved in the regulation of latency that centre on the functions of the virus-encoded latency-associated transcripts (LATs), epigenetic regulation of the latent virus genome and the molecular events that precipitate reactivation. This review considers current knowledge and hypotheses relating to the mechanisms involved in the establishment, maintenance and reactivation herpes simplex virus latency. PMID:22150699

A Herpes Simplex Virus Type 1 Mutant Expressing a Baculovirus Inhibitor of Apoptosis Gene in Place of Latency-Associated Transcript Has a Wild-Type Reactivation Phenotype in the Mouse

PubMed Central

Jin, Ling; Perng, Guey-Chuen; Mott, Kevin R.; Osorio, Nelson; Naito, Julia; Brick, David J.; Carpenter, Dale; Jones, Clinton; Wechsler, Steven L.

2005-01-01

The latency-associated transcript (LAT) is essential for the wild-type herpes simplex virus type 1 (HSV-1) high-reactivation phenotype since LAT− mutants have a low-reactivation phenotype. We previously reported that LAT can decrease apoptosis and proposed that this activity is involved in LAT's ability to enhance the HSV-1 reactivation phenotype. The first 20% of the primary 8.3-kb LAT transcript is sufficient for enhancing the reactivation phenotype and for decreasing apoptosis, supporting this proposal. For this study, we constructed an HSV-1 LAT− mutant that expresses the baculovirus antiapoptosis gene product cpIAP under control of the LAT promoter and in place of the LAT region mentioned above. Mice were ocularly infected with this mutant, designated dLAT-cpIAP, and the reactivation phenotype was determined using the trigeminal ganglion explant model. dLAT-cpIAP had a reactivation phenotype similar to that of wild-type virus and significantly higher than that of (i) the LAT− mutant dLAT2903; (ii) dLAT1.5, a control virus containing the same LAT deletion as dLAT-cpIAP, but with no insertion of foreign DNA, thereby controlling for potential readthrough transcription past the cpIAP insert; and (iii) dLAT-EGFP, a control virus identical to dLAT-cpIAP except that it contained the enhanced green fluorescent protein open reading frame (ORF) in place of the cpIAP ORF, thereby controlling for expression of a random foreign gene instead of the cpIAP gene. These results show that an antiapoptosis gene with no sequence similarity to LAT can efficiently substitute for the LAT function involved in enhancing the in vitro-induced HSV-1 reactivation phenotype in the mouse. PMID:16160155

HSV-1 Genome Subnuclear Positioning and Associations with Host-Cell PML-NBs and Centromeres Regulate LAT Locus Transcription during Latency in Neurons

PubMed Central

Catez, Frédéric; Picard, Christel; Held, Kathrin; Gross, Sylvain; Rousseau, Antoine; Theil, Diethilde; Sawtell, Nancy; Labetoulle, Marc; Lomonte, Patrick

2012-01-01

Major human pathologies are caused by nuclear replicative viruses establishing life-long latent infection in their host. During latency the genomes of these viruses are intimately interacting with the cell nucleus environment. A hallmark of herpes simplex virus type 1 (HSV-1) latency establishment is the shutdown of lytic genes expression and the concomitant induction of the latency associated (LAT) transcripts. Although the setting up and the maintenance of the latent genetic program is most likely dependent on a subtle interplay between viral and nuclear factors, this remains uninvestigated. Combining the use of in situ fluorescent-based approaches and high-resolution microscopic analysis, we show that HSV-1 genomes adopt specific nuclear patterns in sensory neurons of latently infected mice (28 days post-inoculation, d.p.i.). Latent HSV-1 genomes display two major patterns, called “Single” and “Multiple”, which associate with centromeres, and with promyelocytic leukemia nuclear bodies (PML-NBs) as viral DNA-containing PML-NBs (DCP-NBs). 3D-image reconstruction of DCP-NBs shows that PML forms a shell around viral genomes and associated Daxx and ATRX, two PML partners within PML-NBs. During latency establishment (6 d.p.i.), infected mouse TGs display, at the level of the whole TG and in individual cells, a substantial increase of PML amount consistent with the interferon-mediated antiviral role of PML. “Single” and “Multiple” patterns are reminiscent of low and high-viral genome copy-containing neurons. We show that LAT expression is significantly favored within the “Multiple” pattern, which underlines a heterogeneity of LAT expression dependent on the viral genome copy number, pattern acquisition, and association with nuclear domains. Infection of PML-knockout mice demonstrates that PML/PML-NBs are involved in virus nuclear pattern acquisition, and negatively regulate the expression of the LAT. This study demonstrates that nuclear domains including PML-NBs and centromeres are functionally involved in the control of HSV-1 latency, and represent a key level of host/virus interaction. PMID:22912575

Latency-associated transcript (LAT) exon 1 controls herpes simplex virus species-specific phenotypes: reactivation in the guinea pig genital model and neuron subtype-specific latent expression of LAT.

PubMed

Bertke, Andrea S; Patel, Amita; Imai, Yumi; Apakupakul, Kathleen; Margolis, Todd P; Krause, Philip R

2009-10-01

Herpes simplex virus 1 (HSV-1) and HSV-2 cause similar acute infections but differ in their abilities to reactivate from trigeminal and lumbosacral dorsal root ganglia. During latency, HSV-1 and HSV-2 also preferentially express their latency-associated transcripts (LATs) in different sensory neuronal subtypes that are positive for A5 and KH10 markers, respectively. Chimeric virus studies showed that LAT region sequences influence both of these viral species-specific phenotypes. To further map the LAT region sequences responsible for these phenotypes, we constructed the chimeric virus HSV2-LAT-E1, in which exon 1 (from the LAT TATA to the intron splice site) was replaced by the corresponding sequence from HSV-1 LAT. In intravaginally infected guinea pigs, HSV2-LAT-E1 reactivated inefficiently relative to the efficiency of its rescuant and wild-type HSV-2, but it yielded similar levels of viral DNA, LAT, and ICP0 during acute and latent infection. HSV2-LAT-E1 preferentially expressed the LAT in A5+ neurons (as does HSV-1), while the chimeric viruses HSV2-LAT-P1 (LAT promoter swap) and HSV2-LAT-S1 (LAT sequence swap downstream of the promoter) exhibited neuron subtype-specific latent LAT expression phenotypes more similar to that of HSV-2 than that of HSV-1. Rescuant viruses displayed the wild-type HSV-2 phenotypes of efficient reactivation in the guinea pig genital model and a tendency to express LAT in KH10+ neurons. The region that is critical for HSV species-specific differences in latency and reactivation thus lies between the LAT TATA and the intron splice site, and minor differences in the 5' ends of chimeric sequences in HSV2-LAT-E1 and HSV2-LAT-S1 point to sequences immediately downstream of the LAT TATA.

Latency-Associated Transcript (LAT) Exon 1 Controls Herpes Simplex Virus Species-Specific Phenotypes: Reactivation in the Guinea Pig Genital Model and Neuron Subtype-Specific Latent Expression of LAT▿

PubMed Central

Bertke, Andrea S.; Patel, Amita; Imai, Yumi; Apakupakul, Kathleen; Margolis, Todd P.; Krause, Philip R.

2009-01-01

Herpes simplex virus 1 (HSV-1) and HSV-2 cause similar acute infections but differ in their abilities to reactivate from trigeminal and lumbosacral dorsal root ganglia. During latency, HSV-1 and HSV-2 also preferentially express their latency-associated transcripts (LATs) in different sensory neuronal subtypes that are positive for A5 and KH10 markers, respectively. Chimeric virus studies showed that LAT region sequences influence both of these viral species-specific phenotypes. To further map the LAT region sequences responsible for these phenotypes, we constructed the chimeric virus HSV2-LAT-E1, in which exon 1 (from the LAT TATA to the intron splice site) was replaced by the corresponding sequence from HSV-1 LAT. In intravaginally infected guinea pigs, HSV2-LAT-E1 reactivated inefficiently relative to the efficiency of its rescuant and wild-type HSV-2, but it yielded similar levels of viral DNA, LAT, and ICP0 during acute and latent infection. HSV2-LAT-E1 preferentially expressed the LAT in A5+ neurons (as does HSV-1), while the chimeric viruses HSV2-LAT-P1 (LAT promoter swap) and HSV2-LAT-S1 (LAT sequence swap downstream of the promoter) exhibited neuron subtype-specific latent LAT expression phenotypes more similar to that of HSV-2 than that of HSV-1. Rescuant viruses displayed the wild-type HSV-2 phenotypes of efficient reactivation in the guinea pig genital model and a tendency to express LAT in KH10+ neurons. The region that is critical for HSV species-specific differences in latency and reactivation thus lies between the LAT TATA and the intron splice site, and minor differences in the 5′ ends of chimeric sequences in HSV2-LAT-E1 and HSV2-LAT-S1 point to sequences immediately downstream of the LAT TATA. PMID:19641003

Influence of Herpes Simplex Virus 1 Latency-Associated Transcripts on the Establishment and Maintenance of Latency in the ROSA26R Reporter Mouse Model

PubMed Central

Nicoll, M. P.; Proença, J. T.; Connor, V.

2012-01-01

Herpes simplex virus 1 (HSV-1) can establish life-long latent infection in sensory neurons, from which periodic reactivation can occur. During latency, viral gene expression is largely restricted to the latency-associated transcripts (LATs). While not essential for any phase of latency, to date the LATs have been shown to increase the efficiency of both establishment and reactivation of latency in small-animal models. We sought to investigate the role of LAT expression in the frequency of latency establishment within the ROSA26R reporter mouse model utilizing Cre recombinase-encoding recombinant viruses harboring deletions of the core LAT promoter (LAP) region. HSV-1 LAT expression was observed to influence the number of latently infected neurons in trigeminal but not dorsal root ganglia. Furthermore, the relative frequencies of latency establishment of LAT-positive and LAT-negative viruses are influenced by the inoculum dose following infection of the mouse whisker pads. Finally, analysis of the infected cell population at two latent time points revealed a relative loss of latently infected cells in the absence of LAT expression. We conclude that the HSV-1 LATs facilitate the long-term stability of the latent cell population within the infected host and that interpretation of LAT establishment phenotypes is influenced by infection methodology. PMID:22696655

The Characteristics of Herpes Simplex Virus Type 1 Infection in Rhesus Macaques and the Associated Pathological Features.

PubMed

Fan, Shengtao; Cai, Hongzhi; Xu, Xingli; Feng, Min; Wang, Lichun; Liao, Yun; Zhang, Ying; He, Zhanlong; Yang, Fengmei; Yu, Wenhai; Wang, Jingjing; Zhou, Jumin; Li, Qihan

2017-01-30

As one of the major pathogens for human herpetic diseases, herpes simplex virus type 1 (HSV1) causes herpes labialis, genital herpes and herpetic encephalitis. Our aim here was to investigate the infectious process of HSV1 in rhesus macaques and the pathological features induced during this infection. Clinical symptoms that manifested in the rhesus macaque during HSV1 infection included vesicular lesions and their pathological features. Viral distribution in the nervous tissues and associated pathologic changes indicated the typical systematic pathological processes associated with viral distribution of HSV1.Interestingly, vesicular lesions recurred in oral skin or in mucosa associated with virus shedding in macaques within four to five months post-infection,and viral latency-associated transcript (LAT) mRNA was found in the trigeminal ganglia (TG)on day 365 post-infection. Neutralization testing and enzyme-linked immunospot (ELISpot) detection of specific T cell responses confirmed the specific immunity induced by HSV1 infection. Thus, rhesus macaques could serve as an infectious model for HSV1 due to their typical clinical symptoms and the pathological recurrence associated with viral latency in nervous tissues.

Expression of Herpes Simplex Virus 1-Encoded MicroRNAs in Human Trigeminal Ganglia and Their Relation to Local T-Cell Infiltrates ▿

PubMed Central

Held, Kathrin; Junker, Andreas; Dornmair, Klaus; Meinl, Edgar; Sinicina, Inga; Brandt, Thomas; Theil, Diethilde; Derfuss, Tobias

2011-01-01

Herpes simplex type 1 (HSV-1) is a neurotropic virus which establishes lifelong latency in human trigeminal ganglia (TG). Currently, two nonexclusive control mechanisms of HSV-1 latency are discussed: antiviral CD8+ T cells and viral microRNAs (miRNAs) encoded by the latency associated transcript (LAT). We investigate here to what extent these mechanisms may contribute to the maintenance of HSV-1 latency. We show that only a small proportion of LAT+ neurons is surrounded by T cells in human TG. This indicates that viral latency in human TG might be controlled by other mechanisms such as viral miRNAs. Therefore, we assessed TG sections for the presence of HSV-1 miRNA, DNA, and mRNA by combining LAT in situ hybridization, T-cell immunohistochemistry, and single cell analysis of laser-microdissected sensory neurons. Quantitative reverse transcription-PCR (RT-PCR) revealed that LAT+ neurons with or without surrounding T cells were always positive for HSV-1 miRNAs and DNA. Furthermore, ICP0 mRNA could rarely be detected only in LAT+ neurons, as analyzed by single-cell RT-PCR. In contrast, in LAT− neurons that were surrounded by T cells, neither miRNAs nor the DNA of HSV-1, HSV-2, or varicella-zoster virus could be detected. These data indicate that the majority of LAT+ neurons is not directly controlled by T cells. However, miRNA expression in every latently infected neuron would provide an additional checkpoint before viral replication is initiated. PMID:21795359

Herpes Simplex Virus 2 Latency-Associated Transcript (LAT) region mutations do not identify a role for LAT-Associated Micro RNAs in viral reactivation in the Guinea Pig Genital Model.

PubMed

Kawamura, Yoshiki; Bosch-Marce, Marta; Tang, Shuang; Patel, Amita; Krause, Philip R

2018-05-02

Despite the long-standing observation that herpes simplex virus (HSV) Latency-Associated Transcript (LAT) promoter-deletion viruses show impaired recurrence phenotypes in relevant animal models, the mechanism by which these sequences exert this phenotypic effect is unknown. We constructed and evaluated four mutant HSV-2 viruses with targeted mutations in the LAT promoter and LAT-associated miRNAs affecting (1) the LAT TATA box, (2) the LAT ICP4-binding site, (3) miR-I and miR-II (miR-I/II), which both target ICP34.5, and (4) miR-III, which targets ICP0. While the LAT-TATA box mutant caused milder acute infections than wild-type (WT), there was no difference in recurrence phenotype between these viruses. LAT and miRNA expression during latency were not impaired by this mutation, suggesting that other promoter elements may be more important for latent HSV-2 LAT expression. Mutation of the LAT ICP4-binding site also did not cause an in vivo phenotypic difference between mutant and WT viruses. Acute infection and reactivation from latency of the miR-I/II mutant was similar to that of its rescuant, although slightly reduced in severity relative to the wild-type virus. The miR-III mutant also exhibited WT phenotypes in acute and recurrent phases of infection. While not ruling out an effect of these elements in human latency or reactivation, these findings do not identify a specific role for LAT or LAT-associated miRNAs in the HSV-2 LAT promoter deletion phenotype in guinea pigs. Thus, other sequences in this region may play a more important role in the long-studied LAT-associated phenotype in animals. IMPORTANCE While it has been known for several decades that specific HSV-1 and HSV-2 sequences near the LAT promoter are required for efficient viral reactivation in animal models, the mechanism is still not known. We constructed four mutant viruses with the goal of identifying critical sequence elements and of specifically testing the hypothesis that microRNAs that are expressed during latency play a role. Determination that specific LAT promoter sequences and miRNA sequences do not influence viral reactivation of HSV-2 helps to narrow down the search for the mechanism by which the virus controls its latency and recurrence phenotype. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Characterization of a spliced exon product of herpes simplex type-1 latency-associated transcript in productively infected cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Wen; Mukerjee, Ruma; Gartner, Jared J.

2006-12-20

The latency-associated transcripts (LATs) of herpes simplex virus type-1 (HSV-1) are the only viral RNAs accumulating during latent infections in the sensory ganglia of the peripheral nervous system. The major form of LAT that accumulates in latently infected neurons is a 2 kb intron, spliced from a much less abundant 8.3 primary transcript. The spliced exon mRNA has been hard to detect. However, in this study, we have examined the spliced exon RNA in productively infected cells using ribonuclease protection (RPA), and quantitative RT-PCR (q-PCR) assays. We were able to detect the LAT exon RNA in productively infected SY5Y cellsmore » (a human neuronal cell line). The level of the LAT exon RNA was found to be approximately 5% that of the 2 kb intron RNA and thus is likely to be relatively unstable. Quantitative RT-PCR (q-PCR) assays were used to examine the LAT exon RNA and its properties. They confirmed that the LAT exon mRNA is present at a very low level in productively infected cells, compared to the levels of other viral transcripts. Furthermore, experiments showed that the LAT exon mRNA is expressed as a true late gene, and appears to be polyadenylated. In SY5Y cells, in contrast to most late viral transcripts, the LAT exon RNA was found to be mainly nuclear localized during the late stage of a productive infection. Interestingly, more LAT exon RNA was found in the cytoplasm in differentiated compared to undifferentiated SY5Y cells, suggesting the nucleocytoplasmic distribution of the LAT exon RNA and its related function may be influenced by the differentiation state of cells.« less

A 2.5-Kilobase Deletion Containing a Cluster of Nine MicroRNAs in the Latency-Associated-Transcript Locus of the Pseudorabies Virus Affects the Host Response of Porcine Trigeminal Ganglia during Established Latency

PubMed Central

Mahjoub, Nada; Dhorne-Pollet, Sophie; Fuchs, Walter; Endale Ahanda, Marie-Laure; Lange, Elke; Klupp, Barbara; Arya, Anoop; Loveland, Jane E.; Lefevre, François; Mettenleiter, Thomas C.

2014-01-01

ABSTRACT The alphaherpesvirus pseudorabies virus (PrV) establishes latency primarily in neurons of trigeminal ganglia when only the transcription of the latency-associated transcript (LAT) locus is detected. Eleven microRNAs (miRNAs) cluster within the LAT, suggesting a role in establishment and/or maintenance of latency. We generated a mutant (M) PrV deleted of nine miRNA genes which displayed properties that were almost identical to those of the parental PrV wild type (WT) during propagation in vitro. Fifteen pigs were experimentally infected with either WT or M virus or were mock infected. Similar levels of virus excretion and host antibody response were observed in all infected animals. At 62 days postinfection, trigeminal ganglia were excised and profiled by deep sequencing and quantitative RT-PCR. Latency was established in all infected animals without evidence of viral reactivation, demonstrating that miRNAs are not essential for this process. Lower levels of the large latency transcript (LLT) were found in ganglia infected by M PrV than in those infected by WT PrV. All PrV miRNAs were expressed, with highest expression observed for prv-miR-LLT1, prv-miR-LLT2 (in WT ganglia), and prv-miR-LLT10 (in both WT and M ganglia). No evidence of differentially expressed porcine miRNAs was found. Fifty-four porcine genes were differentially expressed between WT, M, and control ganglia. Both viruses triggered a strong host immune response, but in M ganglia gene upregulation was prevalent. Pathway analyses indicated that several biofunctions, including those related to cell-mediated immune response and the migration of dendritic cells, were impaired in M ganglia. These findings are consistent with a function of the LAT locus in the modulation of host response for maintaining a latent state. IMPORTANCE This study provides a thorough reference on the establishment of latency by PrV in its natural host, the pig. Our results corroborate the evidence obtained from the study of several LAT mutants of other alphaherpesviruses encoding miRNAs from their LAT regions. Neither PrV miRNA expression nor high LLT expression levels are essential to achieve latency in trigeminal ganglia. Once latency is established by PrV, the only remarkable differences are found in the pattern of host response. This indicates that, as in herpes simplex virus, LAT functions as an immune evasion locus. PMID:25320324

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

PubMed

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

2010-06-18

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

CTCF Binding Sites in the Herpes Simplex Virus 1 Genome Display Site-Specific CTCF Occupation, Protein Recruitment, and Insulator Function.

PubMed

Washington, Shannan D; Musarrat, Farhana; Ertel, Monica K; Backes, Gregory L; Neumann, Donna M

2018-04-15

There are seven conserved CTCF binding domains in the herpes simplex virus 1 (HSV-1) genome. These binding sites individually flank the latency-associated transcript (LAT) and the immediate early (IE) gene regions, suggesting that CTCF insulators differentially control transcriptional domains in HSV-1 latency. In this work, we show that two CTCF binding motifs in HSV-1 display enhancer blocking in a cell-type-specific manner. We found that CTCF binding to the latent HSV-1 genome was LAT dependent and that the quantity of bound CTCF was site specific. Following reactivation, CTCF eviction was dynamic, suggesting that each CTCF site was independently regulated. We explored whether CTCF sites recruit the polycomb-repressive complex 2 (PRC2) to establish repressive domains through a CTCF-Suz12 interaction and found that Suz12 colocalized to the CTCF insulators flanking the ICP0 and ICP4 regions and, conversely, was removed at early times postreactivation. Collectively, these data support the idea that CTCF sites in HSV-1 are independently regulated and may contribute to lytic-latent HSV-1 control in a site-specific manner. IMPORTANCE The role of chromatin insulators in DNA viruses is an area of interest. It has been shown in several beta- and gammaherpesviruses that insulators likely control the lytic transcriptional profile through protein recruitment and through the formation of three-dimensional (3D) chromatin loops. The ability of insulators to regulate alphaherpesviruses has been understudied to date. The alphaherpesvirus HSV-1 has seven conserved insulator binding motifs that flank regions of the genome known to contribute to the establishment of latency. Our work presented here contributes to the understanding of how insulators control transcription of HSV-1. Copyright © 2018 American Society for Microbiology.

Herpes simplex virus 1 microRNAs expressed abundantly during latent infection are not essential for latency in mouse trigeminal ganglia

PubMed Central

Kramer, Martha F.; Jurak, Igor; Pesola, Jean M.; Boissel, Sandrine; Knipe, David M.; Coen, Donald M.

2013-01-01

Several herpes simplex virus 1 microRNAs are encoded within or near the latency associated transcript (LAT) locus, and are expressed abundantly during latency. Some of these microRNAs can repress the expression of important viral proteins and are hypothesized to play important roles in establishing and/or maintaining latent infections. We found that in lytically infected cells and in acutely infected mouse ganglia, expression of LAT-encoded microRNAs was weak and unaffected by a deletion that includes the LAT promoter. In mouse ganglia latently infected with wild type virus, the microRNAs accumulated to high levels, but deletions of the LAT promoter markedly reduced expression of LAT-encoded microRNAs and also miR-H6, which is encoded upstream of LAT and can repress expression of ICP4. Because these LAT deletion mutants establish and maintain latent infections, these microRNAs are not essential for latency, at least in mouse trigeminal ganglia, but may help promote it. PMID:21782205

Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome.

PubMed

Szymula, Agnieszka; Palermo, Richard D; Bayoumy, Amr; Groves, Ian J; Ba Abdullah, Mohammed; Holder, Beth; White, Robert E

2018-02-01

The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vitro. We generated EBNA-LP knockout (LPKO) EBVs containing a STOP codon within each repeat unit of internal repeat 1 (IR1). EBNA-LP-mutant EBVs established lymphoblastoid cell lines (LCLs) from adult B cells at reduced efficiency, but not from umbilical cord B cells, which died approximately two weeks after infection. Adult B cells only established EBNA-LP-null LCLs with a memory (CD27+) phenotype. Quantitative PCR analysis of virus gene expression after infection identified both an altered ratio of the EBNA genes, and a dramatic reduction in transcript levels of both EBNA2-regulated virus genes (LMP1 and LMP2) and the EBNA2-independent EBER genes in the first 2 weeks. By 30 days post infection, LPKO transcription was the same as wild-type EBV. In contrast, EBNA2-regulated cellular genes were induced efficiently by LPKO viruses. Chromatin immunoprecipitation revealed that EBNA2 and the host transcription factors EBF1 and RBPJ were delayed in their recruitment to all viral latency promoters tested, whereas these same factors were recruited efficiently to several host genes, which exhibited increased EBNA2 recruitment. We conclude that EBNA-LP does not simply co-operate with EBNA2 in activating gene transcription, but rather facilitates the recruitment of several transcription factors to the viral genome, to enable transcription of virus latency genes. Additionally, our findings suggest that EBNA-LP is essential for the survival of EBV-infected naïve B cells.

Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome

PubMed Central

Szymula, Agnieszka; Palermo, Richard D.; Bayoumy, Amr; Groves, Ian J.

2018-01-01

The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vitro. We generated EBNA-LP knockout (LPKO) EBVs containing a STOP codon within each repeat unit of internal repeat 1 (IR1). EBNA-LP-mutant EBVs established lymphoblastoid cell lines (LCLs) from adult B cells at reduced efficiency, but not from umbilical cord B cells, which died approximately two weeks after infection. Adult B cells only established EBNA-LP-null LCLs with a memory (CD27+) phenotype. Quantitative PCR analysis of virus gene expression after infection identified both an altered ratio of the EBNA genes, and a dramatic reduction in transcript levels of both EBNA2-regulated virus genes (LMP1 and LMP2) and the EBNA2-independent EBER genes in the first 2 weeks. By 30 days post infection, LPKO transcription was the same as wild-type EBV. In contrast, EBNA2-regulated cellular genes were induced efficiently by LPKO viruses. Chromatin immunoprecipitation revealed that EBNA2 and the host transcription factors EBF1 and RBPJ were delayed in their recruitment to all viral latency promoters tested, whereas these same factors were recruited efficiently to several host genes, which exhibited increased EBNA2 recruitment. We conclude that EBNA-LP does not simply co-operate with EBNA2 in activating gene transcription, but rather facilitates the recruitment of several transcription factors to the viral genome, to enable transcription of virus latency genes. Additionally, our findings suggest that EBNA-LP is essential for the survival of EBV-infected naïve B cells. PMID:29462212

Coregulatory Interactions among CD8α Dendritic Cells, the Latency-Associated Transcript, and Programmed Death 1 Contribute to Higher Levels of Herpes Simplex Virus 1 Latency

PubMed Central

Mott, Kevin R.; Allen, Sariah J.; Zandian, Mandana

2014-01-01

ABSTRACT The latency-associated transcript (LAT) of herpes simplex virus 1 (HSV-1), CD8α+ dendritic cells (DCs), and programmed death 1 (PD-1) have all been implicated in the HSV-1 latency-reactivation cycle. It is not known, however, whether an interaction between LAT and CD8α+ DCs regulates latency and T-cell exhaustion. To address this question, we used LAT-expressing [LAT(+)] and LAT-negative [LAT(−)] viruses. Depletion of DCs in mice ocularly infected with LAT(+) virus resulted in a reduction in the number of T cells expressing PD-1 in the trigeminal ganglia (TG), whereas depletion of DCs in mice similarly infected with LAT(−) virus did not alter PD-1 expression. CD8α+ DCs, but not CD4+ DCs, infected with LAT(+) virus had higher levels of ICP0, ICP4, thymidine kinase (TK), and PD-1 ligand 1 (PD-L1) transcripts than those infected with LAT(−) virus. Coculture of infected bone marrow (BM)-derived DCs from wild-type (WT) mice, but not infected DCs from CD8α−/− mice, with WT naive T cells contributed to an increase in PD-1 expression. Transfer of bone marrow from WT mice but not CD8α−/− mice to recipient Rag1−/− mice increased the number of latent viral genomes in reconstituted mice infected with the LAT(+) virus. Collectively, these data indicated that a reduction in latency correlated with a decline in the levels of CD8α+ DCs and PD-1 expression. In summary, our results demonstrate an interaction among LAT, PD-1, and CD11c CD8α+ cells that regulates latency in the TG of HSV-1-infected mice. IMPORTANCE Very little is known regarding the interrelationship of LAT, PD-1, and CD8α+ DCs and how such interactions might contribute to relative numbers of latent viral genomes. We show here that (i) in both in vivo and in vitro studies, deficiency of CD8α+ DCs significantly reduced T-cell exhaustion in the presence of LAT(+) virus but not LAT(−) virus; (ii) HSV-1 infectivity was significantly lower in LAT(−)-infected DCs than in their LAT(+)-infected counterparts; and (iii) adoptive transfer of bone marrow (BM) from WT but not CD8α−/− mice to recipient Rag1−/− mice restored latency to the level in WT mice following infection with LAT(+) virus. These studies point to a key role for CD8α+ DCs in T-cell exhaustion in the presence of LAT, which leads to larger numbers of latent viral genomes. Thus, altering this negative function of CD8α+ DCs can potentially be used to generate a more effective vaccine against HSV infection. PMID:24672046

Two open reading frames (ORF1 and ORF2) within the 2.0-kilobase latency-associated transcript of herpes simplex virus type 1 are not essential for reactivation from latency.

PubMed Central

Fareed, M U; Spivack, J G

1994-01-01

The herpes simplex virus type 1 (HSV-1) latency-associated transcripts (LATs) are dispensable for establishment and maintenance of latent infection. However, the LATs have been implicated in reactivation of the virus from its latent state. Since the reported LAT deletion and/or insertion variants that are reactivation impaired contain deletions in the putative LAT promoter, it is not known which LAT sequences are involved in reactivation. To examine the role of the 2.0-kb LAT in the process of reactivation and the functional importance of the putative open reading frames (ORF1 and ORF2) contained within the 2.0-kb LAT, we have constructed an HSV-1 variant that contains a precise deletion and insertion within the LAT-specific DNA sequences using site-directed mutagenesis. The HSV-1 variant FS1001K contains an 1,186-bp deletion starting precisely from the 5' end of the 2.0-kb LAT and, for identification, a XbaI restriction endonuclease site insertion. The FS1001K genome contains no other deletions and/or insertions as analyzed by a variety of restriction endonucleases. The deletion in FS1001K removes the entire 556-bp intron within the 2.0-kb LAT, the first 229 nucleotides of ORF1, and the first 159 nucleotides of ORF2 without having an affect on the RL2 (ICP0) gene. Explant cocultivation reactivation assays indicated that this deletion had a minimal effect on reactivation of the variant FS1001K compared with the parental wild-type virus using a mouse eye model. As expected, Northern (RNA) blot analyses have shown that the variant virus (FS1001K) does not produce the 2.0-kb LAT or the 1.45- to 1.5-kb LAT either in vitro or in vivo; however, FS1001K produces an intact RL2 transcript in tissue culture. These data suggest that the 2.0-kb LAT putative ORF1 and ORF2 (or the first 1,186 bp of the 2.0-kb LAT) are dispensable for explant reactivation of latent HSV-1. Images PMID:7966597

Defining the Transcriptional Landscape during Cytomegalovirus Latency with Single-Cell RNA Sequencing

PubMed Central

2018-01-01

ABSTRACT Primary infection with human cytomegalovirus (HCMV) results in a lifelong infection due to its ability to establish latent infection, with one characterized viral reservoir being hematopoietic cells. Although reactivation from latency causes serious disease in immunocompromised individuals, our molecular understanding of latency is limited. Here, we delineate viral gene expression during natural HCMV persistent infection by analyzing the massive transcriptome RNA sequencing (RNA-seq) atlas generated by the Genotype-Tissue Expression (GTEx) project. This systematic analysis reveals that HCMV persistence in vivo is prevalent in diverse tissues. Notably, we find only viral transcripts that resemble gene expression during various stages of lytic infection with no evidence of any highly restricted latency-associated viral gene expression program. To further define the transcriptional landscape during HCMV latent infection, we also used single-cell RNA-seq and a tractable experimental latency model. In contrast to some current views on latency, we also find no evidence for any highly restricted latency-associated viral gene expression program. Instead, we reveal that latency-associated gene expression largely mirrors a late lytic viral program, albeit at much lower levels of expression. Overall, our work has the potential to revolutionize our understanding of HCMV persistence and suggests that latency is governed mainly by quantitative changes, with a limited number of qualitative changes, in viral gene expression. PMID:29535194

The Epstein-Barr Virus Episome Maneuvers between Nuclear Chromatin Compartments during Reactivation

PubMed Central

Moquin, Stephanie A.; Thomas, Sean; Whalen, Sean; Warburton, Alix; Fernandez, Samantha G.; McBride, Alison A.; Pollard, Katherine S.

2017-01-01

ABSTRACT The human genome is structurally organized in three-dimensional space to facilitate functional partitioning of transcription. We learned that the latent episome of the human Epstein-Barr virus (EBV) preferentially associates with gene-poor chromosomes and avoids gene-rich chromosomes. Kaposi's sarcoma-associated herpesvirus behaves similarly, but human papillomavirus does not. Contacts on the EBV side localize to OriP, the latent origin of replication. This genetic element and the EBNA1 protein that binds there are sufficient to reconstitute chromosome association preferences of the entire episome. Contacts on the human side localize to gene-poor and AT-rich regions of chromatin distant from transcription start sites. Upon reactivation from latency, however, the episome moves away from repressive heterochromatin and toward active euchromatin. Our work adds three-dimensional relocalization to the molecular events that occur during reactivation. Involvement of myriad interchromosomal associations also suggests a role for this type of long-range association in gene regulation. IMPORTANCE The human genome is structurally organized in three-dimensional space, and this structure functionally affects transcriptional activity. We set out to investigate whether a double-stranded DNA virus, Epstein-Barr virus (EBV), uses mechanisms similar to those of the human genome to regulate transcription. We found that the EBV genome associates with repressive compartments of the nucleus during latency and with active compartments during reactivation. This study advances our knowledge of the EBV life cycle, adding three-dimensional relocalization as a novel component to the molecular events that occur during reactivation. Furthermore, the data add to our understanding of nuclear compartments, showing that disperse interchromosomal interactions may be important for regulating transcription. PMID:29142137

Different Mechanisms Regulate Productive Herpes Simplex Virus 1 (HSV-1) and HSV-2 Infections in Adult Trigeminal Neurons

PubMed Central

Ma, AyeAye; Margolis, Mathew S.

2013-01-01

Herpes simplex virus 1 (HSV-1) and HSV-2 establish latency in different neuronal subtypes (A5+ and KH10+) in murine trigeminal ganglia, results which correlate with restricted productive infection in these neurons in vitro. HSV-2 latency-associated transcript (LAT) contains a cis-acting regulatory element near the transcription start site that promotes productive infection in A5+ neurons and a second element in exon 1 that inhibits productive infection in KH10+ neurons. HSV-1 contains no such regulatory sequences, demonstrating different mechanisms for regulating productive HSV infection in neurons. PMID:23514893

Reactivation of Latent HIV-1 Expression by Engineered TALE Transcription Factors.

PubMed

Perdigão, Pedro; Gaj, Thomas; Santa-Marta, Mariana; Barbas, Carlos F; Goncalves, Joao

2016-01-01

The presence of replication-competent HIV-1 -which resides mainly in resting CD4+ T cells--is a major hurdle to its eradication. While pharmacological approaches have been useful for inducing the expression of this latent population of virus, they have been unable to purge HIV-1 from all its reservoirs. Additionally, many of these strategies have been associated with adverse effects, underscoring the need for alternative approaches capable of reactivating viral expression. Here we show that engineered transcriptional modulators based on customizable transcription activator-like effector (TALE) proteins can induce gene expression from the HIV-1 long terminal repeat promoter, and that combinations of TALE transcription factors can synergistically reactivate latent viral expression in cell line models of HIV-1 latency. We further show that complementing TALE transcription factors with Vorinostat, a histone deacetylase inhibitor, enhances HIV-1 expression in latency models. Collectively, these findings demonstrate that TALE transcription factors are a potentially effective alternative to current pharmacological routes for reactivating latent virus and that combining synthetic transcriptional activators with histone deacetylase inhibitors could lead to the development of improved therapies for latent HIV-1 infection.

Combinatorial Effects of the Glucocorticoid Receptor and Krüppel-Like Transcription Factor 15 on Bovine Herpesvirus 1 Transcription and Productive Infection.

PubMed

El-Mayet, Fouad S; Sawant, Laximan; Thunuguntla, Prasanth; Jones, Clinton

2017-11-01

Bovine herpesvirus 1 (BoHV-1), an important bovine pathogen, establishes lifelong latency in sensory neurons. Latently infected calves consistently reactivate from latency following a single intravenous injection of the synthetic corticosteroid dexamethasone. The immediate early transcription unit 1 (IEtu1) promoter, which drives bovine ICP0 (bICP0) and bICP4 expression, is stimulated by dexamethasone because it contains two glucocorticoid receptor (GR) response elements (GREs). Several Krüppel-like transcription factors (KLF), including KLF15, are induced during reactivation from latency, and they stimulate certain viral promoters and productive infection. In this study, we demonstrate that the GR and KLF15 were frequently expressed in the same trigeminal ganglion (TG) neuron during reactivation and cooperatively stimulated productive infection and IEtu1 GREs in mouse neuroblastoma cells (Neuro-2A). We further hypothesized that additional regions in the BoHV-1 genome are transactivated by the GR or stress-induced transcription factors. To test this hypothesis, BoHV-1 DNA fragments (less than 400 bp) containing potential GR and KLF binding sites were identified and examined for transcriptional activation by stress-induced transcription factors. Intergenic regions within the unique long 52 gene (UL52; a component of the DNA primase/helicase complex), bICP4, IEtu2, and the unique short region were stimulated by KLF15 and the GR. Chromatin immunoprecipitation studies revealed that the GR and KLF15 interacted with sequences within IEtu1 GREs and the UL52 fragment. Coimmunoprecipitation studies demonstrated that KLF15 and the GR were associated with each other in transfected cells. Since the GR stimulates KLF15 expression, we suggest that these two transcription factors form a feed-forward loop that stimulates viral gene expression and productive infection following stressful stimuli. IMPORTANCE Bovine herpesvirus 1 (BoHV-1) is an important viral pathogen that causes respiratory disease and suppresses immune responses in cattle; consequently, life-threatening bacterial pneumonia can occur. Following acute infection, BoHV-1 establishes lifelong latency in sensory neurons. Reactivation from latency is initiated by the synthetic corticosteroid dexamethasone. Dexamethasone stimulates lytic cycle viral gene expression in sensory neurons of calves latently infected with BoHV-1, culminating in virus shedding and transmission. Two stress-induced cellular transcription factors, Krüppel-like transcription factor 15 (KLF15) and the glucocorticoid receptor (GR), cooperate to stimulate productive infection and viral transcription. Additional studies demonstrated that KLF15 and the GR form a stable complex and that these stress-induced transcription factors bind to viral DNA sequences, which correlates with transcriptional activation. The ability of the GR and KLF15 to synergistically stimulate viral gene expression and productive infection may be critical for the ability of BoHV-1 to reactivate from latency following stressful stimuli. Copyright © 2017 American Society for Microbiology.

Combinatorial Effects of the Glucocorticoid Receptor and Krüppel-Like Transcription Factor 15 on Bovine Herpesvirus 1 Transcription and Productive Infection

PubMed Central

El-mayet, Fouad S.; Sawant, Laximan; Thunuguntla, Prasanth

2017-01-01

ABSTRACT Bovine herpesvirus 1 (BoHV-1), an important bovine pathogen, establishes lifelong latency in sensory neurons. Latently infected calves consistently reactivate from latency following a single intravenous injection of the synthetic corticosteroid dexamethasone. The immediate early transcription unit 1 (IEtu1) promoter, which drives bovine ICP0 (bICP0) and bICP4 expression, is stimulated by dexamethasone because it contains two glucocorticoid receptor (GR) response elements (GREs). Several Krüppel-like transcription factors (KLF), including KLF15, are induced during reactivation from latency, and they stimulate certain viral promoters and productive infection. In this study, we demonstrate that the GR and KLF15 were frequently expressed in the same trigeminal ganglion (TG) neuron during reactivation and cooperatively stimulated productive infection and IEtu1 GREs in mouse neuroblastoma cells (Neuro-2A). We further hypothesized that additional regions in the BoHV-1 genome are transactivated by the GR or stress-induced transcription factors. To test this hypothesis, BoHV-1 DNA fragments (less than 400 bp) containing potential GR and KLF binding sites were identified and examined for transcriptional activation by stress-induced transcription factors. Intergenic regions within the unique long 52 gene (UL52; a component of the DNA primase/helicase complex), bICP4, IEtu2, and the unique short region were stimulated by KLF15 and the GR. Chromatin immunoprecipitation studies revealed that the GR and KLF15 interacted with sequences within IEtu1 GREs and the UL52 fragment. Coimmunoprecipitation studies demonstrated that KLF15 and the GR were associated with each other in transfected cells. Since the GR stimulates KLF15 expression, we suggest that these two transcription factors form a feed-forward loop that stimulates viral gene expression and productive infection following stressful stimuli. IMPORTANCE Bovine herpesvirus 1 (BoHV-1) is an important viral pathogen that causes respiratory disease and suppresses immune responses in cattle; consequently, life-threatening bacterial pneumonia can occur. Following acute infection, BoHV-1 establishes lifelong latency in sensory neurons. Reactivation from latency is initiated by the synthetic corticosteroid dexamethasone. Dexamethasone stimulates lytic cycle viral gene expression in sensory neurons of calves latently infected with BoHV-1, culminating in virus shedding and transmission. Two stress-induced cellular transcription factors, Krüppel-like transcription factor 15 (KLF15) and the glucocorticoid receptor (GR), cooperate to stimulate productive infection and viral transcription. Additional studies demonstrated that KLF15 and the GR form a stable complex and that these stress-induced transcription factors bind to viral DNA sequences, which correlates with transcriptional activation. The ability of the GR and KLF15 to synergistically stimulate viral gene expression and productive infection may be critical for the ability of BoHV-1 to reactivate from latency following stressful stimuli. PMID:28794031

An M2 Rather than a TH2 Response Contributes to Better Protection against Latency Reactivation following Ocular Infection of Naive Mice with a Recombinant Herpes Simplex Virus 1 Expressing Murine Interleukin-4.

PubMed

Lee, Dhong Hyun; Ghiasi, Homayon

2018-05-15

We found previously that altering macrophage polarization toward M2 responses by injection of colony-stimulating factor 1 (CSF-1) was more effective in reducing both primary and latent infections in mice ocularly infected with herpes simplex virus 1 (HSV-1) than M1 polarization by gamma interferon (IFN-γ) injection. Cytokines can coordinately regulate macrophage and T helper (T H ) responses, with interleukin-4 (IL-4) inducing type 2 T H (T H 2) as well as M2 responses and IFN-γ inducing T H 1 as well as M1 responses. We have now differentiated the contributions of these immune compartments to protection against latency reactivation and corneal scarring by comparing the effects of infection with recombinant HSV-1 in which the latency-associated transcript (LAT) gene was replaced with either the IL-4 (HSV-IL-4) or IFN-γ (HSV-IFN-γ) gene using infection with the parental (LAT-negative) virus as a control. Analysis of peritoneal macrophages in vitro established that the replacement of LAT with the IL-4 or IFN-γ gene did not affect virus infectivity and promoted polarization appropriately. Protection against corneal scarring was significantly higher in mice ocularly infected with HSV-IL-4 than in those infected with HSV-IFN-γ or parental virus. Levels of primary virus replication in the eyes and trigeminal ganglia (TG) were similar in the three groups of mice, but the numbers of gC + cells were lower on day 5 postinfection in the eyes of HSV-IL-4-infected mice than in those infected with HSV-IFN-γ or parental virus. Latency and explant reactivation were lower in both HSV-IL-4- and HSV-IFN-γ-infected mice than in those infected with parental virus, with the lowest level of latency being associated with HSV-IL-4 infection. Higher latency correlated with higher levels of CD8, PD-1, and IFN-γ mRNA, while reduced latency and T-cell exhaustion correlated with lower gC + expression in the TG. Depletion of macrophages increased the levels of latency in all ocularly infected mice compared with their undepleted counterparts, with macrophage depletion increasing latency in the HSV-IL-4 group greater than 3,000-fold. Our results suggest that shifting the innate macrophage immune responses toward M2, rather than M1, responses in HSV-1 infection would improve protection against establishment of latency, reactivation, and eye disease. IMPORTANCE Ocular HSV-1 infections are among the most frequent serious viral eye infections in the United States and a major cause of virus-induced blindness. As establishment of a latent infection in the trigeminal ganglia results in recurrent infection and is associated with corneal scarring, prevention of latency reactivation is a major therapeutic goal. It is well established that absence of latency-associated transcripts (LATs) reduces latency reactivation. Here we demonstrate that recombinant HSV-1 expressing IL-4 (an inducer of T H 2/M2 responses) or IFN-γ (an inducer of T H 1/M1 responses) in place of LAT further reduced latency, with HSV-IL-4 showing the highest overall protective efficacy. In naive mice, this higher protective efficacy was mediated by innate rather than adaptive immune responses. Although both M1 and M2 macrophage responses were protective, shifting macrophages toward an M2 response through expression of IL-4 was more effective in curtailing ocular HSV-1 latency reactivation. Copyright © 2018 American Society for Microbiology.

Identification of Novel Kaposi's Sarcoma-Associated Herpesvirus Orf50 Transcripts: Discovery of New RTA Isoforms with Variable Transactivation Potential

PubMed Central

Wakeman, Brian S.; Izumiya, Yoshihiro

2016-01-01

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus that has been associated with primary effusion lymphoma and multicentric Castleman's disease, as well as its namesake Kaposi's sarcoma. As a gammaherpesvirus, KSHV is able to acutely replicate, enter latency, and reactivate from this latent state. A key protein involved in both acute replication and reactivation from latency is the replication and transcriptional activator (RTA) encoded by the gene Orf50. RTA is a known transactivator of multiple viral genes, allowing it to control the switch between latency and virus replication. We report here the identification of six alternatively spliced Orf50 transcripts that are generated from four distinct promoters. These newly identified promoters are shown to be transcriptionally active in 293T (embryonic kidney), Vero (African-green monkey kidney epithelial), 3T12 (mouse fibroblast), and RAW 264.7 (mouse macrophage) cell lines. Notably, the newly identified Orf50 transcripts are predicted to encode four different isoforms of the RTA which differ by 6 to 10 residues at the amino terminus of the protein. We show the global viral transactivation potential of all four RTA isoforms and demonstrate that all isoforms can transcriptionally activate an array of KSHV promoters to various levels. The pattern of transcriptional activation appears to support a transcriptional interference model within the Orf50 region, where silencing of previously expressed isoforms by transcription initiation from upstream Orf50 promoters has the potential to modulate the pattern of viral gene activation. IMPORTANCE Gammaherpesviruses are associated with the development of lymphomas and lymphoproliferative diseases, as well as several other types of cancer. The human gammaherpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV), is tightly associated with the development of Kaposi's sarcoma and multicentric Castleman's disease, as well as a rare form of B cell lymphoma (primary effusion lymphoma) primarily observed in HIV-infected individuals. RTA is an essential viral gene product involved in the initiation of gammaherpesvirus replication and is conserved among all known gammaherpesviruses. We show here for KSHV that transcription of the gene encoding RTA is complex and leads to the expression of several isoforms of RTA with distinct functions. This observed complexity in KSHV RTA expression and function likely plays a critical role in the regulation of downstream viral and cellular gene expression, leading to the efficient production of mature virions. PMID:27795414

Characterization of herpes simplex virus 2 primary microRNA Transcript regulation.

PubMed

Tang, Shuang; Bosch-Marce, Marta; Patel, Amita; Margolis, Todd P; Krause, Philip R

2015-05-01

In order to understand factors that may influence latency-associated transcription and latency-associated transcript (LAT) phenotypes, we studied the expression of the herpes simplex virus 2 (HSV-2) LAT-associated microRNAs (miRNAs). We mapped the transcription initiation sites of all three primary miRNA transcripts and identified the ICP4-binding sequences at the transcription initiation sites of both HSV-2 LAT (pri-miRNA for miR-I and miR-II, which target ICP34.5, and miR-III, which targets ICP0) and L/ST (a pri-miRNA for miR-I and miR-II) but not at that of the primary miR-H6 (for which the target is unknown). We confirmed activity of the putative HSV-2 L/ST promoter and found that ICP4 trans-activates the L/ST promoter when the ICP4-binding site at its transcription initiation site is mutated, suggesting that ICP4 may play a dual role in regulating transcription of L/ST and, consequently, of miR-I and miR-II. LAT exon 1 (containing LAT enhancer sequences), together with the LAT promoter region, comprises a bidirectional promoter required for the expression of both LAT-encoded miRNAs and miR-H6 in latently infected mouse ganglia. The ability of ICP4 to suppress ICP34.5-targeting miRNAs and to activate lytic viral genes suggests that ICP4 could play a key role in the switch between latency and reactivation. The HSV-2 LAT and viral miRNAs expressed in the LAT region are the most abundant viral transcripts during HSV latency. The balance between the expression of LAT and LAT-associated miRNAs and the expression of lytic viral transcripts from the opposite strand appears to influence whether individual HSV-infected neurons will be latently or productively infected. The outcome of neuronal infection may thus depend on regulation of gene expression of the corresponding primary miRNAs. In the present study, we characterize promoter sequences responsible for miRNA expression, including identification of the primary miRNA 5' ends and evaluation of ICP4 response. These findings provide further insight into the virus' strategy to tightly control expression of lytic cycle genes (especially the neurovirulence factor, ICP34.5) and suggest a mechanism (via ICP4) for the transition from latency to reactivated productive infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Characterization of Herpes Simplex Virus 2 Primary MicroRNA Transcript Regulation

PubMed Central

Bosch-Marce, Marta; Patel, Amita; Margolis, Todd P.

2015-01-01

ABSTRACT In order to understand factors that may influence latency-associated transcription and latency-associated transcript (LAT) phenotypes, we studied the expression of the herpes simplex virus 2 (HSV-2) LAT-associated microRNAs (miRNAs). We mapped the transcription initiation sites of all three primary miRNA transcripts and identified the ICP4-binding sequences at the transcription initiation sites of both HSV-2 LAT (pri-miRNA for miR-I and miR-II, which target ICP34.5, and miR-III, which targets ICP0) and L/ST (a pri-miRNA for miR-I and miR-II) but not at that of the primary miR-H6 (for which the target is unknown). We confirmed activity of the putative HSV-2 L/ST promoter and found that ICP4 trans-activates the L/ST promoter when the ICP4-binding site at its transcription initiation site is mutated, suggesting that ICP4 may play a dual role in regulating transcription of L/ST and, consequently, of miR-I and miR-II. LAT exon 1 (containing LAT enhancer sequences), together with the LAT promoter region, comprises a bidirectional promoter required for the expression of both LAT-encoded miRNAs and miR-H6 in latently infected mouse ganglia. The ability of ICP4 to suppress ICP34.5-targeting miRNAs and to activate lytic viral genes suggests that ICP4 could play a key role in the switch between latency and reactivation. IMPORTANCE The HSV-2 LAT and viral miRNAs expressed in the LAT region are the most abundant viral transcripts during HSV latency. The balance between the expression of LAT and LAT-associated miRNAs and the expression of lytic viral transcripts from the opposite strand appears to influence whether individual HSV-infected neurons will be latently or productively infected. The outcome of neuronal infection may thus depend on regulation of gene expression of the corresponding primary miRNAs. In the present study, we characterize promoter sequences responsible for miRNA expression, including identification of the primary miRNA 5′ ends and evaluation of ICP4 response. These findings provide further insight into the virus' strategy to tightly control expression of lytic cycle genes (especially the neurovirulence factor, ICP34.5) and suggest a mechanism (via ICP4) for the transition from latency to reactivated productive infection. PMID:25673716

The Human Immunodeficiency Virus 1 ASP RNA promotes viral latency by recruiting the Polycomb Repressor Complex 2 and promoting nucleosome assembly

PubMed Central

Zapata, Juan C.; Campilongo, Federica; Barclay, Robert A.; DeMarino, Catherine; Iglesias-Ussel, Maria D.; Kashanchi, Fatah; Romerio, Fabio

2017-01-01

Various epigenetic marks at the HIV-1 5′LTR suppress proviral expression and promote latency. Cellular antisense transcripts known as long noncoding RNAs (lncRNAs) recruit the polycomb repressor complex 2 (PRC2) to gene promoters, which catalyzes trimethylation of lysine 27 on histone H3 (H3K27me3), thus promoting nucleosome assembly and suppressing gene expression. We found that an HIV-1 antisense transcript expressed from the 3′LTR and encoding the antisense protein ASP promotes proviral latency. Expression of ASP RNA reduced HIV-1 replication in Jurkat cells. Moreover, ASP RNA expression promoted the establishment and maintenance of HIV-1 latency in Jurkat E4 cells. We show that this transcript interacts with and recruits PRC2 to the HIV-1 5′LTR, increasing accumulation of the suppressive epigenetic mark H3K27me3, while reducing RNA Polymerase II and thus proviral transcription. Altogether, our results suggest that the HIV-1 ASP transcript promotes epigenetic silencing of the HIV-1 5′LTR and proviral latency through the PRC2 pathway. PMID:28340355

The Human Immunodeficiency Virus 1 ASP RNA promotes viral latency by recruiting the Polycomb Repressor Complex 2 and promoting nucleosome assembly.

PubMed

Zapata, Juan C; Campilongo, Federica; Barclay, Robert A; DeMarino, Catherine; Iglesias-Ussel, Maria D; Kashanchi, Fatah; Romerio, Fabio

2017-06-01

Various epigenetic marks at the HIV-1 5'LTR suppress proviral expression and promote latency. Cellular antisense transcripts known as long noncoding RNAs (lncRNAs) recruit the polycomb repressor complex 2 (PRC2) to gene promoters, which catalyzes trimethylation of lysine 27 on histone H3 (H3K27me3), thus promoting nucleosome assembly and suppressing gene expression. We found that an HIV-1 antisense transcript expressed from the 3'LTR and encoding the antisense protein ASP promotes proviral latency. Expression of ASP RNA reduced HIV-1 replication in Jurkat cells. Moreover, ASP RNA expression promoted the establishment and maintenance of HIV-1 latency in Jurkat E4 cells. We show that this transcript interacts with and recruits PRC2 to the HIV-1 5'LTR, increasing accumulation of the suppressive epigenetic mark H3K27me3, while reducing RNA Polymerase II and thus proviral transcription. Altogether, our results suggest that the HIV-1 ASP transcript promotes epigenetic silencing of the HIV-1 5'LTR and proviral latency through the PRC2 pathway. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Induction of Epstein-Barr Virus Oncoprotein LMP1 by Transcription Factors AP-2 and Early B Cell Factor

PubMed Central

Noda, Chieko; Narita, Yohei; Watanabe, Takahiro; Yoshida, Masahiro; Ashio, Keiji; Sato, Yoshitaka; Goshima, Fumi; Kanda, Teru; Yoshiyama, Hironori; Tsurumi, Tatsuya; Kimura, Hiroshi

2016-01-01

ABSTRACT Latent membrane protein 1 (LMP1) is a major oncogene essential for primary B cell transformation by Epstein-Barr virus (EBV). Previous studies suggested that some transcription factors, such as PU.1, RBP-Jκ, NF-κB, and STAT, are involved in this expression, but the underlying mechanism is unclear. Here, we identified binding sites for PAX5, AP-2, and EBF in the proximal LMP1 promoter (ED-L1p). We first confirmed the significance of PU.1 and POU domain transcription factor binding for activation of the promoter in latency III. We then focused on the transcription factors AP-2 and early B cell factor (EBF). Interestingly, among the three AP-2-binding sites in the LMP1 promoter, two motifs were also bound by EBF. Overexpression, knockdown, and mutagenesis in the context of the viral genome indicated that AP-2 plays an important role in LMP1 expression in latency II in epithelial cells. In latency III B cells, on the other hand, the B cell-specific transcription factor EBF binds to the ED-L1p and activates LMP1 transcription from the promoter. IMPORTANCE Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) is crucial for B cell transformation and oncogenesis of other EBV-related malignancies, such as nasopharyngeal carcinoma and T/NK lymphoma. Its expression is largely dependent on the cell type or condition, and some transcription factors have been implicated in its regulation. However, these previous reports evaluated the significance of specific factors mostly by reporter assay. In this study, we prepared point-mutated EBV at the binding sites of such transcription factors and confirmed the importance of AP-2, EBF, PU.1, and POU domain factors. Our results will provide insight into the transcriptional regulation of the major oncogene LMP1. PMID:26819314

A Cell Culture Model of Latent and Lytic Herpes Simplex Virus Type 1 Infection in Spiral Ganglion.

PubMed

Liu, Yuehong; Li, Shufeng

2015-01-01

Reactivation of latent herpes simplex virus type 1 (HSV-1) in spiral ganglion neurons (SGNs) is supposed to be one of the causes of idiopathic sudden sensorineural hearing loss. This study aims to establish a cell culture model of latent and lytic HSV-1 infection in spiral ganglia. In the presence of acyclovir, primary cultures of SGNs were latently infected with HSV-1 expressing green fluorescent protein. Four days later, these cells were treated with trichostatin A (TSA), a known chemical reactivator of HSV-1. TCID50 was used to measure the titers of virus in cultures on Vero cells. RNA from cultures was detected for the presence of transcripts of ICP27 and latency-associated transcript (LAT) using reverse transcription polymerase chain reaction. There is no detectable infectious HSV-1 in latently infected cultures, whereas they could be observed in both lytically infected and latently infected/TSA-treated cultures. LAT was the only detectable transcript during latent infection, whereas lytic ICP27 transcript was detected in lytically infected and latently infected/TSA-treated cultures. Cultured SGNs can be both latently and lytically infected with HSV-1. Furthermore, latently infected SGNs can be reactivated using TSA, yielding infectious virus.

Latency Entry of Herpes Simplex Virus 1 Is Determined by the Interaction of Its Genome with the Nuclear Environment

PubMed Central

Cohen, Camille; Streichenberger, Nathalie; Texier, Pascale; Takissian, Julie; Rousseau, Antoine; Poccardi, Nolwenn; Welsch, Jérémy; Corpet, Armelle; Schaeffer, Laurent; Labetoulle, Marc; Lomonte, Patrick

2016-01-01

Herpes simplex virus 1 (HSV-1) establishes latency in trigeminal ganglia (TG) sensory neurons of infected individuals. The commitment of infected neurons toward the viral lytic or latent transcriptional program is likely to depend on both viral and cellular factors, and to differ among individual neurons. In this study, we used a mouse model of HSV-1 infection to investigate the relationship between viral genomes and the nuclear environment in terms of the establishment of latency. During acute infection, viral genomes show two major patterns: replication compartments or multiple spots distributed in the nucleoplasm (namely “multiple-acute”). Viral genomes in the “multiple-acute” pattern are systematically associated with the promyelocytic leukemia (PML) protein in structures designated viral DNA-containing PML nuclear bodies (vDCP-NBs). To investigate the viral and cellular features that favor the acquisition of the latency-associated viral genome patterns, we infected mouse primary TG neurons from wild type (wt) mice or knock-out mice for type 1 interferon (IFN) receptor with wt or a mutant HSV-1, which is unable to replicate due to the synthesis of a non-functional ICP4, the major virus transactivator. We found that the inability of the virus to initiate the lytic program combined to its inability to synthesize a functional ICP0, are the two viral features leading to the formation of vDCP-NBs. The formation of the “multiple-latency” pattern is favored by the type 1 IFN signaling pathway in the context of neurons infected by a virus able to replicate through the expression of a functional ICP4 but unable to express functional VP16 and ICP0. Analyses of TGs harvested from HSV-1 latently infected humans showed that viral genomes and PML occupy similar nuclear areas in infected neurons, eventually forming vDCP-NB-like structures. Overall our study designates PML protein and PML-NBs to be major cellular components involved in the control of HSV-1 latency, probably during the entire life of an individual. PMID:27618691

Modeling HSV-1 Latency in Human Embryonic Stem Cell-Derived Neurons

PubMed Central

Pourchet, Aldo; Modrek, Aram S.; Placantonakis, Dimitris G.; Mohr, Ian; Wilson, Angus C.

2017-01-01

Herpes simplex virus 1 (HSV-1) uses latency in peripheral ganglia to persist in its human host, however, recurrent reactivation from this reservoir can cause debilitating and potentially life-threatening disease. Most studies of latency use live-animal infection models, but these are complex, multilayered systems and can be difficult to manipulate. Infection of cultured primary neurons provides a powerful alternative, yielding important insights into host signaling pathways controlling latency. However, small animal models do not recapitulate all aspects of HSV-1 infection in humans and are limited in terms of the available molecular tools. To address this, we have developed a latency model based on human neurons differentiated in culture from an NIH-approved embryonic stem cell line. The resulting neurons are highly permissive for replication of wild-type HSV-1, but establish a non-productive infection state resembling latency when infected at low viral doses in the presence of the antivirals acyclovir and interferon-α. In this state, viral replication and expression of a late viral gene marker are not detected but there is an accumulation of the viral latency-associated transcript (LAT) RNA. After a six-day establishment period, antivirals can be removed and the infected cultures maintained for several weeks. Subsequent treatment with sodium butyrate induces reactivation and production of new infectious virus. Human neurons derived from stem cells provide the appropriate species context to study this exclusively human virus with the potential for more extensive manipulation of the progenitors and access to a wide range of preexisting molecular tools. PMID:28594343

Human Galectin-9 Is a Potent Mediator of HIV Transcription and Reactivation

PubMed Central

Abdel-Mohsen, Mohamed; Chavez, Leonard; Tandon, Ravi; Chew, Glen M.; Deng, Xutao; Danesh, Ali; Keating, Sheila; Lanteri, Marion; Samuels, Michael L.; Hoh, Rebecca; Sacha, Jonah B.; Norris, Philip J.; Niki, Toshiro; Shikuma, Cecilia M.; Hirashima, Mitsuomi; Deeks, Steven G.; Ndhlovu, Lishomwa C.; Pillai, Satish K.

2016-01-01

Identifying host immune determinants governing HIV transcription, latency and infectivity in vivo is critical to developing an HIV cure. Based on our recent finding that the host factor p21 regulates HIV transcription during antiretroviral therapy (ART), and published data demonstrating that the human carbohydrate-binding immunomodulatory protein galectin-9 regulates p21, we hypothesized that galectin-9 modulates HIV transcription. We report that the administration of a recombinant, stable form of galectin-9 (rGal-9) potently reverses HIV latency in vitro in the J-Lat HIV latency model. Furthermore, rGal-9 reverses HIV latency ex vivo in primary CD4+ T cells from HIV-infected, ART-suppressed individuals (p = 0.002), more potently than vorinostat (p = 0.02). rGal-9 co-administration with the latency reversal agent "JQ1", a bromodomain inhibitor, exhibits synergistic activity (p<0.05). rGal-9 signals through N-linked oligosaccharides and O-linked hexasaccharides on the T cell surface, modulating the gene expression levels of key transcription initiation, promoter proximal-pausing, and chromatin remodeling factors that regulate HIV latency. Beyond latent viral reactivation, rGal-9 induces robust expression of the host antiviral deaminase APOBEC3G in vitro and ex vivo (FDR<0.006) and significantly reduces infectivity of progeny virus, decreasing the probability that the HIV reservoir will be replenished when latency is reversed therapeutically. Lastly, endogenous levels of soluble galectin-9 in the plasma of 72 HIV-infected ART-suppressed individuals were associated with levels of HIV RNA in CD4+ T cells (p<0.02) and with the quantity and binding avidity of circulating anti-HIV antibodies (p<0.009), suggesting a role of galectin-9 in regulating HIV transcription and viral production in vivo during therapy. Our data suggest that galectin-9 and the host glycosylation machinery should be explored as foundations for novel HIV cure strategies. PMID:27253379

The Quantity of Latent Viral DNA Correlates with the Relative Rates at Which Herpes Simplex Virus Types 1 and 2 Cause Recurrent Genital Herpes Outbreaks

PubMed Central

Lekstrom-Himes, Julie A.; Pesnicak, Lesley; Straus, Stephen E.

1998-01-01

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) have evolved specific anatomic tropisms and site-dependent rates of reactivation. To determine whether reactivation rates depend on distinct abilities of HSV-1 and -2 to establish latency and to express latency-associated transcripts (LATs), virulent strains of each virus were studied in the guinea pig genital model. Following infection with equivalent titers of virus, the quantities of latent HSV-2 genomes and LATs were higher in lumbosacral ganglia, and HSV-2 infections recurred more frequently and lasted longer than HSV-1 infections. In contrast, if the inoculum of HSV-1 was 10 times that of HSV-2, the quantity of HSV-1 DNA and LATs increased correspondingly and HSV-1 infections were as likely to recur as those with HSV-2. The quantity of latent virus DNA correlates with and may be a major determinant of the site-specific patterns and rates of reactivation of HSV-1 and -2. PMID:9525595

Reactivation of Latent HIV-1 Expression by Engineered TALE Transcription Factors

PubMed Central

Perdigão, Pedro; Gaj, Thomas; Santa-Marta, Mariana; Goncalves, Joao

2016-01-01

The presence of replication-competent HIV-1 –which resides mainly in resting CD4+ T cells–is a major hurdle to its eradication. While pharmacological approaches have been useful for inducing the expression of this latent population of virus, they have been unable to purge HIV-1 from all its reservoirs. Additionally, many of these strategies have been associated with adverse effects, underscoring the need for alternative approaches capable of reactivating viral expression. Here we show that engineered transcriptional modulators based on customizable transcription activator-like effector (TALE) proteins can induce gene expression from the HIV-1 long terminal repeat promoter, and that combinations of TALE transcription factors can synergistically reactivate latent viral expression in cell line models of HIV-1 latency. We further show that complementing TALE transcription factors with Vorinostat, a histone deacetylase inhibitor, enhances HIV-1 expression in latency models. Collectively, these findings demonstrate that TALE transcription factors are a potentially effective alternative to current pharmacological routes for reactivating latent virus and that combining synthetic transcriptional activators with histone deacetylase inhibitors could lead to the development of improved therapies for latent HIV-1 infection. PMID:26933881

The Herpes Simplex Virus Latency-Associated Transcript Gene Is Associated with a Broader Repertoire of Virus-Specific Exhausted CD8+ T Cells Retained within the Trigeminal Ganglia of Latently Infected HLA Transgenic Rabbits

PubMed Central

Srivastava, Ruchi; Dervillez, Xavier; Khan, Arif A.; Chentoufi, Aziz A.; Chilukuri, Sravya; Shukr, Nora; Fazli, Yasmin; Ong, Nicolas N.; Afifi, Rasha E.; Osorio, Nelson; Geertsema, Roger; Nesburn, Anthony B.

2016-01-01

ABSTRACT Persistent pathogens, such as herpes simplex virus 1 (HSV-1), have evolved a variety of immune evasion strategies to avoid being detected and destroyed by the host's immune system. A dynamic cross talk appears to occur between the HSV-1 latency-associated transcript (LAT), the only viral gene that is abundantly transcribed during latency, and the CD8+ T cells that reside in HSV-1 latently infected human and rabbit trigeminal ganglia (TG). The reactivation phenotype of TG that are latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) is significantly higher than TG latently infected with LAT-null mutant (i.e., LAT− TG). Whether LAT promotes virus reactivation by selectively shaping a unique repertoire of HSV-specific CD8+ T cells in LAT+ TG is unknown. In the present study, we assessed the frequency, function, and exhaustion status of TG-resident CD8+ T cells specific to 40 epitopes derived from HSV-1 gB, gD, VP11/12, and VP13/14 proteins, in human leukocyte antigen (HLA-A*0201) transgenic rabbits infected ocularly with LAT+ versus LAT– virus. Compared to CD8+ T cells from LAT– TG, CD8+ T cells from LAT+ TG (i) recognized a broader selection of nonoverlapping HSV-1 epitopes, (ii) expressed higher levels of PD-1, TIM-3, and CTLA-4 markers of exhaustion, and (iii) produced less tumor necrosis factor alpha, gamma interferon, and granzyme B. These results suggest a novel immune evasion mechanism by which the HSV-1 LAT may contribute to the shaping of a broader repertoire of exhausted HSV-specific CD8+ T cells in latently infected TG, thus allowing for increased viral reactivation. IMPORTANCE A significantly larger repertoire of dysfunctional (exhausted) HSV-specific CD8+ T cells were found in the TG of HLA transgenic rabbits latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) than in a more restricted repertoire of functional HSV-specific CD8+ T cells in the TG of HLA transgenic rabbits latently infected with LAT-null mutant (i.e., LAT– TG). These findings suggest that the HSV-1 LAT locus interferes with the host cellular immune response by shaping a broader repertoire of exhausted HSV-specific CD8+ T cells within the latency/reactivation TG site. PMID:26842468

Identification of Novel Kaposi's Sarcoma-Associated Herpesvirus Orf50 Transcripts: Discovery of New RTA Isoforms with Variable Transactivation Potential.

PubMed

Wakeman, Brian S; Izumiya, Yoshihiro; Speck, Samuel H

2017-01-01

Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus that has been associated with primary effusion lymphoma and multicentric Castleman's disease, as well as its namesake Kaposi's sarcoma. As a gammaherpesvirus, KSHV is able to acutely replicate, enter latency, and reactivate from this latent state. A key protein involved in both acute replication and reactivation from latency is the replication and transcriptional activator (RTA) encoded by the gene Orf50 RTA is a known transactivator of multiple viral genes, allowing it to control the switch between latency and virus replication. We report here the identification of six alternatively spliced Orf50 transcripts that are generated from four distinct promoters. These newly identified promoters are shown to be transcriptionally active in 293T (embryonic kidney), Vero (African-green monkey kidney epithelial), 3T12 (mouse fibroblast), and RAW 264.7 (mouse macrophage) cell lines. Notably, the newly identified Orf50 transcripts are predicted to encode four different isoforms of the RTA which differ by 6 to 10 residues at the amino terminus of the protein. We show the global viral transactivation potential of all four RTA isoforms and demonstrate that all isoforms can transcriptionally activate an array of KSHV promoters to various levels. The pattern of transcriptional activation appears to support a transcriptional interference model within the Orf50 region, where silencing of previously expressed isoforms by transcription initiation from upstream Orf50 promoters has the potential to modulate the pattern of viral gene activation. Gammaherpesviruses are associated with the development of lymphomas and lymphoproliferative diseases, as well as several other types of cancer. The human gammaherpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV), is tightly associated with the development of Kaposi's sarcoma and multicentric Castleman's disease, as well as a rare form of B cell lymphoma (primary effusion lymphoma) primarily observed in HIV-infected individuals. RTA is an essential viral gene product involved in the initiation of gammaherpesvirus replication and is conserved among all known gammaherpesviruses. We show here for KSHV that transcription of the gene encoding RTA is complex and leads to the expression of several isoforms of RTA with distinct functions. This observed complexity in KSHV RTA expression and function likely plays a critical role in the regulation of downstream viral and cellular gene expression, leading to the efficient production of mature virions. Copyright © 2016 American Society for Microbiology.

Influence of Herpes Simplex Virus Latency-Associated Transcript (LAT) on the Distribution of Latently Infected Neurons

DTIC Science & Technology

2007-03-20

part of my life, who knows more about herpesviruses than any 8-year-old should, for making me tea and snacks when I was studying or writing, for...of latency (2, 13, 36, 45, 76, 77, 81). However, HSV-2 LAT has not been shown to inhibit apoptosis of neuronal cells. HSV has several anti ...apoptotic genes, including ICP27, ICP22, US3, US5, ICP4, and HSV-1 LAT (4). Only LAT is expressed during latency, suggesting that its anti -apoptotic

Epstein-Barr virus latency switch in human B-cells: a physico-chemical model.

PubMed

Werner, Maria; Ernberg, Ingemar; Zou, Jiezhi; Almqvist, Jenny; Aurell, Erik

2007-08-31

The Epstein-Barr virus is widespread in all human populations and is strongly associated with human disease, ranging from infectious mononucleosis to cancer. In infected cells the virus can adopt several different latency programs, affecting the cells' behaviour. Experimental results indicate that a specific genetic switch between viral latency programs, reprograms human B-cells between proliferative and resting states. Each of these two latency programs makes use of a different viral promoter, Cp and Qp, respectively. The hypothesis tested in this study is that this genetic switch is controlled by both human and viral transcription factors; Oct-2 and EBNA-1. We build a physico-chemical model to investigate quantitatively the dynamical properties of the promoter regulation and experimentally examine protein level variations between the two latency programs. Our experimental results display significant differences in EBNA-1 and Oct-2 levels between resting and proliferating programs. With the model we identify two stable latency programs, corresponding to a resting and proliferating cell. The two programs differ in robustness and transcriptional activity. The proliferating state is markedly more stable, with a very high transcriptional activity from its viral promoter. We predict the promoter activities to be mutually exclusive in the two different programs, and our relative promoter activities correlate well with experimental data. Transitions between programs can be induced, by affecting the protein levels of our transcription factors. Simulated time scales are in line with experimental results. We show that fundamental properties of the Epstein-Barr virus involvement in latent infection, with implications for tumor biology, can be modelled and understood mathematically. We conclude that EBNA-1 and Oct-2 regulation of Cp and Qp is sufficient to establish mutually exclusive expression patterns. Moreover, the modelled genetic control predict both mono- and bistable behavior and a considerable difference in transition dynamics, based on program stability and promoter activities. Both these phenomena we hope can be further investigated experimentally, to increase the understanding of this important switch. Our results also stress the importance of the little known regulation of human transcription factor Oct-2.

Carboxyl-Terminal Amino Acids 1052 to 1082 of the Latency-Associated Nuclear Antigen (LANA) Interact with RBP-Jκ and Are Responsible for LANA-Mediated RTA Repression

PubMed Central

Jin, Yi; He, Zhiheng; Liang, Deguang; Zhang, Quanzhi; Zhang, Hongxing; Deng, Qiang

2012-01-01

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8, is closely associated with several malignancies, including Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. KSHV can establish lifelong latency in the host, but the mechanism is not fully understood. Previous studies have proposed a feedback model in which the viral replication and transcription activator (RTA) can induce the expression of the latency-associated nuclear antigen (LANA) during early infection. LANA, in turn, represses transcription and RTA function to establish and maintain KSHV latency. The interaction between LANA and the recombination signal sequence binding protein Jκ (RBP-Jκ, also called CSL), a major transcriptional repressor of the Notch signaling pathway, is essential for RTA repression. In the present study, we show that the LANA carboxyl-terminal amino acids 1052 to 1082 are responsible for the LANA interaction with RBP-Jκ. The secondary structure of the LANA carboxyl terminus resembles the RBP-Jκ-associated module (RAM) of Notch receptor. Furthermore, deletion of the region of LANA residues 1052 to 1082 resulted in aberrant expression of RTA, leading to elevated viral lytic replication. For the first time, we dissected a conserved RBP-Jκ binding domain in LANA and demonstrated that this domain was indispensable for LANA-mediated repression of KSHV lytic genes, thus helping the virus maintain latency and control viral reactivation. PMID:22379075

Carboxyl-terminal amino acids 1052 to 1082 of the latency-associated nuclear antigen (LANA) interact with RBP-Jκ and are responsible for LANA-mediated RTA repression.

PubMed

Jin, Yi; He, Zhiheng; Liang, Deguang; Zhang, Quanzhi; Zhang, Hongxing; Deng, Qiang; Robertson, Erle S; Lan, Ke

2012-05-01

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8, is closely associated with several malignancies, including Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. KSHV can establish lifelong latency in the host, but the mechanism is not fully understood. Previous studies have proposed a feedback model in which the viral replication and transcription activator (RTA) can induce the expression of the latency-associated nuclear antigen (LANA) during early infection. LANA, in turn, represses transcription and RTA function to establish and maintain KSHV latency. The interaction between LANA and the recombination signal sequence binding protein Jκ (RBP-Jκ, also called CSL), a major transcriptional repressor of the Notch signaling pathway, is essential for RTA repression. In the present study, we show that the LANA carboxyl-terminal amino acids 1052 to 1082 are responsible for the LANA interaction with RBP-Jκ. The secondary structure of the LANA carboxyl terminus resembles the RBP-Jκ-associated module (RAM) of Notch receptor. Furthermore, deletion of the region of LANA residues 1052 to 1082 resulted in aberrant expression of RTA, leading to elevated viral lytic replication. For the first time, we dissected a conserved RBP-Jκ binding domain in LANA and demonstrated that this domain was indispensable for LANA-mediated repression of KSHV lytic genes, thus helping the virus maintain latency and control viral reactivation.

HIV Tat/P-TEFb Interaction: A Potential Target for Novel Anti-HIV Therapies.

PubMed

Asamitsu, Kaori; Fujinaga, Koh; Okamoto, Takashi

2018-04-17

Transcription is a crucial step in the life cycle of the human immunodeficiency virus type 1 (HIV 1) and is primarily involved in the maintenance of viral latency. Both viral and cellular transcription factors, including transcriptional activators, suppressor proteins and epigenetic factors, are involved in HIV transcription from the proviral DNA integrated within the host cell genome. Among them, the virus-encoded transcriptional activator Tat is the master regulator of HIV transcription. Interestingly, unlike other known transcriptional activators, Tat primarily activates transcriptional elongation and initiation by interacting with the cellular positive transcriptional elongation factor b (P-TEFb). In this review, we describe the molecular mechanism underlying how Tat activates viral transcription through interaction with P-TEFb. We propose a novel therapeutic strategy against HIV replication through blocking Tat action.

Application of a nanoflare probe specific to a latency associated transcript for isolation of KHV latently infected cells

PubMed Central

Reed, Aimee N.; Putman, Timothy; Sullivan, Christopher; Jin, Ling

2015-01-01

One of the unique features of herpesvirus infection is latent infection following an initial exposure, which is characterized by viral genome persistence in a small fraction of cells within the latently infected tissue. Investigation of the mechanisms of herpesvirus latency has been very challenging in tissues with only a small fraction of cells that are latently infected. Cyprinid herpesvirus 3, also known as koi herpesvirus (KHV), is an important and deadly pathogen of koi and common carp, Cyprinus carpio. Acute infection can cause up to 100% mortality in exposed fish, and fish that survive the infection become latently infected. KHV becomes latent in a small percentage of B lymphocytes and can reactivate under stressful conditions. During latency, KHV ORF6 transcript is expressed in the latently infected B lymphocytes. In order to study KHV latent infection in cells that are only latently infected, a nanoflare probe specific to ORF6 RNA was used to separate KHV latently infected cells from total peripheral white blood cells (WBC). Using the ORF6 nanoflare probe, less than 1% of peripheral WBC was isolated from KHV latently infected koi. When this enriched population of WBC was examined by real-time PCR specific for KHV, it was estimated that about 1 to 2 copies of viral genome persists in the sorted cells. In addition, KHV ORF6 transcript was shown to be the major transcript expressed during latency by RNA-seq analysis. This study demonstrated that an RNA nanoflare probe could be used to enrich latently infected cells, which can subsequently be used to investigate the molecular mechanisms of KHV latency. PMID:26087404

High-resolution analysis of CpG methylation and in vivo protein-DNA interactions at the alternative Epstein-Barr virus latency promoters Qp and Cp in the nasopharyngeal carcinoma cell line C666-1.

PubMed

Bakos, Agnes; Banati, Ferenc; Koroknai, Anita; Takacs, Maria; Salamon, Daniel; Minarovits-Kormuta, Susanna; Schwarzmann, Fritz; Wolf, Hans; Niller, Hans Helmut; Minarovits, Janos

2007-10-01

Transcripts for the Epstein-Barr virus (EBV) encoded nuclear antigens (EBNAs) are initiated at alternative promoters (Wp, Cp, for EBNA 1-6 transcripts and Qp, for EBNA 1 transcripts only) located in the BamHI W, C or Q fragment of the viral genome. To understand the host-cell dependent expression of EBNAs in EBV-associated tumors (lymphomas and carcinomas) and in vitro transformed cell lines, it is necessary to analyse the regulatory mechanisms governing the activity of the alternative promoters of EBNA transcripts. Such studies focused mainly on lymphoid cell lines carrying latent EBV genomes, due to the lack of EBV-associated carcinoma cell lines maintaining latent EBV genomes during cultivation in tissue culture. We took advantage of the unique nasopharyngeal carcinoma cell line, C666-1, harboring EBV genomes, and undertook a detailed analysis of CpG methylation patterns and in vivo protein-DNA interactions at the latency promoters Qp and Cp. We found that the active, unmethylated Qp was marked with strong footprints of cellular transcription factors and the viral protein EBNA 1. In contrast, we could not detect binding of relevant transcription factors to the methylated, silent Cp. We concluded that the epigenetic marks at Qp and Cp in C666-1 cells of epithelial origin resemble those of group I Burkitt's lymphoma cell lines.

Molecular control of HIV-1 postintegration latency: implications for the development of new therapeutic strategies

PubMed Central

2009-01-01

The persistence of HIV-1 latent reservoirs represents a major barrier to virus eradication in infected patients under HAART since interruption of the treatment inevitably leads to a rebound of plasma viremia. Latency establishes early after infection notably (but not only) in resting memory CD4+ T cells and involves numerous host and viral trans-acting proteins, as well as processes such as transcriptional interference, RNA silencing, epigenetic modifications and chromatin organization. In order to eliminate latent reservoirs, new strategies are envisaged and consist of reactivating HIV-1 transcription in latently-infected cells, while maintaining HAART in order to prevent de novo infection. The difficulty lies in the fact that a single residual latently-infected cell can in theory rekindle the infection. Here, we review our current understanding of the molecular mechanisms involved in the establishment and maintenance of HIV-1 latency and in the transcriptional reactivation from latency. We highlight the potential of new therapeutic strategies based on this understanding of latency. Combinations of various compounds used simultaneously allow for the targeting of transcriptional repression at multiple levels and can facilitate the escape from latency and the clearance of viral reservoirs. We describe the current advantages and limitations of immune T-cell activators, inducers of the NF-κB signaling pathway, and inhibitors of deacetylases and histone- and DNA- methyltransferases, used alone or in combinations. While a solution will not be achieved by tomorrow, the battle against HIV-1 latent reservoirs is well- underway. PMID:19961595

Three Herpes Simplex Virus Type 1 Latency-Associated Transcript Mutants with Distinct and Asymmetric Effects on Virulence in Mice Compared with Rabbits

PubMed Central

Perng, Guey-Chuen; Esmaili, Daniel; Slanina, Susan M.; Yukht, Ada; Ghiasi, Homayon; Osorio, Nelson; Mott, Kevin R.; Maguen, Barak; Jin, Ling; Nesburn, Anthony B.; Wechsler, Steven L.

2001-01-01

Herpes simplex virus type 1 latency-associated transcript (LAT)-null mutants have decreased reactivation but normal virulence in rabbits and mice. We report here on dLAT1.5, a mutant with LAT nucleotides 76 to 1667 deleted. Following ocular infection of rabbits, dLAT1.5 reactivated at a lower rate than its wild-type parent McKrae (6.1 versus 11.8%; P = 0.0025 [chi-square test]). Reactivation was restored in the marker-rescued virus dLAT1.5R (12.6%; P = 0.53 versus wild type), confirming the importance of the deleted region in spontaneous reactivation. Compared with wild-type or marker-rescued virus, dLAT1.5 had similar or slightly reduced virulence in rabbits (based on survival following ocular infection). In contrast, in mice, dLAT1.5 had increased virulence (P < 0.0001). Thus, deletion of LAT nucleotides 76 to 1667 increased viral virulence in mice but not in rabbits. In contrast, we also report here that LAT2.9A, a LAT mutant that we previously reported to have increased virulence in rabbits (G. C. Perng, S. M. Slanina, A. Yuhkt, B. S. Drolet, W. J. Keleher, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 73:920–929, 1999), had decreased virulence in mice (P = 0.03). In addition, we also found that dLAT371, a LAT mutant that we previously reported to have wild-type virulence in rabbits (G. C. Perng, S. M. Slanina, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 70:2014–2018, 1996), had decreased virulence in mice (P < 0.05). Thus, these three mutants, each of which encodes a different LAT RNA, have different virulence phenotypes. dLAT1.5 had wild-type virulence in rabbits but increased virulence in mice. In contrast, LAT2.9A had increased virulence in rabbits but decreased virulence in mice, and dLAT371 had wild-type virulence in rabbits but decreased virulence in mice. Taken together, these results suggest that (i) the 5′ end of LAT and/or a gene that overlaps part of this region is involved in viral virulence, (ii) this virulence appears to have species-specific effects, and (iii) regulation of this virulence may be complex. PMID:11533165

The Role of LAT in Increased CD8+ T Cell Exhaustion in Trigeminal Ganglia of Mice Latently Infected with Herpes Simplex Virus 1▿

PubMed Central

Allen, Sariah J.; Hamrah, Pedram; Gate, David; Mott, Kevin R.; Mantopoulos, Dimosthenis; Zheng, Lixin; Town, Terrence; Jones, Clinton; von Andrian, Ulrich H.; Freeman, Gordon J.; Sharpe, Arlene H.; BenMohamed, Lbachir; Ahmed, Rafi; Wechsler, Steven L.; Ghiasi, Homayon

2011-01-01

Herpes simplex virus (HSV) infection is a classic example of latent viral infection in humans and experimental animal models. The HSV-1 latency-associated transcript (LAT) plays a major role in the HSV-1 latency reactivation cycle and thus in recurrent disease. Whether the presence of LAT leads to generation of dysfunctional T cell responses in the trigeminal ganglia (TG) of latently infected mice is not known. To address this issue, we used LAT-positive [LAT(+)] and LAT-deficient [LAT(−)] viruses to evaluate the effect of LAT on CD8 T cell exhaustion in TG of latently infected mice. The amount of latency as determined by quantitative reverse transcription-PCR (qRT-PCR) of viral DNA in total TG extracts was 3-fold higher with LAT(+) than with LAT(−) virus. LAT expression and increased latency correlated with increased mRNA levels of CD8, PD-1, and Tim-3. PD-1 is both a marker for exhaustion and a primary factor leading to exhaustion, and Tim-3 can also contribute to exhaustion. These results suggested that LAT(+) TG contain both more CD8+ T cells and more CD8+ T cells expressing the exhaustion markers PD-1 and Tim-3. This was confirmed by flow cytometry analyses of expression of CD3/CD8/PD-1/Tim-3, HSV-1, CD8+ T cell pentamer (specific for a peptide derived from residues 498 to 505 of glycoprotein B [gB498–505]), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-α). The functional significance of PD-1 and its ligands in HSV-1 latency was demonstrated by the significantly reduced amount of HSV-1 latency in PD-1- and PD-L1-deficient mice. Together, these results may suggest that both PD-1 and Tim-3 are mediators of CD8+ T cell exhaustion and latency in HSV-1 infection. PMID:21307196

The Herpes Simplex Virus 1 Latency-Associated Transcript Promotes Functional Exhaustion of Virus-Specific CD8+ T Cells in Latently Infected Trigeminal Ganglia: a Novel Immune Evasion Mechanism▿

PubMed Central

Chentoufi, Aziz A.; Kritzer, Elizabeth; Tran, Michael V.; Dasgupta, Gargi; Lim, Chang Hyun; Yu, David C.; Afifi, Rasha E.; Jiang, Xianzhi; Carpenter, Dale; Osorio, Nelson; Hsiang, Chinhui; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

2011-01-01

Following ocular herpes simplex virus 1 (HSV-1) infection of C57BL/6 mice, HSV-specific (HSV-gB498–505 tetramer+) CD8+ T cells are induced, selectively retained in latently infected trigeminal ganglia (TG), and appear to decrease HSV-1 reactivation. The HSV-1 latency-associated transcript (LAT) gene, the only viral gene that is abundantly transcribed during latency, increases reactivation. Previously we found that during latency with HSV-1 strain McKrae-derived viruses, more of the total TG resident CD8 T cells expressed markers of exhaustion with LAT+ virus compared to LAT− virus. Here we extend these findings to HSV-1 strain 17syn+-derived LAT+ and LAT− viruses and to a virus expressing just the first 20% of LAT. Thus, the previous findings were not an artifact of HSV-1 strain McKrae, and the LAT function involved mapped to the first 1.5 kb of LAT. Importantly, to our knowledge, we show here for the first time that during LAT+ virus latency, most of the HSV-1-specific TG resident CD8 T cells were functionally exhausted, as judged by low cytotoxic function and decreased gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) production. This resulted in LAT− TG having more functional HSV-gB498–505 tetramer+ CD8+ T cells compared to LAT+ TG. In addition, LAT expression, in the absence of other HSV-1 gene products, appeared to be able to directly or indirectly upregulate both PD-L1 and major histocompatibility complex class I (MHC-I) on mouse neuroblastoma cells (Neuro2A). These findings may constitute a novel immune evasion mechanism whereby the HSV-1 LAT directly or indirectly promotes functional exhaustion (i.e., dysfunction) of HSV-specific CD8+ T cells in latently infected TG, resulting in increased virus reactivation. PMID:21715478

Scaffold attachment factor B suppresses HIV-1 infection of CD4+ cells by preventing binding of RNA polymerase II to HIV-1's long terminal repeat.

PubMed

Ma, Li; Sun, Li; Jin, Xia; Xiong, Si-Dong; Wang, Jian-Hua

2018-06-10

The 5' end of HIV-1 long terminal repeat (LTR) promoter plays an essential role in driving viral transcription and productive infection. Multiple host and viral factors regulate LTR activity and modulate HIV-1 latency. Manipulation of the HIV-1 LTR provides a potential therapeutic strategy for combating HIV-1 persistence. In this study, we identified an RNA-/DNA-binding protein, Scaffold Attachment Factor B (SAFB1) as a host-cell factor that represses HIV-1 transcription. We found that SAFB1 bound to HIV-1 5`-LTR and significantly repressed 5`-LTR-driven-viral transcription and HIV-1 infection of CD4 + T cells. Mechanistically, SAFB1-mediated repression of HIV-1 transcription and infection was independent of its RNA- and DNA-binding capacities, instead, by binding to phosphorylated RNA polymerase II (RNA pol II), SAFB1 blocked its recruitment to the HIV-1 LTR. Of note, the SAFB1-mediated repression of HIV-1 transcription from proviral DNA maintained HIV-1 latency in CD4 + T cells. In summary, our findings reveal that SAFB1 binds to HIV-1-LTR and physically interacts with phosphorylated RNA pol II, repressing HIV-1 transcription initiation and elongation. Our findings improve the understanding of host modulation of HIV-1 transcription and latency and provide a new host-cell target for improved anti-HIV-1 therapies. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Herpes Simplex Virus Type 2 Triggers Reactivation of Kaposi's Sarcoma-Associated Herpesvirus from Latency and Collaborates with HIV-1 Tat

PubMed Central

Zhu, Xiaolei; Ma, Xinting; Yan, Qin; Zeng, Yi; Guo, Yuanyuan; Feng, Ninghan; Lu, Chun

2012-01-01

Kaposi's sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for Kaposi's sarcoma (KS) development without other cofactors. Previously, we identified that both human immunodeficiency type 1 (HIV-1) Tat and herpes simplex virus 1 (HSV-1) were important cofactors reactivating KSHV from latency. Here, we further investigated the potential of herpes simplex virus 2 (HSV-2) to influence KSHV replication and examined the role of Tat in this procedure. We demonstrated that HSV-2 was a potentially important factor in the pathogenesis of KS, as determined by production of lytic phase mRNA transcripts, viral proteins and infectious viral particles in BCBL-1 cells. These results were further confirmed by an RNA interference experiment using small interfering RNA targeting KSHV Rta and a luciferase reporter assay testing Rta promoter-driven luciferase activity. Mechanistic studies showed that HSV-2 infection activated nuclear factor-kappa B (NF-κB) signaling pathway. Inhibition of NF-κB pathway enhanced HSV-2-mediated KSHV activation, whereas activation of NF-κB pathway suppressed KSHV replication in HSV-2-infected BCBL-1 cells. Additionally, ectopic expression of Tat enhanced HSV-2-induced KSHV replication. These novel findings suggest a role of HSV-2 in the pathogenesis of KS and provide the first laboratory evidence that Tat may participate HSV-2-mediated KSHV activation, implying the complicated pathogenesis of acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients. PMID:22347501

Transcriptional activity across the Epstein-Barr virus genome in Raji cells during latency and after induction of an abortive lytic cycle.

PubMed

Kirchner, E A; Bornkamm, G W; Polack, A

1991-10-01

We have studied the relative rate of transcription across the Epstein-Barr virus genome in the Burkitt's lymphoma cell line Raji by nuclear run-on analysis during latency and after induction of an abortive lytic cycle with 12-0-tetradecanoylphorbol 13-acetate (TPA) and 5-iodo-2'-deoxyuridine (IUdR). During latency the entire, or almost the entire, viral genome was found to be transcriptionally active to a low or intermediate extent, with some variation in activity along the genome. The fragment with the highest transcriptional activity was EcoRI J, which contains the genes encoding the small nuclear RNAs EBER1 and -2, transcribed predominantly by RNA polymerase III. An intermediate level of transcription was observed between positions 10 and 138 (kb), with areas of slightly higher activity on the large internal repeats and the left duplicated region (DL). The remaining part of the viral genome, between position 138 and the termini, and the termini and position 10 (kb) (with the exception of the EcoRI J fragment), showed very little transcriptional activity, except for the intermediately active regions carrying the righthand oriLyt (DR) and the terminal repeats. Upon induction of the viral genome with TPA and IUdR, the viral genome was transcriptionally active at a rate at least tenfold that seen during latency. Polymerases were not equally distributed along the genome after induction; the highest density was found in regions 48 to 58 kb, 82 to 84 kb, 102 to 104 kb, 118 to 122 kb and 142 to 145 kb of the viral genome. High transcriptional activity correlated with distinct transcription units in some cases, i.e. BamHI H1LF1 (DL), BamHI MLF1, BamHI ZLF1/BamHI RLF1 and BamHI X (thymidine kinase), but not in others (BamHI H2). Besides initiation of transcription, other regulatory processes such as stabilization and processing of primary transcripts may also contribute to regulation of virus gene expression. Addition of cycloheximide completely abolished the transcriptional activation of the genome mediated by TPA and IUdR.

Identification of B Cells as a Major Site for Cyprinid Herpesvirus 3 Latency

PubMed Central

Reed, Aimee N.; Izume, Satoko; Dolan, Brian P.; LaPatra, Scott; Kent, Michael; Dong, Jing

2014-01-01

ABSTRACT Cyprinid herpesvirus 3 (CyHV-3), commonly known as koi herpesvirus (KHV), is a member of the Alloherpesviridae, and is a recently discovered emerging herpesvirus that is highly pathogenic for koi and common carp. Our previous study demonstrated that CyHV-3 becomes latent in peripheral white blood cells (WBC). In this study, CyHV-3 latency was further investigated in IgM+ WBC. The presence of the CyHV-3 genome in IgM+ WBC was about 20-fold greater than in IgM− WBC. To determine whether CyHV-3 expressed genes during latency, transcription from all eight open reading frames (ORFs) in the terminal repeat was investigated in IgM+ WBC from koi with latent CyHV-3 infection. Only a spliced ORF6 transcript was found to be abundantly expressed in IgM+ WBC from CyHV-3 latently infected koi. The spliced ORF6 transcript was also detected in vitro during productive infection as early as 1 day postinfection. The ORF6 transcript from in vitro infection begins at −127 bp upstream of the ATG codon and ends +188 bp downstream of the stop codon, +20 bp downstream of the polyadenylation signal. The hypothetical protein of ORF6 contains a consensus sequence with homology to a conserved domain of EBNA-3B and ICP4 from Epstein-Barr virus and herpes simplex virus 1, respectively, both members of the Herpesviridae. This is the first report of latent CyHV-3 in B cells and identification of gene transcription during latency for a member of the Alloherpesviridae. IMPORTANCE This is the first demonstration that a member of the Alloherpesviridae, cyprinid herpesvirus 3 (CyHV-3), establishes a latent infection in the B cells of its host, Cyprinus carpio. In addition, this is the first report of identification of gene transcription during latency for a member of Herpesvirales outside Herpesviridae. This is also the first report that the hypothetical protein of latent transcript of CyHV-3 contains a consensus sequence with homology to a conserved domain of EBNA-3B from Epstein-Barr virus and ICP4 from herpes simplex virus 1, which are genes important for latency. These strongly suggest that latency is evolutionally conserved across vertebrates. PMID:24899202

Identification of B cells as a major site for cyprinid herpesvirus 3 latency.

PubMed

Reed, Aimee N; Izume, Satoko; Dolan, Brian P; LaPatra, Scott; Kent, Michael; Dong, Jing; Jin, Ling

2014-08-01

Cyprinid herpesvirus 3 (CyHV-3), commonly known as koi herpesvirus (KHV), is a member of the Alloherpesviridae, and is a recently discovered emerging herpesvirus that is highly pathogenic for koi and common carp. Our previous study demonstrated that CyHV-3 becomes latent in peripheral white blood cells (WBC). In this study, CyHV-3 latency was further investigated in IgM(+) WBC. The presence of the CyHV-3 genome in IgM(+) WBC was about 20-fold greater than in IgM(-) WBC. To determine whether CyHV-3 expressed genes during latency, transcription from all eight open reading frames (ORFs) in the terminal repeat was investigated in IgM(+) WBC from koi with latent CyHV-3 infection. Only a spliced ORF6 transcript was found to be abundantly expressed in IgM(+) WBC from CyHV-3 latently infected koi. The spliced ORF6 transcript was also detected in vitro during productive infection as early as 1 day postinfection. The ORF6 transcript from in vitro infection begins at -127 bp upstream of the ATG codon and ends +188 bp downstream of the stop codon, +20 bp downstream of the polyadenylation signal. The hypothetical protein of ORF6 contains a consensus sequence with homology to a conserved domain of EBNA-3B and ICP4 from Epstein-Barr virus and herpes simplex virus 1, respectively, both members of the Herpesviridae. This is the first report of latent CyHV-3 in B cells and identification of gene transcription during latency for a member of the Alloherpesviridae. This is the first demonstration that a member of the Alloherpesviridae, cyprinid herpesvirus 3 (CyHV-3), establishes a latent infection in the B cells of its host, Cyprinus carpio. In addition, this is the first report of identification of gene transcription during latency for a member of Herpesvirales outside Herpesviridae. This is also the first report that the hypothetical protein of latent transcript of CyHV-3 contains a consensus sequence with homology to a conserved domain of EBNA-3B from Epstein-Barr virus and ICP4 from herpes simplex virus 1, which are genes important for latency. These strongly suggest that latency is evolutionally conserved across vertebrates. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The full-length microRNA cluster in the intron of large latency transcript is associated with the virulence of pseudorabies virus.

PubMed

Wang, Xin; Zhang, Mei-Mei; Yan, Kai; Tang, Qi; Wu, Yi-Quan; He, Wen-Bo; Chen, Huan-Chun; Liu, Zheng-Fei

2018-07-01

Pseudorabies virus (PRV), the etiological pathogen of Aujeszky's disease, belongs to the Alphaherpesvirus subfamily. Large latency transcript (LLT), the most abundant PRV transcript, harbors a ~ 4.6 kb microRNA (miRNA) cluster-encoding intron. To investigate the function of the LLT miRNA cluster during the life cycle of PRV, we generated a miRNA cluster mutation virus (PRV-∆miR cluster) and revertant virus. Analysis of the growth kinetics of PRV-ΔmiR cluster-infected cells revealed significantly smaller plaques and lower titers than the wild-type and revertant viruses. The mutation virus exhibited increased IE180 and decreased EP0 expression. The clinical symptoms observed in mice infected with PRV-ΔmiR cluster revealed that the miRNA cluster is involved in the pathogenesis of PRV. Physical parameters, virus shedding assays, and the SN 50 titers revealed that the miRNA cluster enhances PRV virulence in pigs. Collectively, our findings suggest that the full-length miRNA cluster is involved in PRV replication and virulence. Copyright © 2018 Elsevier Inc. All rights reserved.

Modeling the effects of vorinostat in vivo reveals both transient and delayed HIV transcriptional activation and minimal killing of latently infected cells

DOE PAGES

Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H.; ...

2015-10-23

Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recentmore » clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Lastly, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo.« less

Modeling the effects of vorinostat in vivo reveals both transient and delayed HIV transcriptional activation and minimal killing of latently infected cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H.

Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recentmore » clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Lastly, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo.« less

The Herpes Simplex Virus Type 1 Latency-Associated Transcript Inhibits Phenotypic and Functional Maturation of Dendritic Cells

PubMed Central

Dervillez, Xavier; Dasgupta, Gargi; Nguyen, Chelsea; Kabbara, Khaled W.; Jiang, Xianzhi; Nesburn, Anthony B.; Wechsler, Steven L.

2012-01-01

Abstract We recently found that the herpes simplex virus-1 (HSV-1) latency-associated transcript (LAT) results in exhaustion of virus-specific CD8+ T cells in latently-infected trigeminal ganglia (TG). In this study we sought to determine if this impairment may involve LAT directly and/or indirectly interfering with DC maturation. We found that a small number of HSV-1 antigen-positive DCs are present in the TG of latently-infected CD11c/eYFP mice; however, this does not imply that these DCs are acutely or latently infected. Some CD8+ T cells are adjacent to DCs, suggesting possible interactions. It has previously been shown that wild-type HSV-1 interferes with DC maturation. Here we show for the first time that this is associated with LAT expression, since compared to LAT(−) virus: (1) LAT(+) virus interfered with expression of MHC class I and the co-stimulatory molecules CD80 and CD86 on the surface of DCs; (2) LAT(+) virus impaired DC production of the proinflammatory cytokines IL-6, IL-12, and TNF-α; and (3) DCs infected in vitro with LAT(+) virus had significantly reduced the ability to stimulate HSV-specific CD8+ T cells. While a similar number of DCs was found in LAT(+) and LAT(−) latently-infected TG of CD11c/eYFP transgenic mice, more HSV-1 Ag-positive DCs and more exhausted CD8 T cells were seen with LAT(+) virus. Consistent with these findings, HSV-specific cytotoxic CD8+ T cells in the TG of mice latently-infected with LAT(+) virus produced less IFN-γ and TNF-α than those from TG of LAT(−)-infected mice. Together, these results suggest a novel immune-evasion mechanism whereby the HSV-1 LAT increases the number of HSV-1 Ag-positive DCs in latently-infected TG, and interferes with DC phenotypic and functional maturation. The effect of LAT on TG-resident DCs may contribute to the reduced function of HSV-specific CD8+ T cells in the TG of mice latently infected with LAT(+) virus. PMID:22512280

HIV-1 transcription and latency: an update

PubMed Central

2013-01-01

Combination antiretroviral therapy, despite being potent and life-prolonging, is not curative and does not eradicate HIV-1 infection since interruption of treatment inevitably results in a rapid rebound of viremia. Reactivation of latently infected cells harboring transcriptionally silent but replication-competent proviruses is a potential source of persistent residual viremia in cART-treated patients. Although multiple reservoirs may exist, the persistence of resting CD4+ T cells carrying a latent infection represents a major barrier to eradication. In this review, we will discuss the latest reports on the molecular mechanisms that may regulate HIV-1 latency at the transcriptional level, including transcriptional interference, the role of cellular factors, chromatin organization and epigenetic modifications, the viral Tat trans-activator and its cellular cofactors. Since latency mechanisms may also operate at the post-transcriptional level, we will consider inhibition of nuclear RNA export and inhibition of translation by microRNAs as potential barriers to HIV-1 gene expression. Finally, we will review the therapeutic approaches and clinical studies aimed at achieving either a sterilizing cure or a functional cure of HIV-1 infection, with a special emphasis on the most recent pharmacological strategies to reactivate the latent viruses and decrease the pool of viral reservoirs. PMID:23803414

Resident T Cells are Unable to Control HSV-1 Activity in the Brain Ependymal Region During Latency1

PubMed Central

Menendez, Chandra M.; Jinkins, Jeremy K.; Carr, Daniel J.J.

2016-01-01

Herpes simplex virus type 1 (HSV-1) is one of the leading etiologies of sporadic viral encephalitis. Early anti-viral intervention is crucial to the survival of herpes simplex encephalitis patients; however, many survivors suffer from long-term neurological deficits. It is currently understood that HSV-1 establishes a latent infection within sensory peripheral neurons throughout the life of the host. However, the tissue residence of latent virus, other than in sensory neurons, and the potential pathogenic consequences of latency remain enigmatic. In the present study, we characterized the lytic and latent infection of HSV-1 in the central nervous system in comparison to the peripheral nervous system following ocular infection in mice. We utilized RT-PCR to detect latency associated transcripts and HSV-1 lytic cycle genes within the brain stem, the ependyma (EP), containing the limbic and cortical areas which also harbor neural progenitor cells, in comparison to the trigeminal ganglia. Unexpectedly, HSV-1 lytic genes, usually identified during acute infection, are uniquely expressed in the EP 60 days post infection when animals are no longer suffering from encephalitis. An inflammatory response was also mounted in the EP by the maintenance of resident memory T cells. However, EP T cells were incapable of controlling HSV-1 infection ex-vivo and secreted less IFN-γ which correlated with expression of a variety of exhaustion-related inhibitory markers. Collectively our data suggest that the persistent viral lytic gene expression during latency is the cause of the chronic inflammatory response leading to the exhaustion of the resident T cells in the EP. PMID:27357149

Transcriptional Downregulation of ORF50/Rta by Methotrexate Inhibits the Switch of Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8 from Latency to Lytic Replication

PubMed Central

Curreli, Francesca; Cerimele, Francesca; Muralidhar, Sumitra; Rosenthal, Leonard J.; Cesarman, Ethel; Friedman-Kien, Alvin E.; Flore, Ornella

2002-01-01

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a cellular dihydrofolate reductase (DHFR) homologue. Methotrexate (MTX), a potent anti-inflammatory agent, inhibits cellular DHFR activity. We investigated the effect of noncytotoxic doses of MTX on latency and lytic KSHV replication in two KSHV-infected primary effusion lymphoma cell lines (BC-3 and BC-1) and in MTX-resistant BC-3 cells (MTX-R-BC-3 cells). Treatment with MTX completely prevented tetradecanoyl phorbol acetate-induced viral DNA replication and strongly decreased viral lytic transcript levels, even in MTX-resistant cells. However, the same treatment had no effect on transcription of cellular genes and KSHV latent genes. One of the lytic transcripts inhibited by MTX, ORF50/Rta (open reading frame), is an immediate-early gene encoding a replication-transcription activator required for expression of other viral lytic genes. Therefore, transcription of genes downstream of ORF50/Rta was inhibited, including those encoding the viral G-protein-coupled receptor (GPCR), viral interleukin-6, and K12/kaposin, which have been shown to be transforming in vitro and oncogenic in mice. Resistance to MTX has been documented in cultured cells and also in patients treated with this drug. However, MTX showed an inhibitory activity even in MTX-R-BC-3 cells. Two currently available antiherpesvirus drugs, cidofovir and foscarnet, had no effect on the transcription of these viral oncogenes and ORF50/Rta. MTX is the first example of a compound shown to downregulate the expression of ORF50/Rta and therefore prevent viral transforming gene transcription. Given that the expression of these genes may be important for tumor development, MTX could play a role in the future management of KSHV-associated malignancies. PMID:11967335

Attenuated Phenotype and Immunogenic Characteristics of a Mutated Herpes Simplex Virus 1 Strain in the Rhesus Macaque.

PubMed

Fan, Shengtao; Xu, Xingli; Liao, Yun; Wang, Yongrong; Wang, Jianbin; Feng, Min; Wang, Lichun; Zhang, Ying; He, Zhanlong; Yang, Fengmei; Fraser, Nigel W; Li, Qihan

2018-05-02

Herpes simplex virus type 1(HSV-1) presents a conundrum to public health worldwide because of its specific pathogenicity and clinical features. Some experimental vaccines, such as the recombinant viral glycoproteins, exhibit the viral immunogenicity of a host-specific immune response, but none of these has achieved a valid epidemiological protective efficacy in the human population. In the present study, we constructed an attenuated HSV-1 strain M3 through the partial deletion of UL7, UL41 , and the latency-associated transcript ( LAT ) using the CRISPR/Cas9 system. The mutant strain exhibited lowered infectivity and virulence in macaques. Neutralization testing and ELISpot detection of the specific T-cell responses confirmed the specific immunity induced by M3 immunization and this immunity defended against the challenges of the wild-type strain and restricted the entry of the wild-type strain into the trigeminal ganglion. These results in rhesus macaques demonstrated the potential of the attenuated vaccine for the prevention of HSV-1 in humans.

CCCTC-Binding Factor Acts as a Heterochromatin Barrier on Herpes Simplex Viral Latent Chromatin and Contributes to Poised Latent Infection

PubMed Central

2018-01-01

ABSTRACT Herpes simplex virus 1 (HSV-1) establishes latent infection in neurons via a variety of epigenetic mechanisms that silence its genome. The cellular CCCTC-binding factor (CTCF) functions as a mediator of transcriptional control and chromatin organization and has binding sites in the HSV-1 genome. We constructed an HSV-1 deletion mutant that lacked a pair of CTCF-binding sites (CTRL2) within the latency-associated transcript (LAT) coding sequences and found that loss of these CTCF-binding sites did not alter lytic replication or levels of establishment of latent infection, but their deletion reduced the ability of the virus to reactivate from latent infection. We also observed increased heterochromatin modifications on viral chromatin over the LAT promoter and intron. We therefore propose that CTCF binding at the CTRL2 sites acts as a chromatin insulator to keep viral chromatin in a form that is poised for reactivation, a state which we call poised latency. PMID:29437926

The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons

PubMed Central

Nicoll, Michael P.; Hann, William; Shivkumar, Maitreyi; Harman, Laura E. R.; Connor, Viv; Coleman, Heather M.; Proença, João T.; Efstathiou, Stacey

2016-01-01

Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir. PMID:27055281

The Tat Inhibitor Didehydro-Cortistatin A Prevents HIV-1 Reactivation from Latency

PubMed Central

Mousseau, Guillaume; Kessing, Cari F.; Fromentin, Rémi; Trautmann, Lydie; Chomont, Nicolas

2015-01-01

ABSTRACT Antiretroviral therapy (ART) inhibits HIV-1 replication, but the virus persists in latently infected resting memory CD4+ T cells susceptible to viral reactivation. The virus-encoded early gene product Tat activates transcription of the viral genome and promotes exponential viral production. Here we show that the Tat inhibitor didehydro-cortistatin A (dCA), unlike other antiretrovirals, reduces residual levels of viral transcription in several models of HIV latency, breaks the Tat-mediated transcriptional feedback loop, and establishes a nearly permanent state of latency, which greatly diminishes the capacity for virus reactivation. Importantly, treatment with dCA induces inactivation of viral transcription even after its removal, suggesting that the HIV promoter is epigenetically repressed. Critically, dCA inhibits viral reactivation upon CD3/CD28 or prostratin stimulation of latently infected CD4+ T cells from HIV-infected subjects receiving suppressive ART. Our results suggest that inclusion of a Tat inhibitor in current ART regimens may contribute to a functional HIV-1 cure by reducing low-level viremia and preventing viral reactivation from latent reservoirs. PMID:26152583

High viral load in lymph nodes and latent human immunodeficiency virus (HIV) in peripheral blood cells of HIV-1-infected chimpanzees.

PubMed Central

Saksela, K; Muchmore, E; Girard, M; Fultz, P; Baltimore, D

1993-01-01

We have examined human immunodeficiency virus type 1 (HIV-1) infection in chimpanzees by analyzing HIV-1 DNA and RNA in lymph nodes and peripheral mononuclear cells (PBMCs). Like certain asymptomatic HIV-infected persons, these chimpanzees had no detectable viral replication in their PBMCs. However, viral replication and a high viral load were observed in the lymphatic tissue. Despite the absence of viral replication in PBMCs, 1/1,000 to 1/10,000 of the PBMCs contained HIV-1 proviral DNA, and HIV transcription could be rapidly induced in these cells in vitro. These results provide direct evidence of cellular latency of HIV in vivo and suggest that HIV infection in chimpanzees may be a useful model for clinical latency of HIV infection in humans. Images PMID:8230463

RNAP II Processivity is a Limiting Step for HIV-1 Transcription Independent of Orientation to and Activity of Endogenous Neighboring Promoters

PubMed Central

Michaels, Katarzyna Kaczmarek; Wolschendorf, Frank; Schiralli Lester, Gillian M.; Natarajan, Malini; Kutsch, Olaf; Henderson, Andrew J.

2015-01-01

Since HIV-1 has a propensity to integrate into actively expressed genes, transcriptional interference from neighboring host promoters has been proposed to contribute to the establishment and maintenance HIV-1 latency. To gain insights into how endogenous promoters influence HIV-1 transcription we utilized a set of inducible T cell lines and characterized whether there were correlations between expression of endogenous genes, provirus and long terminal repeat architecture. We show that neighboring promoters are active but have minimal impact on HIV-1 transcription, in particular, expression of the endogenous gene did not prevent expression of HIV-1 following induction of latent provirus. We also demonstrate that releasing paused RNAP II by diminishing negative elongation factor (NELF) is sufficient to reactivate transcriptionally repressed HIV-1 provirus regardless of the integration site and orientation of the provirus suggesting that NELF-mediated RNAP II pausing is a common mechanism of maintaining HIV-1 latency. PMID:26379089

Cellular Transcription Factors Induced in Trigeminal Ganglia during Dexamethasone-Induced Reactivation from Latency Stimulate Bovine Herpesvirus 1 Productive Infection and Certain Viral Promoters

PubMed Central

Workman, Aspen; Eudy, James; Smith, Lynette; Frizzo da Silva, Leticia; Sinani, Devis; Bricker, Halie; Cook, Emily; Doster, Alan

2012-01-01

Bovine herpesvirus 1 (BHV-1), an alphaherpesvirinae subfamily member, establishes latency in sensory neurons. Elevated corticosteroid levels, due to stress, reproducibly triggers reactivation from latency in the field. A single intravenous injection of the synthetic corticosteroid dexamethasone (DEX) to latently infected calves consistently induces reactivation from latency. Lytic cycle viral gene expression is detected in sensory neurons within 6 h after DEX treatment of latently infected calves. These observations suggested that DEX stimulated expression of cellular genes leads to lytic cycle viral gene expression and productive infection. In this study, a commercially available assay—Bovine Gene Chip—was used to compare cellular gene expression in the trigeminal ganglia (TG) of calves latently infected with BHV-1 versus DEX-treated animals. Relative to TG prepared from latently infected calves, 11 cellular genes were induced more than 10-fold 3 h after DEX treatment. Pentraxin three, a regulator of innate immunity and neurodegeneration, was stimulated 35- to 63-fold after 3 or 6 h of DEX treatment. Two transcription factors, promyelocytic leukemia zinc finger (PLZF) and Slug were induced more than 15-fold 3 h after DEX treatment. PLZF or Slug stimulated productive infection 20- or 5-fold, respectively, and Slug stimulated the late glycoprotein C promoter more than 10-fold. Additional DEX-induced transcription factors also stimulated productive infection and certain viral promoters. These studies suggest that DEX-inducible cellular transcription factors and/or signaling pathways stimulate lytic cycle viral gene expression, which subsequently leads to successful reactivation from latency in a small subset of latently infected neurons. PMID:22190728

The Epstein-Barr virus (EBV) nuclear antigen 1 BamHI F promoter is activated on entry of EBV-transformed B cells into the lytic cycle.

PubMed Central

Lear, A L; Rowe, M; Kurilla, M G; Lee, S; Henderson, S; Kieff, E; Rickinson, A B

1992-01-01

In Epstein-Barr virus (EBV)-positive Burkitt's lymphoma cell lines exhibiting the latency I form of infection (i.e., EBV nuclear antigen 1 [EBNA1] positive in the absence of other latent proteins), the EBNA1 mRNA has a unique BamHI Q/U/K splice structure and is expressed from a novel promoter, Fp, located near the BamHI FQ boundary. This contrasts with the situation in EBV-transformed lymphoblastoid cell lines (LCLs) exhibiting the latency III form of infection (i.e., positive for all latent proteins), in which transcription from the upstream Cp or Wp promoters is the principal source of EBNA mRNAs. We carried out cDNA amplifications with oligonucleotide primer-probe combinations to determine whether Fp is ever active in an LCL environment. The results clearly showed that some LCLs express a Q/U/K-spliced EBNA1 mRNA in addition to the expected Cp/Wp-initiated transcripts; this seemed inconsistent with the concept of Cp/Wp and Fp as mutually exclusive promoters. Here we show that Fp is indeed silent in latency III cells but is activated at an early stage following the switch from latency III into the virus lytic cycle. Four pieces of evidence support this conclusion: (i) examples of coincident Cp/Wp and Fp usage in LCLs are restricted to those lines in which a small subpopulation of cells have spontaneously entered the lytic cycle; (ii) transcripts initiating from Fp can readily be demonstrated in spontaneously productive lines by S1 nuclease protection; (iii) the presence of Fp-initiated transcripts is not affected by acyclovir blockade of the late lytic cycle; and (iv) infection of latently infected LCLs with a recombinant vaccinia virus encoding the EBV immediate-early protein BZLF1, a transcriptional transactivator which normally initiates the lytic cycle, results in the appearance of the diagnostic Q/U/K-spliced transcripts. Images PMID:1331531

Heterogeneous, restricted patterns of Epstein-Barr virus (EBV) latent gene expression in patients with chronic active EBV infection.

PubMed

Yoshioka, M; Ishiguro, N; Ishiko, H; Ma, X; Kikuta, H; Kobayashi, K

2001-10-01

Epstein-Barr virus (EBV) has been shown to infect T lymphocytes and to be associated with a chronic active infection (CAEBV), which has been recognized as a mainly non-neoplastic T-cell lymphoproliferative disorder (T-cell LPD). The systemic distribution of EBV genomes was studied, by real-time PCR, in multiple tissues from six patients with CAEBV, including three patients with T-cell LPD, one patient with B-cell LPD and two patients with undetermined cell-type LPD. There were extremely high loads of EBV genomes in all tissues from the patients. This reflects an abundance of circulating and infiltrating EBV-infected cells and a wide variety of clinical symptoms in the affected tissues. We chose one sample from each patient that was shown by real-time PCR to contain a high load of EBV genomes and examined the expression of EBV latent genes by RT-PCR. EBER1 and EBNA1 transcripts were detected in all samples. Only one sample also expressed EBNA2, LMP1 and LMP2A transcripts in addition to EBER1 and EBNA1 transcripts. Two of the remaining five samples expressed LMP1 and LMP2A transcripts. One sample expressed LMP2A but not LMP1 and EBNA2 transcripts. Another sample expressed EBNA2 but not LMP1 and LMP2A transcripts. The other sample did not express transcripts of any of the other EBNAs or LMPs. None of the samples expressed the viral immediate-early gene BZLF1. These results showed that EBV latent gene expression in CAEBV is heterogeneous and that restricted forms of EBV latency might play a pathogenic role in the development of CAEBV.

X box binding protein XBP-1s transactivates the Kaposi's sarcoma-associated herpesvirus (KSHV) ORF50 promoter, linking plasma cell differentiation to KSHV reactivation from latency.

PubMed

Wilson, Sam J; Tsao, Edward H; Webb, Benjamin L J; Ye, Hongtao; Dalton-Griffin, Lucy; Tsantoulas, Christoforos; Gale, Catherine V; Du, Ming-Qing; Whitehouse, Adrian; Kellam, Paul

2007-12-01

Reactivation of lytic replication from viral latency is a defining property of all herpesviruses. Despite this, the authentic physiological cues for the latent-lytic switch are unclear. Such cues should ensure that viral lytic replication occurs under physiological conditions, predominantly in sites which facilitate transmission to permissive uninfected cells and new susceptible hosts. Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with the B-cell neoplasm primary effusion lymphoma (PEL), in which the virus remains latent. We have previously shown that PEL cells have the gene expression profile and immunophenotype of cycling preplasma cells (plasmablasts). Here, we show that the highly active spliced isoform of plasma cell transcription factor X box binding protein 1 (XBP-1s) is a lytic switch for KSHV. XBP-1s is normally absent in PEL, but the induction of endoplasmic reticulum stress leads to XBP-1s generation, plasma cell-like differentiation, and lytic reactivation of KSHV. XBP-1s binds to and activates the KSHV immediate-early gene ORF50 and synergizes with the ORF50 gene product RTA to induce a full lytic cycle. These data suggest that KSHV remains latent until B-cell terminal differentiation into plasma cells, the transcriptional environment of which provides the physiological "lytic switch" through XBP-1s. This links B-cell terminal differentiation to KSHV lytic reactivation.

Transcription Mapping of the Kaposi’s Sarcoma-Associated Herpesvirus (Human Herpesvirus 8) Genome in a Body Cavity-Based Lymphoma Cell Line (BC-1)

PubMed Central

Sarid, Ronit; Flore, Ornella; Bohenzky, Roy A.; Chang, Yuan; Moore, Patrick S.

1998-01-01

Kaposi’s sarcoma-associated herpesvirus (KSHV) gene transcription in the BC-1 cell line (KSHV and Epstein-Barr virus coinfected) was examined by using Northern analysis with DNA probes extending across the viral genome except for a 3-kb unclonable rightmost region. Three broad classes of viral gene transcription have been identified. Class I genes, such as those encoding the v-cyclin, latency-associated nuclear antigen, and v-FLIP, are constitutively transcribed under standard growth conditions, are unaffected by tetradecanoylphorbol acetate (TPA) induction, and presumably represent latent viral transcripts. Class II genes are primarily clustered in nonconserved regions of the genome and include small polyadenylated RNAs (T0.7 and T1.1) as well as most of the virus-encoded cytokines and signal transduction genes. Class II genes are transcribed without TPA treatment but are induced to higher transcription levels by TPA treatment. Class III genes are primarily structural and replication genes that are transcribed only following TPA treatment and are presumably responsible for lytic virion production. These results indicate that BC-1 cells have detectable transcription of a number of KSHV genes, particularly nonconserved genes involved in cellular signal transduction and regulation, during noninduced (latent) virus culture. PMID:9444993

EGCG debilitates the persistence of EBV latency by reducing the DNA binding potency of nuclear antigen 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ya-Lin; Tsai, Hsing-Lyn; Peng, Chih-Wen, E-mail: pengcw@mail.tcu.edu.tw

Highlights: Black-Right-Pointing-Pointer Two cell-based reporter platforms were established for screening of EBNA1 inhibitors. Black-Right-Pointing-Pointer EGCG acts as an inhibitor to block EBNA1 binding with the cognate oriP sequence. Black-Right-Pointing-Pointer EGCG debilitates EBNA1-dependent transcription enhancement and episome maintenance. Black-Right-Pointing-Pointer EGCG impairs persistence of EBV latency. Black-Right-Pointing-Pointer EGCG is a potent anti-EBV agent for targeting the latent cascade of EBV. -- Abstract: Because the expression of EBNA1 is prevalent in all EBV-associated tumors, it has become one of the most attractive drug targets for the discovery of anti-EBV compounds. In a cell-based reporter system, EBNA1 consistently upregulated the transcription of an oriP-Lucmore » mini-EBV episome by 6- to 8-fold. The treatment of cells with 50 {mu}M EGCG effectively blocked the binding of EBNA1 to oriP-DNA both in vivo and in vitro, which led to the abrogation of EBNA1-dependent episome maintenance and transcriptional enhancement. Importantly, the anti-EBNA1 effects caused by EGCG ultimately impaired the persistence of EBV latent infection. Our data suggest that the inhibition of EBNA1 activity by EGCG could be a promising starting point for the development of new protocols for anti-EBV therapy.« less

Herpes Simplex Virus 1 Infection of Tree Shrews Differs from That of Mice in the Severity of Acute Infection and Viral Transcription in the Peripheral Nervous System

PubMed Central

Li, Lihong; Li, Zhuoran; Wang, Erlin; Yang, Rui; Xiao, Yu; Han, Hongbo; Lang, Fengchao; Li, Xin; Xia, Yujie; Gao, Feng; Li, Qihan; Fraser, Nigel W.

2015-01-01

ABSTRACT Studies of herpes simplex virus (HSV) infections of humans are limited by the use of rodent models such as mice, rabbits, and guinea pigs. Tree shrews (Tupaia belangeri chinensis) are small mammals indigenous to southwest Asia. At behavioral, anatomical, genomic, and evolutionary levels, tree shrews are much closer to primates than rodents are, and tree shrews are susceptible to HSV infection. Thus, we have studied herpes simplex virus 1 (HSV-1) infection in the tree shrew trigeminal ganglion (TG) following ocular inoculation. In situ hybridization, PCR, and quantitative reverse transcription-PCR (qRT-PCR) analyses confirm that HSV-1 latently infects neurons of the TG. When explant cocultivation of trigeminal ganglia was performed, the virus was recovered after 5 days of cocultivation with high efficiency. Swabbing the corneas of latently infected tree shrews revealed that tree shrews shed virus spontaneously at low frequencies. However, tree shrews differ significantly from mice in the expression of key HSV-1 genes, including ICP0, ICP4, and latency-associated transcript (LAT). In acutely infected tree shrew TGs, no level of ICP4 was observed, suggesting the absence of infection or a very weak, acute infection compared to that of the mouse. Immunofluorescence staining with ICP4 monoclonal antibody, and immunohistochemistry detection by HSV-1 polyclonal antibodies, showed a lack of viral proteins in tree shrew TGs during both acute and latent phases of infection. Cultivation of supernatant from homogenized, acutely infected TGs with RS1 cells also exhibited an absence of infectious HSV-1 from tree shrew TGs. We conclude that the tree shrew has an undetectable, or a much weaker, acute infection in the TGs. Interestingly, compared to mice, tree shrew TGs express high levels of ICP0 transcript in addition to LAT during latency. However, the ICP0 transcript remained nuclear, and no ICP0 protein could be seen during the course of mouse and tree shrew TG infections. Taken together, these observations suggest that the tree shrew TG infection differs significantly from the existing rodent models. IMPORTANCE Herpes simplex viruses (HSVs) establish lifelong infection in more than 80% of the human population, and their reactivation leads to oral and genital herpes. Currently, rodent models are the preferred models for latency studies. Rodents are distant from primates and may not fully represent human latency. The tree shrew is a small mammal, a prosimian primate, indigenous to southwest Asia. In an attempt to further develop the tree shrew as a useful model to study herpesvirus infection, we studied the establishment of latency and reactivation of HSV-1 in tree shrews following ocular inoculation. We found that the latent virus, which resides in the sensory neurons of the trigeminal ganglion, could be stress reactivated to produce infectious virus, following explant cocultivation and that spontaneous reactivation could be detected by cell culture of tears. Interestingly, the tree shrew model is quite different from the mouse model of HSV infection, in that the virus exhibited only a mild acute infection following inoculation with no detectable infectious virus from the sensory neurons. The mild infection may be more similar to human infection in that the sensory neurons continue to function after herpes reactivation and the affected skin tissue does not lose sensation. Our findings suggest that the tree shrew is a viable model to study HSV latency. PMID:26512084

The interferon-induced antiviral protein PML (TRIM19) promotes the restriction and transcriptional silencing of lentiviruses in a context-specific, isoform-specific fashion.

PubMed

Masroori, Nasser; Merindol, Natacha; Berthoux, Lionel

2016-03-22

The promyelocytic leukemia (PML) protein, a type I interferon (IFN-I)-induced gene product and a member of the tripartite motif (TRIM) family, modulates the transcriptional activity of viruses belonging to various families. Whether PML has an impact on the replication of HIV-1 has not been fully addressed, but recent studies point to its possible involvement in the restriction of HIV-1 in human cells and in the maintenance of transcriptional latency in human cell lines in which HIV-1 is constitutively repressed. We investigated further the restriction of HIV-1 and a related lentivirus, SIVmac, by PML in murine cells and in a lymphocytic human cell line. In particular, we studied the relevance of PML to IFN-I-mediated inhibition and the role of individual human isoforms. We demonstrate that both human PML (hPML) and murine PML (mPML) inhibit the early post-entry stages of the replication of HIV-1 and a related lentivirus, SIVmac. In addition, HIV-1 was transcriptionally silenced by mPML and by hPML isoforms I, II, IV and VI in MEFs. This PML-mediated transcriptional repression was attenuated in presence of the histone deacetylase inhibitor SAHA. In contrast, depletion of PML had no effect on HIV-1 gene expression in a human T cell line. PML was found to contribute to the inhibition of HIV-1 by IFN-I. Specifically, IFN-α and IFN-β treatments of MEFs enhanced the PML-dependent inhibition of HIV-1 early replication stages. We show that PML can inhibit HIV-1 and other lentiviruses as part of the IFN-I-mediated response. The restriction takes place at two distinct steps, i.e. reverse transcription and transcription, and in an isoform-specific, cellular context-specific fashion. Our results support a model in which PML activates innate immune antilentiviral effectors. These data are relevant to the development of latency reversal-inducing pharmacological agents, since PML was previously proposed as a pharmacological target for such inhibitors. This study also has implications for the development of murine models of HIV-1.

Word Association in L1 and L2: An Exploratory Study of Response Types, Response Times, and Interlingual Mediation

ERIC Educational Resources Information Center

Fitzpatrick, Tess; Izura, Cristina

2011-01-01

Word association responses in first-language (L1) Spanish and second-language (L2) English were investigated by means of response latencies and types of associative response produced. The primary aims were to establish whether (a) some response types are produced more often or faster than others, (b) participants' L2 response time profiles mirror…

Bovine herpesvirus 1 productive infection and immediate early transcription unit 1 promoter are stimulated by the synthetic corticosteroid dexamethasone.

PubMed

Kook, Insun; Henley, Caitlin; Meyer, Florencia; Hoffmann, Federico G; Jones, Clinton

2015-10-01

The primary site for life-long latency of bovine herpesvirus 1 (BHV-1) is sensory neurons. The synthetic corticosteroid dexamethasone consistently induces reactivation from latency; however the mechanism by which corticosteroids mediate reactivation is unclear. In this study, we demonstrate for the first time that dexamethasone stimulates productive infection, in part, because the BHV-1 genome contains more than 100 potential glucocorticoid receptor (GR) response elements (GREs). Immediate early transcription unit 1 (IEtu1) promoter activity, but not IEtu2 or VP16 promoter activity, was stimulated by dexamethasone. Two near perfect consensus GREs located within the IEtu1 promoter were necessary for dexamethasone-mediated stimulation. Electrophoretic mobility shift assays and chromatin immunoprecipitation studies demonstrated that the GR interacts with IEtu1 promoter sequences containing the GREs. Although we hypothesize that DEX-mediated stimulation of IEtu1 promoter activity is important during productive infection and perhaps reactivation from latency, stress likely has pleiotropic effects on virus-infected cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Latent Gammaherpesvirus 68 Infection Induces Distinct Transcriptional Changes in Different Organs

PubMed Central

Canny, Susan P.; Goel, Gautam; Reese, Tiffany A.; Zhang, Xin; Xavier, Ramnik

2014-01-01

Previous studies identified a role for latent herpesvirus infection in cross-protection against infection and exacerbation of chronic inflammatory diseases. Here, we identified more than 500 genes differentially expressed in spleens, livers, or brains of mice latently infected with gammaherpesvirus 68 and found that distinct sets of genes linked to different pathways were altered in the spleen compared to those in the liver. Several of the most differentially expressed latency-specific genes (e.g., the gamma interferon [IFN-γ], Cxcl9, and Ccl5 genes) are associated with known latency-specific phenotypes. Chronic herpesvirus infection, therefore, significantly alters the transcriptional status of host organs. We speculate that such changes may influence host physiology, the status of the immune system, and disease susceptibility. PMID:24155394

LMP1-Induced Sumoylation Influences the Maintenance of Epstein-Barr Virus Latency through KAP1

PubMed Central

Moss, Charles Randall; Whitehurst, Christopher B.; Moody, Cary A.

2015-01-01

ABSTRACT As a herpesvirus, Epstein-Barr virus (EBV) establishes a latent infection that can periodically undergo reactivation, resulting in lytic replication and the production of new infectious virus. Latent membrane protein-1 (LMP1), the principal viral oncoprotein, is a latency-associated protein implicated in regulating viral reactivation and the maintenance of latency. We recently found that LMP1 hijacks the SUMO-conjugating enzyme Ubc9 via its C-terminal activating region-3 (CTAR3) and induces the sumoylation of cellular proteins. Because protein sumoylation can promote transcriptional repression, we hypothesized that LMP1-induced protein sumoylation induces the repression of EBV lytic promoters and helps maintain the viral genome in its latent state. We now show that with inhibition of LMP1-induced protein sumoylation, the latent state becomes less stable or leakier in EBV-transformed lymphoblastoid cell lines. The cells are also more sensitive to viral reactivation induced by irradiation, which results in the increased production and release of infectious virus, as well as increased susceptibility to ganciclovir treatment. We have identified a target of LMP1-mediated sumoylation that contributes to the maintenance of latency in this context: KRAB-associated protein-1 (KAP1). LMP1 CTAR3-mediated sumoylation regulates the function of KAP1. KAP1 also binds to EBV OriLyt and immediate early promoters in a CTAR3-dependent manner, and inhibition of sumoylation processes abrogates the binding of KAP1 to these promoters. These data provide an additional line of evidence that supports our findings that CTAR3 is a distinct functioning regulatory region of LMP1 and confirm that LMP1-induced sumoylation may help stabilize the maintenance of EBV latency. IMPORTANCE Epstein-Barr virus (EBV) latent membrane protein-1 (LMP1) plays an important role in the maintenance of viral latency. Previously, we documented that LMP1 targets cellular proteins to be modified by a ubiquitin-like protein (SUMO). We have now identified a function for this LMP1-induced modification of cellular proteins in the maintenance of EBV latency. Because latently infected cells have to undergo viral reactivation in order to be vulnerable to antiviral drugs, these findings identify a new way to increase the rate of EBV reactivation, which increases cell susceptibility to antiviral therapies. PMID:25948750

Influence of an immunodominant herpes simplex virus type 1 CD8+ T cell epitope on the target hierarchy and function of subdominant CD8+ T cells

PubMed Central

2017-01-01

Herpes simplex virus type 1 (HSV-1) latency in sensory ganglia such as trigeminal ganglia (TG) is associated with a persistent immune infiltrate that includes effector memory CD8+ T cells that can influence HSV-1 reactivation. In C57BL/6 mice, HSV-1 induces a highly skewed CD8+ T cell repertoire, in which half of CD8+ T cells (gB-CD8s) recognize a single epitope on glycoprotein B (gB498-505), while the remainder (non-gB-CD8s) recognize, in varying proportions, 19 subdominant epitopes on 12 viral proteins. The gB-CD8s remain functional in TG throughout latency, while non-gB-CD8s exhibit varying degrees of functional compromise. To understand how dominance hierarchies relate to CD8+ T cell function during latency, we characterized the TG-associated CD8+ T cells following corneal infection with a recombinant HSV-1 lacking the immunodominant gB498-505 epitope (S1L). S1L induced a numerically equivalent CD8+ T cell infiltrate in the TG that was HSV-specific, but lacked specificity for gB498-505. Instead, there was a general increase of non-gB-CD8s with specific subdominant epitopes arising to codominance. In a latent S1L infection, non-gB-CD8s in the TG showed a hierarchy targeting different epitopes at latency compared to at acute times, and these cells retained an increased functionality at latency. In a latent S1L infection, these non-gB-CD8s also display an equivalent ability to block HSV reactivation in ex vivo ganglionic cultures compared to TG infected with wild type HSV-1. These data indicate that loss of the immunodominant gB498-505 epitope alters the dominance hierarchy and reduces functional compromise of CD8+ T cells specific for subdominant HSV-1 epitopes during viral latency. PMID:29206240

Transcriptional regulation of latent feline immunodeficiency virus in peripheral CD4+ T-lymphocytes.

PubMed

McDonnel, Samantha J; Sparger, Ellen E; Luciw, Paul A; Murphy, Brian G

2012-05-01

Feline immunodeficiency virus (FIV), the lentivirus of domestic cats responsible for feline AIDS, establishes a latent infection in peripheral blood CD4+ T-cells approximately eight months after experimental inoculation. In this study, cats experimentally infected with the FIV-C strain in the asymptomatic phase demonstrated an estimated viral load of 1 infected cell per approximately 10(3) CD4+ T-cells, with about 1 copy of viral DNA per cell. Approximately 1 in 10 proviral copies was capable of transcription in the asymptomatic phase. The latent FIV proviral promoter was associated with deacetylated, methylated histones, which is consistent with a condensed chromatin structure. In contrast, the transcriptionally active FIV promoter was associated with histone acetylation and demethylation. In addition, RNA polymerase II appeared to be paused on the latent viral promoter, and short promoter-proximal transcripts were detected. Our findings for the FIV promoter in infected cats are similar to results obtained in studies of human immunodeficiency virus (HIV)-1 latent proviruses in cell culture in vitro studies. Thus, the FIV/cat model may offer insights into in vivo mechanisms of HIV latency and provides a unique opportunity to test novel therapeutic interventions aimed at eradicating latent virus.

O-Linked N-Acetylglucosaminylation of Sp1 Inhibits the Human Immunodeficiency Virus Type 1 Promoter▿

PubMed Central

Jochmann, Ramona; Thurau, Mathias; Jung, Susan; Hofmann, Christian; Naschberger, Elisabeth; Kremmer, Elisabeth; Harrer, Thomas; Miller, Matthew; Schaft, Niels; Stürzl, Michael

2009-01-01

Human immunodeficiency virus type 1 (HIV-1) gene expression and replication are regulated by the promoter/enhancer located in the U3 region of the proviral 5′ long terminal repeat (LTR). The binding of cellular transcription factors to specific regulatory sites in the 5′ LTR is a key event in the replication cycle of HIV-1. Since transcriptional activity is regulated by the posttranslational modification of transcription factors with the monosaccharide O-linked N-acetyl-d-glucosamine (O-GlcNAc), we evaluated whether increased O-GlcNAcylation affects HIV-1 transcription. In the present study we demonstrate that treatment of HIV-1-infected lymphocytes with the O-GlcNAcylation-enhancing agent glucosamine (GlcN) repressed viral transcription in a dose-dependent manner. Overexpression of O-GlcNAc transferase (OGT), the sole known enzyme catalyzing the addition of O-GlcNAc to proteins, specifically inhibited the activity of the HIV-1 LTR promoter in different T-cell lines and in primary CD4+ T lymphocytes. Inhibition of HIV-1 LTR activity in infected T cells was most efficient (>95%) when OGT was recombinantly overexpressed prior to infection. O-GlcNAcylation of the transcription factor Sp1 and the presence of Sp1-binding sites in the LTR were found to be crucial for this inhibitory effect. From this study, we conclude that O-GlcNAcylation of Sp1 inhibits the activity of the HIV-1 LTR promoter. Modulation of Sp1 O-GlcNAcylation may play a role in the regulation of HIV-1 latency and activation and links viral replication to the glucose metabolism of the host cell. Hence, the establishment of a metabolic treatment might supplement the repertoire of antiretroviral therapies against AIDS. PMID:19193796

A Novel Persistence Associated EBV miRNA Expression Profile Is Disrupted in Neoplasia

PubMed Central

Qiu, Jin; Cosmopoulos, Katherine; Pegtel, Michiel; Hopmans, Erik; Murray, Paul; Middeldorp, Jaap; Shapiro, Michael; Thorley-Lawson, David A.

2011-01-01

We have performed the first extensive profiling of Epstein-Barr virus (EBV) miRNAs on in vivo derived normal and neoplastic infected tissues. We describe a unique pattern of viral miRNA expression by normal infected cells in vivo expressing restricted viral latency programs (germinal center: Latency II and memory B: Latency I/0). This includes the complete absence of 15 of the 34 miRNAs profiled. These consist of 12 BART miRNAs (including approximately half of Cluster 2) and 3 of the 4 BHRF1 miRNAs. All but 2 of these absent miRNAs become expressed during EBV driven growth (Latency III). Furthermore, EBV driven growth is accompanied by a 5–10 fold down regulation in the level of the BART miRNAs expressed in germinal center and memory B cells. Therefore, Latency III also expresses a unique pattern of viral miRNAs. We refer to the miRNAs that are specifically expressed in EBV driven growth as the Latency III associated miRNAs. In EBV associated tumors that employ Latency I or II (Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma and gastric carcinoma), the Latency III associated BART but not BHRF1 miRNAs are up regulated. Thus BART miRNA expression is deregulated in the EBV associated tumors. This is the first demonstration that Latency III specific genes (the Latency III associated BARTs) can be expressed in these tumors. The EBV associated tumors demonstrate very similar patterns of miRNA expression yet were readily distinguished when the expression data were analyzed either by heat-map/clustering or principal component analysis. Systematic analysis revealed that the information distinguishing the tumor types was redundant and distributed across all the miRNAs. This resembles “secret sharing” algorithms where information can be distributed among a large number of recipients in such a way that any combination of a small number of recipients is able to understand the message. Biologically, this may be a consequence of functional redundancy between the miRNAs. PMID:21901094

HTLV-1 Tax Mediated Downregulation of miRNAs Associated with Chromatin Remodeling Factors in T Cells with Stably Integrated Viral Promoter

PubMed Central

Rahman, Saifur; Quann, Kevin; Pandya, Devanshi; Singh, Shruti; Khan, Zafar K.; Jain, Pooja

2012-01-01

RNA interference (RNAi) is a natural cellular mechanism to silence gene expression and is predominantly mediated by microRNAs (miRNAs) that target messenger RNA. Viruses can manipulate the cellular processes necessary for their replication by targeting the host RNAi machinery. This study explores the effect of human T-cell leukemia virus type 1 (HTLV-1) transactivating protein Tax on the RNAi pathway in the context of a chromosomally integrated viral long terminal repeat (LTR) using a CD4+ T-cell line, Jurkat. Transcription factor profiling of the HTLV-1 LTR stably integrated T-cell clone transfected with Tax demonstrates increased activation of substrates and factors associated with chromatin remodeling complexes. Using a miRNA microarray and bioinformatics experimental approach, Tax was also shown to downregulate the expression of miRNAs associated with the translational regulation of factors required for chromatin remodeling. These observations were validated with selected miRNAs and an HTLV-1 infected T cells line, MT-2. miR-149 and miR-873 were found to be capable of directly targeting p300 and p/CAF, chromatin remodeling factors known to play critical role in HTLV-1 pathogenesis. Overall, these results are first in line establishing HTLV-1/Tax-miRNA-chromatin concept and open new avenues toward understanding retroviral latency and/or replication in a given cell type. PMID:22496815

Transcription-associated mutational pressure in the Parvovirus B19 genome: Reactivated genomes contribute to the variability of viral populations.

PubMed

Khrustalev, Vladislav Victorovich; Ermalovich, Marina Anatolyevna; Hübschen, Judith M; Khrustaleva, Tatyana Aleksandrovna

2017-12-21

In this study we used non-overlapping parts of the two long open reading frames coding for nonstructural (NS) and capsid (VP) proteins of all available sequences of the Parvovirus B19 subgenotype 1a genome and found out that the rates of A to G, C to T and A to T mutations are higher in the first long reading frame (NS) of the virus than in the second one (VP). This difference in mutational pressure directions for two parts of the same viral genome can be explained by the fact of transcription of just the first long reading frame during the lifelong latency in nonerythroid cells. Adenine deamination (producing A to G and A to T mutations) and cytosine deamination (producing C to T mutations) occur more frequently in transcriptional bubbles formed by DNA "plus" strand of the first open reading frame. These mutations can be inherited only in case of reactivation of the infectious virus due to the help of Adenovirus that allows latent Parvovirus B19 to start transcription of the second reading frame and then to replicate its genome by the rolling circle mechanism using the specific origin. Results of this study provide evidence that the genomes reactivated from latency make significant contributions to the variability of Parvovirus B19. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carcinoma-risk variant of EBNA1 deregulates Epstein-Barr Virus episomal latency.

PubMed

Dheekollu, Jayaraju; Malecka, Kimberly; Wiedmer, Andreas; Delecluse, Henri-Jacques; Chiang, Alan K S; Altieri, Dario C; Messick, Troy E; Lieberman, Paul M

2017-01-31

Epstein-Barr Virus (EBV) latent infection is a causative co-factor for endemic Nasopharyngeal Carcinoma (NPC). NPC-associated variants have been identified in EBV-encoded nuclear antigen EBNA1. Here, we solve the X-ray crystal structure of an NPC-derived EBNA1 DNA binding domain (DBD) and show that variant amino acids are found on the surface away from the DNA binding interface. We show that NPC-derived EBNA1 is compromised for DNA replication and episome maintenance functions. Recombinant virus containing the NPC EBNA1 DBD are impaired in their ability to immortalize primary B-lymphocytes and suppress lytic transcription during early stages of B-cell infection. We identify Survivin as a host protein deficiently bound by the NPC variant of EBNA1 and show that Survivin depletion compromises EBV episome maintenance in multiple cell types. We propose that endemic variants of EBNA1 play a significant role in EBV-driven carcinogenesis by altering key regulatory interactions that destabilize latent infection.

The B-Cell Specific Transcription Factor, Oct-2, Promotes Epstein-Barr Virus Latency by Inhibiting the Viral Immediate-Early Protein, BZLF1

PubMed Central

Robinson, Amanda R.; Kwek, Swee Sen; Kenney, Shannon C.

2012-01-01

The Epstein-Barr virus (EBV) latent-lytic switch is mediated by the BZLF1 immediate-early protein. EBV is normally latent in memory B cells, but cellular factors which promote viral latency specifically in B cells have not been identified. In this report, we demonstrate that the B-cell specific transcription factor, Oct-2, inhibits the function of the viral immediate-early protein, BZLF1, and prevents lytic viral reactivation. Co-transfected Oct-2 reduces the ability of BZLF1 to activate lytic gene expression in two different latently infected nasopharyngeal carcinoma cell lines. Furthermore, Oct-2 inhibits BZLF1 activation of lytic EBV promoters in reporter gene assays, and attenuates BZLF1 binding to lytic viral promoters in vivo. Oct-2 interacts directly with BZLF1, and this interaction requires the DNA-binding/dimerization domain of BZLF1 and the POU domain of Oct-2. An Oct-2 mutant (Δ262–302) deficient for interaction with BZLF1 is unable to inhibit BZLF1-mediated lytic reactivation. However, an Oct-2 mutant defective for DNA-binding (Q221A) retains the ability to inhibit BZLF1 transcriptional effects and DNA-binding. Importantly, shRNA-mediated knockdown of endogenous Oct-2 expression in several EBV-positive Burkitt lymphoma and lymphoblastoid cell lines increases the level of lytic EBV gene expression, while decreasing EBNA1 expression. Moreover, treatments which induce EBV lytic reactivation, such as anti-IgG cross-linking and chemical inducers, also decrease the level of Oct-2 protein expression at the transcriptional level. We conclude that Oct-2 potentiates establishment of EBV latency in B cells. PMID:22346751

Epstein-Barr virus-encoded EBNA2 alters immune checkpoint PD-L1 expression by downregulating miR-34a in B-cell lymphomas.

PubMed

Anastasiadou, Eleni; Stroopinsky, Dina; Alimperti, Stella; Jiao, Alan L; Pyzer, Athalia R; Cippitelli, Claudia; Pepe, Giuseppina; Severa, Martina; Rosenblatt, Jacalyn; Etna, Marilena P; Rieger, Simone; Kempkes, Bettina; Coccia, Eliana M; Sui, Shannan J Ho; Chen, Christopher S; Uccini, Stefania; Avigan, David; Faggioni, Alberto; Trivedi, Pankaj; Slack, Frank J

2018-06-26

Cancer cells subvert host immune surveillance by altering immune checkpoint (IC) proteins. Some Epstein-Barr virus (EBV)-associated tumors have higher Programmed Cell Death Ligand, PD-L1 expression. However, it is not known how EBV alters ICs in the context of its preferred host, the B lymphocyte and in derived lymphomas. Here, we found that latency III-expressing Burkitt lymphoma (BL), diffuse large B-cell lymphomas (DLBCL) or their EBNA2-transfected derivatives express high PD-L1. In a DLBCL model, EBNA2 but not LMP1 is sufficient to induce PD-L1. Latency III-expressing DLBCL biopsies showed high levels of PD-L1. The PD-L1 targeting oncosuppressor microRNA miR-34a was downregulated in EBNA2-transfected lymphoma cells. We identified early B-cell factor 1 (EBF1) as a repressor of miR-34a transcription. Short hairpin RNA (shRNA)-mediated knockdown of EBF1 was sufficient to induce miR-34a transcription, which in turn reduced PD-L1. MiR-34a reconstitution in EBNA2-transfected DLBCL reduced PD-L1 expression and increased its immunogenicity in mixed lymphocyte reactions (MLR) and in three-dimensional biomimetic microfluidic chips. Given the importance of PD-L1 inhibition in immunotherapy and miR-34a dysregulation in cancers, our findings may have important implications for combinatorial immunotherapy, which include IC inhibiting antibodies and miR-34a, for EBV-associated cancers.

Packaging of Human Chromosome 19-Specific Adeno-Associated Virus (AAV) Integration Sites in AAV Virions during AAV Wild-Type and Recombinant AAV Vector Production

PubMed Central

Hüser, Daniela; Weger, Stefan; Heilbronn, Regine

2003-01-01

Adeno-associated virus type 2 (AAV-2) establishes latency by site-specific integration into a unique locus on human chromosome 19, called AAVS1. During the development of a sensitive real-time PCR assay for site-specific integration, AAV-AAVS1 junctions were reproducibly detected in highly purified AAV wild-type and recombinant AAV vector stocks. A series of controls documented that the junctions were packaged in AAV capsids and were newly generated during a single round of AAV production. Cloned junctions displayed variable AAV sequences fused to AAVS1. These data suggest that packaged junctions represent footprints of AAV integration during productive infection. Apparently, AAV latency established by site-specific integration and the helper virus-dependent, productive AAV cycle are more closely related than previously thought. PMID:12663794

ß-catenin, a transcription factor activated by canonical Wnt signaling, is expressed in sensory neurons of calves latently infected with bovine herpesvirus 1

USDA-ARS?s Scientific Manuscript database

Like many a-herpesvirinae subfamily members, bovine herpes virus 1 (BoHV-1) expresses an abundant transcript in latently infected sensory neurons: the latency-related (LR) RNA. LR-RNA encodes a protein (ORF2) that inhibits apoptosis, interacts with Notch family members, interferes with Notch mediate...

HMBA Enhances Prostratin-Induced Activation of Latent HIV-1 via Suppressing the Expression of Negative Feedback Regulator A20/TNFAIP3 in NF-κB Signaling.

PubMed

Chen, Duchu; Wang, Huiping; Aweya, Jude Juventus; Chen, Yanheng; Chen, Meihua; Wu, Xiaomeng; Chen, Xiaonan; Lu, Jing; Chen, Ruichuan; Liu, Min

2016-01-01

In the past decade, much emphasis has been put on the transcriptional activation of HIV-1, which is proposed as a promised strategy for eradicating latent HIV-1 provirus. Two drugs, prostratin and hexamethylene bisacetamide (HMBA), have shown potent effects as inducers for releasing HIV-1 latency when used alone or in combination, although their cellular target(s) are currently not well understood, especially under drug combination. Here, we have shown that HMBA and prostratin synergistically release HIV-1 latency via different mechanisms. While prostratin strongly stimulates HMBA-induced HIV-1 transcription via improved P-TEFb activation, HMBA is capable of boosting NF-κB-dependent transcription initiation by suppressing prostratin-induced expression of the deubiquitinase A20, a negative feedback regulator in the NF-κB signaling pathway. In addition, HMBA was able to increase prostratin-induced phosphorylation and degradation of NF-κB inhibitor IκBα, thereby enhancing and prolonging prostratin-induced nuclear translocation of NF-κB, a prerequisite for stimulation of transcription initiation. Thus, by blocking the negative feedback circuit, HMBA functions as a signaling enhancer of the NF-κB signaling pathway.

A herpes simplex virus type 1 mutant disrupted for microRNA H2 with increased neurovirulence and rate of reactivation

PubMed Central

Jiang, Xianzhi; Brown, Don; Osorio, Nelson; Hsiang, Chinhui; Li, Lily; Chan, Lucas; BenMohamed, Lbachir; Wechsler, Steven L.

2015-01-01

The herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) encodes several microRNAs. One of these, miR-H2, overlaps and is antisense to the ICP0 gene, and appears to decrease expression of the ICP0 protein. To determine if miR-H2 plays a role in the HSV-1 latency-reactivation cycle, we constructed a mutant, McK-ΔH2, in which this microRNA has been disrupted without altering the predicted amino acid sequence of ICP0. McK-ΔH2 produced increased amounts of ICP0. Although replication of McK-ΔH2 was similar to that of its wt McKrae parental virus in RS cells and mouse eyes, McK-ΔH2 was more neurovirulent in Swiss Webster mice than McKrae based on the percent of mice that died from herpes encephalitis following ocular infection. In addition, using a mouse TG explant model of induced reactivation, we show here for the first time that miR-H2 appears to play a role in modulating HSV-1 reactivation. Although the percent of TG from which virus reactivated by day 10 after explant was similar for McK-ΔH2, wt McKrae, and the marker rescued virus McK-ΔH2Res, at earlier times significantly more reactivation was seen with McK-ΔH2. Our results suggest that in the context of the virus, miR-H2 downregulates ICP0 and this moderates both HSV-1 neurovirulence and reactivation. PMID:25645379

Adequate Th2-Type Response Associates with Restricted Bacterial Growth in Latent Mycobacterial Infection of Zebrafish

PubMed Central

Hammarén, Milka Marjut; Luukinen, Bruno Vincent; Pesu, Marko; Rämet, Mika; Parikka, Mataleena

2014-01-01

Tuberculosis is still a major health problem worldwide. Currently it is not known what kind of immune responses lead to successful control and clearance of Mycobacterium tuberculosis. This gap in knowledge is reflected by the inability to develop sufficient diagnostic and therapeutic tools to fight tuberculosis. We have used the Mycobacterium marinum infection model in the adult zebrafish and taken advantage of heterogeneity of zebrafish population to dissect the characteristics of adaptive immune responses, some of which are associated with well-controlled latency or bacterial clearance while others with progressive infection. Differences in T cell responses between subpopulations were measured at the transcriptional level. It was discovered that a high total T cell level was usually associated with lower bacterial loads alongside with a T helper 2 (Th2)-type gene expression signature. At late time points, spontaneous reactivation with apparent symptoms was characterized by a low Th2/Th1 marker ratio and a substantial induction of foxp3 reflecting the level of regulatory T cells. Characteristic gata3/tbx21 has potential as a biomarker for the status of mycobacterial disease. PMID:24968056

Transcriptional Activation Signals Found in the Epstein-Barr Virus (EBV) Latency C Promoter Are Conserved in the Latency C Promoter Sequences from Baboon and Rhesus Monkey EBV-Like Lymphocryptoviruses (Cercopithicine Herpesviruses 12 and 15)

PubMed Central

Fuentes-Pananá, Ezequiel M.; Swaminathan, Sankar; Ling, Paul D.

1999-01-01

The Epstein-Barr virus (EBV) EBNA2 protein is a transcriptional activator that controls viral latent gene expression and is essential for EBV-driven B-cell immortalization. EBNA2 is expressed from the viral C promoter (Cp) and regulates its own expression by activating Cp through interaction with the cellular DNA binding protein CBF1. Through regulation of Cp and EBNA2 expression, EBV controls the pattern of latent protein expression and the type of latency established. To gain further insight into the important regulatory elements that modulate Cp usage, we isolated and sequenced the Cp regions corresponding to nucleotides 10251 to 11479 of the EBV genome (−1079 to +144 relative to the transcription initiation site) from the EBV-like lymphocryptoviruses found in baboons (herpesvirus papio; HVP) and Rhesus macaques (RhEBV). Sequence comparison of the approximately 1,230-bp Cp regions from these primate viruses revealed that EBV and HVP Cp sequences are 64% conserved, EBV and RhEBV Cp sequences are 66% conserved, and HVP and RhEBV Cp sequences are 65% conserved relative to each other. Approximately 50% of the residues are conserved among all three sequences, yet all three viruses have retained response elements for glucocorticoids, two positionally conserved CCAAT boxes, and positionally conserved TATA boxes. The putative EBNA2 100-bp enhancers within these promoters contain 54 conserved residues, and the binding sites for CBF1 and CBF2 are well conserved. Cp usage in the HVP- and RhEBV-transformed cell lines was detected by S1 nuclease protection analysis. Transient-transfection analysis showed that promoters of both HVP and RhEBV are responsive to EBNA2 and that they bind CBF1 and CBF2 in gel mobility shift assays. These results suggest that similar mechanisms for regulation of latent gene expression are conserved among the EBV-related lymphocryptoviruses found in nonhuman primates. PMID:9847397

Transcriptional activation signals found in the Epstein-Barr virus (EBV) latency C promoter are conserved in the latency C promoter sequences from baboon and Rhesus monkey EBV-like lymphocryptoviruses (cercopithicine herpesviruses 12 and 15).

PubMed

Fuentes-Pananá, E M; Swaminathan, S; Ling, P D

1999-01-01

The Epstein-Barr virus (EBV) EBNA2 protein is a transcriptional activator that controls viral latent gene expression and is essential for EBV-driven B-cell immortalization. EBNA2 is expressed from the viral C promoter (Cp) and regulates its own expression by activating Cp through interaction with the cellular DNA binding protein CBF1. Through regulation of Cp and EBNA2 expression, EBV controls the pattern of latent protein expression and the type of latency established. To gain further insight into the important regulatory elements that modulate Cp usage, we isolated and sequenced the Cp regions corresponding to nucleotides 10251 to 11479 of the EBV genome (-1079 to +144 relative to the transcription initiation site) from the EBV-like lymphocryptoviruses found in baboons (herpesvirus papio; HVP) and Rhesus macaques (RhEBV). Sequence comparison of the approximately 1,230-bp Cp regions from these primate viruses revealed that EBV and HVP Cp sequences are 64% conserved, EBV and RhEBV Cp sequences are 66% conserved, and HVP and RhEBV Cp sequences are 65% conserved relative to each other. Approximately 50% of the residues are conserved among all three sequences, yet all three viruses have retained response elements for glucocorticoids, two positionally conserved CCAAT boxes, and positionally conserved TATA boxes. The putative EBNA2 100-bp enhancers within these promoters contain 54 conserved residues, and the binding sites for CBF1 and CBF2 are well conserved. Cp usage in the HVP- and RhEBV-transformed cell lines was detected by S1 nuclease protection analysis. Transient-transfection analysis showed that promoters of both HVP and RhEBV are responsive to EBNA2 and that they bind CBF1 and CBF2 in gel mobility shift assays. These results suggest that similar mechanisms for regulation of latent gene expression are conserved among the EBV-related lymphocryptoviruses found in nonhuman primates.

Transcriptional Reprogramming during Effector-to-Memory Transition Renders CD4+ T Cells Permissive for Latent HIV-1 Infection.

PubMed

Shan, Liang; Deng, Kai; Gao, Hongbo; Xing, Sifei; Capoferri, Adam A; Durand, Christine M; Rabi, S Alireza; Laird, Gregory M; Kim, Michelle; Hosmane, Nina N; Yang, Hung-Chih; Zhang, Hao; Margolick, Joseph B; Li, Linghua; Cai, Weiping; Ke, Ruian; Flavell, Richard A; Siliciano, Janet D; Siliciano, Robert F

2017-10-17

The latent reservoir for HIV-1 in resting memory CD4 + T cells is the major barrier to curing HIV-1 infection. Studies of HIV-1 latency have focused on regulation of viral gene expression in cells in which latent infection is established. However, it remains unclear how infection initially becomes latent. Here we described a unique set of properties of CD4 + T cells undergoing effector-to-memory transition including temporary upregulation of CCR5 expression and rapid downregulation of cellular gene transcription. These cells allowed completion of steps in the HIV-1 life cycle through integration but suppressed HIV-1 gene transcription, thus allowing the establishment of latency. CD4 + T cells in this stage were substantially more permissive for HIV-1 latent infection than other CD4 + T cells. Establishment of latent HIV-1 infection in CD4 + T could be inhibited by viral-specific CD8 + T cells, a result with implications for elimination of latent HIV-1 infection by T cell-based vaccines. Copyright © 2017. Published by Elsevier Inc.

Low Latency Messages on Distributed Memory Multiprocessors

DOE PAGES

Rosing, Matt; Saltz, Joel

1995-01-01

This article describes many of the issues in developing an efficient interface for communication on distributed memory machines. Although the hardware component of message latency is less than 1 ws on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 μs. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. This article describes several tests performed and many of the issues involvedmore » in supporting low latency messages on distributed memory machines.« less

A single point mutation in cyclin T1 eliminates binding to Hexim1, Cdk9 and RNA but not to AFF4 and enforces repression of HIV transcription

PubMed Central

2014-01-01

Background Human immunodeficiency virus (HIV) gene expression is primarily regulated at the step of transcription elongation. The viral Tat protein recruits the Positive Transcription Elongation Factor b (P-TEFb) and the Super Elongation Complex (SEC) to the HIV promoter and enhances transcription by host RNA polymerase II. Results To map residues in the cyclin box of cyclin T1 that mediate the binding of P-TEFb to its interacting host partners and support HIV transcription, a pool of N-terminal cyclin T1 mutants was generated. Binding and functional assays in cells identified specific positions in cyclin T1 that are important for (i) association of P-TEFb with Hexim1, Cdk9 and SEC/AFF4 (ii) supporting Tat-transactivation in murine cells and (iii) inhibition of basal and Tat-dependent HIV transcription in human cells. Significantly, a unique cyclin T1 mutant where a Valine residue at position 107 was mutated to Glutamate (CycT1-V107E) was identified. CycT1-V107E did not bind to Hexim1 or Cdk9, and also could not assemble on HIV TAR or 7SK-snRNA. However, it bound strongly to AFF4 and its association with HIV Tat was slightly impaired. CycT1-V107E efficiently inhibited HIV replication in human T cell lines and in CD4(+) primary cells, and enforced HIV transcription repression in T cell lines that harbor a transcriptionally silenced integrated provirus. Conclusions This study outlines the mechanism by which CycT1-V107E mutant inhibits HIV transcription and enforces viral latency. It defines the importance of N-terminal residues of cyclin T1 in mediating contacts of P-TEFb with its transcription partners, and signifies the requirement of a functional P-TEFb and SEC in mediating HIV transcription. PMID:24985467

A single point mutation in cyclin T1 eliminates binding to Hexim1, Cdk9 and RNA but not to AFF4 and enforces repression of HIV transcription.

PubMed

Kuzmina, Alona; Verstraete, Nina; Galker, Sigal; Maatook, Maayan; Bensaude, Olivier; Taube, Ran

2014-07-01

Human immunodeficiency virus (HIV) gene expression is primarily regulated at the step of transcription elongation. The viral Tat protein recruits the Positive Transcription Elongation Factor b (P-TEFb) and the Super Elongation Complex (SEC) to the HIV promoter and enhances transcription by host RNA polymerase II. To map residues in the cyclin box of cyclin T1 that mediate the binding of P-TEFb to its interacting host partners and support HIV transcription, a pool of N-terminal cyclin T1 mutants was generated. Binding and functional assays in cells identified specific positions in cyclin T1 that are important for (i) association of P-TEFb with Hexim1, Cdk9 and SEC/AFF4 (ii) supporting Tat-transactivation in murine cells and (iii) inhibition of basal and Tat-dependent HIV transcription in human cells. Significantly, a unique cyclin T1 mutant where a Valine residue at position 107 was mutated to Glutamate (CycT1-V107E) was identified. CycT1-V107E did not bind to Hexim1 or Cdk9, and also could not assemble on HIV TAR or 7SK-snRNA. However, it bound strongly to AFF4 and its association with HIV Tat was slightly impaired. CycT1-V107E efficiently inhibited HIV replication in human T cell lines and in CD4(+) primary cells, and enforced HIV transcription repression in T cell lines that harbor a transcriptionally silenced integrated provirus. This study outlines the mechanism by which CycT1-V107E mutant inhibits HIV transcription and enforces viral latency. It defines the importance of N-terminal residues of cyclin T1 in mediating contacts of P-TEFb with its transcription partners, and signifies the requirement of a functional P-TEFb and SEC in mediating HIV transcription.

Interleukin-21 regulates expression of key Epstein-Barr virus oncoproteins, EBNA2 and LMP1, in infected human B cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konforte, Danijela; Department of Immunology, University of Toronto, Toronto, M5S 1A8; Simard, Nathalie

Epstein-Barr virus (EBV) persists for the life of the host by accessing the long-lived memory B cell pool. It has been proposed that EBV uses different combinations of viral proteins, known as latency types, to drive infected B cells to make the transition from resting B cells to memory cells. This process is normally antigen-driven. A major unresolved question is what factors coordinate expression of EBV latency proteins. We have recently described novel type III latency EBV{sup +} B cell lines (OCI-BCLs) that were induced to differentiate into late plasmablasts/early plasma cells in culture with interleukin-21 (IL-21), mimicking normal Bmore » cell development. The objective of this study was to determine whether IL-21-mediated signals also regulate the expression of key EBV latent proteins during this window of development. Here we show that IL-21-reduced gene and protein expression of growth-transforming EBV nuclear antigen 2 (EBNA2) in OCI-BCLs. By contrast, the expression of CD40-like, latent membrane protein 1 (LMP1) strongly increased in these cells suggesting an EBNA2-independent mode of regulation. Same results were also observed in Burkitt's lymphoma line Jijoye and B95-8 transformed lymphoblastoid cell lines. The effect of IL-21 on EBNA2 and LMP1 expression was attenuated by a pharmacological JAK inhibitor indicating involvement of JAK/STAT signalling in this process. Our study also shows that IL-21 induced transcription of ebna1 from the viral Q promoter (Qp)« less

COX-2/PGE2: molecular ambassadors of Kaposi's sarcoma-associated herpes virus oncoprotein-v-FLIP

PubMed Central

Sharma-Walia, N; Patel, K; Chandran, K; Marginean, A; Bottero, V; Kerur, N; Paul, A G

2012-01-01

Kaposi's sarcoma herpesvirus (KSHV) latent oncoprotein viral FLICE (FADD-like interferon converting enzyme)-like inhibitory protein (v-FLIP) or K13, a potent activator of NF-κB, has well-established roles in KSHV latency and oncogenesis. KSHV-induced COX-2 represents a novel strategy employed by KSHV to promote latency and inflammation/angiogenesis/invasion. Here, we demonstrate that v-FLIP/K13 promotes tumorigenic effects via the induction of host protein COX-2 and its inflammatory metabolite PGE2 in an NF-κB-dependent manner. In addition to our previous studies demonstrating COX-2/PGE2's role in transcriptional regulation of KSHV latency promoter and latent gene expression, the current study adds to the complexity that though LANA-1 (latency associated nuclear antigen) is utilizing COX-2/PGE2 as critical factors for its transcriptional regulation, it is the v-FLIP/K13 gene in the KSHV latency cluster that maintains continuous COX-2/PGE2 levels in the infected cells. We demonstrate that COX-2 inhibition, via its chemical inhibitors (NS-398 or celecoxib), reduced v-FLIP/K13-mediated NF-κB induction, and extracellular matrix (ECM) interaction-mediated signaling, mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) levels, and subsequently downregulated detachment-induced apoptosis (anoikis) resistance. vFLIP expression mediated the secretion of cytokines, and spindle cell differentiation activated the phosphorylation of p38, RSK, FAK, Src, Akt and Rac1-GTPase. The COX-2 inhibition in v-FLIP/K13-HMVECs reduced inflammation and invasion/metastasis-related genes, along with reduced anchorage-independent colony formation via modulating ‘extrinsic' as well as ‘intrinsic' cell death pathways. COX-2 blockade in v-FLIP/K13-HMVEC cells drastically augmented cell death induced by removal of essential growth/survival factors secreted in the microenvironment. Transformed cells obtained from anchorage-independent colonies of COX-2 inhibitor-treated v-FLIP/K13-HMVEC cells expressed lower levels of endothelial–mesenchymal transition genes such as slug, snail and twist, and higher expression of the tumor-suppressor gene, E-cadherin. Taken together, our study provides strong evidences that FDA-approved COX-2 inhibitors have great potential in blocking tumorigenic events linked to KSHV's oncogenic protein v-FLIP/K13. PMID:23552603

Role of microRNAs in herpesvirus latency and persistence.

PubMed

Grey, Finn

2015-04-01

The identification of virally encoded microRNAs (miRNAs) has had a major impact on the field of herpes virology. Given their ability to target cellular and viral transcripts, and the lack of immune response to small RNAs, miRNAs represent an ideal mechanism of gene regulation during viral latency and persistence. In this review, we discuss the role of miRNAs in virus latency and persistence, specifically focusing on herpesviruses. We cover the current knowledge on miRNAs in establishing and maintaining virus latency and promoting survival of infected cells through targeting of both viral and cellular transcripts, highlighting key publications in the field. We also discuss potential areas of future research and how novel technologies may aid in determining how miRNAs shape virus latency in the context of herpesvirus infections. © 2015 The Author.

Aberrant intracellular localization of Varicella-Zoster virus regulatory proteins during latency

PubMed Central

Lungu, Octavian; Panagiotidis, Christos A.; Annunziato, Paula W.; Gershon, Anne A.; Silverstein, Saul J.

1998-01-01

Varicella-Zoster virus (VZV) is a herpesvirus that becomes latent in sensory neurons after primary infection (chickenpox) and subsequently may reactivate to cause zoster. The mechanism by which this virus maintains latency, and the factors involved, are poorly understood. Here we demonstrate, by immunohistochemical analysis of ganglia obtained at autopsy from seropositive patients without clinical symptoms of VZV infection that viral regulatory proteins are present in latently infected neurons. These proteins, which localize to the nucleus of cells during lytic infection, predominantly are detected in the cytoplasm of latently infected neurons. The restriction of regulatory proteins from the nucleus of latently infected neurons might interrupt the cascade of virus gene expression that leads to a productive infection. Our findings raise the possibility that VZV has developed a novel mechanism for maintenance of latency that contrasts with the transcriptional repression that is associated with latency of herpes simplex virus, the prototypic alpha herpesvirus. PMID:9618542

Single-Cell RNA-Seq Reveals Transcriptional Heterogeneity in Latent and Reactivated HIV-Infected Cells.

PubMed

Golumbeanu, Monica; Cristinelli, Sara; Rato, Sylvie; Munoz, Miguel; Cavassini, Matthias; Beerenwinkel, Niko; Ciuffi, Angela

2018-04-24

Despite effective treatment, HIV can persist in latent reservoirs, which represent a major obstacle toward HIV eradication. Targeting and reactivating latent cells is challenging due to the heterogeneous nature of HIV-infected cells. Here, we used a primary model of HIV latency and single-cell RNA sequencing to characterize transcriptional heterogeneity during HIV latency and reactivation. Our analysis identified transcriptional programs leading to successful reactivation of HIV expression. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

A Protein Encoded by the Latency-Related Gene of Bovine Herpesvirus 1 Is Expressed in Trigeminal Ganglionic Neurons of Latently Infected Cattle and Interacts with Cyclin-Dependent Kinase 2 during Productive Infection

PubMed Central

Jiang, Yunquan; Hossain, Ashfaque; Winkler, Maria Teresa; Holt, Todd; Doster, Alan; Jones, Clinton

1998-01-01

Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807–3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation. PMID:9733854

A protein encoded by the latency-related gene of bovine herpesvirus 1 is expressed in trigeminal ganglionic neurons of latently infected cattle and interacts with cyclin-dependent kinase 2 during productive infection.

PubMed

Jiang, Y; Hossain, A; Winkler, M T; Holt, T; Doster, A; Jones, C

1998-10-01

Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807-3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation.

Gravireception of the sporangiophore of Phycomyces blakesleeanus

NASA Astrophysics Data System (ADS)

Galland, Paul

The giant, single-celled sporangiophores of the zygomycete Phycomyces blakesleeanus display negative gravitropism. Prior to the formation of a sporangium sporangiophores form an apical organell with about 200 lipid globules that are kept together in a dense mesh of F-actin. The lipid globules generate buoyancy and act thus as gravisusceptors upon reorienting sporangio-phores. Other gravisusceptors, heavy octahedral protein crystals of the central vacuols, operate via sedimentation. The gravireception of sporangiophores is associated with gravity-induced absorbance changes (GIACs) that represent primary responses of gravitropism whose physical nature is presently unknown. We have characterized these GIACs by dual-wavelength spectrometry in earthbound experiments, during parabola flights (22 s microgravity), drop-tower-experiments (4.7 s mi-crogravity) and during a sounding rocket flight (TEXUS-47, 6 min microgravity). GIACs of sporangiophores were measured in vivo with a micro-dual wavelength spectrometer (MDWS) at 460 and 655 nm as well as other pairs of wavelengths extending into the infrared. During parabola flights hypergravity (1.8 x g) elicited an increase of the OD655, while microgravity (102 x g) elicited an instant increase of the OD460. The GIACs of Phycomyces are the fastest graviresponses ever measured for fungi and plants; their latencies were smaller than 300 ms showing that the GIACs represent a very early step in the gravitropic transduction chain. The GIACs are specific for the gravireception, because a gravitropism mutant with a defective madJ gene lacked the GIACs in earthbound and also in microgravity experiments. When ver-tical sporangiophores are tilted by increasing inclination angles, GIACs are elicited that obey the sine-law of gravitropism, i.e. the response depends on the sine of the inclination angle. Upon placing sporangiophores in darkness horizontally the transcriptional activity of a number of genes is modulated within a time span of 5 h and a latency below 30 min. Surprisingly, two genes, wctC and wctD (both white-collar 2-type) that are associated in fungi with blue-light reception, were transiently up-regulated. The transcription of another white-collar-2-type gene, madB, remained, however, unaffected by the gravitropic stimulation.

Transcriptomic Analysis Implicates the p53 Signaling Pathway in the Establishment of HIV-1 Latency in Central Memory CD4 T Cells in an In Vitro Model

PubMed Central

White, Cory H.; Moesker, Bastiaan; Beliakova-Bethell, Nadejda; Martins, Laura J.; Richman, Douglas D.; Planelles, Vicente; Woelk, Christopher H.

2016-01-01

The search for an HIV-1 cure has been greatly hindered by the presence of a viral reservoir that persists despite antiretroviral therapy (ART). Studies of HIV-1 latency in vivo are also complicated by the low proportion of latently infected cells in HIV-1 infected individuals. A number of models of HIV-1 latency have been developed to examine the signaling pathways and viral determinants of latency and reactivation. A primary cell model of HIV-1 latency, which incorporates the generation of primary central memory CD4 T cells (TCM), full-length virus infection (HIVNL4-3) and ART to suppress virus replication, was used to investigate the establishment of HIV latency using RNA-Seq. Initially, an investigation of host and viral gene expression in the resting and activated states of this model indicated that the resting condition was reflective of a latent state. Then, a comparison of the host transcriptome between the uninfected and latently infected conditions of this model identified 826 differentially expressed genes, many of which were related to p53 signaling. Inhibition of the transcriptional activity of p53 by pifithrin-α during HIV-1 infection reduced the ability of HIV-1 to be reactivated from its latent state by an unknown mechanism. In conclusion, this model may be used to screen latency reversing agents utilized in shock and kill approaches to cure HIV, to search for cellular markers of latency, and to understand the mechanisms by which HIV-1 establishes latency. PMID:27898737

Transcriptomic Analysis Implicates the p53 Signaling Pathway in the Establishment of HIV-1 Latency in Central Memory CD4 T Cells in an In Vitro Model.

PubMed

White, Cory H; Moesker, Bastiaan; Beliakova-Bethell, Nadejda; Martins, Laura J; Spina, Celsa A; Margolis, David M; Richman, Douglas D; Planelles, Vicente; Bosque, Alberto; Woelk, Christopher H

2016-11-01

The search for an HIV-1 cure has been greatly hindered by the presence of a viral reservoir that persists despite antiretroviral therapy (ART). Studies of HIV-1 latency in vivo are also complicated by the low proportion of latently infected cells in HIV-1 infected individuals. A number of models of HIV-1 latency have been developed to examine the signaling pathways and viral determinants of latency and reactivation. A primary cell model of HIV-1 latency, which incorporates the generation of primary central memory CD4 T cells (TCM), full-length virus infection (HIVNL4-3) and ART to suppress virus replication, was used to investigate the establishment of HIV latency using RNA-Seq. Initially, an investigation of host and viral gene expression in the resting and activated states of this model indicated that the resting condition was reflective of a latent state. Then, a comparison of the host transcriptome between the uninfected and latently infected conditions of this model identified 826 differentially expressed genes, many of which were related to p53 signaling. Inhibition of the transcriptional activity of p53 by pifithrin-α during HIV-1 infection reduced the ability of HIV-1 to be reactivated from its latent state by an unknown mechanism. In conclusion, this model may be used to screen latency reversing agents utilized in shock and kill approaches to cure HIV, to search for cellular markers of latency, and to understand the mechanisms by which HIV-1 establishes latency.

High-throughput Characterization of HIV-1 Reservoir Reactivation Using a Single-Cell-in-Droplet PCR Assay.

PubMed

Yucha, Robert W; Hobbs, Kristen S; Hanhauser, Emily; Hogan, Louise E; Nieves, Wildaliz; Ozen, Mehmet O; Inci, Fatih; York, Vanessa; Gibson, Erica A; Thanh, Cassandra; Shafiee, Hadi; El Assal, Rami; Kiselinova, Maja; Robles, Yvonne P; Bae, Helen; Leadabrand, Kaitlyn S; Wang, ShuQi; Deeks, Steven G; Kuritzkes, Daniel R; Demirci, Utkan; Henrich, Timothy J

2017-06-01

Reactivation of latent viral reservoirs is on the forefront of HIV-1 eradication research. However, it is unknown if latency reversing agents (LRAs) increase the level of viral transcription from cells producing HIV RNA or harboring transcriptionally-inactive (latent) infection. We therefore developed a microfluidic single-cell-in-droplet (scd)PCR assay to directly measure the number of CD4 + T cells that produce unspliced (us)RNA and multiply spliced (ms)RNA following ex vivo latency reversal with either an histone deacetylase inhibitor (romidepsin) or T cell receptor (TCR) stimulation. Detection of HIV-1 transcriptional activity can also be performed on hundreds of thousands of CD4+ T-cells in a single experiment. The scdPCR method was then applied to CD4 + T cells obtained from HIV-1-infected individuals on antiretroviral therapy. Overall, our results suggest that effects of LRAs on HIV-1 reactivation may be heterogeneous-increasing transcription from active cells in some cases and increasing the number of transcriptionally active cells in others. Genomic DNA and human mRNA isolated from HIV-1 reactivated cells could also be detected and quantified from individual cells. As a result, our assay has the potential to provide needed insight into various reservoir eradication strategies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Piracy of PGE2/EP receptor mediated signaling by Kaposi’s sarcoma associated herpes virus (KSHV/HHV-8) for latency gene expression: Strategy of a successful pathogen

PubMed Central

Paul, Arun George; Sharma-Walia, Neelam; Kerur, Nagaraj; White, Carl; Chandran, Bala

2010-01-01

KSHV is implicated in the pathogenesis of KS, a chronic inflammation associated malignancy. COX-2 and its metabolite PGE2, two pivotal proinflammatory/oncogeneic molecules, are proposed to play roles in the expression of major KSHV latency associated nuclear antigen-1 (LANA-1). Microsomal prostaglandin E2 synthase (mPGES), PGE2 and its receptors (EP1, EP2, EP3, and EP4) were detected in KS lesions with the distinct staining of EP2/EP4 in KS lesions. In latently infected endothelial TIVE-LTC cells, EP receptor antagonists down-regulated LANA-1 expression as well as Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB, which are also some of the signal molecules proposed to be important in KS pathogenesis. Exogenous PGE2 and EP receptor agonists induced the LANA-1 promoter in 293 cells, and YY1, Sp1, Oct-1, Oct-6, C/EBP and c-Jun transcription factors appear to be involved in this induction. PGE2/EP receptor induced LANA-1 promoter activity was down-regulated significantly by the inhibition of Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB. These findings implicate the inflammatory PGE2/EP receptors and the associated signal molecules in herpes virus latency and uncover a novel paradigm that demonstrates the evolution of KSHV genome plasticity to utilize inflammatory response for its survival advantage of maintaining latent gene expression. This data also suggests that potential use of anti-COX-2 and anti-EP receptor therapy may not only ameliorate the chronic inflammation associated with KS but could also lead to elimination of the KSHV latent infection and the associated KS lesions. PMID:20388794

Gammaherpesvirus-driven plasma cell differentiation regulates virus reactivation from latently infected B lymphocytes.

PubMed

Liang, Xiaozhen; Collins, Christopher M; Mendel, Justin B; Iwakoshi, Neal N; Speck, Samuel H

2009-11-01

Gammaherpesviruses chronically infect their host and are tightly associated with the development of lymphoproliferative diseases and lymphomas, as well as several other types of cancer. Mechanisms involved in maintaining chronic gammaherpesvirus infections are poorly understood and, in particular, little is known about the mechanisms involved in controlling gammaherpesvirus reactivation from latently infected B cells in vivo. Recent evidence has linked plasma cell differentiation with reactivation of the human gammaherpesviruses EBV and KSHV through induction of the immediate-early viral transcriptional activators by the plasma cell-specific transcription factor XBP-1s. We now extend those findings to document a role for a gammaherpesvirus gene product in regulating plasma cell differentiation and thus virus reactivation. We have previously shown that the murine gammaherpesvirus 68 (MHV68) gene product M2 is dispensable for virus replication in permissive cells, but plays a critical role in virus reactivation from latently infected B cells. Here we show that in mice infected with wild type MHV68, virus infected plasma cells (ca. 8% of virus infected splenocytes at the peak of viral latency) account for the majority of reactivation observed upon explant of splenocytes. In contrast, there is an absence of virus infected plasma cells at the peak of latency in mice infected with a M2 null MHV68. Furthermore, we show that the M2 protein can drive plasma cell differentiation in a B lymphoma cell line in the absence of any other MHV68 gene products. Thus, the role of M2 in MHV68 reactivation can be attributed to its ability to manipulate plasma cell differentiation, providing a novel viral strategy to regulate gammaherpesvirus reactivation from latently infected B cells. We postulate that M2 represents a new class of herpesvirus gene products (reactivation conditioners) that do not directly participate in virus replication, but rather facilitate virus reactivation by manipulating the cellular milieu to provide a reactivation competent environment.

Direct non-productive HIV-1 infection in a T-cell line is driven by cellular activation state and NFκB

PubMed Central

2014-01-01

Background Molecular latency allows HIV-1 to persist in resting memory CD4+ T-cells as transcriptionally silent provirus integrated into host chromosomal DNA. Multiple transcriptional regulatory mechanisms for HIV-1 latency have been described in the context of progressive epigenetic silencing and maintenance. However, our understanding of the determinants critical for the establishment of latency in newly infected cells is limited. Results In this study, we used a recently described, doubly fluorescent HIV-1 latency model to dissect the role of proviral integration sites and cellular activation state on direct non-productive infections at the single cell level. Proviral integration site mapping of infected Jurkat T-cells revealed that productively and non-productively infected cells are indistinguishable in terms of genomic landmarks, surrounding epigenetic landscapes, and proviral orientation relative to host genes. However, direct non-productive infections were inversely correlated with both cellular activation state and NFκB activity. Furthermore, modulating NFκB with either small molecules or by conditional overexpression of NFκB subunits was sufficient to alter the propensity of HIV-1 to directly enter a non-productive latent state in newly infected cells. Importantly, this modulatory effect was limited to a short time window post-infection. Conclusions Taken together, our data suggest that cellular activation state and NFκB activity during the time of infection, but not the site of proviral integration, are important regulators of direct HIV-1 non-productive infections. PMID:24502247

A Tribute to Professor Steven L. Wechsler (1948-2016): The Man and the Scientist.

PubMed

Nesburn, Anthony B; BenMohamed, Lbachir

2017-01-01

Professor Steven L. Wechsler, a world-renowned eye researcher and virologist, passed away unexpectedly on June 12, 2016 at the age of 68. Many scientists came to know Professor Wechsler as a gifted researcher in the field of ocular Herpes Simplex Virus (HSV-1) latency, reactivation, and pathogenesis. Professor Wechsler published over 150 peer-reviewed scientific papers during his career, pushing forward the frontiers of his field eye research. His colleagues would say, 'Steve literally wrote the book on herpes latency and reactivation.' He was the first to show that the HSV-1 latency-associated transcript (LAT) is essential for the HSV-1 high spontaneous reactivation phenotype and that LAT has anti-apoptosis activity. This discovery of LAT's anti-apoptosis activity, which is a key factor in how the LAT gene enhances reactivation, was published in Science in 2000 and created a new paradigm that greatly increased understanding of HSV-1 latency and reactivation. In collaboration with Professor Lbachir BenMohamed, an immunologist, they later demonstrated that LAT also acts as an immune evasion gene. He was a caring scientist who truly enjoyed working and sharing his experience and expertise with young researchers. He will be remembered as a significant pillar within scientific and ocular herpes research communities worldwide. Professor Wechsler's dedication to science, his compassionate character, and wonderful sense of humor were exemplary. We, who were his friends and colleagues, will mourn his passing deeply.

Unique Epstein-Barr virus (EBV) latent gene expression, EBNA promoter usage and EBNA promoter methylation status in chronic active EBV infection.

PubMed

Yoshioka, Mikio; Kikuta, Hideaki; Ishiguro, Nobuhisa; Ma, Xiaoming; Kobayashi, Kunihiko

2003-05-01

Chronic active Epstein-Barr virus infection (CAEBV) has been considered to be a non-neoplastic T-cell lymphoproliferative disease associated with Epstein-Barr virus (EBV) infection. In EBV-associated diseases, the cell phenotype-dependent differences in EBV latent gene expression may reflect the strategy of the virus in relation to latent infection. We previously reported that EBV latent gene expression was restricted; EBV nuclear antigen 1 (EBNA1) transcripts were consistently detected in all spleen samples from five CAEBV patients, but EBNA2 transcripts were detected in only one sample. EBV latent gene expression is controlled by distinct usage of three EBNA promoters (Cp, Wp and Qp). In this study, we examined the EBNA promoter usage by RT-PCR and the methylation status in the Cp and Wp regions using bisulfite PCR analysis in spleen samples from CAEBV patients. EBNA1 transcripts were unexpectedly initiated not from Qp but from Cp in all samples in spite of the restricted form of latency. Furthermore, while Cp was active, Cp was heavily methylated, indicating that CAEBV has unique EBV latent gene expression, EBNA promoter usage and EBNA promoter methylation status, in part due to unique splicing of Cp-initiated transcripts and an activation mechanism in hypermethylated Cp.

Permissive Sense and Antisense Transcription from the 5′ and 3′ Long Terminal Repeats of Human T-Cell Leukemia Virus Type 1

PubMed Central

Polakowski, Nicholas; Hoang, Kimson

2016-01-01

ABSTRACT Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus, and, as such, its genome becomes chromosomally integrated following infection. The resulting provirus contains identical 5′ and 3′ peripheral long terminal repeats (LTRs) containing bidirectional promoters. Antisense transcription from the 3′ LTR regulates expression of a single gene, hbz, while sense transcription from the 5′ LTR controls expression of all other viral genes, including tax. Both the HBZ and Tax proteins are implicated in the development of adult T-cell leukemia (ATL), a T-cell malignancy caused by HTLV-1 infection. However, these proteins appear to harbor opposing molecular functions, indicating that they may act independently and at different time points prior to leukemogenesis. Here, we used bidirectional reporter constructs to test whether transcriptional interference serves as a mechanism that inhibits simultaneous expression of Tax and HBZ. We found that sense transcription did not interfere with antisense transcription from the 3′ LTR and vice versa, even with strong transcription emanating from the opposing direction. Therefore, bidirectional transcription across the provirus might not restrict hbz or tax expression. Single-cell analyses revealed that antisense transcription predominates in the absence of Tax, which transactivates viral sense transcription. Interestingly, a population of Tax-expressing cells exhibited antisense but not activated sense transcription. Consistent with the ability of Tax to induce cell cycle arrest, this population was arrested in G0/G1 phase. These results imply that cell cycle arrest inhibits Tax-mediated activation of sense transcription without affecting antisense transcription, which may be important for long-term viral latency. IMPORTANCE The chromosomally integrated form of the retrovirus human T-cell leukemia virus type 1 (HTLV-1) contains identical DNA sequences, known as long terminal repeats (LTRs), at its 5′ and 3′ ends. The LTRs modulate transcription in both forward (sense) and reverse (antisense) directions. We found that sense transcription from the 5′ LTR does not interfere with antisense transcription from the 3′ LTR, allowing viral genes encoded on opposite DNA strands to be simultaneously transcribed. Two such genes are tax and hbz, and while they are thought to function at different times during the course of infection to promote leukemogenesis of infected T cells, our results indicate that they can be simultaneously transcribed. We also found that the ability of Tax to induce cell cycle arrest inhibits its fundamental function of activating viral sense transcription but does not affect antisense transcription. This regulatory mechanism may be important for long-term HTLV-1 infection. PMID:26792732

Variables associated with detection probability, detection latency, and behavioral responses of Golden-winged Warblers (Vermivora chrysoptera)

USGS Publications Warehouse

Aldinger, Kyle R.; Wood, Petra B.

2015-01-01

Detection probability during point counts and its associated variables are important considerations for bird population monitoring and have implications for conservation planning by influencing population estimates. During 2008–2009, we evaluated variables hypothesized to be associated with detection probability, detection latency, and behavioral responses of male Golden-winged Warblers in pastures in the Monongahela National Forest, West Virginia, USA. This is the first study of male Golden-winged Warbler detection probability, detection latency, or behavioral response based on point-count sampling with known territory locations and identities for all males. During 3-min passive point counts, detection probability decreased as distance to a male's territory and time since sunrise increased. During 3-min point counts with playback, detection probability decreased as distance to a male's territory increased, but remained constant as time since sunrise increased. Detection probability was greater when point counts included type 2 compared with type 1 song playback, particularly during the first 2 min of type 2 song playback. Golden-winged Warblers primarily use type 1 songs (often zee bee bee bee with a higher-pitched first note) in intersexual contexts and type 2 songs (strident, rapid stutter ending with a lower-pitched buzzy note) in intrasexual contexts. Distance to a male's territory, ordinal date, and song playback type were associated with the type of behavioral response to song playback. Overall, ~2 min of type 2 song playback may increase the efficacy of point counts for monitoring populations of Golden-winged Warblers by increasing the conspicuousness of males for visual identification and offsetting the consequences of surveying later in the morning. Because playback may interfere with the ability to detect distant males, it is important to follow playback with a period of passive listening. Our results indicate that even in relatively open pasture vegetation, detection probability of male Golden-winged Warblers is imperfect and highly variable.

MicroRNA-155 Reinforces HIV Latency*

PubMed Central

Ruelas, Debbie S.; Chan, Jonathan K.; Oh, Eugene; Heidersbach, Amy J.; Hebbeler, Andrew M.; Chavez, Leonard; Verdin, Eric; Rape, Michael; Greene, Warner C.

2015-01-01

The presence of a small number of infected but transcriptionally dormant cells currently thwarts a cure for the more than 35 million individuals infected with HIV. Reactivation of these latently infected cells may result in three fates: 1) cell death due to a viral cytopathic effect, 2) cell death due to immune clearance, or 3) a retreat into latency. Uncovering the dynamics of HIV gene expression and silencing in the latent reservoir will be crucial for developing an HIV-1 cure. Here we identify and characterize an intracellular circuit involving TRIM32, an HIV activator, and miR-155, a microRNA that may promote a return to latency in these transiently activated reservoir cells. Notably, we demonstrate that TRIM32, an E3 ubiquitin ligase, promotes reactivation from latency by directly modifying IκBα, leading to a novel mechanism of NF-κB induction not involving IκB kinase activation. PMID:25873391

Effects of the synthetic corticosteroid dexamethasone on bovine herpesvirus 1 productive infection.

PubMed

Zhu, Liqian; Thompson, Jesse; Ma, Fangrui; Eudy, James; Jones, Clinton

2017-05-01

Sensory neurons are a primary site for life-long latency of bovine herpesvirus 1 (BoHV-1). The synthetic corticosteroid dexamethasone induces reactivation from latency and productive infection, in part because the BoHV-1 genome contains more than 100 glucocorticoid receptor (GR) responsive elements (GREs). Two GREs in the immediate early transcription unit 1 promoter are required for dexamethasone induction. Recent studies also demonstrated that the serum and glucocorticoid receptor protein kinase (SGK) family stimulated BoHV-1 replication. Consequently, we hypothesized that dexamethasone influences several aspects of productive infection. In this study, we demonstrated that dexamethasone increased expression of the immediate early protein bICP4, certain late transcripts, and UL23 (thymidine kinase) by four hours after infection. SGK1 expression and Akt phosphorylation were also stimulated during early stages of infection and dexamethasone treatment further increased this effect. These studies suggest that stress, as mimicked by dexamethasone treatment, has the potential to stimulate productive infection by multiple pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

Narcolepsy type 1 and hypersomnia associated with a psychiatric disorder show different slow wave activity dynamics.

PubMed

Walacik-Ufnal, Ewa; Piotrowska, Anna Justyna; Wołyńczyk-Gmaj, Dorota; Januszko, Piotr; Gmaj, Bartłomiej; Ufnal, Marcin; Kabat, Marek; Wojnar, Marcin

2017-01-01

The aim of the study was to compare electrophysiological parameters of night sleep in narcolepsy type 1 and hypersomnia associated with a psychiatric disorder. Fortyfour patients: 15 with narcolepsy type 1, 14 with hypersomnia associated with a psychiatric disorder and 15 age- and sex-matched controls participated in the study. The study subjects filled in the Athens Insomnia Scale (AIS) and the Beck Depression Inventory (BDI). The severity of daytime sleepiness was quantified subjectively using the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), and objectively using the Multiple Sleep Latency Test (MSLT). All subjects underwent polysomnography (PSG) on the two consecutive nights. The data from the second night was analysed. The slow wave activity (SWA, 1-4 Hz) was calculated for the three consecutive sleep cycles, and topographic delta power maps were plotted. In contrast to narcoleptics, psychiatric hypersomniacs had undisturbed nocturnal sleep, high sleep efficiency, normal non-rapid eye movement (NREM) and rapid eye movement (REM) sleep proportions, normal REM latency and sleep latencies on MSLT and PSG. The subjective and objective sleepiness was significantly higher in narcolepsy group than in psychiatric hypersomnia group. In all the study groups SWA was the most prominent in frontal areas, while the greatest between-group differences were found in the central areas. There were significant differences between the groups in SWA in the second NREM episode. The highest SWA was observed in the hypersomnia group, while the lowest in the narcolepsy group. Psychiatric hypersomniacs and controls did not differ in the SWA exponential decline over consecutive NREM episodes, whereas narcoleptics exhibited a steeper dissipation of sleep pressure from the first to the second NREM episode. In conclusion, narcolepsy type1 and hypersomnia associated with psychiatric disorder differ in the SWA dynamics. Narcoleptics presented with the altered dynamics of sleep homeostasis, whereas psychiatric hypersomniacs showed normal nocturnal sleep and normal sleep homeostasis.

Selective HDAC Inhibition for the Disruption of Latent HIV-1 Infection

PubMed Central

Barton, Kirston M.; Archin, Nancie M.; Keedy, Kara S.; Espeseth, Amy S.; Zhang, Yan-ling; Gale, Jennifer; Wagner, Florence F.; Holson, Edward B.; Margolis, David M.

2014-01-01

Selective histone deacetylase (HDAC) inhibitors have emerged as a potential anti-latency therapy for persistent human immunodeficiency virus type 1 (HIV-1) infection. We utilized a combination of small molecule inhibitors and short hairpin (sh)RNA-mediated gene knockdown strategies to delineate the key HDAC(s) to be targeted for selective induction of latent HIV-1 expression. Individual depletion of HDAC3 significantly induced expression from the HIV-1 promoter in the 2D10 latency cell line model. However, depletion of HDAC1 or −2 alone or in combination did not significantly induce HIV-1 expression. Co-depletion of HDAC2 and −3 resulted in a significant increase in expression from the HIV-1 promoter. Furthermore, concurrent knockdown of HDAC1, −2, and −3 resulted in a significant increase in expression from the HIV-1 promoter. Using small molecule HDAC inhibitors of differing selectivity to ablate the residual HDAC activity that remained after (sh)RNA depletion, the effect of depletion of HDAC3 was further enhanced. Enzymatic inhibition of HDAC3 with the selective small-molecule inhibitor BRD3308 activated HIV-1 transcription in the 2D10 cell line. Furthermore, ex vivo exposure to BRD3308 induced outgrowth of HIV-1 from resting CD4+ T cells isolated from antiretroviral-treated, aviremic HIV+ patients. Taken together these findings suggest that HDAC3 is an essential target to disrupt HIV-1 latency, and inhibition of HDAC2 may also contribute to the effort to purge and eradicate latent HIV-1 infection. PMID:25136952

Quercetin-induced apoptosis prevents EBV infection

PubMed Central

Lee, Minjung; Son, Myoungki; Ryu, Eunhyun; Shin, Yu Su; Kim, Jong Gwang; Kang, Byung Woog; Sung, Gi-Ho; Cho, Hyosun; Kang, Hyojeung

2015-01-01

Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma. PMID:26059439

Entry of Herpes Simplex Virus Type 1 (HSV-1) into the Distal Axons of Trigeminal Neurons Favors the Onset of Nonproductive, Silent Infection

PubMed Central

Eing, Bodo R.; Müller, Marcus; King, Nicholas J. C.; Klupp, Barbara; Mettenleiter, Thomas C.; Kühn, Joachim E.

2012-01-01

Following productive, lytic infection in epithelia, herpes simplex virus type 1 (HSV-1) establishes a lifelong latent infection in sensory neurons that is interrupted by episodes of reactivation. In order to better understand what triggers this lytic/latent decision in neurons, we set up an organotypic model based on chicken embryonic trigeminal ganglia explants (TGEs) in a double chamber system. Adding HSV-1 to the ganglion compartment (GC) resulted in a productive infection in the explants. By contrast, selective application of the virus to distal axons led to a largely nonproductive infection that was characterized by the poor expression of lytic genes and the presence of high levels of the 2.0-kb major latency-associated transcript (LAT) RNA. Treatment of the explants with the immediate-early (IE) gene transcriptional inducer hexamethylene bisacetamide, and simultaneous co-infection of the GC with HSV-1, herpes simplex virus type 2 (HSV-2) or pseudorabies virus (PrV) helper virus significantly enhanced the ability of HSV-1 to productively infect sensory neurons upon axonal entry. Helper-virus-induced transactivation of HSV-1 IE gene expression in axonally-infected TGEs in the absence of de novo protein synthesis was dependent on the presence of functional tegument protein VP16 in HSV-1 helper virus particles. After the establishment of a LAT-positive silent infection in TGEs, HSV-1 was refractory to transactivation by superinfection of the GC with HSV-1 but not with HSV-2 and PrV helper virus. In conclusion, the site of entry appears to be a critical determinant in the lytic/latent decision in sensory neurons. HSV-1 entry into distal axons results in an insufficient transactivation of IE gene expression and favors the establishment of a nonproductive, silent infection in trigeminal neurons. PMID:22589716

Epstein-Barr virus-derived EBNA2 regulates STAT3 activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muromoto, Ryuta; Ikeda, Osamu; Okabe, Kanako

The Epstein-Barr virus (EBV)-encoded latency protein EBNA2 is a nuclear transcriptional activator that is essential for EBV-induced cellular transformation. Here, we show that EBNA2 interacts with STAT3, a signal transducer for an interleukin-6 family cytokine, and enhances the transcriptional activity of STAT3 by influencing its DNA-binding activity. Furthermore, EBNA2 cooperatively acts on STAT3 activation with LMP1. These data demonstrate that EBNA2 acts as a transcriptional coactivator of STAT3.

The OTT-MAL fusion oncogene activates RBPJ-mediated transcription and induces acute megakaryoblastic leukemia in a knockin mouse model

PubMed Central

Mercher, Thomas; Raffel, Glen D.; Moore, Sandra A.; Cornejo, Melanie G.; Baudry-Bluteau, Dominique; Cagnard, Nicolas; Jesneck, Jonathan L.; Pikman, Yana; Cullen, Dana; Williams, Ifor R.; Akashi, Koichi; Shigematsu, Hirokazu; Bourquin, Jean-Pierre; Giovannini, Marco; Vainchenker, William; Levine, Ross L.; Lee, Benjamin H.; Bernard, Olivier A.; Gilliland, D. Gary

2009-01-01

Acute megakaryoblastic leukemia (AMKL) is a form of acute myeloid leukemia (AML) associated with a poor prognosis. The genetics and pathophysiology of AMKL are not well understood. We generated a knockin mouse model of the one twenty-two–megakaryocytic acute leukemia (OTT-MAL) fusion oncogene that results from the t(1;22)(p13;q13) translocation specifically associated with a subtype of pediatric AMKL. We report here that OTT-MAL expression deregulated transcriptional activity of the canonical Notch signaling pathway transcription factor recombination signal binding protein for immunoglobulin κ J region (RBPJ) and caused abnormal fetal megakaryopoiesis. Furthermore, cooperation between OTT-MAL and an activating mutation of the thrombopoietin receptor myeloproliferative leukemia virus oncogene (MPL) efficiently induced a short-latency AMKL that recapitulated all the features of human AMKL, including megakaryoblast hyperproliferation and maturation block, thrombocytopenia, organomegaly, and extensive fibrosis. Our results establish that concomitant activation of RBPJ (Notch signaling) and MPL (cytokine signaling) transforms cells of the megakaryocytic lineage and suggest that specific targeting of these pathways could be of therapeutic value for human AMKL. PMID:19287095

Serotonin transporter polymorphism modifies the association between depressive symptoms and sleep onset latency complaint in elderly people: results from the 'InveCe.Ab' study.

PubMed

Polito, Letizia; Davin, Annalisa; Vaccaro, Roberta; Abbondanza, Simona; Govoni, Stefano; Racchi, Marco; Guaita, Antonio

2015-04-01

Previous studies have documented the involvement of the central nervous system serotonin in promoting wakefulness. There are few and conflicting results over whether there is an actual association between bearing the short allele of serotonin transporter promoter polymorphism (5-HTTLPR) and worse sleep quality. This study examined whether sleep onset latency complaint is associated with the 5-HTTLPR triallelic polymorphism in the SLC6A4 gene promoter and whether this polymorphism influences the relationship between sleep onset latency complaint and depressive symptoms in elderly people. A total of 1321 community-dwelling individuals aged 70-74 years were interviewed for sleep onset latency complaint and for sleep medication consumption. Participants' genomic DNA was typed for 5-HTTLPR and rs25531 polymorphisms. Depressive symptoms were evaluated with the Geriatric Depression Scale Short form and general medical comorbidity was assessed by the Cumulative Illness Rating Scale. The presence of a past history of depression was recorded. The S' allele of the 5-HTTLPR triallelic polymorphism was associated with sleep onset latency complaint. This association was maintained after adjusting for depressive symptoms, sex, age, history of depression and medical comorbidity. After stratification for 5-HTTLPR/rs25531, only in S'S' individuals high depressive symptoms were actually associated with sleep onset latency complaint. These data indicate that the low-expressing 5-HTTLPR triallelic polymorphism is an independent risk factor for sleep onset latency disturbance. Furthermore, the 5-HTTLPR genotype influences the association between depressive symptoms and sleep onset latency complaint. © 2014 European Sleep Research Society.

Role of defective Oct-2 and OCA-B expression in immunoglobulin production and Kaposi's sarcoma-associated herpesvirus lytic reactivation in primary effusion lymphoma.

PubMed

Di Bartolo, Daniel L; Hyjek, Elizabeth; Keller, Shannon; Guasparri, Ilaria; Deng, Hongyu; Sun, Ren; Chadburn, Amy; Knowles, Daniel M; Cesarman, Ethel

2009-05-01

Primary effusion lymphoma (PEL) is a distinct type of B-cell non-Hodgkin lymphoma characterized by the presence of Kaposi's sarcoma-associated herpesvirus (KSHV/human herpesvirus 8). Despite having a genotype and gene expression signature of highly differentiated B cells, PEL does not usually express surface or cytoplasmic immunoglobulin (Ig). We show the lack of Oct-2 and OCA-B transcription factors to be responsible, at least in part, for this defect in Ig production. Like Ig genes, ORF50, the key regulator of the switch from latency to lytic reactivation, contains an octamer motif within its promoter. We therefore examined the impact of Oct-2 and OCA-B on ORF50 activation. The binding of Oct-1 to the ORF50 promoter has been shown to significantly enhance ORF50 transactivation. We found that Oct-2, on the other hand, inhibited ORF50 expression and consequently lytic reactivation by competing with Oct-1 for the octamer motif in the ORF50 promoter. Our data suggest that Oct-2 downregulation in infected cells would be favorable to KSHV in allowing for efficient viral reactivation.

Evaluation of actigraphy-measured sleep patterns among children with disabilities and associations with caregivers’ educational attainment: results from a cross-sectional study

PubMed Central

Chen, Xiaoli; Velez, Juan Carlos; Barbosa, Clarita; Pepper, Micah; Gelaye, Bizu; Redline, Susan; Williams, Michelle A

2015-01-01

Objectives To use wrist-actrigrphy to collect objective measures of sleep and to characterise actigraphy-measured sleep patterns among children with disabilities. We also assessed the extent to which, if at all, caregivers’ education is associated with children's sleep disturbances. Design Cross-sectional study. Setting A rehabilitation centre in the Patagonia region, Chile. Methods This study was conducted among 125 children aged 6–12 years with disabilities (boys: 55.2%) and their primary caregivers in Chile. Children wore ActiSleep monitors for 7 days. A general linear model was fitted to generate least-square means and SEs of sleep efficiency (proportion of the sleep period spent asleep) across caregivers’ education levels adjusting for children's age, sex, disability type, caregiver–child relationship and caregivers’ age. Multivariable logistic regression analyses were conducted to estimate ORs and 95% CIs of longer sleep latency (≥30 min) and longer wake after sleep onset (WASO) (≥90 min) (a measure of sleep fragmentation) in relation to caregivers’ educational attainment. Results Median sleep latency was 27.3 min, WASO 88.1 min and sleep duration 8.0 h. Mean sleep efficiency was 80.0%. Caregivers’ education was positively and significantly associated with children's sleep efficiency (p trend<0.001). Adjusted mean sleep efficiency was 75.7% (SE=1.4) among children of caregivers high school education. Compared to children whose caregivers had >high school, children of caregivers with

Evaluation of actigraphy-measured sleep patterns among children with disabilities and associations with caregivers' educational attainment: results from a cross-sectional study.

PubMed

Chen, Xiaoli; Velez, Juan Carlos; Barbosa, Clarita; Pepper, Micah; Gelaye, Bizu; Redline, Susan; Williams, Michelle A

2015-12-07

To use wrist-actrigrphy to collect objective measures of sleep and to characterise actigraphy-measured sleep patterns among children with disabilities. We also assessed the extent to which, if at all, caregivers' education is associated with children's sleep disturbances. Cross-sectional study. A rehabilitation centre in the Patagonia region, Chile. This study was conducted among 125 children aged 6-12 years with disabilities (boys: 55.2%) and their primary caregivers in Chile. Children wore ActiSleep monitors for 7 days. A general linear model was fitted to generate least-square means and SEs of sleep efficiency (proportion of the sleep period spent asleep) across caregivers' education levels adjusting for children's age, sex, disability type, caregiver-child relationship and caregivers' age. Multivariable logistic regression analyses were conducted to estimate ORs and 95% CIs of longer sleep latency (≥ 30 min) and longer wake after sleep onset (WASO) (≥ 90 min) (a measure of sleep fragmentation) in relation to caregivers' educational attainment. Median sleep latency was 27.3 min, WASO 88.1 min and sleep duration 8.0 h. Mean sleep efficiency was 80.0%. Caregivers' education was positively and significantly associated with children's sleep efficiency (p trend<0.001). Adjusted mean sleep efficiency was 75.7% (SE=1.4) among children of caregivers high school education. Compared to children whose caregivers had >high school, children of caregivers with

Detection and characterization of latent HSV RNA by in situ and northern blot hybridization in guinea pigs.

PubMed

Burke, R L; Hartog, K; Croen, K D; Ostrove, J M

1991-04-01

Following intravaginal infection of guinea pigs, herpes simplex virus establishes a latent infection in the sensory lumbosacral ganglia. Using the techniques of in situ and Northern blot hybridization, we have characterized this latent HSV-2 virus and compared it to latent HSV-1 at the same anatomical site. For HSV-2, a single 1.8-kb latency-associated transcript (LAT) was detected. In contrast, as described for latent HSV-1 in the trigeminal ganglia of rabbits and mice, two HSV-1 LAT species were detected in the lumbosacral ganglia, an abundant transcript of 1.8 kb and a less abundant transcript of 1.55 kb. Despite these differences in LAT expression, the clinical course of the acute and recurrent genital disease was similar for both viruses. LAT was detected in 0.3-6.0% of the sensory neurons of sacral but not in lumbar ganglia. The abundance of LAT correlated with the severity of the initial infection, but not with the frequency of recurrent disease. Thus, vaccination strategies that substantially reduced or eliminated symptomatic disease following challenge infection appeared to block the establishment of a latent infection.

MicroRNA regulation of viral immunity, latency, and carcinogenesis of selected tumor viruses and HIV.

PubMed

Wang, Ling; Li, Guangyu; Yao, Zhi Q; Moorman, Jonathan P; Ning, Shunbin

2015-09-01

MicroRNAs (miRNAs) function as key regulators in immune responses and cancer development. In the contexts of infection with oncogenic viruses, miRNAs are engaged in viral persistence, latency establishment and maintenance, and oncogenesis. In this review, we summarize the potential roles and mechanisms of viral and cellular miRNAs in the host-pathogen interactions during infection with selected tumor viruses and HIV, which include (i) repressing viral replication and facilitating latency establishment by targeting viral transcripts, (ii) evading innate and adaptive immune responses via toll-like receptors, RIG-I-like receptors, T-cell receptor, and B-cell receptor pathways by targeting signaling molecules such as TRAF6, IRAK1, IKKε, and MyD88, as well as downstream targets including regulatory cytokines such as tumor necrosis factor α, interferon γ, interleukin 10, and transforming growth factor β, (iii) antagonizing intrinsic and extrinsic apoptosis pathways by targeting pro-apoptotic or anti-apoptotic gene transcripts such as the Bcl-2 family and caspase-3, (iv) modulating cell proliferation and survival through regulation of the Wnt, PI3K/Akt, Erk/MAPK, and Jak/STAT signaling pathways, as well as the signaling pathways triggered by viral oncoproteins such as Epstein-Barr Virus LMP1, by targeting Wnt-inhibiting factor 1, SHIP, pTEN, and SOCSs, and (v) regulating cell cycle progression by targeting cell cycle inhibitors such as p21/WAF1 and p27/KIP1. Further elucidation of the interaction between miRNAs and these key biological events will facilitate our understanding of the pathogenesis of viral latency and oncogenesis and may lead to the identification of miRNAs as novel targets for developing new therapeutic or preventive interventions. Copyright © 2015 John Wiley & Sons, Ltd.

Regulation of Innate Immune Responses by Bovine Herpesvirus 1 and Infected Cell Protein 0 (bICP0)

PubMed Central

Jones, Clinton

2009-01-01

Bovine herpesvirus 1 (BoHV-1) infected cell protein 0 (bICP0) is an important transcriptional regulatory protein that stimulates productive infection. In transient transfection assays, bICP0 also inhibits interferon dependent transcription. bICP0 can induce degradation of interferon stimulatory factor 3 (IRF3), a cellular transcription factor that is crucial for activating beta interferon (IFN-β) promoter activity. Recent studies also concluded that interactions between bICP0 and IRF7 inhibit trans-activation of IFN-β promoter activity. The C3HC4 zinc RING (really important new gene) finger located near the amino terminus of bICP0 is important for all known functions of bICP0. A recombinant virus that contains a single amino acid change in a well conserved cysteine residue of the C3HC4 zinc RING finger of bICP0 grows poorly in cultured cells, and does not reactivate from latency in cattle confirming that the C3HC4 zinc RING finger is crucial for viral growth and pathogenesis. A bICP0 deletion mutant does not induce plaques in permissive cells, but induces autophagy in a cell type dependent manner. In summary, the ability of bICP0 to stimulate productive infection, and repress IFN dependent transcription plays a crucial role in the BoHV-1 infection cycle. PMID:21994549

Meningioma patients diagnosed 2007-2009 and the association with use of mobile and cordless phones: a case-control study.

PubMed

Carlberg, Michael; Söderqvist, Fredrik; Hansson Mild, Kjell; Hardell, Lennart

2013-07-19

To study the association between use of wireless phones and meningioma. We performed a case-control study on brain tumour cases of both genders aged 18-75 years and diagnosed during 2007-2009. One population-based control matched on gender and age was used to each case. Here we report on meningioma cases including all available controls. Exposures were assessed by a questionnaire. Unconditional logistic regression analysis was performed. In total 709 meningioma cases and 1,368 control subjects answered the questionnaire. Mobile phone use in total produced odds ratio (OR) = 1.0, 95% confidence interval (CI) = 0.7-1.4 and cordless phone use gave OR = 1.1, 95% CI = 0.8-1.5. The risk increased statistically significant per 100 h of cumulative use and highest OR was found in the fourth quartile (>2,376 hours) of cumulative use for all studied phone types. There was no statistically significant increased risk for ipsilateral mobile or cordless phone use, for meningioma in the temporal lobe or per year of latency. Tumour volume was not related to latency or cumulative use in hours of wireless phones. No conclusive evidence of an association between use of mobile and cordless phones and meningioma was found. An indication of increased risk was seen in the group with highest cumulative use but was not supported by statistically significant increasing risk with latency. Results for even longer latency periods of wireless phone use than in this study are desirable.

Transcription mapping and expression patterns of genes in the major immediate-early region of Kaposi's sarcoma-associated herpesvirus.

PubMed

Saveliev, Alexei; Zhu, Fan; Yuan, Yan

2002-08-01

Viral immediate-early (IE) genes are the first class of viral genes expressed during primary infection or reactivation from latency. They usually encode regulatory proteins that play crucial roles in viral life cycle. In a previous study, four regions in the KSHV genome were found to be actively transcribed in the immediate-early stage of viral reactivation in primary effusion lymphoma cells. Three immediate-early transcripts were characterized in these regions, as follows: mRNAs for ORF50 (KIE-1), ORF-45 (KIE-2), and ORF K4.2 (KIE-3) (F. X. Zhu, T. Cusano, and Y. Yuan, 1999, J. Virol. 73, 5556-5567). In the present study, we further analyzed the expression of genes in these IE regions in BC-1 and BCBL-1 cells. One of the immediate-early regions (KIE-1) that encompasses ORF50 and other genes was intensively studied to establish a detailed transcription map and expression patterns of genes in this region. This study led to identification of several novel IE transcripts in this region. They include a 2.6-kb mRNA which encodes ORF48/ORF29b, a family of transcripts that are complementary to ORF50 mRNA and a novel K8 IE mRNA of 1.5 kb. Together with the IE mRNA for ORF50 which was identified previously, four immediate-early genes have been mapped to KIE-1 region. Therefore, we would designate KIE-1 the major immediate-early region of KSHV. In addition, we showed that transcription of K8 gene is controlled by two promoters, yielding two transcripts, an immediate-early mRNA of 1.5 kb and a delayed-early mRNA of 1.3 kb.

A selective inhibition of c-Fos/activator protein-1 as a potential therapeutic target for intervertebral disc degeneration and associated pain.

PubMed

Makino, Hiroto; Seki, Shoji; Yahara, Yasuhito; Shiozawa, Shunichi; Aikawa, Yukihiko; Motomura, Hiraku; Nogami, Makiko; Watanabe, Kenta; Sainoh, Takeshi; Ito, Hisakatsu; Tsumaki, Noriyuki; Kawaguchi, Yoshiharu; Yamazaki, Mitsuaki; Kimura, Tomoatsu

2017-12-05

Intervertebral disc (IVD) degeneration is a major cause of low back pain. The transcription factor c-Fos/Activator Protein-1 (AP-1) controls the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) that contribute to the pathogenesis IVD degeneration. We investigated the effects of inhibition of c-Fos/AP-1 on IVD degeneration and associated pain. A selective inhibitor, T-5224, significantly suppressed the interleukin-1β-induced up-regulation of Mmp-3, Mmp-13 and Adamts-5 transcription in human nucleus pulposus cells and in a mouse explant culture model of IVD degeneration. We used a tail disc percutaneous needle puncture method to further assess the effects of oral administration of T-5224 on IVD degeneration. Analysis of disc height, T2-magnetic resonance imaging (MRI) findings, and histology revealed that IVD degeneration was significantly mitigated by T-5224. Further, oral administration of T-5224 ameliorated pain as indicated by the extended tail-flick latency in response to heat stimulation of rats with needle-puncture-induced IVD degeneration. These findings suggest that the inhibition of c-Fos/AP-1 prevents disc degeneration and its associated pain and that T-5224 may serve as a drug for the prevention of IVD degeneration.

The β-catenin signaling pathway stimulates bovine herpesvirus 1 productive infection.

PubMed

Zhu, Liqian; Thunuguntla, Prasanth; Liu, Yilin; Hancock, Morgan; Jones, Clinton

2017-01-01

Bovine herpes virus 1 (BoHV-1), an important bovine pathogen, causes conjunctivitis and disorders in the upper respiratory tract. Following acute infection, BoHV1 establishes life-long latency in sensory neurons. Recent studies demonstrated that viral gene products expressed in trigeminal ganglionic neurons during latency stabilize β-catenin levels, an important signaling molecule that interacts with a family of DNA binding proteins (T-cell factors) and subsequently stimulates transcription. In this study, we provide new evidence demonstrating that BoHV-1 transiently increased β-catenin protein levels in bovine kidney (CRIB) cells, but not in rabbit skin cells. β-catenin dependent transcription was also stimulated by infection of CRIB cells. The β-catenin small molecule inhibitor (iCRT14) significantly reduced the levels of BoHV-1 virus during productive infection of CRIB cells and rabbit skin cells. In summary, these studies suggested the ability of β-catenin to stimulate cell survival and cell cycle regulatory factors enhances productive infection in non-neuronal cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Basal shuttle of NF-κB/IκBα in resting T lymphocytes regulates HIV-1 LTR dependent expression

PubMed Central

Coiras, Mayte; López-Huertas, María Rosa; Rullas, Joaquín; Mittelbrunn, Maria; Alcamí, José

2007-01-01

Background In HIV-infected T lymphocytes, NF-κB/Rel transcription factors are major elements involved in the activation of LTR-dependent transcription from latency. Most NF-κB heterodimer p65/p50 is sequestered as an inactive form in the cytoplasm of resting T lymphocytes via its interaction with IκB inhibitors. In these cells, both absolute HIV latency and low level ongoing HIV replication have been described. These situations could be related to differences in the balance between NF-κB and IκBα ratio. Actually, control of IκBα by cellular factors such as Murr-1 plays a critical role in maintaining HIV latency in unstimulated T lymphocytes. Formerly, our group demonstrated the presence of nuclear IκBα in T cells after PMA activation. Now we attempt to determine the dynamics of NF-κB/IκBα nucleocytosolic transport in absence of activation as a mechanism to explain both the maintenance of latency and the existence of low level ongoing HIV replication in resting CD4+ T lymphocytes. Results and conclusion We show that the inhibition of the nuclear export by leptomycin B in resting CD4+ T cells resulted in nuclear accumulation of both IκBα and p65/RelA, as well as formation of NF-κB/IκBα complexes. This proves the existence of a rapid shuttling of IκBα between nucleus and cytosol even in absence of cellular activation. The nuclear accumulation of IκBα in resting CD4+ T lymphocytes results in inhibition of HIV-LTR dependent transcription as well as restrains HIV replication in CD4+ T lymphocytes. On the other hand, basal NF-κB activity detected in resting CD4+ T lymphocytes was related to low level HIV replication in these cells. PMID:17686171

Interaction of Adenovirus E1A with the HHV8 Promoter of Latent Genes: E1A Proteins are Able to Activate the HHV-8 LANAp in MV3 Reporter Cells

PubMed Central

Koehler-Hansner, Karin; Flore, Ornella; Opalka, Bertram; Hengge, Ulrich R

2008-01-01

Human herpesvirus 8 (HHV-8) is associated with Kaposi’s sarcoma, body cavity-based lymphoma, and Castleman’s disease. Adenoviral (Ad) E1A proteins regulate the activity of cellular and viral promoters/enhancers and transcription factors and can suppress tumorigenicity of human cancers. As (i) HHV-8 and Ad may co-exist in immunocompromised patients and (ii) E1A might be considered as therapeutic transgene for HHV-8-associated neoplasms we investigated whether the promoter of the latency-associated nuclear antigen (LANAp) controlling expression of vCyclin, vFLIP, and LANA proteins required for latent type infection is regulated by E1A. Transfection experiments in MV3 melanoma cells revealed activation of the LANAp by Ad5 E1A constructs containing an intact N terminus (aa 1-119). In particular, an Ad12 E1A mutant, Spm2, lacking six consecutive alanine residues in the “spacer” region activated the HHV-8 promoter about 15-fold compared to vector controls. In summary, we report the activation of the LANAp by E1A as a novel interaction of E1A with a viral promoter. These data may have relevance for the management of viral infections in immunocompromised patients. A role for E1A as a therapeutic in this context remains to be defined. PMID:19440465

Neuregulin 1 transcripts are differentially expressed in schizophrenia and regulated by 5′ SNPs associated with the disease

PubMed Central

Law, Amanda J.; Lipska, Barbara K.; Weickert, Cynthia Shannon; Hyde, Thomas M.; Straub, Richard E.; Hashimoto, Ryota; Harrison, Paul J.; Kleinman, Joel E.; Weinberger, Daniel R.

2006-01-01

Genetic variation in neuregulin 1 (NRG1) is associated with schizophrenia. The disease-associated SNPs are noncoding, and their functional implications remain unknown. We hypothesized that differential expression of the NRG1 gene explains its association to the disease. We examined four of the disease-associated SNPs that make up the original risk haplotype in the 5′ upstream region of the gene for their effects on mRNA abundance of NRG1 types I–IV in human postmortem hippocampus. Diagnostic comparisons revealed a 34% increase in type I mRNA in schizophrenia and an interaction of diagnosis and genotype (SNP8NRG221132) on this transcript. Of potentially greater interest, a single SNP within the risk haplotype (SNP8NRG243177) and a 22-kb block of this core haplotype are associated with mRNA expression for the novel type IV isoform in patients and controls. Bioinformatic promoter analyses indicate that both SNPs lead to a gain/loss of putative binding sites for three transcription factors, serum response factor, myelin transcription factor-1, and High Mobility Group Box Protein-1. These data implicate variation in isoform expression as a molecular mechanism for the genetic association of NRG1 with schizophrenia. PMID:16618933

Indomethacin treatment prior to pentylenetetrazole-induced seizures downregulates the expression of il1b and cox2 and decreases seizure-like behavior in zebrafish larvae.

PubMed

Barbalho, Patrícia Gonçalves; Lopes-Cendes, Iscia; Maurer-Morelli, Claudia Vianna

2016-03-09

It has been demonstrated that the zebrafish model of pentylenetetrazole (PTZ)-evoked seizures and the well-established rodent models of epilepsy are similar pertaining to behavior, electrographic features, and c-fos expression. Although this zebrafish model is suitable for studying seizures, to date, inflammatory response after seizures has not been investigated using this model. Because a relationship between epilepsy and inflammation has been established, in the present study we investigated the transcript levels of the proinflammatory cytokines interleukin-1 beta (il1b) and cyclooxygenase-2 (cox2a and cox2b) after PTZ-induced seizures in the brain of zebrafish 7 days post fertilization. Furthermore, we exposed the fish to the nonsteroidal anti-inflammatory drug indomethacin prior to PTZ, and we measured its effect on seizure latency, number of seizure behaviors, and mRNA expression of il1b, cox2b, and c-fos. We used quantitative real-time PCR to assess the mRNA expression of il1b, cox2a, cox2b, and c-fos, and visual inspection was used to monitor seizure latency and the number of seizure-like behaviors. We found a short-term upregulation of il1b, and we revealed that cox2b, but not cox2a, was induced after seizures. Indomethacin treatment prior to PTZ-induced seizures downregulated the mRNA expression of il1b, cox2b, and c-fos. Moreover, we observed that in larvae exposed to indomethacin, seizure latency increased and the number of seizure-like behaviors decreased. This is the first study showing that il1b and cox-2 transcripts are upregulated following PTZ-induced seizures in zebrafish. In addition, we demonstrated the anticonvulsant effect of indomethacin based on (1) the inhibition of PTZ-induced c-fos transcription, (2) increase in seizure latency, and (3) decrease in the number of seizure-like behaviors. Furthermore, anti-inflammatory effect of indomethacin is clearly demonstrated by the downregulation of the mRNA expression of il1b and cox2b. Our results are supported by previous evidences suggesting that zebrafish is a suitable alternative for studying inflammation, seizures, and the effect of anti-inflammatory compounds on seizure suppression.

Felid Herpesvirus Type 1 Infection in Cats: A Natural Host Model for Alphaherpesvirus Pathogenesis

PubMed Central

Maes, Roger

2012-01-01

Feline herpesvirus 1 (FeHV-1) is an alphaherpesvirus that causes feline viral rhinotracheitis, an important viral disease of cats on a worldwide basis. Acute FeHV-1 infection is associated with both upper respiratory and ocular signs. Following the acute phase of the disease lifelong latency is established, primarily in sensory neuronal cells. As is the case with human herpes simplex viruses, latency reactivation can result in recrudescence, which can manifest itself in the form of serious ocular lesions. FeHV-1 infection in cats is a natural host model that is useful for the identification of viral virulence genes that play a role in replication at the mucosal portals of entry or are mediators of the establishment, maintenance, or reactivation of latency. It is also a model system for defining innate and adaptive immunity mechanisms and for immunization strategies that can lead to better protection against this and other alphaherpesvirus infections. PMID:23762586

Cutaneous Papillomavirus E6 oncoproteins associate with MAML1 to repress transactivation and NOTCH signaling

PubMed Central

Brimer, Nicole; Lyons, Charles; Wallberg, Annika E.; Vande Pol, Scott B.

2011-01-01

Papillomavirus E6 oncoproteins associate with LXXLL motifs on target cellular proteins to alter their function. Using a proteomic approach, we found the E6 oncoproteins of cutaneous papillomaviruses Bovine Papillomavirus Type 1 (BE6) and HPV types 1 and 8 (1E6 and 8E6) associated with the MAML1 transcriptional co-activator. All three E6 proteins bind to an acidic LXXLL motif at the carboxy-terminus of MAML1 and repress transactivation by MAML1. MAML1 is best known as the co-activator and effector of NOTCH induced transcription, and BPV-1 E6 represses synthetic NOTCH responsive promoters, endogenous NOTCH responsive promoters, and is found in a complex with MAML1 in stably transformed cells. BPV-1 induced papillomas show characteristics of repressed NOTCH signal transduction, including suprabasal expression of integrins, talin, and basal type keratins, and delayed expression of the NOTCH dependent HES1 transcription factor. These observations give rise to a model whereby papillomavirus oncoproteins including BPV-1 E6 and the cancer associated HPV-8 E6 repress Notch induced transcription, thereby delaying keratinocyte differentiation. PMID:22249263

An acutely and latently expressed herpes simplex virus 2 viral microRNA inhibits expression of ICP34.5, a viral neurovirulence factor.

PubMed

Tang, Shuang; Bertke, Andrea S; Patel, Amita; Wang, Kening; Cohen, Jeffrey I; Krause, Philip R

2008-08-05

Latency-associated transcript (LAT) sequences regulate herpes simplex virus (HSV) latency and reactivation from sensory neurons. We found a HSV-2 LAT-related microRNA (miRNA) designated miR-I in transfected and infected cells in vitro and in acutely and latently infected ganglia of guinea pigs in vivo. miR-I is also expressed in human sacral dorsal root ganglia latently infected with HSV-2. miR-I is expressed under the LAT promoter in vivo in infected sensory ganglia. We also predicted and identified a HSV-1 LAT exon-2 viral miRNA in a location similar to miR-I, implying a conserved mechanism in these closely related viruses. In transfected and infected cells, miR-I reduces expression of ICP34.5, a key viral neurovirulence factor. We hypothesize that miR-I may modulate the outcome of viral infection in the peripheral nervous system by functioning as a molecular switch for ICP34.5 expression.

Quantitative multi-target RNA profiling in Epstein-Barr virus infected tumor cells.

PubMed

Greijer, A E; Ramayanti, O; Verkuijlen, S A W M; Novalić, Z; Juwana, H; Middeldorp, J M

2017-03-01

Epstein-Barr virus (EBV) is etiologically linked to multiple acute, chronic and malignant diseases. Detection of EBV-RNA transcripts in tissues or biofluids besides EBV-DNA can help in diagnosing EBV related syndromes. Sensitive EBV transcription profiling yields new insights on its pathogenic role and may be useful for monitoring virus targeted therapy. Here we describe a multi-gene quantitative RT-PCR profiling method that simultaneously detects a broad spectrum (n=16) of crucial latent and lytic EBV transcripts. These transcripts include (but are not restricted to), EBNA1, EBNA2, LMP1, LMP2, BARTs, EBER1, BARF1 and ZEBRA, Rta, BGLF4 (PK), BXLF1 (TK) and BFRF3 (VCAp18) all of which have been implicated in EBV-driven oncogenesis and viral replication. With this method we determine the amount of RNA copies per infected (tumor) cell in bulk populations of various origin. While we confirm the expected RNA profiles within classic EBV latency programs, this sensitive quantitative approach revealed the presence of rare cells undergoing lytic replication. Inducing lytic replication in EBV tumor cells supports apoptosis and is considered as therapeutic approach to treat EBV-driven malignancies. This sensitive multi-primed quantitative RT-PCR approach can provide broader understanding of transcriptional activity in latent and lytic EBV infection and is suitable for monitoring virus-specific therapy responses in patients with EBV associated cancers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Meningioma patients diagnosed 2007–2009 and the association with use of mobile and cordless phones: a case–control study

PubMed Central

2013-01-01

Background To study the association between use of wireless phones and meningioma. Methods We performed a case–control study on brain tumour cases of both genders aged 18–75 years and diagnosed during 2007–2009. One population-based control matched on gender and age was used to each case. Here we report on meningioma cases including all available controls. Exposures were assessed by a questionnaire. Unconditional logistic regression analysis was performed. Results In total 709 meningioma cases and 1,368 control subjects answered the questionnaire. Mobile phone use in total produced odds ratio (OR) = 1.0, 95% confidence interval (CI) = 0.7-1.4 and cordless phone use gave OR = 1.1, 95% CI = 0.8-1.5. The risk increased statistically significant per 100 h of cumulative use and highest OR was found in the fourth quartile (>2,376 hours) of cumulative use for all studied phone types. There was no statistically significant increased risk for ipsilateral mobile or cordless phone use, for meningioma in the temporal lobe or per year of latency. Tumour volume was not related to latency or cumulative use in hours of wireless phones. Conclusions No conclusive evidence of an association between use of mobile and cordless phones and meningioma was found. An indication of increased risk was seen in the group with highest cumulative use but was not supported by statistically significant increasing risk with latency. Results for even longer latency periods of wireless phone use than in this study are desirable. PMID:23870102

Autophagy Genes Enhance Murine Gammaherpesvirus 68 Reactivation From Latency by Preventing Virus-induced Systemic Inflammation

PubMed Central

Park, Sunmin; Buck, Michael D.; Desai, Chandni; Zhang, Xin; Loginicheva, Ekaterina; Martinez, Jennifer; Freeman, Michael L.; Saitoh, Tatsuya; Akira, Shizuo; Guan, Jun-Lin; He, You-Wen; Blackman, Marcia A.; Handley, Scott A.; Levine, Beth; Green, Douglas R.; Reese, Tiffany A.; Artyomov, Maxim N.; Virgin, Herbert W.

2016-01-01

SUMMARY Host genes that regulate systemic inflammation upon chronic viral infection are incompletely understood. Murine γ-herpesvirus 68 (MHV68) infection is characterized by latency in macrophages, and reactivation is inhibited by Interferon-γ (IFN-γ). Using a Lysozyme-M-cre (LysMcre) expression system, we show that deletion of autophagy-related (Atg) genes Fip200, beclin 1, Atg14, Atg16L1, Atg7, Atg3, and Atg5, in the myeloid compartment, inhibited MHV68 reactivation in macrophages. Atg5-deficiency did not alter reactivation from B cells, and effects on reactivation from macrophages were not explained by alterations in productive viral replication or the establishment of latency. Rather, chronic MHV68 infection triggered increased systemic inflammation, increased T cell production of IFN-γ and an IFN-γ-induced transcriptional signature in macrophages from Atg gene-deficient mice. The Atg5-related reactivation defect was partially reversed by neutralization of IFN-γ. Thus Atg genes in myeloid cells dampen virus-induced systemic inflammation, creating an environment that fosters efficient MHV68 reactivation from latency. PMID:26764599

High Diversity and Variability in the Vaginal Microbiome in Women following Preterm Premature Rupture of Membranes (PPROM): A Prospective Cohort Study

PubMed Central

Paramel Jayaprakash, Teenus; Wagner, Emily C.; van Schalkwyk, Julie; Albert, Arianne Y. K.; Hill, Janet E.; Money, Deborah M.

2016-01-01

Objective To characterize the vaginal microbiota of women following preterm premature rupture of membranes (PPROM), and determine if microbiome composition predicts latency duration and perinatal outcomes. Design A prospective cohort study Setting Canada Population Women with PPROM between 24+0 and 33+6 weeks gestational age (GA). Methods Microbiome profiles, based on pyrosequencing of the cpn60 universal target, were generated from vaginal samples at time of presentation with PPROM, weekly thereafter, and at delivery. Main Outcome Measures Vaginal microbiome composition, latency duration, gestational age at delivery, perinatal outcomes. Results Microbiome profiles were generated from 70 samples from 36 women. Mean GA at PPROM was 28.8 wk (mean latency 2.7 wk). Microbiome profiles were highly diverse but sequences representing Megasphaera type 1 and Prevotella spp. were detected in all vaginal samples. Only 13/70 samples were dominated by Lactobacillus spp. Microbiome profiles at the time of membrane rupture did not cluster by gestational age at PPROM, latency duration, presence of chorioamnionitis or by infant outcomes. Mycoplasma and/or Ureaplasma were detected by PCR in 81% (29/36) of women, and these women had significantly lower GA at delivery and correspondingly lower birth weight infants than Mycoplasma and/or Ureaplasma negative women. Conclusion Women with PPROM had mixed, abnormal vaginal microbiota but the microbiome profile at PPROM did not correlate with latency duration. Prevotella spp. and Megasphaera type I were ubiquitous. The presence of Mollicutes in the vaginal microbiome was associated with lower GA at delivery. The microbiome was remarkably unstable during the latency period. PMID:27861554

Inhibition of latent membrane protein 1 impairs the growth and tumorigenesis of latency II Epstein-Barr virus-transformed T cells.

PubMed

Ndour, Papa Alioune; Brocqueville, Guillaume; Ouk, Tan-Sothéa; Goormachtigh, Gautier; Morales, Olivier; Mougel, Alexandra; Bertout, Julie; Melnyk, Oleg; Fafeur, Véronique; Feuillard, Jean; Coll, Jean; Adriaenssens, Eric

2012-04-01

Epstein-Barr virus (EBV) is a common human herpesvirus. Infection with EBV is associated with several human malignancies in which the virus expresses a set of latent proteins, among which is latent membrane protein 1 (LMP1). LMP1 is able to transform numerous cell types and is considered the main oncogenic protein of EBV. The mechanism of action is based on mimicry of activated members of the tumor necrosis factor (TNF) receptor superfamily, through the ability of LMP1 to bind similar adapters and to activate signaling pathways. We previously generated two unique models: a monocytic cell line and a lymphocytic (NC5) cell line immortalized by EBV that expresses the type II latency program. Here we generated LMP1 dominant negative forms (DNs), based on fusion between green fluorescent protein (GFP) and transformation effector site 1 (TES1) or TES2 of LMP1. Then we generated cell lines conditionally expressing these DNs. These DNs inhibit NF-κB and Akt pathways, resulting in the impairment of survival processes and increased apoptosis in these cell lines. This proapoptotic effect is due to reduced interaction of LMP1 with specific adapters and the recruitment of these adapters to DNs, which enable the generation of an apoptotic complex involving TRADD, FADD, and caspase 8. Similar results were obtained with cell lines displaying a latency III program in which LMP1-DNs decrease cell viability. Finally, we prove that synthetic peptides display similar inhibitory effects in EBV-infected cells. DNs derived from LMP1 could be used to develop therapeutic approaches for malignant diseases associated with EBV.

Inhibition of Latent Membrane Protein 1 Impairs the Growth and Tumorigenesis of Latency II Epstein-Barr Virus-Transformed T Cells

PubMed Central

Ndour, Papa Alioune; Brocqueville, Guillaume; Ouk, Tan-Sothéa; Goormachtigh, Gautier; Morales, Olivier; Mougel, Alexandra; Bertout, Julie; Melnyk, Oleg; Fafeur, Véronique; Feuillard, Jean; Coll, Jean

2012-01-01

Epstein-Barr virus (EBV) is a common human herpesvirus. Infection with EBV is associated with several human malignancies in which the virus expresses a set of latent proteins, among which is latent membrane protein 1 (LMP1). LMP1 is able to transform numerous cell types and is considered the main oncogenic protein of EBV. The mechanism of action is based on mimicry of activated members of the tumor necrosis factor (TNF) receptor superfamily, through the ability of LMP1 to bind similar adapters and to activate signaling pathways. We previously generated two unique models: a monocytic cell line and a lymphocytic (NC5) cell line immortalized by EBV that expresses the type II latency program. Here we generated LMP1 dominant negative forms (DNs), based on fusion between green fluorescent protein (GFP) and transformation effector site 1 (TES1) or TES2 of LMP1. Then we generated cell lines conditionally expressing these DNs. These DNs inhibit NF-κB and Akt pathways, resulting in the impairment of survival processes and increased apoptosis in these cell lines. This proapoptotic effect is due to reduced interaction of LMP1 with specific adapters and the recruitment of these adapters to DNs, which enable the generation of an apoptotic complex involving TRADD, FADD, and caspase 8. Similar results were obtained with cell lines displaying a latency III program in which LMP1-DNs decrease cell viability. Finally, we prove that synthetic peptides display similar inhibitory effects in EBV-infected cells. DNs derived from LMP1 could be used to develop therapeutic approaches for malignant diseases associated with EBV. PMID:22258264

Case-control study of the association between malignant brain tumours diagnosed between 2007 and 2009 and mobile and cordless phone use.

PubMed

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Mild, Kjell Hansson

2013-12-01

Previous studies have shown a consistent association between long-term use of mobile and cordless phones and glioma and acoustic neuroma, but not for meningioma. When used these phones emit radiofrequency electromagnetic fields (RF-EMFs) and the brain is the main target organ for the handheld phone. The International Agency for Research on Cancer (IARC) classified in May, 2011 RF-EMF as a group 2B, i.e. a 'possible' human carcinogen. The aim of this study was to further explore the relationship between especially long-term (>10 years) use of wireless phones and the development of malignant brain tumours. We conducted a new case-control study of brain tumour cases of both genders aged 18-75 years and diagnosed during 2007-2009. One population-based control matched on gender and age (within 5 years) was used to each case. Here, we report on malignant cases including all available controls. Exposures on e.g. use of mobile phones and cordless phones were assessed by a self-administered questionnaire. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index using the whole control sample. Of the cases with a malignant brain tumour, 87% (n=593) participated, and 85% (n=1,368) of controls in the whole study answered the questionnaire. The odds ratio (OR) for mobile phone use of the analogue type was 1.8, 95% confidence interval (CI)=1.04‑3.3, increasing with >25 years of latency (time since first exposure) to an OR=3.3, 95% CI=1.6-6.9. Digital 2G mobile phone use rendered an OR=1.6, 95% CI=0.996-2.7, increasing with latency >15-20 years to an OR=2.1, 95% CI=1.2-3.6. The results for cordless phone use were OR=1.7, 95% CI=1.1-2.9, and, for latency of 15-20 years, the OR=2.1, 95% CI=1.2-3.8. Few participants had used a cordless phone for >20-25 years. Digital type of wireless phones (2G and 3G mobile phones, cordless phones) gave increased risk with latency >1-5 years, then a lower risk in the following latency groups, but again increasing risk with latency >15-20 years. Ipsilateral use resulted in a higher risk than contralateral mobile and cordless phone use. Higher ORs were calculated for tumours in the temporal and overlapping lobes. Using the meningioma cases in the same study as reference entity gave somewhat higher ORs indicating that the results were unlikely to be explained by recall or observational bias. This study confirmed previous results of an association between mobile and cordless phone use and malignant brain tumours. These findings provide support for the hypothesis that RF-EMFs play a role both in the initiation and promotion stages of carcinogenesis.

Epstein-Barr Virus EBNA1 Protein Regulates Viral Latency through Effects on let-7 MicroRNA and Dicer

PubMed Central

Mansouri, Sheila; Pan, Qun; Blencowe, Benjamin J.; Claycomb, Julie M.

2014-01-01

ABSTRACT The EBNA1 protein of Epstein-Barr virus (EBV) plays multiple roles in EBV latent infection, including altering cellular pathways relevant for cancer. Here we used microRNA (miRNA) cloning coupled with high-throughput sequencing to identify the effects of EBNA1 on cellular miRNAs in two nasopharyngeal carcinoma cell lines. EBNA1 affected a small percentage of cellular miRNAs in both cell lines, in particular, upregulating multiple let-7 family miRNAs, including let-7a. The effects of EBNA1 on let-7a were verified by demonstrating that EBNA1 silencing in multiple EBV-positive carcinomas downregulated let-7a. Accordingly, the let-7a target, Dicer, was found to be partially downregulated by EBNA1 expression (at the mRNA and protein levels) and upregulated by EBNA1 silencing in EBV-positive cells. Reporter assays based on the Dicer 3′ untranslated region with and without let-7a target sites indicated that the effects of EBNA1 on Dicer were mediated by let-7a. EBNA1 was also found to induce the expression of let-7a primary RNAs in a manner dependent on the EBNA1 transcriptional activation region, suggesting that EBNA1 induces let-7a by transactivating the expression of its primary transcripts. Consistent with previous reports that Dicer promotes EBV reactivation, we found that a let-7a mimic inhibited EBV reactivation to the lytic cycle, while a let-7 sponge increased reactivation. The results provide a mechanism by which EBNA1 could promote EBV latency by inducing let-7 miRNAs. IMPORTANCE The EBNA1 protein of Epstein-Barr virus (EBV) contributes in multiple ways to the latent mode of EBV infection that leads to lifelong infection. In this study, we identify a mechanism by which EBNA1 helps to maintain EBV infection in a latent state. This involves induction of a family of microRNAs (let-7 miRNAs) that in turn decreases the level of the cellular protein Dicer. We demonstrate that let-7 miRNAs inhibit the reactivation of latent EBV, providing an explanation for our previous observation that EBNA1 promotes latency. In addition, since decreased levels of Dicer have been associated with metastatic potential, EBNA1 may increase metastases by downregulating Dicer. PMID:25031339

Two bHLH-type transcription factors, JA-ASSOCIATED MYC2-LIKE2 and JAM3, are transcriptional repressors and affect male fertility

PubMed Central

Nakata, Masaru; Ohme-Takagi, Masaru

2013-01-01

The jasmonate (JA) plant hormones regulate responses to biotic and abiotic stress and aspects of plant development, including male fertility in Arabidopsis thaliana. The bHLH-type transcription factor JA-ASSOCIATED MYC2-LIKE1 (JAM1) negatively regulates JA signaling and gain-of-function JAM1 transgenic plants have impaired JA-mediated male fertility. Here we report that JAM2 and JAM3, 2 bHLHs closely related to JAM1, also act as transcriptional repressors. Moreover, overexpression of JAM2 and JAM3 also results in reduced male fertility. These results suggest that JAM1, JAM2, and JAM3 act redundantly as negative regulators of JA-mediated male fertility. PMID:24056034

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997-2003 and 2007-2009 and use of mobile and cordless phones.

PubMed

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Mild, Kjell Hansson

2013-10-01

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20-80 years, diagnosed during 1997-2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007-2009 including both men and women aged 18-75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0-4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8-21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1-2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8-4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1-2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7-26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1-2.0 increasing to OR = 8.1, 95% CI = 2.0-32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2-9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless phones. OR increased per 100 h cumulative use and per year of latency for mobile phones and cordless phones, though the increase was not statistically significant for cordless phones. The percentage tumour volume increased per year of latency and per 100 h of cumulative use, statistically significant for analogue phones. This study confirmed previous results demonstrating an association between mobile and cordless phone use and acoustic neuroma.

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997–2003 and 2007–2009 and use of mobile and cordless phones

PubMed Central

HARDELL, LENNART; CARLBERG, MICHAEL; SÖDERQVIST, FREDRIK; MILD, KJELL HANSSON

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20–80 years, diagnosed during 1997–2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007–2009 including both men and women aged 18–75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0–4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8–21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1–2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8–4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1–2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7–26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1–2.0 increasing to OR = 8.1, 95% CI = 2.0–32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2–9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless phones. OR increased per 100 h cumulative use and per year of latency for mobile phones and cordless phones, though the increase was not statistically significant for cordless phones. The percentage tumour volume increased per year of latency and per 100 h of cumulative use, statistically significant for analogue phones. This study confirmed previous results demonstrating an association between mobile and cordless phone use and acoustic neuroma. PMID:23877578

Exosomes from uninfected cells activate transcription of latent HIV-1.

PubMed

Barclay, Robert A; Schwab, Angela; DeMarino, Catherine; Akpamagbo, Yao; Lepene, Benjamin; Kassaye, Seble; Iordanskiy, Sergey; Kashanchi, Fatah

2017-07-14

HIV-1 infection causes AIDS, infecting millions worldwide. The virus can persist in a state of chronic infection due to its ability to become latent. We have previously shown a link between HIV-1 infection and exosome production. Specifically, we have reported that exosomes transport viral proteins and RNA from infected cells to neighboring uninfected cells. These viral products could then elicit an innate immune response, leading to activation of the Toll-like receptor and NF-κB pathways. In this study, we asked whether exosomes from uninfected cells could activate latent HIV-1 in infected cells. We observed that irrespective of combination antiretroviral therapy, both short- and long-length viral transcripts were increased in wild-type HIV-1-infected cells exposed to purified exosomes from uninfected cells. A search for a possible mechanism for this finding revealed that the exosomes increase RNA polymerase II loading onto the HIV-1 promoter in the infected cells. These viral transcripts, which include trans-activation response (TAR) RNA and a novel RNA that we termed TAR- gag , can then be packaged into exosomes and potentially be exported to neighboring uninfected cells, leading to increased cellular activation. To better decipher the exosome release pathways involved, we used siRNA to suppress expression of ESCRT (endosomal sorting complex required for transport) proteins and found that ESCRT II and IV significantly control exosome release. Collectively, these results imply that exosomes from uninfected cells activate latent HIV-1 in infected cells and that true transcriptional latency may not be possible in vivo , especially in the presence of combination antiretroviral therapy.

A Gammaherpesvirus Bcl-2 Ortholog Blocks B Cell Receptor-Mediated Apoptosis and Promotes the Survival of Developing B Cells In Vivo

PubMed Central

Coleman, Carrie B.; McGraw, Jennifer E.; Feldman, Emily R.; Roth, Alexa N.; Keyes, Lisa R.; Grau, Katrina R.; Cochran, Stephanie L.; Waldschmidt, Thomas J.; Liang, Chengyu; Forrest, J. Craig; Tibbetts, Scott A.

2014-01-01

Gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV, HHV-8) establish lifelong latency in their hosts and are associated with the development of several types of malignancies, including a subset of B cell lymphomas. These viruses are thought to co-opt the process of B cell differentiation to latently infect a fraction of circulating memory B cells, resulting in the establishment of a stable latency setpoint. However, little is known about how this infected memory B cell compartment is maintained throughout the life of the host. We have previously demonstrated that immature and transitional B cells are long-term latency reservoirs for murine gammaherpesvirus 68 (MHV68), suggesting that infection of developing B cells contributes to the maintenance of lifelong latency. During hematopoiesis, immature and transitional B cells are subject to B cell receptor (BCR)-mediated negative selection, which results in the clonal deletion of autoreactive B cells. Interestingly, numerous gammaherpesviruses encode homologs of the anti-apoptotic protein Bcl-2, suggesting that virus inhibition of apoptosis could subvert clonal deletion. To test this, we quantified latency establishment in mice inoculated with MHV68 vBcl-2 mutants. vBcl-2 mutant viruses displayed a marked decrease in the frequency of immature and transitional B cells harboring viral genome, but this attenuation could be rescued by increased host Bcl-2 expression. Conversely, vBcl-2 mutant virus latency in early B cells and mature B cells, which are not targets of negative selection, was remarkably similar to wild-type virus. Finally, in vivo depletion of developing B cells during chronic infection resulted in decreased mature B cell latency, demonstrating a key role for developing B cells in the maintenance of lifelong latency. Collectively, these findings support a model in which gammaherpesvirus latency in circulating mature B cells is sustained in part through the recurrent infection and vBcl-2-mediated survival of developing B cells. PMID:24516386

Latent Herpes Simplex Virus 1 Infection Does Not Induce Apoptosis in Human Trigeminal Ganglia

PubMed Central

Lindemann, Anja; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Hüfner, Katharina

2015-01-01

Herpes simplex virus 1 (HSV-1) can establish lifelong latency in human trigeminal ganglia. Latently infected ganglia contain CD8+ T cells, which secrete granzyme B and are thus capable of inducing neuronal apoptosis. Using immunohistochemistry and single-cell reverse transcription-quantitative PCR (RT-qPCR), higher frequency and transcript levels of caspase-3 were found in HSV-1-negative compared to HSV-1-positive ganglia and neurons, respectively. No terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay-positive neurons were detected. The infiltrating T cells do not induce apoptosis in latently infected neurons. PMID:25762734

Mapping the architecture of the HIV-lTat circuit: A decision-making circuit that lacks bistability and exploits stochastic noise

PubMed Central

Razooky, Brandon S.; Weinberger, Leor S.

2014-01-01

Upon infection of a CD4+ T cell, HIV-l appears to ‘choose’ between two alternate fates: active replication or a long-lived dormant statetermed proviral latency. A transcriptional positive-feedback loop generated by the HIV-l Tat protein appears sufficient to mediate this decision. Here, we describea coupled wet-lab and computational approach that uses mathematical modeling and live-cell time-lapse microscopy to map the architecture of the HIV-l Tat transcriptional regulatorycircuit and generate predictive models of HIV-l latency. This approach provided the first characterization of a ‘decision-making’ circuit that lacks bistability andinstead exploits stochastic fluctuations in cellular molecules (i.e. noise) to generate a decision between an on or off transcriptional state. PMID:21167940

A5-positive primary sensory neurons are nonpermissive for productive infection with herpes simplex virus 1 in vitro.

PubMed

Bertke, Andrea S; Swanson, Sophia M; Chen, Jenny; Imai, Yumi; Kinchington, Paul R; Margolis, Todd P

2011-07-01

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) establish latency and express the latency-associated transcript (LAT) preferentially in different murine sensory neuron populations, with most HSV-1 LAT expression in A5(+) neurons and most HSV-2 LAT expression in KH10(+) neurons. To study the mechanisms regulating the establishment of HSV latency in specific subtypes of neurons, cultured dissociated adult murine trigeminal ganglion (TG) neurons were assessed for relative permissiveness for productive infection. In contrast to that for neonatal TG, the relative distribution of A5(+) and KH10(+) neurons in cultured adult TG was similar to that seen in vivo. Productive infection with HSV was restricted, and only 45% of cultured neurons could be productively infected with either HSV-1 or HSV-2. A5(+) neurons supported productive infection with HSV-2 but were selectively nonpermissive for productive infection with HSV-1, a phenomenon that was not due to restricted viral entry or DNA uncoating, since HSV-1 expressing β-galactosidase under the control of the neurofilament promoter was detected in ∼90% of cultured neurons, with no preference for any neuronal subtype. Infection with HSV-1 reporter viruses expressing enhanced green fluorescent protein (EGFP) from immediate early (IE), early, and late gene promoters indicated that the block to productive infection occurred before IE gene expression. Trichostatin A treatment of quiescently infected neurons induced productive infection preferentially from non-A5(+) neurons, demonstrating that the nonpermissive neuronal subtype is also nonpermissive for reactivation. Thus, HSV-1 is capable of entering the majority of sensory neurons in vitro; productive infection occurs within a subset of these neurons; and this differential distribution of productive infection is determined at or before the expression of the viral IE genes.

A5-Positive Primary Sensory Neurons Are Nonpermissive for Productive Infection with Herpes Simplex Virus 1 In Vitro▿

PubMed Central

Bertke, Andrea S.; Swanson, Sophia M.; Chen, Jenny; Imai, Yumi; Kinchington, Paul R.; Margolis, Todd P.

2011-01-01

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) establish latency and express the latency-associated transcript (LAT) preferentially in different murine sensory neuron populations, with most HSV-1 LAT expression in A5+ neurons and most HSV-2 LAT expression in KH10+ neurons. To study the mechanisms regulating the establishment of HSV latency in specific subtypes of neurons, cultured dissociated adult murine trigeminal ganglion (TG) neurons were assessed for relative permissiveness for productive infection. In contrast to that for neonatal TG, the relative distribution of A5+ and KH10+ neurons in cultured adult TG was similar to that seen in vivo. Productive infection with HSV was restricted, and only 45% of cultured neurons could be productively infected with either HSV-1 or HSV-2. A5+ neurons supported productive infection with HSV-2 but were selectively nonpermissive for productive infection with HSV-1, a phenomenon that was not due to restricted viral entry or DNA uncoating, since HSV-1 expressing β-galactosidase under the control of the neurofilament promoter was detected in ∼90% of cultured neurons, with no preference for any neuronal subtype. Infection with HSV-1 reporter viruses expressing enhanced green fluorescent protein (EGFP) from immediate early (IE), early, and late gene promoters indicated that the block to productive infection occurred before IE gene expression. Trichostatin A treatment of quiescently infected neurons induced productive infection preferentially from non-A5+ neurons, demonstrating that the nonpermissive neuronal subtype is also nonpermissive for reactivation. Thus, HSV-1 is capable of entering the majority of sensory neurons in vitro; productive infection occurs within a subset of these neurons; and this differential distribution of productive infection is determined at or before the expression of the viral IE genes. PMID:21507969

Lack of evidence for intertypic recombinants in the pathogenesis of recurrent genital infections with herpes simplex virus type 1.

PubMed

Fife, K H; Boggs, D

1986-01-01

Clinical observations indicate that herpes simplex virus type 1 (HSV-1) is significantly less likely than herpes simplex virus type 2 (HSV-2) to establish latency in (or reactivate from) sacral ganglionic tissue. In an effort to identify viral functions associated with latency, we analyzed HSV-1 isolates from three patients with established recurrent genital herpes and sought evidence of DNA sequences and proteins similar to those found in HSV-2. By restriction endonuclease cleavage patterns and by DNA hybridization analysis using either whole HSV-2 DNA or several cloned segments of HSV-2 DNA as probes, we found that the three HSV-1 isolates from patients with recurrent genital herpes showed no unusual homology to HSV-2 as compared with other HSV-1 isolates. Similarly, the proteins of these isolates could not be distinguished from those of other HSV-1 isolates and were distinct from those of HSV-2. At this level of resolution, there was no evidence to suggest that these recurrent genital HSV-1 isolates were intertypic recombinants, nor did they show any other unusual similarity to HSV-2.

Heat shock factor 1 upregulates transcription of Epstein-Barr Virus nuclear antigen 1 by binding to a heat shock element within the BamHI-Q promoter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Feng-Wei; Wu, Xian-Rui; Liu, Wen-Ju

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is essential for maintenance of the episome and establishment of latency. In this study, we observed that heat treatment effectively induced EBNA1 transcription in EBV-transformed B95-8 and human LCL cell lines. Although Cp is considered as the sole promoter used for the expression of EBNA1 transcripts in the lymphoblastoid cell lines, the RT-PCR results showed that the EBNA1 transcripts induced by heat treatment arise from Qp-initiated transcripts. Using bioinformatics, a high affinity and functional heat shock factor 1 (HSF1)-binding element within the - 17/+4 oligonucleotide of the Qp was found, and was determinedmore » by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Moreover, heat shock and exogenous HSF1 expression induced Qp activity in reporter assays. Further, RNA interference-mediated HSF1 gene silencing attenuated heat-induced EBNA1 expression in B95-8 cells. These results provide evidence that EBNA1 is a new target for the transcription factor HSF1.« less

Herpes Simplex Virus 1 Reactivates from Autonomic Ciliary Ganglia Independently from Sensory Trigeminal Ganglia To Cause Recurrent Ocular Disease

PubMed Central

Lee, Sungseok; Ives, Angela M.

2015-01-01

ABSTRACT Herpes simplex virus 1 (HSV-1) and HSV-2 establish latency in sensory and autonomic neurons after ocular or genital infection, but their recurrence patterns differ. HSV-1 reactivates from latency to cause recurrent orofacial disease, and while HSV-1 also causes genital lesions, HSV-2 recurs more efficiently in the genital region and rarely causes ocular disease. The mechanisms regulating these anatomical preferences are unclear. To determine whether differences in latent infection and reactivation in autonomic ganglia contribute to differences in HSV-1 and HSV-2 anatomical preferences for recurrent disease, we compared HSV-1 and HSV-2 clinical disease, acute and latent viral loads, and viral gene expression in sensory trigeminal and autonomic superior cervical and ciliary ganglia in a guinea pig ocular infection model. HSV-2 produced more severe acute disease, correlating with higher viral DNA loads in sensory and autonomic ganglia, as well as higher levels of thymidine kinase expression, a marker of productive infection, in autonomic ganglia. HSV-1 reactivated in ciliary ganglia, independently from trigeminal ganglia, to cause more frequent recurrent symptoms, while HSV-2 replicated simultaneously in autonomic and sensory ganglia to cause more persistent disease. While both HSV-1 and HSV-2 expressed the latency-associated transcript (LAT) in the trigeminal and superior cervical ganglia, only HSV-1 expressed LAT in ciliary ganglia, suggesting that HSV-2 is not reactivation competent or does not fully establish latency in ciliary ganglia. Thus, differences in replication and viral gene expression in autonomic ganglia may contribute to differences in HSV-1 and HSV-2 acute and recurrent clinical disease. IMPORTANCE Herpes simplex virus 1 (HSV-1) and HSV-2 establish latent infections, from which the viruses reactivate to cause recurrent disease throughout the life of the host. However, the viruses exhibit different manifestations and frequencies of recurrent disease. HSV-1 and HSV-2 establish latency in both sensory and autonomic ganglia. Autonomic ganglia are more responsive than sensory ganglia to stimuli associated with recurrent disease in humans, such as stress and hormone fluctuations, suggesting that autonomic ganglia may play an important role in recurrent disease. We show that HSV-1 can reactivate from autonomic ganglia, independently from sensory ganglia, to cause recurrent ocular disease. We found no evidence that HSV-2 could reactivate from autonomic ganglia independently from sensory ganglia after ocular infection, but HSV-2 did replicate in both ganglia simultaneously to cause persistent disease. Thus, viral replication and reactivation in autonomic ganglia contribute to different clinical disease manifestations of HSV-1 and HSV-2 after ocular infection. PMID:26041294

Subjectively measured ejaculation latency time and its association with different sexual activities while controlling for age and relationship length.

PubMed

Jern, Patrick; Santtila, Pekka; Johansson, Ada; Varjonen, Markus; Witting, Katarina; von der Pahlen, Bettina; Sandnabba, Kenneth

2009-09-01

Recently, attempts to formulate valid and suitable definitions for (different subcategories of) premature ejaculation have resulted in substantial progress in the pursuit to gain knowledge about ejaculatory function. However, the association between ejaculatory dysfunction and different types of sexual activities has yet to be thoroughly investigated, and (due to conflicting results between studies) the potential effects of age and relationship length still need to be taken into account. The aim of this study is to investigate the associations of age, relationship length, frequency of different sexual activities, and different modes of achieving ejaculation with self-reported ejaculation latency time. The main outcome is establishing associations between age, relationship length, self-reported ejaculation latency time, and frequency of different kinds of sexual activities and different modes of achieving ejaculation (such as achieving ejaculation through oral or vaginal sex). Statistical analyses of data on age, relationship length, self-reported ejaculation latency time, and frequency of different sexual activities and different modes of achieving ejaculation were conducted on a population-based sample of 3,189 males aged 18-48 years (mean = 29.9 years, standard deviation = 6.94). Age and relationship length were significantly negatively associated with self-reported ejaculation latency time. Frequency of different kinds of sexual behavior generally had a positive association with self-reported ejaculation latency time, as had different modes of achieving ejaculation. The findings highlight the need for more extensive studies on and increased knowledge of different aspects of ejaculatory function before a valid and suitable definition for premature ejaculation can be formulated.

Visual Evoked Potential to Assess Retinopathy in Gestational Diabetes Mellitus.

PubMed

Hari Kumar, K V S; Ahmad, F M H; Sood, Sandeep; Mansingh, Sudhir

2016-04-01

We evaluated for early retinopathy using the visual evoked potential (VEP) in patients with gestational diabetes mellitus (GDM) and type 2 diabetes mellitus during pregnancy. All patients with GDM and type 2 diabetes seen between June and October of 2014 were included in this cross-sectional, observational study. Patients with secondary diabetes, ocular or major illness were excluded from the study. VEP was recorded in both eyes to derive prominent positive peak latency (P100), amplitude and initial negative deflection (N75) latency. The data were compared with 10 gestational age-matched controls with normal glucose tolerance. Appropriate statistical methods were used for comparison among the 3 groups. The study participants (40 with GDM, 10 with type 2 diabetes, 10 with normal glucose tolerance) had a median (25th to 75th interquartile range) age of 26 (24.3, 30) years, a gestational age of 24.5 (21, 27) weeks and weights of 66.8 (63.4, 71.5) kg. The P100 latencies were comparable among the 3 groups (p=0.0577). However, patients with any diabetes (GDM and type 2 diabetes) had prolonged P100 latencies (p=0.0139) and low P100 amplitudes (p=0.0391) in comparison to controls. P100 latency showed a direct correlation with hyperglycemia (p=0.0118). Our data showed that VEP abnormalities are detectable even in the short-term hyperglycemia of GDM and type 2 diabetes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

The effect of CD4 receptor downregulation and its downstream signaling molecules on HIV-1 latency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Kyung-Chang; School of Life Science and Biotechnology, Korea University, Seoul; Kim, Hyeon Guk

2011-01-14

Research highlights: {yields} CD4 receptors were downregulated on the surface of HIV-1 latently infected cells. {yields} CD4 downstream signaling molecules were suppressed in HIV-1 latently infected cells. {yields} HIV-1 progeny can be reactivated by induction of T-cell activation signal molecules. {yields} H3K4me3 and H3K9ac were highly enriched in CD4 downstream signaling molecules. {yields} HIV-1 latency can be maintained by the reduction of downstream signaling molecules. -- Abstract: HIV-1 can establish a latent infection in memory CD4 + T cells to evade the host immune response. CD4 molecules can act not only as the HIV-1 receptor for entry but also asmore » the trigger in an intracellular signaling cascade for T-cell activation and proliferation via protein tyrosine kinases. Novel chronic HIV-1-infected A3.01-derived (NCHA) cells were used to examine the involvement of CD4 downstream signaling in HIV-1 latency. CD4 receptors in NCHA cells were dramatically downregulated on its surface but were slightly decreased in whole-cell lysates. The expression levels of CD4 downstream signaling molecules, including P56{sup Lck}, ZAP-70, LAT, and c-Jun, were sharply decreased in NCHA cells. The lowered histone modifications of H3K4me3 and H3K9ac correlated with the downregulation of P56{sup Lck}, ZAP-70, and LAT in NCHA cells. AP-1 binding activity was also reduced in NCHA cells. LAT and c-Jun suppressed in NCHA cells were highly induced after PMA treatment. In epigenetic analysis, other signal transduction molecules which are associated with active and/or latent HIV-1 infection showed normal states in HIV-1 latently infected cells compared to A3.01 cells. In conclusion, we demonstrated that the HIV-1 latent state is sustained by the reduction of downstream signaling molecules via the downregulation of CD4 and the attenuated activity of transcription factor as AP-1. The HIV-1 latency model via T-cell deactivation may provide some clues for the development of the new antireservoir therapy.« less

Identification of Caspase Cleavage Sites in KSHV Latency-Associated Nuclear Antigen and Their Effects on Caspase-Related Host Defense Responses.

PubMed

Davis, David A; Naiman, Nicole E; Wang, Victoria; Shrestha, Prabha; Haque, Muzammel; Hu, Duosha; Anagho, Holda A; Carey, Robert F; Davidoff, Katharine S; Yarchoan, Robert

2015-07-01

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, is the causative agent of three hyperproliferative disorders: Kaposi's sarcoma, primary effusion lymphoma (PEL) and multicentric Castleman's disease. During viral latency a small subset of viral genes are produced, including KSHV latency-associated nuclear antigen (LANA), which help the virus thwart cellular defense responses. We found that exposure of KSHV-infected cells to oxidative stress, or other inducers of apoptosis and caspase activation, led to processing of LANA and that this processing could be inhibited with the pan-caspase inhibitor Z-VAD-FMK. Using sequence, peptide, and mutational analysis, two caspase cleavage sites within LANA were identified: a site for caspase-3 type caspases at the N-terminus and a site for caspase-1 and-3 type caspases at the C-terminus. Using LANA expression plasmids, we demonstrated that mutation of these cleavage sites prevents caspase-1 and caspase-3 processing of LANA. This indicates that these are the principal sites that are susceptible to caspase cleavage. Using peptides spanning the identified LANA cleavage sites, we show that caspase activity can be inhibited in vitro and that a cell-permeable peptide spanning the C-terminal cleavage site could inhibit cleavage of poly (ADP-ribose) polymerase and increase viability in cells undergoing etoposide-induced apoptosis. The C-terminal peptide of LANA also inhibited interleukin-1 beta (IL-1β) production from lipopolysaccharide-treated THP-1 cells by more than 50%. Furthermore, mutation of the two cleavage sites in LANA led to a significant increase in IL-1β production in transfected THP-1 cells; this provides evidence that these sites function to blunt the inflammasome, which is known to be activated in latently infected PEL cells. These results suggest that specific caspase cleavage sites in KSHV LANA function to blunt apoptosis as well as interfere with the caspase-1-mediated inflammasome, thus thwarting key cellular defense mechanisms.

[Analysis for the association between genetic polymorphisms of XRCC1, XPD, XRCC3, CCND1 and the latency of the occupational chronic benzene poisoning].

PubMed

Xu, Jian-ning; Huang, Hui-long; Wang, Quan-kai; Wang, Ya-wen; Yang, Min; Zheng, Yu-xin

2007-03-01

To explore the association between genetic polymorphisms of XRCC1, XPD, XRCC3 and CCND1 and latency of occupational chronic benzene poisoning. 80 patients diagnosed with occupational chronic benzene poisoning were investigated. PCR-RFLP was applied to detect the single nucleotide polymorphisms of C26304T, G27466A, G28152A, G36189A of XRCC1, C22541A, C23591T, A35931C of XPD, C18067T of XRCC3 and G870A of CCND1. Their relationship with the latency of chronic benzene poisoning was analyzed by Kaplan-Meier method. The association of XRCC1 G27466A subgroup with the latency of chronic benzene poisoning was observed, as well as that of CCDN1G870A subgroup. The benzene-exposed workers with XRCC1 27466G/G homozygous wild genotype developed chronic benzene poisoning 6.9 years later than those had homozygous (27466A/A) or heterozygous (27466G/A) mutant alleles. On the other hand, the latency developing chronic benzene poisoning was longer in workers with homozygous (CCND1 870A/A) or heterozygous (CCND1 870G/A) mutant alleles than in those carrying 870G/G homozygous wild genotype (14.9 vs. 8.7 years). The polymorphisms of XRCC1 and CCND1 potentially modify the latency of the chronic benzene poisoning among workers exposed to benzene.

Knockout of NMDA receptors in parvalbumin interneurons recreates autism-like phenotypes.

PubMed

Saunders, John A; Tatard-Leitman, Valerie M; Suh, Jimmy; Billingslea, Eddie N; Roberts, Timothy P; Siegel, Steven J

2013-04-01

Autism is a disabling neurodevelopmental disorder characterized by social deficits, language impairment, and repetitive behaviors with few effective treatments. New evidence suggests that autism has reliable electrophysiological endophenotypes and that these measures may be caused by n-methyl-d-aspartic acid receptor (NMDAR) disruption on parvalbumin (PV)-containing interneurons. These findings could be used to create new translational biomarkers. Recent developments have allowed for cell-type selective knockout of NMDARs in order to examine the perturbations caused by disrupting specific circuits. This study examines several electrophysiological and behavioral measures disrupted in autism using a PV-selective reduction in NMDA R1 subunit. Mouse electroencephalograph (EEG) was recorded in response to auditory stimuli. Event-related potential (ERP) component amplitude and latency analysis, social testing, and premating ultrasonic vocalizations (USVs) recordings were performed. Correlations were examined between the ERP latency and behavioral measures. The N1 ERP latency was delayed, sociability was reduced, and mating USVs were impaired in PV-selective NMDA Receptor 1 Knockout (NR1 KO) as compared with wild-type mice. There was a significant correlation between N1 latency and sociability but not between N1 latency and premating USV power or T-maze performance. The increases in N1 latency, impaired sociability, and reduced vocalizations in PV-selective NR1 KO mice mimic similar changes found in autism. Electrophysiological changes correlate to reduced sociability, indicating that the local circuit mechanisms controlling N1 latency may be utilized in social function. Therefore, we propose that behavioral and electrophysiological alterations in PV-selective NR1 KO mice may serve as a useful model for therapeutic development in autism. Autism Res 2013, 6: 69-77. © 2013 International Society for Autism Research, Wiley Periodicals, Inc. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.

Epstein-Barr Virus MicroRNA miR-BART20-5p Suppresses Lytic Induction by Inhibiting BAD-Mediated caspase-3-Dependent Apoptosis

PubMed Central

Kim, Hyoji; Choi, Hoyun

2015-01-01

ABSTRACT Epstein-Barr virus (EBV) is a human gammaherpesvirus associated with a variety of tumor types. EBV can establish latency or undergo lytic replication in host cells. In general, EBV remains latent in tumors and expresses a limited repertoire of latent proteins to avoid host immune surveillance. When the lytic cycle is triggered by some as-yet-unknown form of stimulation, lytic gene expression and progeny virus production commence. Thus far, the exact mechanism of EBV latency maintenance and the in vivo triggering signal for lytic induction have yet to be elucidated. Previously, we have shown that the EBV microRNA miR-BART20-5p directly targets the immediate early genes BRLF1 and BZLF1 as well as Bcl-2-associated death promoter (BAD) in EBV-associated gastric carcinoma. In this study, we found that both mRNA and protein levels of BRLF1 and BZLF1 were suppressed in cells following BAD knockdown and increased after BAD overexpression. Progeny virus production was also downregulated by specific knockdown of BAD. Our results demonstrated that caspase-3-dependent apoptosis is a prerequisite for BAD-mediated EBV lytic cycle induction. Therefore, our data suggest that miR-BART20-5p plays an important role in latency maintenance and tumor persistence of EBV-associated gastric carcinoma by inhibiting BAD-mediated caspase-3-dependent apoptosis, which would trigger immediate early gene expression. IMPORTANCE EBV has an ability to remain latent in host cells, including EBV-associated tumor cells hiding from immune surveillance. However, the exact molecular mechanisms of EBV latency maintenance remain poorly understood. Here, we demonstrated that miR-BART20-5p inhibited the expression of EBV immediate early genes indirectly, by suppressing BAD-induced caspase-3-dependent apoptosis, in addition to directly, as we previously reported. Our study suggests that EBV-associated tumor cells might endure apoptotic stress to some extent and remain latent with the aid of miR-BART20-5p. Blocking the expression or function of BART20-5p may expedite EBV-associated tumor cell death via immune attack and apoptosis. PMID:26581978

Trade-off between synergy and efficacy in combinations of HIV-1 latency-reversing agents.

PubMed

Gupta, Vipul; Dixit, Narendra M

2018-02-01

Eradicating HIV-1 infection is difficult because of the reservoir of latently infected cells that gets established soon after infection, remains hidden from antiretroviral drugs and host immune responses, and retains the capacity to reignite infection following the cessation of treatment. Drugs called latency-reversing agents (LRAs) are being developed to reactivate latently infected cells and render them susceptible to viral cytopathicity or immune killing. Whereas individual LRAs have failed to induce adequate reactivation, pairs of LRAs have been identified recently that act synergistically and hugely increase reactivation levels compared to individual LRAs. The maximum synergy achievable with LRA pairs is of clinical importance, as it would allow latency-reversal with minimal drug exposure. Here, we employed stochastic simulations of HIV-1 transcription and translation in latently infected cells to estimate this maximum synergy. We incorporated the predominant mechanisms of action of the two most promising classes of LRAs, namely, protein kinase C agonists and histone deacetylase inhibitors, and quantified the activity of individual LRAs in the two classes by mapping our simulations to corresponding in vitro experiments. Without any adjustable parameters, our simulations then quantitatively captured experimental observations of latency-reversal when the LRAs were used in pairs. Performing simulations representing a wide range of drug concentrations, we estimated the maximum synergy achievable with these LRA pairs. Importantly, we found with all the LRA pairs we considered that concentrations yielding the maximum synergy did not yield the maximum latency-reversal. Increasing concentrations to increase latency-reversal compromised synergy, unravelling a trade-off between synergy and efficacy in LRA combinations. The maximum synergy realizable with LRA pairs would thus be restricted by the desired level of latency-reversal, a constrained optimum we elucidated with our simulations. We expect this trade-off to be important in defining optimal LRA combinations that would maximize synergy while ensuring adequate latency-reversal.

A distinct subgroup of cardiomyopathy patients characterized by transcriptionally active cardiotropic erythrovirus and altered cardiac gene expression.

PubMed

Kuhl, U; Lassner, D; Dorner, A; Rohde, M; Escher, F; Seeberg, B; Hertel, E; Tschope, C; Skurk, C; Gross, U M; Schultheiss, H-P; Poller, W

2013-09-01

Recent studies have detected erythrovirus genomes in the hearts of cardiomyopathy and cardiac transplant patients. Assessment of the functional status of viruses may provide clinically important information beyond detection of the viral genomes. Here, we report transcriptional activation of cardiotropic erythrovirus to be associated with strongly altered myocardial gene expression in a distinct subgroup of cardiomyopathy patients. Endomyocardial biopsies (EMBs) from 415 consecutive cardiac erythrovirus (B19V)-positive patients with clinically suspected cardiomyopathy were screened for virus-encoded VP1/VP2 mRNA indicating transcriptional activation of the virus, and correlated with cardiac host gene expression patterns in transcriptionally active versus latent infections, and in virus-free control hearts. Transcriptional activity was detected in baseline biopsies of only 66/415 patients (15.9 %) harbouring erythrovirus. At the molecular level, significant differences between cardiac B19V-positive patients with transcriptionally active versus latent virus were revealed by expression profiling of EMBs. Importantly, latent B19V infection was indistinguishable from controls. Genes involved encode proteins of antiviral immune response, B19V receptor complex, and mitochondrial energy metabolism. Thus, functional mapping of erythrovirus allows definition of a subgroup of B19V-infected cardiomyopathy patients characterized by virus-encoded VP1/VP2 transcripts and anomalous host myocardial transcriptomes. Cardiac B19V reactivation from latency, as reported here for the first time, is a key factor required for erythrovirus to induce altered cardiac gene expression in a subgroup of cardiomyopathy patients. Virus genome detection is insufficient to assess pathogenic potential, but additional transcriptional mapping should be incorporated into future pathogenetic and therapeutic studies both in cardiology and transplantation medicine.

Use of PCR with Sequence-specific Primers for High-Resolution Human Leukocyte Antigen Typing of Patients with Narcolepsy

PubMed Central

Woo, Hye In; Joo, Eun Yeon; Lee, Kyung Wha

2012-01-01

Background Narcolepsy is a neurologic disorder characterized by excessive daytime sleepiness, symptoms of abnormal rapid eye movement (REM) sleep, and a strong association with HLA-DRB1*1501, -DQA1*0102, and -DQB1*0602. Here, we investigated the clinico-physical characteristics of Korean patients with narcolepsy, their HLA types, and the clinical utility of high-resolution PCR with sequence-specific primers (PCR-SSP) as a simple typing method for identifying DRB1*15/16, DQA1, and DQB1 alleles. Methods The study population consisted of 67 consecutively enrolled patients having unexplained daytime sleepiness and diagnosed narcolepsy based on clinical and neurological findings. Clinical data and the results of the multiple sleep latency test and polysomnography were reviewed, and HLA typing was performed using both high-resolution PCR-SSP and sequence-based typing (SBT). Results The 44 narcolepsy patients with cataplexy displayed significantly higher frequencies of DRB1*1501 (Pc= 0.003), DQA1*0102 (Pc=0.001), and DQB1*0602 (Pc=0.014) than the patients without cataplexy. Among patients carrying DRB1*1501-DQB1*0602 or DQA1*0102, the frequencies of a mean REM sleep latency of less than 20 min in nocturnal polysomnography and clinical findings, including sleep paralysis and hypnagogic hallucination were significantly higher. SBT and PCR-SSP showed 100% concordance for high-resolution typing of DRB1*15/16 alleles and DQA1 and DQB1 loci. Conclusions The clinical characteristics and somnographic findings of narcolepsy patients were associated with specific HLA alleles, including DRB1*1501, DQA1*0102, and DQB1*0602. Application of high-resolution PCR-SSP, a reliable and simple method, for both allele- and locus-specific HLA typing of DRB1*15/16, DQA1, and DQB1 would be useful for characterizing clinical status among subjects with narcolepsy. PMID:22259780

BZLF1, an Epstein-Barr virus immediate-early protein, induces p65 nuclear translocation while inhibiting p65 transcriptional function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrison, Thomas E.; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; Kenney, Shannon C.

We have previously demonstrated that the Epstein-Barr virus immediate-early BZLF1 protein interacts with, and is inhibited by, the NF-{kappa}B family member p65. However, the effects of BZLF1 on NF-{kappa}B activity have not been intensively studied. Here we show that BZLF1 inhibits p65-dependent gene expression. BZLF1 inhibited the ability of IL-1, as well as transfected p65, to activate the expression of two different NF-{kappa}B-responsive genes, ICAM-1 and I{kappa}B-{alpha}. BZLF1 also reduced the constitutive level of I{kappa}B-{alpha} protein in HeLa and A549 cells, and increased the amount of nuclear NF-{kappa}B to a similar extent as tumor necrosis factor-alpha (TNF-{alpha}) treatment. In spitemore » of this BZLF1-associated increase in the nuclear form of NF-{kappa}B, BZLF1 did not induce binding of NF-{kappa}B to NF-{kappa}B responsive promoters (as determined by chromatin immunoprecipitation assay) in vivo, although TNF-{alpha} treatment induced NF-{kappa}B binding as expected. Overexpression of p65 dramatically inhibited the lytic replication cycle of EBV in 293-EBV cells, confirming that NF-{kappa}B also inhibits BZLF1 transcriptional function. Our results are consistent with a model in which BZLF1 inhibits the transcriptional function of p65, resulting in decreased transcription of I{kappa}B-{alpha}, decreased expression of I{kappa}B-{alpha} protein, and subsequent translocation of NF-{kappa}B to the nucleus. This nuclear translocation of NF-{kappa}B may promote viral latency by negatively regulating BZLF1 transcriptional activity. In situations where p65 activity is limiting in comparison to BZLF1, the ability of BZLF1 to inhibit p65 transcriptional function may protect the virus from the host immune system during the lytic form of infection.« less

An acutely and latently expressed herpes simplex virus 2 viral microRNA inhibits expression of ICP34.5, a viral neurovirulence factor

PubMed Central

Tang, Shuang; Bertke, Andrea S.; Patel, Amita; Wang, Kening; Cohen, Jeffrey I.; Krause, Philip R.

2008-01-01

Latency-associated transcript (LAT) sequences regulate herpes simplex virus (HSV) latency and reactivation from sensory neurons. We found a HSV-2 LAT-related microRNA (miRNA) designated miR-I in transfected and infected cells in vitro and in acutely and latently infected ganglia of guinea pigs in vivo. miR-I is also expressed in human sacral dorsal root ganglia latently infected with HSV-2. miR-I is expressed under the LAT promoter in vivo in infected sensory ganglia. We also predicted and identified a HSV-1 LAT exon-2 viral miRNA in a location similar to miR-I, implying a conserved mechanism in these closely related viruses. In transfected and infected cells, miR-I reduces expression of ICP34.5, a key viral neurovirulence factor. We hypothesize that miR-I may modulate the outcome of viral infection in the peripheral nervous system by functioning as a molecular switch for ICP34.5 expression. PMID:18678906

Case-control study of the association between malignant brain tumours diagnosed between 2007 and 2009 and mobile and cordless phone use

PubMed Central

HARDELL, LENNART; CARLBERG, MICHAEL; SÖDERQVIST, FREDRIK; MILD, KJELL HANSSON

2013-01-01

Previous studies have shown a consistent association between long-term use of mobile and cordless phones and glioma and acoustic neuroma, but not for meningioma. When used these phones emit radiofrequency electromagnetic fields (RF-EMFs) and the brain is the main target organ for the hand-held phone. The International Agency for Research on Cancer (IARC) classified in May, 2011 RF-EMF as a group 2B, i.e. a ‘possible’ human carcinogen. The aim of this study was to further explore the relationship between especially long-term (>10 years) use of wireless phones and the development of malignant brain tumours. We conducted a new case-control study of brain tumour cases of both genders aged 18–75 years and diagnosed during 2007–2009. One population-based control matched on gender and age (within 5 years) was used to each case. Here, we report on malignant cases including all available controls. Exposures on e.g. use of mobile phones and cordless phones were assessed by a self-administered questionnaire. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index using the whole control sample. Of the cases with a malignant brain tumour, 87% (n=593) participated, and 85% (n=1,368) of controls in the whole study answered the questionnaire. The odds ratio (OR) for mobile phone use of the analogue type was 1.8, 95% confidence interval (CI)=1.04–3.3, increasing with >25 years of latency (time since first exposure) to an OR=3.3, 95% CI=1.6–6.9. Digital 2G mobile phone use rendered an OR=1.6, 95% CI=0.996–2.7, increasing with latency >15–20 years to an OR=2.1, 95% CI=1.2–3.6. The results for cordless phone use were OR=1.7, 95% CI=1.1–2.9, and, for latency of 15–20 years, the OR=2.1, 95% CI=1.2–3.8. Few participants had used a cordless phone for >20–25 years. Digital type of wireless phones (2G and 3G mobile phones, cordless phones) gave increased risk with latency >1–5 years, then a lower risk in the following latency groups, but again increasing risk with latency >15–20 years. Ipsilateral use resulted in a higher risk than contralateral mobile and cordless phone use. Higher ORs were calculated for tumours in the temporal and overlapping lobes. Using the meningioma cases in the same study as reference entity gave somewhat higher ORs indicating that the results were unlikely to be explained by recall or observational bias. This study confirmed previous results of an association between mobile and cordless phone use and malignant brain tumours. These findings provide support for the hypothesis that RF-EMFs play a role both in the initiation and promotion stages of carcinogenesis. PMID:24064953

Repressive LTR Nucleosome Positioning by the BAF Complex Is Required for HIV Latency

PubMed Central

Hakre, Shweta; Moshkin, Yuri; Verdin, Eric; Mahmoudi, Tokameh

2011-01-01

Persistence of a reservoir of latently infected memory T cells provides a barrier to HIV eradication in treated patients. Several reports have implicated the involvement of SWI/SNF chromatin remodeling complexes in restricting early steps in HIV infection, in coupling the processes of integration and remodeling, and in promoter/LTR transcription activation and repression. However, the mechanism behind the seemingly contradictory involvement of SWI/SNF in the HIV life cycle remains unclear. Here we addressed the role of SWI/SNF in regulation of the latent HIV LTR before and after transcriptional activation. We determined the predicted nucleosome affinity of the LTR sequence and found a striking reverse correlation when compared to the strictly positioned in vivo LTR nucleosomal structure; sequences encompassing the DNase hypersensitive regions displayed the highest nucleosome affinity, while the strictly positioned nucleosomes displayed lower affinity for nucleosome formation. To examine the mechanism behind this reverse correlation, we used a combinatorial approach to determine DNA accessibility, histone occupancy, and the unique recruitment and requirement of BAF and PBAF, two functionally distinct subclasses of SWI/SNF at the LTR of HIV-infected cells before and after activation. We find that establishment and maintenance of HIV latency requires BAF, which removes a preferred nucleosome from DHS1 to position the repressive nucleosome-1 over energetically sub-optimal sequences. Depletion of BAF resulted in de-repression of HIV latency concomitant with a dramatic alteration in the LTR nucleosome profile as determined by high resolution MNase nucleosomal mapping. Upon activation, BAF was lost from the HIV promoter, while PBAF was selectively recruited by acetylated Tat to facilitate LTR transcription. Thus BAF and PBAF, recruited during different stages of the HIV life cycle, display opposing function on the HIV promoter. Our data point to the ATP-dependent BRG1 component of BAF as a putative therapeutic target to deplete the latent reservoir in patients. PMID:22140357

Repressive LTR nucleosome positioning by the BAF complex is required for HIV latency.

PubMed

Rafati, Haleh; Parra, Maribel; Hakre, Shweta; Moshkin, Yuri; Verdin, Eric; Mahmoudi, Tokameh

2011-11-01

Persistence of a reservoir of latently infected memory T cells provides a barrier to HIV eradication in treated patients. Several reports have implicated the involvement of SWI/SNF chromatin remodeling complexes in restricting early steps in HIV infection, in coupling the processes of integration and remodeling, and in promoter/LTR transcription activation and repression. However, the mechanism behind the seemingly contradictory involvement of SWI/SNF in the HIV life cycle remains unclear. Here we addressed the role of SWI/SNF in regulation of the latent HIV LTR before and after transcriptional activation. We determined the predicted nucleosome affinity of the LTR sequence and found a striking reverse correlation when compared to the strictly positioned in vivo LTR nucleosomal structure; sequences encompassing the DNase hypersensitive regions displayed the highest nucleosome affinity, while the strictly positioned nucleosomes displayed lower affinity for nucleosome formation. To examine the mechanism behind this reverse correlation, we used a combinatorial approach to determine DNA accessibility, histone occupancy, and the unique recruitment and requirement of BAF and PBAF, two functionally distinct subclasses of SWI/SNF at the LTR of HIV-infected cells before and after activation. We find that establishment and maintenance of HIV latency requires BAF, which removes a preferred nucleosome from DHS1 to position the repressive nucleosome-1 over energetically sub-optimal sequences. Depletion of BAF resulted in de-repression of HIV latency concomitant with a dramatic alteration in the LTR nucleosome profile as determined by high resolution MNase nucleosomal mapping. Upon activation, BAF was lost from the HIV promoter, while PBAF was selectively recruited by acetylated Tat to facilitate LTR transcription. Thus BAF and PBAF, recruited during different stages of the HIV life cycle, display opposing function on the HIV promoter. Our data point to the ATP-dependent BRG1 component of BAF as a putative therapeutic target to deplete the latent reservoir in patients.

Latent herpes simplex virus 1 infection does not induce apoptosis in human trigeminal Ganglia.

PubMed

Himmelein, Susanne; Lindemann, Anja; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Hüfner, Katharina

2015-05-01

Herpes simplex virus 1 (HSV-1) can establish lifelong latency in human trigeminal ganglia. Latently infected ganglia contain CD8(+) T cells, which secrete granzyme B and are thus capable of inducing neuronal apoptosis. Using immunohistochemistry and single-cell reverse transcription-quantitative PCR (RT-qPCR), higher frequency and transcript levels of caspase-3 were found in HSV-1-negative compared to HSV-1-positive ganglia and neurons, respectively. No terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay-positive neurons were detected. The infiltrating T cells do not induce apoptosis in latently infected neurons. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Doxorubicin resistance in breast cancer is driven by light at night-induced disruption of the circadian melatonin signal.

PubMed

Xiang, Shulin; Dauchy, Robert T; Hauch, Adam; Mao, Lulu; Yuan, Lin; Wren, Melissa A; Belancio, Victoria P; Mondal, Debasis; Frasch, Tripp; Blask, David E; Hill, Steven M

2015-08-01

Chemotherapeutic resistance, particularly to doxorubicin (Dox), represents a major impediment to successfully treating breast cancer and is linked to elevated tumor metabolism and tumor over-expression and/or activation of various families of receptor- and non-receptor-associated tyrosine kinases. Disruption of circadian time structure and suppression of nocturnal melatonin production by dim light exposure at night (dLEN), as occurs with shift work, and/or disturbed sleep-wake cycles, is associated with a significantly increased risk of an array of diseases, including breast cancer. Melatonin inhibits human breast cancer growth via mechanisms that include the suppression of tumor metabolism and inhibition of expression or phospho-activation of the receptor kinases AKT and ERK1/2 and various other kinases and transcription factors. We demonstrate in tissue-isolated estrogen receptor alpha-positive (ERα+) MCF-7 human breast cancer xenografts, grown in nude rats maintained on a light/dark cycle of LD 12:12 in which dLEN is present during the dark phase (suppressed endogenous nocturnal melatonin), a significant shortening of tumor latency-to-onset, increased tumor metabolism and growth, and complete intrinsic resistance to Dox therapy. Conversely, a LD 12:12 dLEN environment incorporating nocturnal melatonin replacement resulted in significantly lengthened tumor latency-to-onset, tumor regression, suppression of nighttime tumor metabolism, and kinase and transcription factor phosphorylation, while Dox sensitivity was completely restored. Melatonin acts as both a tumor metabolic inhibitor and circadian-regulated kinase inhibitor to reestablish the sensitivity of breast tumors to Dox and drive tumor regression, indicating that dLEN-induced circadian disruption of nocturnal melatonin production contributes to a complete loss of tumor sensitivity to Dox chemotherapy. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Activation of HIV Transcription by the Viral Tat Protein Requires a Demethylation Step Mediated by Lysine-specific Demethylase 1 (LSD1/KDM1)

PubMed Central

Sakane, Naoki; Kwon, Hye-Sook; Pagans, Sara; Kaehlcke, Katrin; Mizusawa, Yasuhiro; Kamada, Masafumi; Lassen, Kara G.; Chan, Jonathan; Greene, Warner C.; Schnoelzer, Martina; Ott, Melanie

2011-01-01

The essential transactivator function of the HIV Tat protein is regulated by multiple posttranslational modifications. Although individual modifications are well characterized, their crosstalk and dynamics of occurrence during the HIV transcription cycle remain unclear. We examine interactions between two critical modifications within the RNA-binding domain of Tat: monomethylation of lysine 51 (K51) mediated by Set7/9/KMT7, an early event in the Tat transactivation cycle that strengthens the interaction of Tat with TAR RNA, and acetylation of lysine 50 (K50) mediated by p300/KAT3B, a later process that dissociates the complex formed by Tat, TAR RNA and the cyclin T1 subunit of the positive transcription elongation factor b (P-TEFb). We find K51 monomethylation inhibited in synthetic Tat peptides carrying an acetyl group at K50 while acetylation can occur in methylated peptides, albeit at a reduced rate. To examine whether Tat is subject to sequential monomethylation and acetylation in cells, we performed mass spectrometry on immunoprecipitated Tat proteins and generated new modification-specific Tat antibodies against monomethylated/acetylated Tat. No bimodified Tat protein was detected in cells pointing to a demethylation step during the Tat transactivation cycle. We identify lysine-specific demethylase 1 (LSD1/KDM1) as a Tat K51-specific demethylase, which is required for the activation of HIV transcription in latently infected T cells. LSD1/KDM1 and its cofactor CoREST associates with the HIV promoter in vivo and activate Tat transcriptional activity in a K51-dependent manner. In addition, small hairpin RNAs directed against LSD1/KDM1 or inhibition of its activity with the monoamine oxidase inhibitor phenelzine suppresses the activation of HIV transcription in latently infected T cells. Our data support the model that a LSD1/KDM1/CoREST complex, normally known as a transcriptional suppressor, acts as a novel activator of HIV transcription through demethylation of K51 in Tat. Small molecule inhibitors of LSD1/KDM1 show therapeutic promise by enforcing HIV latency in infected T cells. PMID:21876670

Latency reversal and viral clearance to cure HIV-1.

PubMed

Margolis, David M; Garcia, J Victor; Hazuda, Daria J; Haynes, Barton F

2016-07-22

Research toward a cure for human immunodeficiency virus type 1 (HIV-1) infection has joined prevention and treatment efforts in the global public health agenda. A major approach to HIV eradication envisions antiretroviral suppression, paired with targeted therapies to enforce the expression of viral antigen from quiescent HIV-1 genomes, and immunotherapies to clear latent infection. These strategies are targeted to lead to viral eradication--a cure for AIDS. Paired testing of latency reversal and clearance strategies has begun, but additional obstacles to HIV eradication may emerge. Nevertheless, there is reason for optimism that advances in long-acting antiretroviral therapy and HIV prevention strategies will contribute to efforts in HIV cure research and that the implementation of these efforts will synergize to markedly blunt the effect of the HIV pandemic on society. Copyright © 2016, American Association for the Advancement of Science.

An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression.

PubMed

Darcis, Gilles; Kula, Anna; Bouchat, Sophie; Fujinaga, Koh; Corazza, Francis; Ait-Ammar, Amina; Delacourt, Nadège; Melard, Adeline; Kabeya, Kabamba; Vanhulle, Caroline; Van Driessche, Benoit; Gatot, Jean-Stéphane; Cherrier, Thomas; Pianowski, Luiz F; Gama, Lucio; Schwartz, Christian; Vila, Jorge; Burny, Arsène; Clumeck, Nathan; Moutschen, Michel; De Wit, Stéphane; Peterlin, B Matija; Rouzioux, Christine; Rohr, Olivier; Van Lint, Carine

2015-07-01

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART) is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET) bromodomain inhibitors (BETi) are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb)-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC) agonists (prostratin, bryostatin-1 and ingenol-B), which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151)). Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA combinations exhibiting such a potent effect and represent a proof-of-concept for the co-administration of two different types of LRAs as a potential strategy to reduce the size of the latent HIV-1 reservoirs.

An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression

PubMed Central

Bouchat, Sophie; Fujinaga, Koh; Corazza, Francis; Ait-Ammar, Amina; Delacourt, Nadège; Melard, Adeline; Kabeya, Kabamba; Vanhulle, Caroline; Van Driessche, Benoit; Gatot, Jean-Stéphane; Cherrier, Thomas; Pianowski, Luiz F.; Gama, Lucio; Schwartz, Christian; Vila, Jorge; Burny, Arsène; Clumeck, Nathan; Moutschen, Michel; De Wit, Stéphane; Peterlin, B. Matija; Rouzioux, Christine; Rohr, Olivier; Van Lint, Carine

2015-01-01

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART) is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET) bromodomain inhibitors (BETi) are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb)-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC) agonists (prostratin, bryostatin-1 and ingenol-B), which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151)). Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA combinations exhibiting such a potent effect and represent a proof-of-concept for the co-administration of two different types of LRAs as a potential strategy to reduce the size of the latent HIV-1 reservoirs. PMID:26225566

Molecular analysis of critical sequences within the EBNA-2 type 1 gene from Epstein-Barr virus isolates from patients with infectious mononucleosis, tonsillar hyperplasia, and HIV infection.

PubMed

Al-Homsi, A S; Berger, C; van Baarle, D; Kersten, M J; Klein, M R; McQuain, C; van Oers, R; Knecht, H

1998-06-01

EBNA-2 is the first protein to be detected after infection of primary B lymphocytes by Epstein-Barr virus (EBV) and plays an essential role as transcriptional activator in EBV-induced lymphocyte transformation. We analysed by PCR and sequencing regions of the EBNA-2 type 1 gene from isolates from 13 children with infectious mononucleosis (IM), 6 children with tonsillar hyperplasia (TH), and 9 patients with HIV infection followed longitudinally. We found in all three groups of patients frequent non-silent point mutations at positions 48990, 48991, 49021, 49057, 49083, 49089, 49091, 49113, 49119, 49140, 49156, and a triplet insertion at position 49136. While 4 out of 13 samples from patients with IM showed a mosaic pattern suggesting co-existence of more than 1 substrain of EBNA-2 type 1, none of the samples from TH showed this pattern consistent with substrain selection during clinical latency. No sequence changes were noted over time in samples derived from patients with HIV infection. We conclude that in analogy to the coexistence of several subtypes of EBNA-1 in healthy EBV carriers, samples from IM can harbor more than one subtype of the EBNA-2 type 1 gene.

Decreased survival of glioma patients with astrocytoma grade IV (glioblastoma multiforme) associated with long-term use of mobile and cordless phones.

PubMed

Carlberg, Michael; Hardell, Lennart

2014-10-16

On 31 May 2011 the WHO International Agency for Research on Cancer (IARC) categorised radiofrequency electromagnetic fields (RF-EMFs) from mobile phones, and from other devices that emit similar non-ionising electromagnetic fields, as a Group 2B, i.e., a "possible", human carcinogen. A causal association would be strengthened if it could be shown that the use of wireless phones has an impact on the survival of glioma patients. We analysed survival of 1678 glioma patients in our 1997-2003 and 2007-2009 case-control studies. Use of wireless phones in the >20 years latency group (time since first use) yielded an increased hazard ratio (HR) = 1.7, 95% confidence interval (CI) = 1.2-2.3 for glioma. For astrocytoma grade IV (glioblastoma multiforme; n = 926) mobile phone use yielded HR = 2.0, 95% CI = 1.4-2.9 and cordless phone use HR = 3.4, 95% CI = 1.04-11 in the same latency category. The hazard ratio for astrocytoma grade IV increased statistically significant per year of latency for wireless phones, HR = 1.020, 95% CI = 1.007-1.033, but not per 100 h cumulative use, HR = 1.002, 95% CI = 0.999-1.005. HR was not statistically significant increased for other types of glioma. Due to the relationship with survival the classification of IARC is strengthened and RF-EMF should be regarded as human carcinogen requiring urgent revision of current exposure guidelines.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Togi, Sumihito; Nakasuji, Misa; Muromoto, Ryuta

Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded latency-associated nuclear antigen (LANA), which interacts with cellular proteins, plays a central role in modification of viral and/or cellular gene expression. Here, we show that LANA associates with glucocorticoid receptor (GR), and that LANA enhances the transcriptional activity of GR. Co-immunoprecipitation revealed a physical interaction between LANA and GR in transiently transfected 293T and HeLa cells. In human B-lymphoma cells, LANA overexpression enhanced GR activity and cell growth suppression following glucocorticoid stimulation. Furthermore, confocal microscopy showed that activated GR was bound to LANA and accumulated in the nucleus, leading to an increase in binding of activatedmore » GR to the glucocorticoid response element of target genes. Taken together, KSHV-derived LANA acts as a transcriptional co-activator of GR. Our results might suggest a careful use of glucocorticoids in the treatment of patients with KSHV-related malignancies such as Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman disease. - Highlights: • KSHV-LANA enhances the transcriptional activity of GR in 293T and HeLa cells. • KSHV-LANA physically associates with GR. • KSHV-LANA enhances GR activation and cell growth suppression in human B-lymphocytes. • KSHV-LANA influences the nuclear retention and DNA binding activity of GR.« less

Narcolepsy in Southern Chinese patients: clinical characteristics, HLA typing and seasonality of birth.

PubMed

Wing, Y K; Chen, L; Fong, S Y Y; Ng, M H L; Ho, C K W; Cheng, S H; Tang, N L S; Li, A M

2008-11-01

To report clinical characteristics, human leukocyte antigen (HLA) typing and seasonality of birth of a series of 54 Southern Chinese patients suffering from narcolepsy. All subjects underwent detailed medical and psychiatric interviews and a standardised nocturnal polysomnogram followed by a daytime Multiple Sleep Latency Test. Each subject also completed a set of sleep questionnaires. HLA typing was performed in 91% of subjects. A total of 78% and 22% of patients were diagnosed with suffering from cataplectic and non-cataplectic narcolepsy, respectively. The majority (n = 47, 87%) of patients were referred to our sleep clinic for excessive daytime sleepiness (EDS). The cataplectic narcolepsy differed from non-cataplectic narcolepsy by having more rapid eye movement (REM)-related clinical symptoms (more sleep paralysis and sleep-related hallucination) and sleep disturbances (shorter REM latency), as well as tighter association with HLA DQB1*0602. A bi-modal peak pattern was observed at 11 and 39 years old. A similar bi-modal pattern also occurred for EDS and cataplexy. Excess winter births were observed for this series of patients. 81% of patients with cataplectic narcolepsy were DQB1*0602-positive. There were no differences between early- and late-onset cases in the association with positive DQB1*0602 (71.4% vs 60%). Narcolepsy had prominent pernicious effects on various social, academic, family and mental aspects in our patients. In our Southern Chinese narcolepsy series, bi-modal peak pattern of age of onset, excess winter birth and tight association of HLA DQB1*0602 with cataplectic narcolepsy were found.

Reactivation of latent HIV-1 by a wide variety of butyric acid-producing bacteria.

PubMed

Imai, Kenichi; Yamada, Kiyoshi; Tamura, Muneaki; Ochiai, Kuniyasu; Okamoto, Takashi

2012-08-01

Latently infected cells harbor human immunodeficiency virus type 1 (HIV-1) proviral DNA copies integrated in heterochromatin, allowing persistence of transcriptionally silent proviruses. It is widely accepted that hypoacetylation of histone proteins by histone deacetylases (HDACs) is involved in maintaining the HIV-1 latency by repressing viral transcription. HIV-1 replication can be induced from latently infected cells by environmental factors, such as inflammation and co-infection with other microbes. It is known that a bacterial metabolite butyric acid inhibits catalytic action of HDAC and induces transcription of silenced genes including HIV-1 provirus. There are a number of such bacteria in gut, vaginal, and oral cavities that produce butyric acid during their anaerobic glycolysis. Since these organs are known to be the major site of HIV-1 transmission and its replication, we explored a possibility that explosive viral replication in these organs could be ascribable to butyric acid produced from anaerobic resident bacteria. In this study, we demonstrate that the culture supernatant of various bacteria producing butyric acid could greatly reactivate the latently-infected HIV-1. These bacteria include Fusobacterium nucleatum (commonly present in oral cavity, and gut), Clostridium cochlearium, Eubacterium multiforme (gut), and Anaerococcus tetradius (vagina). We also clarified that butyric acid in these culture supernatants could induce histone acetylation and HIV-1 replication by inhibiting HDAC. Our observations indicate that butyric acid-producing bacteria could be involved in AIDS progression by reactivating the latent HIV provirus and, subsequently, by eliminating such bacterial infection may contribute to the prevention of the AIDS development and transmission.

An animal model for human EBV-associated hemophagocytic syndrome: herpesvirus papio frequently induces fatal lymphoproliferative disorders with hemophagocytic syndrome in rabbits.

PubMed

Hayashi, K; Ohara, N; Teramoto, N; Onoda, S; Chen, H L; Oka, T; Kondo, E; Yoshino, T; Takahashi, K; Yates, J; Akagi, T

2001-04-01

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis. However, the animal model for EBV-AHS has not been developed. We reported the first animal model for EBV-AHS using rabbits infected with EBV-related herpesvirus of baboon (HVP). Eleven of 13 (85%) rabbits inoculated intravenously with HVP-producing cells developed fatal lymphoproliferative disorders (LPD) between 22 and 105 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in nine of these 11 rabbits. The peroral spray of cell-free HVP induced the virus infection with increased anti-EBV-viral capsid antigen-IgG titers in three of five rabbits, and two of these three infected rabbits died of LPD with HPS. Autopsy revealed hepatosplenomegaly and swollen lymph nodes. Atypical lymphoid T cells expressing EBV-encoded small RNA-1 infiltrated diffusely in many organs, frequently involving the lymph nodes, spleen, and liver. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by polymerase chain reaction or Southern blot analysis. Reverse transcriptase-polymerase chain reaction revealed both HVP-EBNA1 and HVP-EBNA2 transcripts, suggesting latency type III infection. These data indicate that the high rate of rabbit LPD with HPS induction is caused by HVP. This system is useful for studying the pathogenesis, prevention, and treatment of human EBV-AHS.

An Animal Model for Human EBV-Associated Hemophagocytic Syndrome

PubMed Central

Hayashi, Kazuhiko; Ohara, Nobuya; Teramoto, Norihiro; Onoda, Sachiyo; Chen, Hong-Li; Oka, Takashi; Kondo, Eisaku; Yoshino, Tadashi; Takahashi, Kiyoshi; Yates, John; Akagi, Tadaatsu

2001-01-01

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis. However, the animal model for EBV-AHS has not been developed. We reported the first animal model for EBV-AHS using rabbits infected with EBV-related herpesvirus of baboon (HVP). Eleven of 13 (85%) rabbits inoculated intravenously with HVP-producing cells developed fatal lymphoproliferative disorders (LPD) between 22 and 105 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in nine of these 11 rabbits. The peroral spray of cell-free HVP induced the virus infection with increased anti-EBV-viral capsid antigen-IgG titers in three of five rabbits, and two of these three infected rabbits died of LPD with HPS. Autopsy revealed hepatosplenomegaly and swollen lymph nodes. Atypical lymphoid T cells expressing EBV-encoded small RNA-1 infiltrated diffusely in many organs, frequently involving the lymph nodes, spleen, and liver. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by polymerase chain reaction or Southern blot analysis. Reverse transcriptase-polymerase chain reaction revealed both HVP-EBNA1 and HVP-EBNA2 transcripts, suggesting latency type III infection. These data indicate that the high rate of rabbit LPD with HPS induction is caused by HVP. This system is useful for studying the pathogenesis, prevention, and treatment of human EBV-AHS. PMID:11290571

Auditory brain stem response and cortical evoked potentials in children with type 1 diabetes mellitus.

PubMed

Radwan, Heba Mohammed; El-Gharib, Amani Mohamed; Erfan, Adel Ali; Emara, Afaf Ahmad

2017-05-01

Delay in ABR and CAEPs wave latencies in children with type 1DM indicates that there is abnormality in the neural conduction in DM patients. The duration of DM has greater effect on auditory function than the control of DM. Diabetes mellitus (DM) is a common endocrine and metabolic disorder. Evoked potentials offer the possibility to perform a functional evaluation of neural pathways in the central nervous system. To investigate the effect of type 1 diabetes mellitus (T1DM) on auditory brain stem response (ABR) and cortical evoked potentials (CAEPs). This study included two groups: a control group (GI), which consisted of 20 healthy children with normal peripheral hearing, and a study group (GII), which consisted of 30 children with type I DM. Basic audiological evaluation, ABR, and CAEPs were done in both groups. Delayed absolute latencies of ABR and CAEPs waves were found. Amplitudes showed no significant difference between both groups. Positive correlation was found between ABR wave latencies and duration of DM. No correlation was found between ABR, CAEPs, and glycated hemoglobin.

Increased Transcript Complexity in Genes Associated with Chronic Obstructive Pulmonary Disease

PubMed Central

Lackey, Lela; McArthur, Evonne; Laederach, Alain

2015-01-01

Genome-wide association studies aim to correlate genotype with phenotype. Many common diseases including Type II diabetes, Alzheimer’s, Parkinson’s and Chronic Obstructive Pulmonary Disease (COPD) are complex genetic traits with hundreds of different loci that are associated with varied disease risk. Identifying common features in the genes associated with each disease remains a challenge. Furthermore, the role of post-transcriptional regulation, and in particular alternative splicing, is still poorly understood in most multigenic diseases. We therefore compiled comprehensive lists of genes associated with Type II diabetes, Alzheimer’s, Parkinson’s and COPD in an attempt to identify common features of their corresponding mRNA transcripts within each gene set. The SERPINA1 gene is a well-recognized genetic risk factor of COPD and it produces 11 transcript variants, which is exceptional for a human gene. This led us to hypothesize that other genes associated with COPD, and complex disorders in general, are highly transcriptionally diverse. We found that COPD-associated genes have a statistically significant enrichment in transcript complexity stemming from a disproportionately high level of alternative splicing, however, Type II Diabetes, Alzheimer’s and Parkinson’s disease genes were not significantly enriched. We also identified a subset of transcriptionally complex COPD-associated genes (~40%) that are differentially expressed between mild, moderate and severe COPD. Although the genes associated with other lung diseases are not extensively documented, we found preliminary data that idiopathic pulmonary disease genes, but not cystic fibrosis modulators, are also more transcriptionally complex. Interestingly, complex COPD transcripts are more often the product of alternative acceptor site usage. To verify the biological importance of these alternative transcripts, we used RNA-sequencing analyses to determine that COPD-associated genes are frequently expressed in lung and liver tissues and are regulated in a tissue-specific manner. Additionally, many complex COPD-associated genes are spliced differently between COPD and non-COPD patients. Our analysis therefore suggests that post-transcriptional regulation, particularly alternative splicing, is an important feature specific to COPD disease etiology that warrants further investigation. PMID:26480348

Emotionality of Colors: An Implicit Link between Red and Dominance.

PubMed

Mentzel, Stijn V; Schücker, Linda; Hagemann, Norbert; Strauss, Bernd

2017-01-01

The color red has been shown to alter emotions, physiology, psychology, and behavior. Research has suggested that these alterations could possibly be due to a link between red and perceived dominance. In this study we examined if the color red is implicitly associated to the concept of dominance. In addition, we similarly hypothesized that blue is implicitly linked to rest. A modified Stroop word evaluation task was used in which 30 participants (23.07 ± 4.42 years) were asked to classify words shown in either red, blue, or gray (control condition), as being either dominant- or rest-related. The responses were recorded and analyzed for latency time and accuracy. The results revealed a significant word type × color interaction effect for both latency times, F (2,56) = 5.09, p = 0.009, [Formula: see text] = 0.15, and accuracy, F (1.614,45.193) = 8.57, p = 0.001, [Formula: see text] = 0.23. On average participants showed significantly shorter latency times and made less errors when categorizing dominance words shown in red, compared to blue and gray. The measured effects show strong evidence for an implicit red-dominance association and a partial red-rest disassociation. It is discussed that this association can possibly affect emotionality, with the presentation of red eliciting a dominant emotional and behavioral response.

ENDOTHELIN-STIMULATED HUMAN B-TYPE NATRIURETIC PEPTIDE GENE EXPRESSION IS MEDIATED BY YY1 IN ASSOCIATION WITH HDAC2

PubMed Central

Glenn, Denis J.; Wang, Feng; Chen, Songcang; Nishimoto, Minobu; Gardner, David G.

2009-01-01

Increased B-type natriuretic peptide (BNP) gene expression is regarded as one of the hallmarks of cardiac myocyte hypertrophy. Here we demonstrate that both basal and endothelin-1 (ET-1) -dependent stimulation of human (h) BNP gene transcription requires the presence of an intact Yin Yang 1 (YY1) binding site positioned at -62 bp relative to the transcription start site. Mutation of this site reduced both basal and stimulated hBNP promoter activity. This site was shown to bind YY1 both in vitro and within the context of the intact cell. The latter interaction increased following ET-1 treatment. Exposure to ET-1 also resulted in increased nuclear localization of YY1 and a reduction in acetylation of the YY1 protein. Overexpression of wild type YY1 increased both basal and endothelin-stimulated hBNP promoter activity, while a carboxy terminal deletion mutant of YY1 was devoid of activity. Treatment with the histone deacetylase inhibitor trichostatin A (TSA) resulted in decreased hBNP reporter activity. YY1 was shown to associate with histone deacetylase 2 (HDAC2), and HDAC2 was shown to associate directly with the hBNP promoter in the intact cell. Collectively these findings demonstrate that YY1 plays an important role in regulating the transcriptional activity of the hBNP gene promoter. These data suggest a model in which YY1 activates hBNP transcription through interaction with HDAC2. PMID:19139378

Lactic Acid Downregulates Viral MicroRNA To Promote Epstein-Barr Virus-Immortalized B Lymphoblastic Cell Adhesion and Growth.

PubMed

Mo, Xiaohui; Wei, Fang; Tong, Yin; Ding, Ling; Zhu, Qing; Du, Shujuan; Tan, Fei; Zhu, Caixia; Wang, Yuyan; Yu, Qian; Liu, Yeqiang; Robertson, Erle S; Yuan, Zhenghong; Cai, Qiliang

2018-05-01

High plasma lactate is associated with poor prognosis of many malignancies, but its role in virally mediated cancer progression and underlying molecular mechanisms are unclear. Epstein-Barr virus (EBV), the first human oncogenic virus, causes several cancers, including B-cell lymphoma. Here, we report that lactate dehydrogenase A (LDH-A) expression and lactate production are elevated in EBV-immortalized B lymphoblastic cells, and lactic acid (LA; acidic lactate) at low concentration triggers EBV-infected B-cell adhesion, morphological changes, and proliferation in vitro and in vivo Moreover, LA-induced responses of EBV-infected B cells uniquely occurs in viral latency type III, and it is dramatically associated with the inhibition of global viral microRNAs, particularly the miR-BHRF1 cluster, and the high expression of SMAD3 , JUN , and COL1A genes. The introduction of miR-BHRF1-1 blocks the LA-induced effects of EBV-infected B cells. Thus, this may be a novel mechanism to explain EBV-immortalized B lymphoblastic cell malignancy in an LA microenvironment. IMPORTANCE The tumor microenvironment is complicated, and lactate, which is created by cell metabolism, contributes to an acidic microenvironment that facilitates cancer progression. However, how LA operates in virus-associated cancers is unclear. Thus, we studied how EBV (the first tumor virus identified in humans; it is associated with many cancers) upregulates the expression of LDH-A and lactate production in B lymphoma cells. Elevated LA induces adhesion and the growth of EBV-infected B cells by inhibiting viral microRNA transcription. Thus, we offer a novel understanding of how EBV utilizes an acidic microenvironment to promote cancer development. Copyright © 2018 American Society for Microbiology.

LMO1 Synergizes with MYCN to Promote Neuroblastoma Initiation and Metastasis.

PubMed

Zhu, Shizhen; Zhang, Xiaoling; Weichert-Leahey, Nina; Dong, Zhiwei; Zhang, Cheng; Lopez, Gonzalo; Tao, Ting; He, Shuning; Wood, Andrew C; Oldridge, Derek; Ung, Choong Yong; van Ree, Janine H; Khan, Amish; Salazar, Brittany M; Lummertz da Rocha, Edroaldo; Zimmerman, Mark W; Guo, Feng; Cao, Hong; Hou, Xiaonan; Weroha, S John; Perez-Atayde, Antonio R; Neuberg, Donna S; Meves, Alexander; McNiven, Mark A; van Deursen, Jan M; Li, Hu; Maris, John M; Look, A Thomas

2017-09-11

A genome-wide association study identified LMO1, which encodes an LIM-domain-only transcriptional cofactor, as a neuroblastoma susceptibility gene that functions as an oncogene in high-risk neuroblastoma. Here we show that dβh promoter-mediated expression of LMO1 in zebrafish synergizes with MYCN to increase the proliferation of hyperplastic sympathoadrenal precursor cells, leading to a reduced latency and increased penetrance of neuroblastomagenesis. The transgenic expression of LMO1 also promoted hematogenous dissemination and distant metastasis, which was linked to neuroblastoma cell invasion and migration, and elevated expression levels of genes affecting tumor cell-extracellular matrix interaction, including loxl3, itga2b, itga3, and itga5. Our results provide in vivo validation of LMO1 as an important oncogene that promotes neuroblastoma initiation, progression, and widespread metastatic dissemination. Copyright © 2017 Elsevier Inc. All rights reserved.

A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrian

Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2more » oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. In conclusion, our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice.« less

A new role of SNAI2 in post-lactational involution of the mammary gland links it to luminal breast cancer development

PubMed Central

Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrián; Sáez-Freire, María del Mar; García-Cenador, Begoña; García-Criado, Javier; Pérez-Andrés, Martín; de Matos, Alberto Orfao; Cañamero, Marta; Mao, Jian-Hua; Gridley, Thomas; Castellanos-Martín, Andrés; Pérez-Losada, Jesús

2015-01-01

Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pre-tumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2 oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load- were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper post-lactational involution of the breast. At three days post-lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels pAKT1, resulting in decreased apoptosis. The presence of abundant non-involuted ducts was still present at 30 days post-lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres, and to an increase in the number of tumors. Our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of post-lactational involution and breast tumorigenesis in Snai2-null mutant mice. PMID:26096931

A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development

DOE PAGES

Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrian; ...

2015-06-22

Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2more » oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. In conclusion, our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice.« less

EBV-driven B-cell lymphoproliferative disorders: from biology, classification and differential diagnosis to clinical management

PubMed Central

Ok, Chi Young; Li, Ling; Young, Ken H

2015-01-01

Epstein–Barr virus (EBV) is a ubiquitous herpesvirus, affecting >90% of the adult population. EBV targets B-lymphocytes and achieves latent infection in a circular episomal form. Different latency patterns are recognized based on latent gene expression pattern. Latent membrane protein-1 (LMP-1) mimics CD40 and, when self-aggregated, provides a proliferation signal via activating the nuclear factor-kappa B, Janus kinase/signal transducer and activator of transcription, phosphoinositide 3-kinase/Akt (PI3K/Akt) and mitogen-activated protein kinase pathways to promote cellular proliferation. LMP-1 also induces BCL-2 to escape from apoptosis and gives a signal for cell cycle progression by enhancing cyclin-dependent kinase 2 and phosphorylation of retinoblastoma (Rb) protein and by inhibiting p16 and p27. LMP-2A blocks the surface immunoglobulin-mediated lytic cycle reactivation. It also activates the Ras/PI3K/Akt pathway and induces Bcl-xL expression to promote B-cell survival. Recent studies have shown that ebv-microRNAs can provide extra signals for cellular proliferation, cell cycle progression and anti-apoptosis. EBV is well known for association with various types of B-lymphocyte, T-lymphocyte, epithelial cell and mesenchymal cell neoplasms. B-cell lymphoproliferative disorders encompass a broad spectrum of diseases, from benign to malignant. Here we review our current understanding of EBV-induced lymphomagenesis and focus on biology, diagnosis and management of EBV-associated B-cell lymphoproliferative disorders. PMID:25613729

Epstein-Barr Virus MicroRNA miR-BART20-5p Suppresses Lytic Induction by Inhibiting BAD-Mediated caspase-3-Dependent Apoptosis.

PubMed

Kim, Hyoji; Choi, Hoyun; Lee, Suk Kyeong

2016-02-01

Epstein-Barr virus (EBV) is a human gammaherpesvirus associated with a variety of tumor types. EBV can establish latency or undergo lytic replication in host cells. In general, EBV remains latent in tumors and expresses a limited repertoire of latent proteins to avoid host immune surveillance. When the lytic cycle is triggered by some as-yet-unknown form of stimulation, lytic gene expression and progeny virus production commence. Thus far, the exact mechanism of EBV latency maintenance and the in vivo triggering signal for lytic induction have yet to be elucidated. Previously, we have shown that the EBV microRNA miR-BART20-5p directly targets the immediate early genes BRLF1 and BZLF1 as well as Bcl-2-associated death promoter (BAD) in EBV-associated gastric carcinoma. In this study, we found that both mRNA and protein levels of BRLF1 and BZLF1 were suppressed in cells following BAD knockdown and increased after BAD overexpression. Progeny virus production was also downregulated by specific knockdown of BAD. Our results demonstrated that caspase-3-dependent apoptosis is a prerequisite for BAD-mediated EBV lytic cycle induction. Therefore, our data suggest that miR-BART20-5p plays an important role in latency maintenance and tumor persistence of EBV-associated gastric carcinoma by inhibiting BAD-mediated caspase-3-dependent apoptosis, which would trigger immediate early gene expression. EBV has an ability to remain latent in host cells, including EBV-associated tumor cells hiding from immune surveillance. However, the exact molecular mechanisms of EBV latency maintenance remain poorly understood. Here, we demonstrated that miR-BART20-5p inhibited the expression of EBV immediate early genes indirectly, by suppressing BAD-induced caspase-3-dependent apoptosis, in addition to directly, as we previously reported. Our study suggests that EBV-associated tumor cells might endure apoptotic stress to some extent and remain latent with the aid of miR-BART20-5p. Blocking the expression or function of BART20-5p may expedite EBV-associated tumor cell death via immune attack and apoptosis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Decreased Survival of Glioma Patients with Astrocytoma Grade IV (Glioblastoma Multiforme) Associated with Long-Term Use of Mobile and Cordless Phones

PubMed Central

Carlberg, Michael; Hardell, Lennart

2014-01-01

On 31 May 2011 the WHO International Agency for Research on Cancer (IARC) categorised radiofrequency electromagnetic fields (RF-EMFs) from mobile phones, and from other devices that emit similar non-ionising electromagnetic fields, as a Group 2B, i.e., a “possible”, human carcinogen. A causal association would be strengthened if it could be shown that the use of wireless phones has an impact on the survival of glioma patients. We analysed survival of 1678 glioma patients in our 1997–2003 and 2007–2009 case-control studies. Use of wireless phones in the >20 years latency group (time since first use) yielded an increased hazard ratio (HR) = 1.7, 95% confidence interval (CI) = 1.2–2.3 for glioma. For astrocytoma grade IV (glioblastoma multiforme; n = 926) mobile phone use yielded HR = 2.0, 95% CI = 1.4–2.9 and cordless phone use HR = 3.4, 95% CI = 1.04–11 in the same latency category. The hazard ratio for astrocytoma grade IV increased statistically significant per year of latency for wireless phones, HR = 1.020, 95% CI = 1.007–1.033, but not per 100 h cumulative use, HR = 1.002, 95% CI = 0.999–1.005. HR was not statistically significant increased for other types of glioma. Due to the relationship with survival the classification of IARC is strengthened and RF-EMF should be regarded as human carcinogen requiring urgent revision of current exposure guidelines. PMID:25325361

Food insecurity is associated with poor sleep outcomes among US adults.

PubMed

Ding, Meng; Keiley, Margaret K; Garza, Kimberly B; Duffy, Patricia A; Zizza, Claire A

2015-03-01

Although food insecure (FI) adults are at risk of chronic conditions, little research attention is given to their health behaviors, such as sleep. We examined the associations between adult food security status and sleep duration, sleep latency, and sleep complaints reported to a health care professional. Our population-based sample included 5637 men and 5264 women (≥22 y) who participated in the NHANES 2005-2010. Food security status was assessed with USDA's 10-item adult Food Security Survey Module. Self-reported information about sleep duration, sleep latency, and sleep complaints to a health care professional were used as sleep outcomes. Multiple linear, stratified by sex, and logistic regression models were used to estimate the association between food security status and the 3 sleep outcomes. Very low food secure (FS) women reported significantly shorter sleep duration than fully FS women (difference: -30 ± 5.2 min; P < 0.01); however, no relation to sleep duration was observed among men. Among men, participants who were marginally FS (4 ± 1.1 min), low FS (4 ± 1.7 min), and very low FS (5 ± 1.8 min) reported significantly longer sleep latency than fully FS men (P < 0.05), but no association with sleep latency was observed among women. The divergent patterns in sleep duration and latency were likely because of our reference groups reporting undesirable sleep outcomes; fully FS men reported inadequate sleep and fully FS women reported long sleep latency. Among both men and women, marginally FS (OR: 1.64; 95% CI: 1.24, 2.16), low FS (OR: 1.63; 95% CI: 1.16, 2.30), and very low FS (OR: 1.99; 95% CI: 1.36, 2.92) participants were more likely to report sleep complaints than their fully FS counterparts (P < 0.05). Poor sleep quantity and quality may predispose FI adults to adverse health outcomes. © 2015 American Society for Nutrition.

Anytime Prediction: Efficient Ensemble Methods for Any Computational Budget

DTIC Science & Technology

2014-01-21

difficult problem and is the focus of this work. 1.1 Motivation The number of machine learning applications which involve real time and latency sensitive pre...significantly increasing latency , and the computational costs associated with hosting a service are often critical to its viability. For such...balancing training costs, concerns such as scalability and tractability are often more important, as opposed to factors such as latency which are more

Inflammatory and neurodegeneration markers during asymptomatic HSV-1 reactivation.

PubMed

Martin, Carolina; Aguila, Blanca; Araya, Paulina; Vio, Karin; Valdivia, Sharin; Zambrano, Angara; Concha, Margarita I; Otth, Carola

2014-01-01

Currently, it is unclear whether asymptomatic recurrent reactivations of herpes simplex virus type 1 (HSV-1) occur in the central nervous systems of infected people, and if these events could lead to a progressive deterioration of neuronal function. In this context, HSV-1 constitutes an important candidate to be included among the risk factors for the development of neuropathies associated with chronic neuroinflammation. The aim of this study was to assess in vivo inflammatory and neurodegenerative markers in the brain during productive and latent HSV-1 infection using a mouse model of herpes simplex encephalitis. Neuroinflammation and neurodegeneration markers were evaluated in mice trigeminal ganglia and cerebral cortex during HSV-1 infection, by immunohistochemistry, western blot, and RT-PCR. Neuronal ICP4 viral antigen expression indicative of a reactivation episode during asymptomatic latency of HSV-1 infection in mice was accompanied by upregulation of neuroinflammatory (toll-like receptor-4, interferon α/β, and p-IRF3) and early neurodegenerative markers (phospho-tau and TauC3). HSV-1 reactivation from latency induced neuroinflammatory and neurodegenerative markers in the brain of asymptomatic mice suggesting that recurrent reactivations could be associated with cumulative neuronal dysfunctions.

Human Cytomegalovirus Major Immediate Early 1 Protein Targets Host Chromosomes by Docking to the Acidic Pocket on the Nucleosome Surface

PubMed Central

Mücke, Katrin; Paulus, Christina; Bernhardt, Katharina; Gerrer, Katrin; Schön, Kathrin; Fink, Alina; Sauer, Eva-Maria; Asbach-Nitzsche, Alexandra; Harwardt, Thomas; Kieninger, Bärbel; Kremer, Werner; Kalbitzer, Hans Robert

2014-01-01

The 72-kDa immediate early 1 (IE1) protein encoded by human cytomegalovirus (hCMV) is a nuclearly localized promiscuous regulator of viral and cellular transcription. IE1 has long been known to associate with host mitotic chromatin, yet the mechanisms underlying this interaction have not been specified. In this study, we identify the cellular chromosome receptor for IE1. We demonstrate that the viral protein targets human nucleosomes by directly binding to core histones in a nucleic acid-independent manner. IE1 exhibits two separable histone-interacting regions with differential binding specificities for H2A-H2B and H3-H4. The H2A-H2B binding region was mapped to an evolutionarily conserved 10-amino-acid motif within the chromatin-tethering domain (CTD) of IE1. Results from experimental approaches combined with molecular modeling indicate that the IE1 CTD adopts a β-hairpin structure, docking with the acidic pocket formed by H2A-H2B on the nucleosome surface. IE1 binds to the acidic pocket in a way similar to that of the latency-associated nuclear antigen (LANA) of the Kaposi's sarcoma-associated herpesvirus. Consequently, the IE1 and LANA CTDs compete for binding to nucleosome cores and chromatin. Our work elucidates in detail how a key viral regulator is anchored to human chromosomes and identifies the nucleosomal acidic pocket as a joint target of proteins from distantly related viruses. Based on the striking similarities between the IE1 and LANA CTDs and the fact that nucleosome targeting by IE1 is dispensable for productive replication even in “clinical” strains of hCMV, we speculate that the two viral proteins may serve analogous functions during latency of their respective viruses. PMID:24227840

Pooled analysis of case-control studies on malignant brain tumours and the use of mobile and cordless phones including living and deceased subjects.

PubMed

Hardell, Lennart; Carlberg, Michael; Hansson Mild, Kjell

2011-05-01

We studied the association between use of mobile and cordless phones and malignant brain tumours. Pooled analysis was performed of two case-control studies on patients with malignant brain tumours diagnosed during 1997-2003 and matched controls alive at the time of study inclusion and one case-control study on deceased patients and controls diagnosed during the same time period. Cases and controls or relatives to deceased subjects were interviewed using a structured questionnaire. Replies were obtained for 1,251 (85%) cases and 2,438 (84%) controls. The risk increased with latency period and cumulative use in hours for both mobile and cordless phones. Highest risk was found for the most common type of glioma, astrocytoma, yielding in the >10 year latency group for mobile phone use odds ratio (OR) = 2.7, 95% confidence interval (CI) = 1.9-3.7 and cordless phone use OR = 1.8, 95% CI = 1.2-2.9. In a separate analysis, these phone types were independent risk factors for glioma. The risk for astrocytoma was highest in the group with first use of a wireless phone before the age of 20; mobile phone use OR = 4.9, 95% CI = 2.2-11, cordless phone use OR = 3.9, 95% CI = 1.7-8.7. In conclusion, an increased risk was found for glioma and use of mobile or cordless phone. The risk increased with latency time and cumulative use in hours and was highest in subjects with first use before the age of 20.

Cognition and event-related potentials in adult-onset non-demented myotonic dystrophy type 1.

PubMed

Tanaka, H; Arai, M; Harada, M; Hozumi, A; Hirata, K

2012-02-01

To clarify the cognitive and event-related potentials (ERPs) profiles of adult-onset genetically-proven non-demented myotonic dystrophy type 1 (DM1). Fourteen DM1 patients and matched 14 normal controls were enrolled. DM1 patients were compared with normal controls, using a variety of neuropsychological tests; an auditory "oddball" counting paradigm for the ERPs, and low-resolution brain electromagnetic tomography (LORETA). For patients, ERPs and neuropsychological parameters were correlated with CTG repeat size, duration of illness, grip strength, and arterial blood gas analysis. Frontal lobe dysfunction, prolonged N1 latency, and attenuated N2/P3 amplitudes were observed in DM1. Longer CTG repeat size was associated with fewer categories achieved on Wisconsin Card Sorting Test. Greater grip strength was associated with better scores on color-word "interference" of Stroop test. P3 latency was negatively correlated with PaO(2). LORETA revealed significant hypoactivities at the orbitofrontal and medial temporal lobe, cingulate, and insula. There was no correlation between ERPs and CTG expansion. Adult-onset non-demented DM1 presented frontal lobe dysfunction. Absence of correlations between CTG repeat size and objective ERP parameters suggested CTG expansion in lymphocytes does not directly contribute to cognitive dysfunction. CTG expansion in lymphocytes does not directly contribute to cognitive dysfunction of adult-onset non-demented DM1. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Conditional mutagenesis in vivo reveals cell type- and infection stage-specific requirements for LANA in chronic MHV68 infection

PubMed Central

Salinas, Eduardo; Sifford, Jeffrey M.; Oldenburg, Darby G.

2018-01-01

Gammaherpesvirus (GHV) pathogenesis is a complex process that involves productive viral replication, dissemination to tissues that harbor lifelong latent infection, and reactivation from latency back into a productive replication cycle. Traditional loss-of-function mutagenesis approaches in mice using murine gammaherpesvirus 68 (MHV68), a model that allows for examination of GHV pathogenesis in vivo, have been invaluable for defining requirements for specific viral gene products in GHV infection. But these approaches are insufficient to fully reveal how viral gene products contribute when the encoded protein facilitates multiple processes in the infectious cycle and when these functions vary over time and from one host tissue to another. To address this complexity, we developed an MHV68 genetic platform that enables cell-type-specific and inducible viral gene deletion in vivo. We employed this system to re-evaluate functions of the MHV68 latency-associated nuclear antigen (mLANA), a protein with roles in both viral replication and latency. Cre-mediated deletion in mice of loxP-flanked ORF73 demonstrated the necessity of mLANA in B cells for MHV68 latency establishment. Impaired latency during the transition from draining lymph nodes to blood following mLANA deletion also was observed, supporting the hypothesis that B cells are a major conduit for viral dissemination. Ablation of mLANA in infected germinal center (GC) B cells severely impaired viral latency, indicating the importance of viral passage through the GC for latency establishment. Finally, induced ablation of mLANA during latency resulted in complete loss of affected viral genomes, indicating that mLANA is critically important for maintenance of viral genomes during stable latency. Collectively, these experiments provide new insights into LANA homolog functions in GHV colonization of the host and highlight the potential of a new MHV68 genetic platform to foster a more complete understanding of viral gene functions at discrete stages of GHV pathogenesis. PMID:29364981

The effects of age and mood on saccadic function in older individuals.

PubMed

Shafiq-Antonacci, R; Maruff, P; Whyte, S; Tyler, P; Dudgeon, P; Currie, J

1999-11-01

To investigate the effect of age and mood on saccadic function, we recorded prosaccades, predictive saccades, and antisaccades from 238 cognitively normal, physically healthy volunteers aged 44 to 85 years old. Mood levels were measured using the State-Trait Anxiety Inventory and Center for Epidemiological Studies Depression Scale inventories. Small, but significant, positive relationships with age were observed for the mean latency and associated variability of latency for all types of saccades, as well as the antisaccade error rate. Saccade velocity or accuracy was unaffected by age. Increasing levels of depression had a minor negative influence on the antisaccade latency, whereas increasing levels of anxiety raised the antisaccade error rate marginally.

Single-cell analysis of Daxx and ATRX-dependent transcriptional repression

PubMed Central

Newhart, Alyshia; Rafalska-Metcalf, Ilona U.; Yang, Tian; Negorev, Dmitri G.; Janicki, Susan M.

2012-01-01

Summary Histone H3.3 is a constitutively expressed H3 variant implicated in the epigenetic inheritance of chromatin structures. Recently, the PML-nuclear body (PML-NB)/Nuclear Domain 10 (ND10) proteins, Daxx and ATRX, were found to regulate replication-independent histone H3.3 chromatin assembly at telomeres and pericentric heterochromatin. As it is not completely understood how PML-NBs/ND10s regulate transcription and resistance to viral infection, we have used a CMV-promoter-regulated inducible transgene array, at which Daxx and ATRX are enriched, to delineate the mechanisms through which they regulate transcription. When integrated into HeLa cells, which express both Daxx and ATRX, the array is refractory to activation. However, transcription can be induced when ICP0, the HSV-1 E3 ubiquitin ligase required to reverse latency, is expressed. As ATRX and Daxx are depleted from the activated array in ICP0-expressing HeLa cells, this suggests that they are required to maintain a repressed chromatin environment. As histone H3.3 is strongly recruited to the ICP0-activated array but does not co-localize with the DNA, this also suggests that chromatin assembly is blocked during activation. The conclusion that the Daxx and ATRX pathway is required for transcriptional repression and chromatin assembly at this site is further supported by the finding that an array integrated into the ATRX-negative U2OS cell line can be robustly activated and that histone H3.3 is similarly recruited and unincorporated into the chromatin. Therefore, this study has important implications for understanding gene silencing, viral latency and PML-NB/ND10 function. PMID:22976303

Short- and long-latency auditory evoked potentials in individuals with vestibular dysfunction.

PubMed

Santos Filha, Valdete Alves Valentins Dos; Bruckmann, Mirtes; Garcia, Michele Vargas

2018-01-01

Purpose Evaluate the auditory pathway at the brainstem and cortical levels in individuals with peripheral vestibular dysfunction. Methods The study sample was composed 19 individuals aged 20-80 years that presented exam results suggestive of Peripheral Vestibular Disorder (PVD) or Vestibular Dysfunction (VD). Participants underwent evaluation of the auditory pathway through Brainstem Auditory Evoked Potentials (BAEP) (short latency) and P1, N1, P2, N2, and P300 cortical potentials (long latency). Results Nine individuals presented diagnosis of VD and 10 participants were diagnosed with PVD. The overall average of the long latency potentials of the participants was within the normal range, whereas an increased mean was observed in the short latency of waves III and V of the left ear, as well as in the I - III interpeak interval of both ears. Association of the auditory potentials with VD and PVD showed statistically significant correlation only in the III - V interpeak interval of the right ear for short latency. Comparison between the long and short latencies in the groups showed differences between VD and PVD, but without statistical significance. Conclusion No statistically significant correlation was observed between VD/PVD and the auditory evoked potentials; however, for the long latency potentials, individuals with VD presented higher latency in P1, N1, P2, and N2, where as participants with PVD showed higher latency in P300. In the short latency potentials, there was an increase in the absolute latencies in the VD group and in the interpeak intervals in the PVD group.

Infected Peripheral Blood Mononuclear Cells Transmit Latent Varicella Zoster Virus Infection to the Guinea Pig Enteric Nervous System

PubMed Central

Gan, Lin; Wang, Mingli; Chen, Jason J.; Gershon, Michael D.; Gershon, Anne A.

2014-01-01

Latent wild-type (WT) and vaccine (vOka) varicella-zoster virus (VZV) are found in the human enteric nervous system (ENS). VZV also infects guinea pig enteric neurons in vitro, establishes latency and can be reactivated. We therefore determined whether lymphocytes infected in vitro with VZV secrete infectious virions and can transfer infection in vivo to the ENS of recipient guinea pigs. T lymphocytes (CD3-immunoreactive) were preferentially infected following co-culture of guinea pig or human peripheral blood mononuclear cells with VZV-infected HELF. VZV proliferated in the infected T cells and expressed immediate early and late VZV genes. Electron microscopy confirmed that VZV-infected T cells produced encapsulated virions. Extracellular virus, however, was pleomorphic, suggesting degradation occurred prior to release, which was confirmed by the failure of VZV-infected T cells to secrete infectious virions. Intravenous injection of WT- or vOka-infected PBMCs, nevertheless, transmitted VZV to recipient animals (guinea pig > human lymphocytes). Two days post-inoculation, lung and liver, but not gut, contained DNA and transcripts encoding ORFs 4, 40, 66 and 67. Twenty-eight days after infection, gut contained DNA and transcripts encoding ORFs 4 and 66 but neither DNA nor transcripts could any longer be found in lung or liver. In situ hybridization revealed VZV DNA in enteric neurons, which also expressed ORF63p (but not ORF68p) immunoreactivity. Observations suggest that VZV infects T cells, which can transfer VZV to and establish latency in enteric neurons in vivo. Guinea pigs may be useful for studies of VZV pathogenesis in the ENS. PMID:24965252

78 FR 49308 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... latency fiber connection option, and provide a waiver of installation fees for subscriptions through..., including a 40Gb fiber connection, a 10Gb fiber connection, a 1Gb fiber connection, and a 1Gb copper... fiber connection offering, which uses new ultra- low latency switches.\\4\\ A switch is a type of network...

Morning-evening preference: sleep pattern spectrum and lifestyle habits among Japanese junior high school pupils.

PubMed

Gaina, Alexandru; Sekine, Michikazu; Kanayama, Hitomi; Takashi, Yamagami; Hu, Lizhen; Sengoku, Kayo; Kagamimori, Sadanobu

2006-01-01

We surveyed the sleep-wake patterns and lifestyle habits in a sample of Japanese first to third year junior high school children (n=638, age 12 to 15 yrs), of whom 29.3% were evening type, 64.1% intermediate type, and 6.6% morning type in preference. The morningness-eveningness (M-E) score was lower (more evening typed), 16.1 vs. 15.4 in first compared to third year students. There were significant gender differences, with girls showing a greater evening preference. Evening preference was associated with longer sleep latency, shortened sleep duration during schooldays and weekends, bad morning feeling, and episodes of daytime sleepiness. In contrast, morning preference was associated with higher sleep drive and better sleep-wake parameters and lifestyle habits. Our results suggest the morning preference should be promoted among junior high school children to increase the likelihood of more regular sleep-wake patterns and lifestyle habits.

[NARCOLEPSY WITH CATAPLEXY: TYPE 1 NARCOLEPSY].

PubMed

Dauvilliers, Yves; Lopez, Régis

2016-06-01

Narcolepsy with cataplexy or narcolepsy type 1 in a rare, disabling sleep disorder, with a prevalence of 20 to 30 per 100,000. Its onset peaks in the second decade. The main features are excessive daytime sleepiness and cataplexy or sudden less of muscle tone triggered by emotional situations. Other less consistent symptoms include hypnagogic hallucinations, sleep paralysis, disturbed nighttime sleep, and weight gain. Narcolepsy with cataplexy remains a clinical diagnosis but nighttime and daytime polysomnography (multiple sleep latency tests) are useful to document mean sleep latency below 8 min and at least two sleep-onset REM periods. HLA typing shows an association with HLA DQB1*0602 in more than 92% of cases but was not included in the new diagnostic criteria. In contrast, a low hypocretin-1/orexin-A levels (values below 110 pg/mL) in the cerebrospinal fluid was highly specific for narcolepsy with cataplexy and was included in the recent diagnostic criteria for narcolepsy. The deficiency of the hypocretin system is well-established in human narcoleptics with a reduction of cerebrospinal fluid hypocretin levels in relation with an early loss of hypocretin neurons. The cause of human narcolepsy remains unknown, however an autoimmune process in most probable acting on a highly genetic background with environmental factors such as streptococcal infections, and H1N1 AS03-adjuvanted vaccine named Pandemrix.

Tax relieves transcriptional repression by promoting histone deacetylase 1 release from the human T-cell leukemia virus type 1 long terminal repeat.

PubMed

Lu, Hanxin; Pise-Masison, Cynthia A; Linton, Rebecca; Park, Hyeon Ung; Schiltz, R Louis; Sartorelli, Vittorio; Brady, John N

2004-07-01

Expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated by the viral transcriptional activator Tax. Tax activates viral transcription through interaction with the cellular transcription factor CREB and the coactivators CBP/p300. In this study, we have analyzed the role of histone deacetylase 1 (HDAC1) on HTLV-1 gene expression from an integrated template. First we show that trichostatin A, an HDAC inhibitor, enhances Tax expression in HTLV-1-transformed cells. Second, using a cell line containing a single-copy HTLV-1 long terminal repeat, we demonstrate that overexpression of HDAC1 represses Tax transactivation. Furthermore, a chromatin immunoprecipitation assay allowed us to analyze the interaction of transcription factors, coactivators, and HDACs with the basal and activated HTLV-1 promoter. We demonstrate that HDAC1 is associated with the inactive, but not the Tax-transactivated, HTLV-1 promoter. In vitro and in vivo glutathione S-transferase-Tax pull-down and coimmunoprecipitation experiments demonstrated that there is a direct physical association between Tax and HDAC1. Importantly, biotinylated chromatin pull-down assays demonstrated that Tax inhibits and/or dissociates the binding of HDAC1 to the HTLV-1 promoter. Our results provide evidence that Tax interacts directly with HDAC1 and regulates binding of the repressor to the HTLV-1 promoter.

Molecular Basis of Latency in Pathogenic Human Viruses

NASA Astrophysics Data System (ADS)

Garcia-Blanco, Mariano A.; Cullen, Bryan R.

1991-11-01

Several human viruses are able to latently infect specific target cell populations in vivo. Analysis of the replication cycles of herpes simplex virus, Epstein-Barr virus, and human immunodeficiency virus suggests that the latent infections established by these human pathogens primarily result from a lack of host factors critical for the expression of viral early gene products. The subsequent activation of specific cellular transcription factors in response to extracellular stimuli can induce the expression of these viral regulatory proteins and lead to a burst of lytic viral replication. Latency in these eukaryotic viruses therefore contrasts with latency in bacteriophage, which is maintained primarily by the expression of virally encoded repressors of lytic replication.

Hypocretin-1 Levels Associate with Fragmented Sleep in Patients with Narcolepsy Type 1.

PubMed

Alakuijala, Anniina; Sarkanen, Tomi; Partinen, Markku

2016-05-01

We aimed to analyze nocturnal sleep characteristics of patients with narcolepsy type 1 (narcolepsy with cataplexy) measured by actigraphy in respect to cerebrospinal fluid hypocretin-1 levels of the same patients. Actigraphy recording of 1-2 w and hypocretin-1 concentration analysis were done to thirty-six unmedicated patients, aged 7 to 63 y, 50% female. Twenty-six of them had hypocretin-1 levels under 30 pg/mL and the rest had levels of 31-79 pg/mL. According to actigraphy, patients with very low hypocretin levels had statistically significantly longer sleep latency (P = 0.033) and more fragmented sleep, indicated by both the number of immobile phases of 1 min (P = 0.020) and movement + fragmentation index (P = 0.049). There were no statistically significant differences in the actual sleep time or circadian rhythm parameters measured by actigraphy. Actigraphy gives additional information about the stabilization of sleep in patients with narcolepsy type 1. Very low hypocretin levels associate with more wake intruding into sleep. © 2016 Associated Professional Sleep Societies, LLC.

Tissue-Specific and Genetic Regulation of Insulin Sensitivity-Associated Transcripts in African Americans

PubMed Central

Sharma, Neeraj K.; Sajuthi, Satria P.; Chou, Jeff W.; Calles-Escandon, Jorge; Demons, Jamehl; Rogers, Samantha; Ma, Lijun; Palmer, Nicholette D.; McWilliams, David R.; Beal, John; Comeau, Mary E.; Cherry, Kristina; Hawkins, Gregory A.; Menon, Lata; Kouba, Ethel; Davis, Donna; Burris, Marcie; Byerly, Sara J.; Easter, Linda; Bowden, Donald W.; Freedman, Barry I.; Langefeld, Carl D.

2016-01-01

Context: Compared with European Americans, African Americans (AAs) are more insulin resistant, have a higher insulin secretion response to glucose, and develop type 2 diabetes more often. Molecular processes and/or genetic variations contributing to altered glucose homeostasis in high-risk AAs remain uncharacterized. Objective: Adipose and muscle transcript expression profiling and genotyping were performed in 260 AAs to identify genetic regulatory mechanisms associated with insulin sensitivity (SI). We hypothesized that: 1) transcription profiles would reveal tissue-specific modulation of physiologic pathways with SI, and 2) a subset of SI-associated transcripts would be controlled by DNA sequence variants as expression quantitative traits, and these variants in turn would be associated with SI. Design and Settings: The cross-sectional research study was performed in a clinical research unit. Participants: Unrelated nondiabetic AAs were recruited for the study. Main Outcome Measures: SI was measured by frequently sampled iv glucose tolerance test. Results: The expression levels of 2212 transcripts in adipose and 145 transcripts in muscle were associated with SI. Genes involved in eIF2, eIF4-p70S6K, and mTOR signaling were modulated with SI in both tissues. Genes involved in leukocyte extravasation signaling showed adipose-specific regulation, and genes involved in oxidative phosphorylation had discordant regulation between tissues. Intersecting cis-expression quantitative trait loci results with data from transcript-SI association analysis identified cis-regulatory single nucleotide polymorphisms for 363 and 42 SI-associated transcripts in adipose and muscle, respectively. Cis-eSNPs for three SI-associated adipose transcripts, NINJ1, AGA, and CLEC10A were associated with SI. Abrogation of NINJ1 induction in THP1 macrophages modulated expression of genes in chemokine signaling, cell adhesion, and angiogenesis pathways. Conclusion: This study identified multiple pathways associated with SI; particularly discordant tissue-specific regulation of the oxidative phosphorylation pathway, and adipose-specific regulation of transcripts in the leukocyte extravasation signaling pathway that seem to be important in insulin resistance. Identification of single nucleotide polymorphisms associated with SI and with modulation of expression of SI-associated transcripts, including NINJ1, reveals novel genetic regulatory mechanisms of insulin resistance in AAs. PMID:26789776

FBI-1, a factor that binds to the HIV-1 inducer of short transcripts (IST), is a POZ domain protein.

PubMed Central

Morrison, D J; Pendergrast, P S; Stavropoulos, P; Colmenares, S U; Kobayashi, R; Hernandez, N

1999-01-01

The HIV-1 promoter directs the synthesis of two classes of transcripts, short, non-polyadenylated transcripts and full-length, polyadenylated transcripts. The synthesis of short transcripts is activated by a bipartite DNA element, the inducer of short transcripts or IST, located downstream of the HIV-1 transcriptional start site, while the synthesis of full-length transcripts is activated by the viral activator Tat. Tat binds to the RNA element TAR, which is encoded largely between the two IST half-elements. Upon activation by Tat, the synthesis of short RNAs is repressed. We have previously purified a factor called FBI-1 (for factor that binds to IST) whose binding to wild-type and mutated ISTs correlated well with the abilities of these ISTs to direct the synthesis of short transcripts. Here, we report the cloning of cDNAs encoding FBI-1. FBI-1 contains a POZ domain at its N-terminus and four Krüppel-type zinc fingers at its C-terminus. The C-terminus is sufficient for specific binding, and FBI-1 can form homomers through its POZ domain and, in vivo, through its zinc finger domain as well. In addition, FBI-1 associates with Tat, suggesting that repression of the short transcripts by Tat may be mediated through interactions between the two factors. PMID:9973611

FBI-1, a factor that binds to the HIV-1 inducer of short transcripts (IST), is a POZ domain protein.

PubMed

Morrison, D J; Pendergrast, P S; Stavropoulos, P; Colmenares, S U; Kobayashi, R; Hernandez, N

1999-03-01

The HIV-1 promoter directs the synthesis of two classes of transcripts, short, non-polyadenylated transcripts and full-length, polyadenylated transcripts. The synthesis of short transcripts is activated by a bipartite DNA element, the inducer of short transcripts or IST, located downstream of the HIV-1 transcriptional start site, while the synthesis of full-length transcripts is activated by the viral activator Tat. Tat binds to the RNA element TAR, which is encoded largely between the two IST half-elements. Upon activation by Tat, the synthesis of short RNAs is repressed. We have previously purified a factor called FBI-1 (for factor that binds to IST) whose binding to wild-type and mutated ISTs correlated well with the abilities of these ISTs to direct the synthesis of short transcripts. Here, we report the cloning of cDNAs encoding FBI-1. FBI-1 contains a POZ domain at its N-terminus and four Krüppel-type zinc fingers at its C-terminus. The C-terminus is sufficient for specific binding, and FBI-1 can form homomers through its POZ domain and, in vivo, through its zinc finger domain as well. In addition, FBI-1 associates with Tat, suggesting that repression of the short transcripts by Tat may be mediated through interactions between the two factors.

The high mobility group AT-hook 1 protein stimulates bovine herpesvirus 1 productive infection.

PubMed

Zhu, Liqian; Jones, Clinton

2017-06-15

Bovine herpesvirus 1 (BoHV-1) is an important pathogen of cattle that causes clinical symptoms in the upper respiratory tract and conjunctivitis. Like most alpha-herpesvirinae subfamily members, BoHV-1 establishes latency in sensory neurons. Stress consistently induces reactivation from latency, which is essential for virus transmission. Recent studies demonstrated that a viral protein (ORF2) expressed in a subset of latently infected neurons is associated with β-catenin and the high mobility group AT-hook 1 protein (HMGA1), which correlates with increased expression of these proteins in latently infected neurons. Since HMGA1 is primarily expressed in actively growing cells, binds to the minor groove of A+T rich regions in double-stranded DNA, and mediates gene transcription, we hypothesized that HMGA1 regulates BoHV-1 productive infection. Studies in this report indicated that productive infection increased HMGA1 protein levels and re-localized the protein in the nucleus. Netropsin, a small molecule that binds to the minor groove of DNA and prevents HMGA1 from interacting with DNA inhibited viral replication and interfered with the ability of BoHV-1 to induce HMGA1 re-localization. Furthermore, netropsin reduced RNA and protein expression of two viral regulatory proteins (bICP0 and bICP22) during productive infection, but increased bICP4 levels. Small interfering RNAs (siRNAs) that specifically target HMGA1 reduced HMGA1 RNA levels and virus production confirming HMGA1 stimulates productive infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Pooled analysis of Swedish case-control studies during 1997-2003 and 2007-2009 on meningioma risk associated with the use of mobile and cordless phones.

PubMed

Carlberg, Michael; Hardell, Lennart

2015-06-01

A pooled analysis of two case-control studies on meningioma with patients diagnosed during 1997-2003 and 2007-2009 was conducted. Both genders were included, aged 20-80 and 18-75 years, respectively, at the time of diagnosis. Population-based controls, matched according to age and gender, were enrolled. Exposure was assessed by questionnaire. In the entire study, cases with all brain tumor types were included. The whole reference group was used in the unconditional logistic regression analysis on meningioma, with adjustments for gender, age, year of diagnosis and socio-economic index (SEI). In total, 1,625 meningioma cases and 3,530 controls were analyzed. Overall no association with use of mobile or cordless phones was found. In the fourth quartile of use (>1,436 h) somewhat increased risk was found for mobile phones yielding an odds ratio (OR)=1.2, 95% confidence intervals (CI)=0.9-1.6 and cordless phones OR=1.7, 95% CI=1.3-2.2. Higher risk was calculated in the highest decile (>3,358 h), OR=1.5, 95% CI=0.99-2.1 and OR=2.0, 95% CI=1.4-2.8, respectively. In addition, the longest latency time gave somewhat increased risk for both phone types although the result was not statistically significant. There was no association for ipsilateral use or anatomical tumor location. The present study showed a somewhat increased risk among heavy users of mobile and cordless phones. Since meningioma is generally a slow-growing tumor, longer latency period is necessary for definitive conclusions.

Upregulation of distinct collagen transcripts in post-surgery scar tissue: a study of conjunctival fibrosis.

PubMed

Seet, Li-Fong; Toh, Li Zhen; Chu, Stephanie W L; Finger, Sharon N; Chua, Jocelyn L L; Wong, Tina T

2017-06-01

Excessive accumulation of collagen is often used to assess the development of fibrosis. This study aims to identify collagen genes that define fibrosis in the conjunctiva following glaucoma filtration surgery (GFS). Using the mouse model of GFS, we have identified collagen transcripts that were upregulated in the fibrotic phase of wound healing via RNA-seq. The collagen transcripts that were increased the most were encoded by Col8a1 , Col11a1 and Col8a2 Further analysis of the Col8a1 , Col11a1 and Col8a2 transcripts revealed their increase by 67-, 54- and 18-fold, respectively, in the fibrotic phase, compared with 12-fold for Col1a1 , the most commonly evaluated collagen gene for fibrosis. However, only type I collagen was significantly upregulated at the protein level in the fibrotic phase. Type VIII and type I collagens colocalized in fibrous structures and in ACTA2-positive pericytes, and appeared to compensate for each other in expression levels. Type XI collagen showed low colocalization with both type VIII and type I collagens but can be found in association with macrophages. Furthermore, we show that both mouse and human conjunctival fibroblasts expressed elevated levels of the most highly expressed collagen genes in response to TGFβ2 treatment. Importantly, conjunctival tissues from individuals whose GF surgeries have failed due to scarring showed 3.60- and 2.78-fold increases in type VIII and I collagen transcripts, respectively, compared with those from individuals with no prior surgeries. These data demonstrate that distinct collagen transcripts are expressed at high levels in the conjunctiva after surgery and their unique expression profiles may imply differential influences on the fibrotic outcome. © 2017. Published by The Company of Biologists Ltd.

Transcriptional responses associated with sulfur mustard and thermal burns in porcine skin.

PubMed

Rogers, James V; McDougal, James N; Price, Jennifer A; Reid, Frances M; Graham, John S

2008-01-01

In military and civilian environments, serious cutaneous damage can result from thermal burns or exposure to the blistering agent sulfur mustard [bis (2-chloroethyl) sulfide; HD]. Similar therapies have historically been used to treat cutaneous thermal and HD injuries; however, the underlying molecular mechanisms of tissue damage and wound healing may differ between the types of burns. Using microarray analysis, this study assessed the transcriptional responses to cutaneous HD and thermal injury at 48 hours post-exposure to identify molecular networks and genes associated with each type of skin injury. Ventral abdominal sites on each of 4 weanling swine were exposed to 400 mul of undiluted HD or a heated brass rod (70 degrees C) for 8 minutes and 45-60 seconds, respectively. At 48 hours post-exposure, total RNA was isolated from excised skin samples and hybridized to Affymetrix GeneChip Porcine Genome Arrays (containing 20,201 genes). Both HD and thermal exposure promoted significant transcriptional changes where 290 and 267 transcripts were increased and 197 and 707 transcripts were decreased with HD and thermal exposure, respectively. HD- and thermal-injured skin expressed 149 increased and 148 decreased common transcripts. Comparison of the 10 most significantly changed biological functions for HD and thermal exposures identified 7 overlapping functional groups. Canonical pathways analysis revealed 15 separate signaling pathways containing transcripts associated with both HD and thermal exposure. Within these pathways, 5 transcripts (CXCR4, FGFR2, HMOX1, IL1R1, and TLR4) were identified as known targets for existing phase II/III clinical trial or Food and Drug Administration (FDA)-approved drugs. This study is the first to directly assess transcriptional changes in porcine skin subjected to HD or thermal injury over the same time period.

Sumoylation of the Epstein-Barr Virus BZLF1 Protein Inhibits Its Transcriptional Activity and Is Regulated by the Virus-Encoded Protein Kinase▿

PubMed Central

Hagemeier, Stacy R.; Dickerson, Sarah J.; Meng, Qiao; Yu, Xianming; Mertz, Janet E.; Kenney, Shannon C.

2010-01-01

The Epstein-Barr virus (EBV) immediate-early protein BZLF1 (Z) mediates the switch between latent and lytic EBV infection. Z not only activates early lytic viral gene transcription but also plays a direct role in lytic viral genome replication. Although a small fraction of Z is known to be sumoylated, the effects of this posttranslational modification on various different Z functions have not been well defined. In this report, we show that only the lysine at amino acid residue 12 is required for the sumoylation of Z, and that Z can be sumoylated by SUMO isoforms 1, 2, and 3. We also demonstrate that the sumo-defective Z mutants ZK12A and ZK12R have enhanced transcriptional activity. The sumoylated and nonsumoylated forms of Z were found to have a similar cellular location, both being localized primarily within the nuclear matrix. The Z sumo-defective mutants were, however, partially defective for disrupting promyelocytic leukemia (PML) bodies compared to the ability of wild-type Z. In addition, we show that lytic viral genome replication does not require the sumoylation of Z, although a Z mutant altered at both amino acids 12 and 13 is replication defective. Furthermore, we show that the sumoylation of Z is greatly increased (from less than 1 to about 11%) in lytically induced 293 cells infected with an EBV mutant virus deleted for the EBV-encoded protein kinase (EBV-PK) compared to that of 293 cells infected with wild-type EBV, and that the overexpression of EBV-PK leads to the reduced sumoylation of Z in EBV-negative cells. Our results suggest that the sumoylation of Z helps to promote viral latency, and that EBV-PK inhibits Z sumoylation during viral reactivation. PMID:20181712

Antiviral effects of herpes simplex virus specific anti-sense nucleic acids.

PubMed

Cantin, E M; Podsakoff, G; Willey, D E; Openshaw, H

1992-01-01

We have targeted mRNA sequences encompassing the translation initiation codon of the essential herpes simplex virus type 1 (HSV-1) IE3 gene with three kinds of anti-sense molecule. Addition of a 15mer oligodeoxyribonucleoside methylphosphonate to tissue culture cells resulted in suppression of viral replication. HSV-1 replication was also inhibited in cultured cells containing anti-sense vectors expressing transcripts complementary to the IE3 mRNA. We have also constructed a ribozyme which upon base pairing with the target IE3 mRNA induces cleavage at the predicted GUC site. A major obstacle to anti-sense studies in animals is drug delivery of preformed antisense molecules to ganglionic neurons, the site of HSV latency and reactivation. We speculate as to how this may be accomplished through carrier compounds which are taken up by nerve terminals and transported by retrograde axoplasmic flow. By the same route, HSV itself may be used as an anti-sense vector.

RNA N6-adenosine methylation (m6A) steers epitranscriptomic control of herpesvirus replication

PubMed Central

Ye, Fengchun

2017-01-01

Latency is a hallmark of all herpesviruses, during which the viral genomes are silenced through DNA methylation and suppressive histone modifications. When latent herpesviruses reactivate to undergo productive lytic replication, the suppressive epigenetic marks are replaced with active ones to allow for transcription of viral genes. Interestingly, by using Kaposi’s sarcoma-associated herpesvirus (KSHV) as a model, we recently demonstrated that the newly transcribed viral RNAs are also subjected to post-transcriptional N6-adenosine methylation (m6A). Blockade of this post-transcriptional event abolishes viral protein expression and halts virion production. We found that m6A modification controls RNA splicing, stability, and protein translation to regulate viral lytic gene expression and replication. Thus, our finding for the first time reveals a critical role of this epitranscriptomic mechanism in the control of herpesviral replication, which shall shed lights on development of novel strategies for the control of herpesviral infection. PMID:29082271

Identification of Viral MicroRNAs Expressed in Human Sacral Ganglia Latently Infected with Herpes Simplex Virus 2▿

PubMed Central

Umbach, Jennifer L.; Wang, Kening; Tang, Shuang; Krause, Philip R.; Mont, Erik K.; Cohen, Jeffrey I.; Cullen, Bryan R.

2010-01-01

Deep sequencing of small RNAs isolated from human sacral ganglia latently infected with herpes simplex virus 2 (HSV-2) was used to identify HSV-2 microRNAs (miRNAs) expressed during latent infection. This effort resulted in the identification of five distinct HSV-2 miRNA species, two of which, miR-H3/miR-I and miR-H4/miR-II, have been previously reported. Three novel HSV-2 miRNAs were also identified, and two of these, miR-H7 and miR-H9, are derived from the latency-associated transcript (LAT) and are located antisense to the viral transcript encoding transactivator ICP0. A third novel HSV-2 miRNA, miR-H10, is encoded within the unique long (UL) region of the genome, 3′ to the UL15 open reading frame, and is presumably excised from a novel, latent HSV-2 transcript distinct from LAT. PMID:19889786

Identification of viral microRNAs expressed in human sacral ganglia latently infected with herpes simplex virus 2.

PubMed

Umbach, Jennifer L; Wang, Kening; Tang, Shuang; Krause, Philip R; Mont, Erik K; Cohen, Jeffrey I; Cullen, Bryan R

2010-01-01

Deep sequencing of small RNAs isolated from human sacral ganglia latently infected with herpes simplex virus 2 (HSV-2) was used to identify HSV-2 microRNAs (miRNAs) expressed during latent infection. This effort resulted in the identification of five distinct HSV-2 miRNA species, two of which, miR-H3/miR-I and miR-H4/miR-II, have been previously reported. Three novel HSV-2 miRNAs were also identified, and two of these, miR-H7 and miR-H9, are derived from the latency-associated transcript (LAT) and are located antisense to the viral transcript encoding transactivator ICP0. A third novel HSV-2 miRNA, miR-H10, is encoded within the unique long (U(L)) region of the genome, 3' to the U(L)15 open reading frame, and is presumably excised from a novel, latent HSV-2 transcript distinct from LAT.

Chromatin Regulation and the Histone Code in HIV Latency
.

PubMed

Turner, Anne-Marie W; Margolis, David M

2017-06-01

The formation of a latent reservoir of Human Immunodeficiency Virus (HIV) infection hidden from immune clearance remains a significant obstacle to approaches to eradicate HIV infection. Towards an understanding of the mechanisms of HIV persistence, there is a growing body of work implicating epigenetic regulation of chromatin in establishment and maintenance of this latent reservoir. Here we discuss recent advances in the field of chromatin regulation, specifically in our understanding of the histone code, and how these discoveries relate to our current knowledge of the chromatin mechanisms linked to HIV transcriptional repression and the reversal of latency. We also examine mechanisms unexplored in the context of HIV latency and briefly discuss current therapies aimed at the induction of proviral expression within latently infected cells. We aim to emphasize that a greater understanding of the epigenetic mechanisms which govern HIV latency could lead to new therapeutic targets for latency reversal and clearance cure strategies.

Chromatin Regulation and the Histone Code in HIV Latency


PubMed Central

Turner, Anne-Marie W.; Margolis, David M.

2017-01-01

The formation of a latent reservoir of Human Immunodeficiency Virus (HIV) infection hidden from immune clearance remains a significant obstacle to approaches to eradicate HIV infection. Towards an understanding of the mechanisms of HIV persistence, there is a growing body of work implicating epigenetic regulation of chromatin in establishment and maintenance of this latent reservoir. Here we discuss recent advances in the field of chromatin regulation, specifically in our understanding of the histone code, and how these discoveries relate to our current knowledge of the chromatin mechanisms linked to HIV transcriptional repression and the reversal of latency. We also examine mechanisms unexplored in the context of HIV latency and briefly discuss current therapies aimed at the induction of proviral expression within latently infected cells. We aim to emphasize that a greater understanding of the epigenetic mechanisms which govern HIV latency could lead to new therapeutic targets for latency reversal and clearance cure strategies. PMID:28656010

SIRT1 Suppresses Human T-Cell Leukemia Virus Type 1 Transcription

PubMed Central

Tang, Hei-Man Vincent; Gao, Wei-Wei; Chan, Chi-Ping; Cheng, Yun; Deng, Jian-Jun; Yuen, Kit-San; Iha, Hidekatsu

2015-01-01

ABSTRACT Human T-cell leukemia virus type 1 (HTLV-1)-associated diseases are poorly treatable, and HTLV-1 vaccines are not available. High proviral load is one major risk factor for disease development. HTLV-1 encodes Tax oncoprotein, which activates transcription from viral long terminal repeats (LTR) and various types of cellular promoters. Counteracting Tax function might have prophylactic and therapeutic benefits. In this work, we report on the suppression of Tax activation of HTLV-1 LTR by SIRT1 deacetylase. The transcriptional activity of Tax on the LTR was largely ablated when SIRT1 was overexpressed, but Tax activation of NF-κB was unaffected. On the contrary, the activation of the LTR by Tax was boosted when SIRT1 was depleted. Treatment of cells with resveratrol shunted Tax activity in a SIRT1-dependent manner. The activation of SIRT1 in HTLV-1-transformed T cells by resveratrol potently inhibited HTLV-1 proviral transcription and Tax expression, whereas compromising SIRT1 by specific inhibitors augmented HTLV-1 mRNA expression. The administration of resveratrol also decreased the production of cell-free HTLV-1 virions from MT2 cells and the transmission of HTLV-1 from MT2 cells to uninfected Jurkat cells in coculture. SIRT1 associated with Tax in HTLV-1-transformed T cells. Treatment with resveratrol prevented the interaction of Tax with CREB and the recruitment of CREB, CRTC1, and p300 to Tax-responsive elements in the LTR. Our work demonstrates the negative regulatory function of SIRT1 in Tax activation of HTLV-1 transcription. Small-molecule activators of SIRT1 such as resveratrol might be considered new prophylactic and therapeutic agents in HTLV-1-associated diseases. IMPORTANCE Human T-cell leukemia virus type 1 (HTLV-1) causes a highly lethal blood cancer or a chronic debilitating disease of the spinal cord. Treatments are unsatisfactory, and vaccines are not available. Disease progression is associated with robust expression of HTLV-1 genes. Suppressing HTLV-1 gene expression might have preventive and therapeutic benefits. It is therefore critical that host factors controlling HTLV-1 gene expression be identified and characterized. This work reveals a new host factor that suppresses HTLV-1 gene expression and a natural compound that activates this suppression. Our findings not only provide new knowledge of the host control of HTLV-1 gene expression but also suggest a new strategy of using natural compounds for prevention and treatment of HTLV-1-associated diseases. PMID:26063426

5-Azacytidine Can Induce Lethal Mutagenesis in Human Immunodeficiency Virus Type 1▿ †

PubMed Central

Dapp, Michael J.; Clouser, Christine L.; Patterson, Steven; Mansky, Louis M.

2009-01-01

Ribonucleosides inhibit human immunodeficiency virus type 1 (HIV-1) replication by mechanisms that have not been fully elucidated. Here, we report the antiviral mechanism for the ribonucleoside analog 5-azacytidine (5-AZC). We hypothesized that the anti-HIV-1 activity of 5-AZC was due to an increase in the HIV-1 mutation rate following its incorporation into viral RNA during transcription. However, we demonstrate that 5-AZC's primary antiviral activity can be attributed to its effect on the early phase of HIV-1 replication. Furthermore, the antiviral activity was associated with an increase in the frequency of viral mutants, suggesting that 5-AZC's primary target is reverse transcription. Sequencing analysis showed an enrichment in G-to-C transversion mutations and further supports the idea that reverse transcription is an antiviral target of 5-AZC. These results indicate that 5-AZC is incorporated into viral DNA following reduction to 5-aza-2′-deoxycytidine. Incorporation into the viral DNA leads to an increase in mutant frequency that is consistent with lethal mutagenesis during reverse transcription as the primary antiviral mechanism of 5-AZC. Antiviral activity and increased mutation frequency were also associated with the late phase of HIV-1 replication; however, 5-AZC's effect on the late phase was less robust. These results reveal that the primary antiviral mechanism of 5-AZC can be attributed to its ability to increase the HIV-1 mutation frequency through viral-DNA incorporation during reverse transcription. Our observations indicate that 5-AZC can affect two steps in HIV-1 replication (i.e., transcription and reverse transcription) but that its primary antiviral activity is due to incorporation during reverse transcription. PMID:19726509

Analysis of vestibular testing in patients with vestibular schwannoma based on the nerve of origin, the localization, and the size of the tumor.

PubMed

Suzuki, Mitsuya; Yamada, Chikako; Inoue, Rika; Kashio, Akinori; Saito, Yuki; Nakanishi, Wakako

2008-10-01

We aimed to analyze the factors influencing caloric response and vestibular evoked myogenic potential (VEMP) in vestibular schwannoma. The subjects comprised 130 patients with unilateral vestibular schwannoma pathologically diagnosed by surgery. Caloric response and the amplitude and latency of VEMP were measured and analyzed based on the nerve of origin, localization, and size of the tumor. The tumors were classified into 3 types based on localization: intracanalicular, intermediate, and medial; and into 4 grades based on size: 9 mm or less, 10 to 19 mm, 20 to 29 mm, and 30 mm or greater. : Abnormal rates of caloric response and VEMP in patients with tumors arising from the superior vestibular nerve were not significantly different from those in patients with tumors of the inferior vestibular nerve. In the intermediate and medial type-but not in the intracanalicular type-a significant difference in tumor size was observed between patients with normal caloric response and those with canal paresis as also between patients with normal VEMP and those with abnormal VEMP. In patients with tumors that maximally measured 10 to 19 mm or of the intermediate type, the p- and n-wave latencies of VEMP were significantly prolonged compared with those in the normal opposite ear. 1) The nerve of origin of tumors cannot be predicted based on caloric response and VEMP. 2) In the intermediate and medial types, caloric response and the VEMP amplitude are significantly diminished in association with an increase in tumor size. 3) Prolonged VEMP latencies seem to be not only caused by tumor compression to the brainstem or vestibular spinal tract but also by tumor compression isolated to the inferior vestibular nerve.

NLR-Associating Transcription Factor bHLH84 and Its Paralogs Function Redundantly in Plant Immunity

PubMed Central

Xu, Fang; Kapos, Paul; Cheng, Yu Ti; Li, Meng; Zhang, Yuelin; Li, Xin

2014-01-01

In plants and animals, nucleotide-binding and leucine-rich repeat domain containing (NLR) immune receptors are utilized to detect the presence or activities of pathogen-derived molecules. However, the mechanisms by which NLR proteins induce defense responses remain unclear. Here, we report the characterization of one basic Helix-loop-Helix (bHLH) type transcription factor (TF), bHLH84, identified from a reverse genetic screen. It functions as a transcriptional activator that enhances the autoimmunity of NLR mutant snc1 (suppressor of npr1-1, constitutive 1) and confers enhanced immunity in wild-type backgrounds when overexpressed. Simultaneously knocking out three closely related bHLH paralogs attenuates RPS4-mediated immunity and partially suppresses the autoimmune phenotypes of snc1, while overexpression of the other two close paralogs also renders strong autoimmunity, suggesting functional redundancy in the gene family. Intriguingly, the autoimmunity conferred by bHLH84 overexpression can be largely suppressed by the loss-of-function snc1-r1 mutation, suggesting that SNC1 is required for its proper function. In planta co-immunoprecipitation revealed interactions between not only bHLH84 and SNC1, but also bHLH84 and RPS4, indicating that bHLH84 associates with these NLRs. Together with previous finding that SNC1 associates with repressor TPR1 to repress negative regulators, we hypothesize that nuclear NLR proteins may interact with both transcriptional repressors and activators during immune responses, enabling potentially faster and more robust transcriptional reprogramming upon pathogen recognition. PMID:25144198

Prior Corneal Scarification and Injection of Immune Serum are Not Required Before Ocular HSV-1 Infection for UV-B-Induced Virus Reactivation and Recurrent Herpetic Corneal Disease in Latently Infected Mice

PubMed Central

BenMohamed, Lbachir; Osorio, Nelson; Khan, Arif A.; Srivastava, Ruchi; Huang, Lei; Krochmal, John J.; Garcia, Jairo M.; Simpson, Jennifer L.; Wechsler, Steven L.

2017-01-01

Purpose Blinding ocular herpetic disease in humans is due to spontaneous reactivation of herpes simplex virus type 1 (HSV-1) from latency, rather than to primary acute infection. Mice latently infected with HSV-1 undergo little or no in vivo spontaneous reactivation with accompanying virus shedding in tears. HSV-1 reactivation can be induced in latently infected mice by several in vivo procedures, with UV-B-induced reactivation being one commonly used method. In the UV-B model, corneas are scarified (lightly scratched) just prior to ocular infection to increase efficiency of the primary infection and immune serum containing HSV-1 neutralizing antibodies is injected intraperitoneally (i.p.) to increase survival and decrease acute corneal damage. Since scarification can significantly alter host gene transcription in the cornea and in the trigeminal ganglia (TG; the site of HSV-1 latency) and since injection of immune serum likely modulates innate and adaptive herpes immunity, we investigated eliminating both treatments. Material and Methods Mice were infected with HSV-1 with or without corneal scarification and immune serum. HSV-1 reactivation and recurrent disease were induced by UV-B irradiation. Results When corneal scarification and immune serum were both eliminated, UV-B irradiation still induced both HSV-1 reactivation, as measured by shedding of reactivated virus in tears and herpetic eye disease, albeit at reduced levels compared to the original procedure. Conclusion Despite the reduced reactivation and disease, avoidance of both corneal scarification and immune serum should improve the clinical relevance of the UV-B mouse model. PMID:26398722

Molecular Pathology of Adult T-Cell Leukemia/Lymphoma.

PubMed

Ohshima, Koichi

2015-01-01

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm of highly pleomorphic lymphoid cells. ATLL is usually widely disseminated, and it is caused by human T-cell leukemia virus type 1 (HTLV-1). It is a disease with a long latency, and affected individuals are usually exposed to the virus very early in life. The cumulative incidence of ATLL is estimated to be 2.5% among HTLV-1 carriers. ATLL cells express CD2, CD3, CD5, CD4, and CD25, as well as CCR4 and FoxP3 of the regulatory T-cell marker. HTLV-1 is causally linked to ATLL, but infection alone is not sufficient to result in neoplastic transformation. A significant finding in this connection is that the Tax viral protein leads to transcriptional activation of many genes, while the HTLV-1 basic leucine zipper factor is thought to be important for T-cell proliferation and oncogenesis. Half of ATLL cases retain the ability to express HTLV-1 Tax, which is a target of HTLV-1-specific cytotoxic T lymphocytes (CTL). An increase in HTLV-1-specific CTL responses is observed in some asymptomatic HTLV-1 carriers. Although HTLV-1-specific CTL are also present in the peripheral blood of ATLL patients, they do not expand sufficiently. We investigated the clinicopathological features and analyzed the staining of Tax-specific CTL and FoxP3. Tax-specific CTL correlated inversely with FoxP3, an increase in the ratio of CD163+ tumor-associated macrophages was associated with worse clinical prognosis, and ATLL cell lines proliferated significantly following direct co-culture with M2 macrophages. Several clinical variants of ATLL have been identified: acute, lymphomatous, chronic, and smoldering. Oligo-array comparative genomic hybridization revealed that genomic loss of 9p21.3 was a significant characteristic of acute-type, but not of chronic-type ATLL. Furthermore, we found that genomic alteration of CD58, which is implicated in immune escape, is more frequently observed in acute than in chronic ATLL. Interestingly, the chronic cases with cell cycle deregulation and disruption of immunosurveillance mechanism were associated with faster progression to acute ATLL. Immune evasion, microenvironment, and genetic alteration are therefore important in the multi-step progression of ATLL lymphomagenesis. © 2015 S. Karger AG, Basel.

Genetic Variants in Transcription Factors Are Associated With the Pharmacokinetics and Pharmacodynamics of Metformin

PubMed Central

Goswami, S; Yee, SW; Stocker, S; Mosley, JD; Kubo, M; Castro, R; Mefford, JA; Wen, C; Liang, X; Witte, J; Brett, C; Maeda, S; Simpson, MD; Hedderson, MM; Davis, RL; Roden, DM; Giacomini, KM; Savic, RM

2014-01-01

One-third of type 2 diabetes patients do not respond to metformin. Genetic variants in metformin transporters have been extensively studied as a likely contributor to this high failure rate. Here, we investigate, for the first time, the effect of genetic variants in transcription factors on metformin pharmacokinetics (PK) and response. Overall, 546 patients and healthy volunteers contributed their genome-wide, pharmacokinetic (235 subjects), and HbA1c data (440 patients) for this analysis. Five variants in specificity protein 1 (SP1), a transcription factor that modulates the expression of metformin transporters, were associated with changes in treatment HbA1c (P < 0.01) and metformin secretory clearance (P < 0.05). Population pharmacokinetic modeling further confirmed a 24% reduction in apparent clearance in homozygous carriers of one such variant, rs784888. Genetic variants in other transcription factors, peroxisome proliferator–activated receptor-α and hepatocyte nuclear factor 4-α, were significantly associated with HbA1c change only. Overall, our study highlights the importance of genetic variants in transcription factors as modulators of metformin PK and response. PMID:24853734

Multiple sleep latency test in narcolepsy type 1 and narcolepsy type 2: A 5-year follow-up study.

PubMed

Huang, Yu-Shu; Guilleminault, Christian; Lin, Cheng-Hui; Chen, Chia-Hsiang; Chin, Wei-Chih; Chen, Tzu-Shuang

2018-05-29

Excessively sleepy teenagers and young adults without sleep-disordered breathing are diagnosed with either narcolepsy type 1 or narcolepsy type 2, or hypersomnia, based on the presence/absence of cataplexy and the results of a multiple sleep latency test. However, there is controversy surrounding this nomenclature. We will try to find the differences between different diagnoses of hypersomnia from the results of the long-term follow-up evaluation of a sleep study. We diagnosed teenagers who had developed excessive daytime sleepiness based on the criteria of the International Classification of Sleep Disorders, 3rd edition. Each individual received the same clinical neurophysiologic testing every year for 5 years after the initial diagnosis of narcolepsy type 1 (n = 111) or type 2 (n = 46). The follow-up evaluation demonstrated that narcolepsy type 1 (narcolepsy-cataplexy) is a well-defined clinical entity, with very reproducible clinical neurophysiologic findings over time, whereas patients with narcolepsy type 2 presented clear clinical and test variability. By the fifth year of the follow-up evaluation, 17.6% of subjects did not meet the diagnostic criteria of narcolepsy type 2, and 23.9% didn't show any two sleep-onset rapid eye movement periods in multiple sleep latency during the 5-year follow-up. Therefore narcolepsy type 1 (narcolepsy-cataplexy) is a well-defined syndrome, with the presentation clearly related to the known consequences of destruction of hypocretin/orexin neurons. Narcolepsy type 2 covers patients with clinical and test variability over time, thus bringing into question the usage of the term "narcolepsy" to label these patients. © 2018 European Sleep Research Society.

Human I-mfa domain proteins specifically interact with KSHV LANA and affect its regulation of Wnt signaling-dependent transcription

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp; Eizuru, Yoshito

2010-06-04

Kaposi's sarcoma-associated herpes virus (KSHV)-encoded latency-associated nuclear antigen (LANA) protein has been reported to interact with glycogen synthase kinase 3{beta} (GSK-3{beta}) and to negatively regulate its activity, leading to stimulation of GSK-3{beta}-dependent {beta}-catenin degradation. We show here that the I-mfa domain proteins, HIC (human I-mfa domain-containing protein) and I-mfa (inhibitor of MyoD family a), interacted in vivo with LANA through their C-terminal I-mfa domains. This interaction affected the intracellular localization of HIC, inhibited the LANA-dependent transactivation of a {beta}-catenin-regulated reporter construct, and decreased the level of the LANA.GSK-3{beta} complex. These data reveal for the first time that I-mfa domain proteinsmore » interact with LANA and negatively regulate LANA-mediated activation of Wnt signaling-dependent transcription by inhibiting the formation of the LANA.GSK-3{beta} complex.« less

Association of Neuropeptide-Y (NPY) and Interleukin-1beta (IL1B), Genotype-Phenotype Correlation and Plasma Lipids with Type-II Diabetes

PubMed Central

Mansuri, Mohmmad Shoab; Ansarullah; Laddha, Naresh C.; Thakker, Ami; Ramachandran, A. V.; Begum, Rasheedunnisa

2016-01-01

Background Neuropeptide Y (NPY) is known to play a role in the regulation of satiety, energy balance, body weight, and insulin release. Interleukin-1beta (IL1B) has been associated with loss of beta-cell mass in type-II diabetes (TIID). Objectives The present study attempts to investigate the association of NPY exon2 +1128 T/C (Leu7Pro; rs16139), NPY promoter -399 T/C (rs16147) and IL1B -511 C/T (rs16944) polymorphisms with TIID and their correlation with plasma lipid levels, BMI, and IL1B transcript levels. Methods PCR-RFLP was used for genotyping these polymorphisms in a case-control study involving 558 TIID patients and 1085 healthy age-matched controls from Gujarat. Linkage disequilibrium and haplotype analysis of the NPY polymorphic sites were performed to assess their association with TIID. IL1B transcript levels in PBMCs were also assessed in 108 controls and 101 patients using real-time PCR. Results Our results show significant association of both structural and promoter polymorphisms of NPY (p<0.0001 and p<0.0001 respectively) in patients with TIID. However, the IL1B C/T polymorphism did not show any association (p = 0.3797) with TIID patients. Haplotype analysis revealed more frequent association of CC and CT haplotypes (p = 3.34 x 10−5, p = 6.04 x 10−9) in diabetics compared to controls and increased the risk of diabetes by 3.02 and 2.088 respectively. Transcript levels of IL1B were significantly higher (p<0.0001) in patients as compared to controls. Genotype-phenotype correlation of IL1B polymorphism did not show any association with its higher transcript levels. In addition, NPY +1128 T/C polymorphism was found to be associated with increased plasma LDL levels (p = 0.01). Conclusion The present study provides an evidence for a strong correlation between structural and promoter polymorphisms of NPY gene and upregulation of IL1B transcript levels with susceptibility to TIID and altering the lipid metabolism in Gujarat population. PMID:27749914

Association of Neuropeptide-Y (NPY) and Interleukin-1beta (IL1B), Genotype-Phenotype Correlation and Plasma Lipids with Type-II Diabetes.

PubMed

Patel, Roma; Dwivedi, Mitesh; Mansuri, Mohmmad Shoab; Ansarullah; Laddha, Naresh C; Thakker, Ami; Ramachandran, A V; Begum, Rasheedunnisa

2016-01-01

Neuropeptide Y (NPY) is known to play a role in the regulation of satiety, energy balance, body weight, and insulin release. Interleukin-1beta (IL1B) has been associated with loss of beta-cell mass in type-II diabetes (TIID). The present study attempts to investigate the association of NPY exon2 +1128 T/C (Leu7Pro; rs16139), NPY promoter -399 T/C (rs16147) and IL1B -511 C/T (rs16944) polymorphisms with TIID and their correlation with plasma lipid levels, BMI, and IL1B transcript levels. PCR-RFLP was used for genotyping these polymorphisms in a case-control study involving 558 TIID patients and 1085 healthy age-matched controls from Gujarat. Linkage disequilibrium and haplotype analysis of the NPY polymorphic sites were performed to assess their association with TIID. IL1B transcript levels in PBMCs were also assessed in 108 controls and 101 patients using real-time PCR. Our results show significant association of both structural and promoter polymorphisms of NPY (p<0.0001 and p<0.0001 respectively) in patients with TIID. However, the IL1B C/T polymorphism did not show any association (p = 0.3797) with TIID patients. Haplotype analysis revealed more frequent association of CC and CT haplotypes (p = 3.34 x 10-5, p = 6.04 x 10-9) in diabetics compared to controls and increased the risk of diabetes by 3.02 and 2.088 respectively. Transcript levels of IL1B were significantly higher (p<0.0001) in patients as compared to controls. Genotype-phenotype correlation of IL1B polymorphism did not show any association with its higher transcript levels. In addition, NPY +1128 T/C polymorphism was found to be associated with increased plasma LDL levels (p = 0.01). The present study provides an evidence for a strong correlation between structural and promoter polymorphisms of NPY gene and upregulation of IL1B transcript levels with susceptibility to TIID and altering the lipid metabolism in Gujarat population.

Identification of key transcription factors in caerulein-induced pancreatitis through expression profiling data

PubMed Central

QI, DACHUAN; WU, BO; TONG, DANIAN; PAN, YE; CHEN, WEI

2015-01-01

The current study aimed to isolate key transcription factors (TFs) in caerulein-induced pancreatitis, and to identify the difference between wild type and Mist1 knockout (KO) mice, in order to elucidate the contribution of Mist1 to pancreatitis. The gene profile of GSE3644 was downloaded from the Gene Expression Omnibus database then analyzed using the t-test. The isolated differentially expressed genes (DEGs) were mapped into a transcriptional regulatory network derived from the Integrated Transcription Factor Platform database and in the network, the interaction pairs involving at least one DEG were screened. Fisher’s exact test was used to analyze the functional enrichment of the target genes. A total of 1,555 and 3,057 DEGs were identified in the wild type and Mist1KO mice treated with caerulein, respectively. DEGs screened in Mist1KO mice were predominantly enriched in apoptosis, mitogen-activated protein kinase signaling and other cancer-associated pathways. A total of 188 and 51 TFs associated with pathopoiesis were isolated in Mist1KO and wild type mice, respectively. Out of the top 10 TFs (ranked by P-value), 7 TFs, including S-phase kinase-associated protein 2 (Skp2); minichromosome maintenance complex component 3 (Mcm3); cell division cycle 6 (Cdc6); cyclin B1 (Ccnb1); mutS homolog 6 (Msh6); cyclin A2 (Ccna2); and cyclin B2 (Ccnb2), were expressed in the two types of mouse. These TFs were predominantly involved in phosphorylation, DNA replication, cell division and DNA mismatch repair. In addition, specific TFs, including minichromosome maintenance complex component 7 (Mcm7); lymphoid-specific helicase (Hells); and minichromosome maintenance complex component 6 (Mcm6), that function in the unwinding of DNA were identified to participate in Mist1KO pancreatitis. The DEGs, including Cdc6, Mcm6, Msh6 and Wdr1 are closely associated with the regulation of caerulein-induced pancreatitis. Furthermore, other identified TFs were also involved in this type of regulation. PMID:25975747

Electrical peripheral nerve stimulation relieves bone cancer pain by inducing Arc protein expression in the spinal cord dorsal horn

PubMed Central

Sun, Ke-fu; Feng, Wan-wen; Liu, Yue-peng; Dong, Yan-bin; Gao, Li; Yang, Hui-lin

2018-01-01

Objective The analgesic effect on chronic pain of peripheral nerve stimulation (PNS) has been proven, but its underlying mechanism remains unknown. Therefore, this study aimed to assess the analgesic effect of PNS on bone cancer pain in a rat model and to explore the underlying mechanism. Materials and methods PNS on sciatic nerves with bipolar electrode was performed in both naïve and bone cancer pain model rats. Then, the protein levels of activity-regulated cytoskeleton-associated protein (Arc), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid–type glutamate receptor 1 (GluA1), and phosphate N-methyl-d-aspartic acid-type glutamate receptor subunit 2B (pGluNR2B) in spinal cord were evaluated by immunohistochemistry and Western blotting. Thermal paw withdraw latency and mechanical paw withdraw threshold were used to estimate the analgesic effect of PNS on bone cancer pain. Intrathecal administration of Arc shRNA was used to inhibit Arc expression in the spinal cord. Results PNS at 60 and 120 Hz for 20 min overtly induced Arc expression in the spinal cord, increased thermal pain thresholds in naïve rats, and relieved bone cancer pain; meanwhile, 10 Hz PNS did not achieve those results. In addition, PNS at 60 and 120 Hz also reduced the expression of GluA1, but not pGluNR2B, in the spinal cord. Finally, the anti-nociceptive effect and GluA1 downregulation induced by PNS were inhibited by intrathecal administration of Arc shRNA. Conclusion PNS (60 Hz, 0.3 mA) can relieve bone-cancer-induced allodynia and hyperalgesia by upregulating Arc protein expression and then by decreasing GluA1 transcription in the spinal cord dorsal horn. PMID:29606887

Tranylcypromine Reduces Herpes Simplex Virus 1 Infection in Mice

PubMed Central

Yao, Hui-Wen; Lin, Pin-Hung; Shen, Fang-Hsiu; Perng, Guey-Chuen; Tung, Yuk-Ying

2014-01-01

Herpes simplex virus 1 (HSV-1) infects the majority of the human population and establishes latency by maintaining viral genomes in neurons of sensory ganglia. Latent virus can undergo reactivation to cause recurrent infection. Both primary and recurrent infections can cause devastating diseases, including encephalitis and corneal blindness. Acyclovir is used to treat patients, but virus resistance to acyclovir is frequently reported. Recent in vitro findings reveal that pretreatment of cells with tranylcypromine (TCP), a drug widely used in the clinic to treat neurological disorders, restrains HSV-1 gene transcription by inhibiting the histone-modifying enzyme lysine-specific demethylase 1. The present study was designed to examine the anti-HSV-1 efficacy of TCP in vivo because of the paucity of reports on this issue. Using the murine model, we found that TCP decreased the severity of wild-type-virus-induced encephalitis and corneal blindness, infection with the acyclovir-resistant (thymidine kinase-negative) HSV-1 mutant, and tissue viral loads. Additionally, TCP blocked in vivo viral reactivation in trigeminal ganglia. These results support the therapeutic potential of TCP for controlling HSV-1 infection. PMID:24590478

Distinct promoter activation mechanisms modulate noise-driven HIV gene expression

NASA Astrophysics Data System (ADS)

Chavali, Arvind K.; Wong, Victor C.; Miller-Jensen, Kathryn

2015-12-01

Latent human immunodeficiency virus (HIV) infections occur when the virus occupies a transcriptionally silent but reversible state, presenting a major obstacle to cure. There is experimental evidence that random fluctuations in gene expression, when coupled to the strong positive feedback encoded by the HIV genetic circuit, act as a ‘molecular switch’ controlling cell fate, i.e., viral replication versus latency. Here, we implemented a stochastic computational modeling approach to explore how different promoter activation mechanisms in the presence of positive feedback would affect noise-driven activation from latency. We modeled the HIV promoter as existing in one, two, or three states that are representative of increasingly complex mechanisms of promoter repression underlying latency. We demonstrate that two-state and three-state models are associated with greater variability in noisy activation behaviors, and we find that Fano factor (defined as variance over mean) proves to be a useful noise metric to compare variability across model structures and parameter values. Finally, we show how three-state promoter models can be used to qualitatively describe complex reactivation phenotypes in response to therapeutic perturbations that we observe experimentally. Ultimately, our analysis suggests that multi-state models more accurately reflect observed heterogeneous reactivation and may be better suited to evaluate how noise affects viral clearance.

A Novel Thyroid Hormone Mediated Regulation of HSV-1 Gene Expression and Replication is Specific to Neuronal Cells and Associated with Disruption of Chromatin Condensation

PubMed Central

Chen, Feng; Palem, Jay; Balish, Matthew; Figliozzi, Robert; Ajavon, Amakoe; Hsia, S Victor

2014-01-01

Previously we showed that thyroid hormone (T3) regulated the Herpes Simplex Virus Type -1 (HSV-1) gene expression and replication through its nuclear receptor TR via histone modification and chromatin remodeling in a neuroblastoma cell line neuro-2a cells (N2a). This observation suggested that T3 regulation may be neuron-specific and have implication in HSV-1 latency and reactivation. In this study, our in vitro latency/reactivation model demonstrated that removal of T3 can de-repress the HSV-1 replication and favor reactivation. Transfection studies and infection assays indicated that HSV-1 thymidine kinase (TK), a key viral gene during reactivation, was repressed by TR/T3 in cells with neuronal origin but not in non-neuronal cells. Additional studies showed that RCC1 (Regulator of Chromosome Condensation 1) was sequestered but efficiently detected upon viral infection in N2a cells. Western blot analyses indicated that addition of T3 repressed the RCC1 expression upon infection. It is likely that diminution of RCC1 upon infection in neuronal cells under the influence of TR/T3 may lead to repression of viral replication/gene expression thus promote latency. Together these results demonstrated that TR/T3 mediated regulation is specific to neuronal cells and differential chromosome condensation may play a critical role in this process. PMID:25346944

Cooperative action in eukaryotic gene regulation: Physical properties of a viral example

NASA Astrophysics Data System (ADS)

Werner, Maria; Zhu, Lizhe; Aurell, Erik

2007-12-01

The Epstein-Barr virus (EBV) infects more than 90% of the human population, and causes glandular fever as well as several more serious diseases. It is a tumor virus, and has been widely studied as a model system for cell transformation in humans. A central feature of the EBV life cycle is its ability to persist in human B cells in different latency states, denoted latency I, II, and III. In latency III the host cell is driven to cell proliferation and hence expansion of the viral population without entering the lytic pathway, while the latency I state is almost completely dormant. We here study the effective cooperativity of the viral C promoter, active in latency III EBV cell lines. We show that the unusually large number of binding sites of two competing transcription factors, one viral and one from the host, serves to make the switch sharper (higher Hill coefficient), either by cooperative binding between molecules of the same species when they bind, or by competition between the two species if there is sufficient steric hindrance.

The ICSD-3 and DSM-5 guidelines for diagnosing narcolepsy: clinical relevance and practicality.

PubMed

Ruoff, Chad; Rye, David

2016-07-20

Narcolepsy is a chronic neurological disease manifesting as difficulty with maintaining continuous wake and sleep. Clinical presentation varies but requires excessive daytime sleepiness (EDS) occurring alone or together with features of rapid-eye movement (REM) sleep dissociation (e.g., cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis), and disrupted nighttime sleep. Narcolepsy with cataplexy is associated with reductions of cerebrospinal fluid (CSF) hypocretin due to destruction of hypocretin peptide-producing neurons in the hypothalamus in individuals with a specific genetic predisposition. Updated diagnostic criteria include the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) and International Classification of Sleep Disorders Third Edition (ICSD-3). DSM-5 criteria require EDS in association with any one of the following: (1) cataplexy; (2) CSF hypocretin deficiency; (3) REM sleep latency ≤15 minutes on nocturnal polysomnography (PSG); or (4) mean sleep latency ≤8 minutes on multiple sleep latency testing (MSLT) with ≥2 sleep-onset REM-sleep periods (SOREMPs). ICSD-3 relies more upon objective data in addition to EDS, somewhat complicating the diagnostic criteria: 1) cataplexy and either positive MSLT/PSG findings or CSF hypocretin deficiency; (2) MSLT criteria similar to DSM-5 except that a SOREMP on PSG may count as one of the SOREMPs required on MSLT; and (3) distinct division of narcolepsy into type 1, which requires the presence of cataplexy or documented CSF hypocretin deficiency, and type 2, where cataplexy is absent, and CSF hypocretin levels are either normal or undocumented. We discuss limitations of these criteria such as variability in clinical presentation of cataplexy, particularly when cataplexy may be ambiguous, as well as by age; multiple and/or invasive CSF diagnostic test requirements; and lack of normative diagnostic test data (e.g., MSLT) in certain populations. While ICSD-3 criteria reflect narcolepsy pathophysiology, DSM-5 criteria have greater clinical practicality, suggesting that valid and reliable biomarkers to help standardize narcolepsy diagnosis would be welcomed.

The Role of Epigenetic Regulation in Epstein-Barr Virus-Associated Gastric Cancer

PubMed Central

Nishikawa, Jun; Iizasa, Hisashi; Nakamura, Munetaka; Saito, Mari; Sasaki, Sho; Shimokuri, Kanami; Yanagihara, Masashi; Sakai, Kouhei; Suehiro, Yutaka; Yamasaki, Takahiro; Sakaida, Isao

2017-01-01

The Epstein–Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma (EBVaGC), all tumor cells harbor the clonal EBV genome. The expression of latent EBV genes is strictly regulated through the methylation of EBV DNA. The methylation of viral DNA regulates the type of EBV latency, and methylation of the tumor suppressor genes is a key abnormality in EBVaGC. The methylation frequencies of several tumor suppressor genes and cell adhesion molecules are significantly higher in EBVaGC than in control cases. EBV-derived microRNAs repress translation from viral and host mRNAs. EBV regulates the expression of non-coding RNA in gastric carcinoma. With regard to the clinical application of demethylating agents against EBVaGC, we investigated the effects of decitabine against the EBVaGC cell lines. Decitabine inhibited the cell growth of EBVaGC cells. The promoter regions of p73 and Runt-related transcription factor 3(RUNX3) were demethylated, and their expression was upregulated by the treatment. We review the role of epigenetic regulation in the development and maintenance of EBVaGC and discuss the therapeutic application of DNA demethylating agents for EBVaGC. PMID:28757548

The Role of Epigenetic Regulation in Epstein-Barr Virus-Associated Gastric Cancer.

PubMed

Nishikawa, Jun; Iizasa, Hisashi; Yoshiyama, Hironori; Nakamura, Munetaka; Saito, Mari; Sasaki, Sho; Shimokuri, Kanami; Yanagihara, Masashi; Sakai, Kouhei; Suehiro, Yutaka; Yamasaki, Takahiro; Sakaida, Isao

2017-07-25

The Epstein-Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma (EBVaGC), all tumor cells harbor the clonal EBV genome. The expression of latent EBV genes is strictly regulated through the methylation of EBV DNA. The methylation of viral DNA regulates the type of EBV latency, and methylation of the tumor suppressor genes is a key abnormality in EBVaGC. The methylation frequencies of several tumor suppressor genes and cell adhesion molecules are significantly higher in EBVaGC than in control cases. EBV-derived microRNAs repress translation from viral and host mRNAs. EBV regulates the expression of non-coding RNA in gastric carcinoma. With regard to the clinical application of demethylating agents against EBVaGC, we investigated the effects of decitabine against the EBVaGC cell lines. Decitabine inhibited the cell growth of EBVaGC cells. The promoter regions of p73 and Runt-related transcription factor 3(RUNX3) were demethylated, and their expression was upregulated by the treatment. We review the role of epigenetic regulation in the development and maintenance of EBVaGC and discuss the therapeutic application of DNA demethylating agents for EBVaGC.

Meta-analysis of long-term mobile phone use and the association with brain tumours.

PubMed

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Hansson Mild, Kjell

2008-05-01

We evaluated long-term use of mobile phones and the risk for brain tumours in case-control studies published so far on this issue. We identified ten studies on glioma and meta-analysis yielded OR = 0.9, 95% CI = 0.8-1.1. Latency period of > or =10-years gave OR = 1.2, 95% CI = 0.8-1.9 based on six studies, for ipsilateral use (same side as tumour) OR = 2.0, 95% CI = 1.2-3.4 (four studies), but contralateral use did not increase the risk significantly, OR = 1.1, 95% CI = 0.6-2.0. Meta-analysis of nine studies on acoustic neuroma gave OR = 0.9, 95% CI = 0.7-1.1 increasing to OR = 1.3, 95% CI = 0.6-2.8 using > or =10-years latency period (four studies). Ipsilateral use gave OR = 2.4, 95% CI = 1.1-5.3 and contra-lateral OR = 1.2, 95% CI = 0.7-2.2 in the > or =10-years latency period group (three studies). Seven studies gave results for meningioma yielding overall OR = 0.8, 95% CI = 0.7-0.99. Using > or =10-years latency period OR = 1.3, 95% CI = 0.9-1.8 was calculated (four studies) increasing to OR = 1.7, 95% CI = 0.99-3.1 for ipsilateral use and OR = 1.0, 95% CI = 0.3-3.1 for contralateral use (two studies). We conclude that this meta-analysis gave a consistent pattern of an association between mobile phone use and ipsilateral glioma and acoustic neuroma using > or =10-years latency period.

Investigation of koi herpesvirus latency in koi.

PubMed

Eide, Kathleen E; Miller-Morgan, Tim; Heidel, Jerry R; Kent, Michael L; Bildfell, Rob J; Lapatra, Scott; Watson, Gregory; Jin, Ling

2011-05-01

Koi herpesvirus (KHV) has recently been classified as a member of the family of Alloherpesviridae within the order of Herpesvirales. One of the unique features of Herpesviridae is latent infection following a primary infection. However, KHV latency has not been recognized. To determine if latency occurs in clinically normal fish from facilities with a history of KHV infection or exposure, the presence of the KHV genome was investigated in healthy koi by PCR and Southern blotting. KHV DNA, but not infectious virus or mRNAs from lytic infection, was detected in white blood cells from investigated koi. Virus shedding was examined via tissue culture and reverse transcription-PCR (RT-PCR) testing of gill mucus and feces from six koi every other day for 1 month. No infectious virus or KHV DNA was detected in fecal secretion or gill swabs, suggesting that neither acute nor persistent infection was present. To determine if KHV latent infections can be reactivated, six koi were subjected to a temperature stress regime. KHV DNA and infectious virus were detected in both gill and fecal swabs by day 8 following temperature stress. KHV DNA was also detectable in brain, spleen, gills, heart, eye, intestine, kidney, liver, and pancreas in euthanized koi 1 month post-temperature stress. Our study suggests that KHV may become latent in leukocytes and other tissues, that it can be reactivated from latency by temperature stress, and that it may be more widespread in the koi population than previously suspected.

Investigation of Koi Herpesvirus Latency in Koi▿

PubMed Central

Eide, Kathleen E.; Miller-Morgan, Tim; Heidel, Jerry R.; Kent, Michael L.; Bildfell, Rob J.; LaPatra, Scott; Watson, Gregory; Jin, Ling

2011-01-01

Koi herpesvirus (KHV) has recently been classified as a member of the family of Alloherpesviridae within the order of Herpesvirales. One of the unique features of Herpesviridae is latent infection following a primary infection. However, KHV latency has not been recognized. To determine if latency occurs in clinically normal fish from facilities with a history of KHV infection or exposure, the presence of the KHV genome was investigated in healthy koi by PCR and Southern blotting. KHV DNA, but not infectious virus or mRNAs from lytic infection, was detected in white blood cells from investigated koi. Virus shedding was examined via tissue culture and reverse transcription-PCR (RT-PCR) testing of gill mucus and feces from six koi every other day for 1 month. No infectious virus or KHV DNA was detected in fecal secretion or gill swabs, suggesting that neither acute nor persistent infection was present. To determine if KHV latent infections can be reactivated, six koi were subjected to a temperature stress regime. KHV DNA and infectious virus were detected in both gill and fecal swabs by day 8 following temperature stress. KHV DNA was also detectable in brain, spleen, gills, heart, eye, intestine, kidney, liver, and pancreas in euthanized koi 1 month post-temperature stress. Our study suggests that KHV may become latent in leukocytes and other tissues, that it can be reactivated from latency by temperature stress, and that it may be more widespread in the koi population than previously suspected. PMID:21389134

Medroxyprogesterone acetate inhibits CD8+ T cell viral specific effector function and induces herpes simplex virus type 1 reactivation

PubMed Central

Cherpes, Thomas L.; Busch, James L.; Sheridan, Brian S.; Harvey, Stephen A. K.; Hendricks, Robert L.

2008-01-01

Clinical research suggests hormonal contraceptive use is associated with increased frequencies of herpes simplex virus (HSV) reactivation and shedding. We examined the effects of medroxyprogesterone acetate (MPA), the compound most commonly used for injectable hormonal contraception, on HSV-1 reactivation and CD8+ T cell function in murine trigeminal ganglia (TG). In ex vivo TG cultures, MPA dramatically inhibited canonical CD8+ T cell effector functions, including IFN-γ production and lytic granule release, and increased HSV-1 reactivation from latency. In vivo, MPA treatment of latently infected ovariectomized mice inhibited IFN-γ production and lytic granule release by TG resident CD8+ T cells stimulated directly ex vivo. RNA specific for the essential immediate early viral gene ICP4 as well as viral genome DNA copy number were increased in mice that received MPA during latency, suggesting that treatment increased in vivo reactivation. The increase in HSV-1 copy number appeared to be the result of a two-tine effect, as MPA induced higher reactivation frequencies from latently infected explanted TG neurons in the presence or absence of CD45+ cells. Our data suggest hormonal contraceptives that contain MPA may promote increased frequency of HSV reactivation from latency through the combinatory effects of inhibiting protective CD8+ T cell responses and by a leukocyte-independent effect on infected neurons. PMID:18606648

Cortical Auditory Evoked Potentials with Simple (Tone Burst) and Complex (Speech) Stimuli in Children with Cochlear Implant

PubMed Central

Martins, Kelly Vasconcelos Chaves; Gil, Daniela

2017-01-01

Introduction  The registry of the component P1 of the cortical auditory evoked potential has been widely used to analyze the behavior of auditory pathways in response to cochlear implant stimulation. Objective  To determine the influence of aural rehabilitation in the parameters of latency and amplitude of the P1 cortical auditory evoked potential component elicited by simple auditory stimuli (tone burst) and complex stimuli (speech) in children with cochlear implants. Method  The study included six individuals of both genders aged 5 to 10 years old who have been cochlear implant users for at least 12 months, and who attended auditory rehabilitation with an aural rehabilitation therapy approach. Participants were submitted to research of the cortical auditory evoked potential at the beginning of the study and after 3 months of aural rehabilitation. To elicit the responses, simple stimuli (tone burst) and complex stimuli (speech) were used and presented in free field at 70 dB HL. The results were statistically analyzed, and both evaluations were compared. Results  There was no significant difference between the type of eliciting stimulus of the cortical auditory evoked potential for the latency and the amplitude of P1. There was a statistically significant difference in the P1 latency between the evaluations for both stimuli, with reduction of the latency in the second evaluation after 3 months of auditory rehabilitation. There was no statistically significant difference regarding the amplitude of P1 under the two types of stimuli or in the two evaluations. Conclusion  A decrease in latency of the P1 component elicited by both simple and complex stimuli was observed within a three-month interval in children with cochlear implant undergoing aural rehabilitation. PMID:29018498

Cross-cancer profiling of molecular alterations within the human autophagy interaction network

PubMed Central

Lebovitz, Chandra B; Robertson, A Gordon; Goya, Rodrigo; Jones, Steven J; Morin, Ryan D; Marra, Marco A; Gorski, Sharon M

2015-01-01

Aberrant activation or disruption of autophagy promotes tumorigenesis in various preclinical models of cancer, but whether the autophagy pathway is a target for recurrent molecular alteration in human cancer patient samples is unknown. To address this outstanding question, we surveyed 211 human autophagy-associated genes for tumor-related alterations to DNA sequence and RNA expression levels and examined their association with patient survival outcomes in multiple cancer types with sequence data from The Cancer Genome Atlas consortium. We found 3 (RB1CC1/FIP200, ULK4, WDR45/WIPI4) and one (ATG7) core autophagy genes to be under positive selection for somatic mutations in endometrial carcinoma and clear cell renal carcinoma, respectively, while 29 autophagy regulators and pathway interactors, including previously identified KEAP1, NFE2L2, and MTOR, were significantly mutated in 6 of the 11 cancer types examined. Gene expression analyses revealed that GABARAPL1 and MAP1LC3C/LC3C transcripts were less abundant in breast cancer and non-small cell lung cancers than in matched normal tissue controls; ATG4D transcripts were increased in lung squamous cell carcinoma, as were ATG16L2 transcripts in kidney cancer. Unsupervised clustering of autophagy-associated mRNA levels in tumors stratified patient overall survival in 3 of 9 cancer types (acute myeloid leukemia, clear cell renal carcinoma, and head and neck cancer). These analyses provide the first comprehensive resource of recurrently altered autophagy-associated genes in human tumors, and highlight cancer types and subtypes where perturbed autophagy may be relevant to patient overall survival. PMID:26208877

Sleep-stage sequencing of sleep-onset REM periods in MSLT predicts treatment response in patients with narcolepsy.

PubMed

Drakatos, Panagis; Patel, Kishankumar; Thakrar, Chiraag; Williams, Adrian J; Kent, Brian D; Leschziner, Guy D

2016-04-01

Current treatment recommendations for narcolepsy suggest that modafinil should be used as a first-line treatment ahead of conventional stimulants or sodium oxybate. In this study, performed in a tertiary sleep disorders centre, treatment responses were examined following these recommendations, and the ability of sleep-stage sequencing of sleep-onset rapid eye movement periods in the multiple sleep latency test to predict treatment response. Over a 3.5-year period, 255 patients were retrospectively identified in the authors' database as patients diagnosed with narcolepsy, type 1 (with cataplexy) or type 2 (without) using clinical and polysomnographic criteria. Eligible patients were examined in detail, sleep study data were abstracted and sleep-stage sequencing of sleep-onset rapid eye movement periods were analysed. Response to treatment was graded utilizing an internally developed scale. Seventy-five patients were included (39% males). Forty (53%) were diagnosed with type 1 narcolepsy with a mean follow-up of 2.37 ± 1.35 years. Ninety-seven percent of the patients were initially started on modafinil, and overall 59% reported complete response on the last follow-up. Twenty-nine patients (39%) had the sequence of sleep stage 1 or wake to rapid eye movement in all of their sleep-onset rapid eye movement periods, with most of these diagnosed as narcolepsy type 1 (72%). The presence of this specific sleep-stage sequence in all sleep-onset rapid eye movement periods was associated with worse treatment response (P = 0.0023). Sleep-stage sequence analysis of sleep-onset rapid eye movement periods in the multiple sleep latency test may aid the prediction of treatment response in narcoleptics and provide a useful prognostic tool in clinical practice, above and beyond their classification as narcolepsy type 1 or 2. © 2015 European Sleep Research Society.

Profiling of EBV-Encoded microRNAs in EBV-Associated Hemophagocytic Lymphohistiocytosis.

PubMed

Zhou, Chen; Xie, Zhengde; Gao, Liwei; Liu, Chunyan; Ai, Junhong; Zhang, Li; Shen, Kunling

2015-10-01

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a life-threatening complication of EBV infection. MicroRNAs (miRNAs) were small non-coding RNA, and EBV could encode miRNAs that are involved in the progression of infection. However, the profiles of EBV-miRNAs in EBV-HLH were unknown. Here, we aimed to profile the expression of EBV-miRNAs in children with EBV-HLH by analyzing 44 known EBV-miRNAs, encoded within the BamHI fragment H rightward open reading frame 1 (BHRF1) and the BamHI-A region rightward transcript (BART), in plasma and cellular targets by real-time quantitative PCR. The study included 15 children with EBV-HLH, 15 children with infectious mononucleosis (IM), and 15 healthy controls. CD8(+) T cells were found to be the cellular target of EBV infection in EBV-HLH, while CD19(+) B cells were infected with EBV in IM. We also found the greater levels of several miRNAs encoded by BART in EBV-HLH, compared to those in IM and healthy controls, whereas the levels of BHRF1 miRNAs were lower than those in IM. The profile and pattern of EBV-miRNAs in EBV-HLH indicated that EBV could display type II latency in EBV-HLH. Importantly, the level of plasma miR-BART16-1 continued decreasing during the whole chemotherapy, suggesting that plasma miR-BART16-1 could be a potential biomarker for monitoring EBV-HLH progression. The pathogenesis of EBV-HLH might be attributed to the abundance of EBV-miRNAs in EBV-HLH. These findings help elucidate the roles of EBV miRNAs in EBV-HLH, enabling the understanding of the basis of this disease and providing clues for its treatment.

Epstein-Barr Virus Type 2 Infects T Cells in Healthy Kenyan Children.

PubMed

Coleman, Carrie B; Daud, Ibrahim I; Ogolla, Sidney O; Ritchie, Julie A; Smith, Nicholas A; Sumba, Peter O; Dent, Arlene E; Rochford, Rosemary

2017-09-15

The 2 strains of Epstein-Barr virus (EBV), EBV type 1 (EBV-1) and EBV-2, differ in latency genes, suggesting that they use distinct mechanisms to establish latency. We previously reported that EBV-2 infects T cells in vitro. In this study, we tested the possibility that EBV-2 infects T cells in vivo. Purified T-cell fractions isolated from children positive for EBV-1 or EBV-2 and their mothers were examined for the presence of EBV and for EBV type. We detected EBV-2 in all T-cell samples obtained from EBV-2-infected children at 12 months of age, with some children retaining EBV-2-positive T cells through 24 months of age, suggesting that EBV-2 persists in T cells. We were unable to detect EBV-2 in T-cell samples from mothers but could detect EBV-2 in samples of their breast milk and saliva. These data suggest that EBV-2 uses T cells as an additional latency reservoir but that, over time, the frequency of infected T cells may drop below detectable levels. Alternatively, EBV-2 may establish a prolonged transient infection in the T-cell compartment. Collectively, these novel findings demonstrate that EBV-2 infects T cells in vivo and suggest EBV-2 may use the T-cell compartment to establish latency. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Ocular HSV-1: Is the Cornea a Reservoir for Viral Latency or a Fast Pit Stop?

PubMed Central

Kennedy, David P.; Clement, Christian; Arceneaux, Richard L.; Bhattacharjee, Partha S.; Huq, Tashfin S.; Hill, James M.

2010-01-01

Purpose To present a review supporting and refuting evidence from mouse, rabbit, non-human primate, and human studies of herpes simplex virus type 1 (HSV-1) concerning corneal latency. Methods More than 50 research papers on HSV-1 published in peer-reviewed journals were examined. Results Infectious HSV-1 has been found in mouse denervated tissues and in tissues with negative cultures from the corresponding ganglion. However, the different mouse strains have shown varied responses to different strains of HSV, making it difficult to relate such findings to humans. Rabbit studies provide excellent evidence for HSV-1 corneal latency including data on HSV-1 migration from the cornea into the corneoscleral rim and on the distribution of HSV-1 DNA in the cornea. However, the available methods for the detection of infectious HSV-1 may not be sensitive enough to detect low-level infection. Infectious HSV-1 has been successfully isolated from the tears of non-human primates in the absence of detectable corneal lesions. The recurrence of corneal ulcers in non-human primates before the appearance of infectious HSV-1 in tears suggests that the origin of the HSV-1 is the cornea, rather than the TG. Human studies presented evidence of both ganglion and corneal latency. Conclusion Understanding HSV-1 disease progression and the possibility of corneal latency could lead to more effective treatments for herpetic keratitis. However, it is unlikely that operational latency in the cornea will be definitively proven unless a new method with higher sensitivity for the detection of infectious virus is developed. PMID:21304287

Short-term administration of disulfiram for reversal of latent HIV infection: a phase 2 dose-escalation study.

PubMed

Elliott, Julian H; McMahon, James H; Chang, Christina C; Lee, Sulggi A; Hartogensis, Wendy; Bumpus, Namandje; Savic, Rada; Roney, Janine; Hoh, Rebecca; Solomon, Ajantha; Piatak, Michael; Gorelick, Robert J; Lifson, Jeff; Bacchetti, Peter; Deeks, Steven G; Lewin, Sharon R

2015-12-01

In vitro, disulfiram activated HIV transcription in a primary T-cell model of HIV latency and in a pilot clinical study increased plasma HIV RNA in individuals with adequate drug exposure. We assessed the effect of disulfiram on HIV transcription in a dose-escalation study. In this prospective dose-escalation study, to optimise disulfiram exposure we included adults with HIV on suppressive antiretroviral therapy, with plasma HIV RNA of less than 50 copies per mL and a CD4 cell count greater than 350 cells per μL. Participants were allocated sequentially to one of three dosing groups (500 mg, 1000 mg, and 2000 mg) and received disulfiram daily for 3 days. Only the staff who did laboratory assays were masked to group assignment. The primary endpoint was change in cell-associated unspliced HIV RNA in CD4 cells. The primary analysis method was a negative binomial regression, with the number of copies as the outcome variable and the input total RNA or plasma volume as an exposure variable, which is equivalent to modelling copies or input. We used these models to estimate changes from before disulfiram to timepoints during and after disulfiram administration. This study is registered with ClinicalTrials.gov, number NCT01944371. Of 34 participants screened for eligibility at The Alfred Hospital (Melbourne, VIC, Australia), and San Francisco General Hospital (San Francisco, CA, USA), 30 people were enrolled between Sept 24, 2013, and March 31, 2014. The estimated fold increases in cell-associated unspliced HIV RNA from baseline were 1·7 (95% CI 1·3-2·2; p<0·0001) to the timepoint during disulfiram treatment and 2·1 (1·5-2·9; p<0·0001) to the timepoint after disulfiram in the 500 mg group; 1·9 (1·6-2·4; p<0·0001) and 2·5 (1·9-3·3; p<0·0001) in the 1000 mg group; and 1·6 (1·2-2·1; p=0·0026) and 2·1 (1·5-3·1; p=0·0001) in the 2000 mg group. No deaths occurred, and no serious adverse events were noted. Disulfiram was well tolerated at all doses. Short-term administration of disulfiram resulted in increases in cell-associated unspliced HIV RNA at all doses, consistent with activating HIV latency. Disulfiram may be suited for future studies of combination and prolonged therapy to activate latent HIV. The Foundation for AIDS Research (amfAR); National Institute of Allergy and Infectious Diseases, National Institutes of Health; Australian National Health and Medical Research Council. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low latency messages on distributed memory multiprocessors

NASA Technical Reports Server (NTRS)

Rosing, Matthew; Saltz, Joel

1993-01-01

Many of the issues in developing an efficient interface for communication on distributed memory machines are described and a portable interface is proposed. Although the hardware component of message latency is less than one microsecond on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 microseconds. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. Based on several tests that were run on the iPSC/860, an interface that will better match current distributed memory machines is proposed. The model used in the proposed interface consists of a computation processor and a communication processor on each node. Communication between these processors and other nodes in the system is done through a buffered network. Information that is transmitted is either data or procedures to be executed on the remote processor. The dual processor system is better suited for efficiently handling asynchronous communications compared to a single processor system. The ability to send data or procedure is very flexible for minimizing message latency, based on the type of communication being performed. The test performed and the proposed interface are described.

Glutamine Deprivation Causes Enhanced Plating Efficiency of a Herpes Simplex Virus Type 1 ICP0-Null Mutant ▿

PubMed Central

Bringhurst, Ryan M.; Dominguez, Antonia A.; Schaffer, Priscilla A.

2008-01-01

Isoleucine deprivation of cellular monolayers prior to infection has been reported to result in partial complementation of a herpes simplex virus type 1 (HSV-1) ICP0 null (ICP0−) mutant. We now report that glutamine deprivation alone is able to enhance the plating efficiency of an ICP0− virus and that isoleucine deprivation has little or no effect. Because a low glutamine level is associated with stress and because stress is known to induce reactivation, low levels of glutamine may be relevant to the reactivation of HSV-1 from latency. Additionally, we demonstrate that arginine and methionine deprivation result in partial complementation of the ICP0− virus. PMID:18768961

Noxious heat threshold temperature and pronociceptive effects of allyl isothiocyanate (mustard oil) in TRPV1 or TRPA1 gene-deleted mice.

PubMed

Tékus, Valéria; Horváth, Ádám; Hajna, Zsófia; Borbély, Éva; Bölcskei, Kata; Boros, Melinda; Pintér, Erika; Helyes, Zsuzsanna; Pethő, Gábor; Szolcsányi, János

2016-06-01

To investigate the roles of TRPV1 and TRPA1 channels in baseline and allyl isothiocyanate (AITC)-evoked nociceptive responses by comparing wild-type and gene-deficient mice. In contrast to conventional methods of thermonociception measuring reflex latencies, we used our novel methods to determine the noxious heat threshold. It was revealed that the heat threshold of the tail measured by an increasing-temperature water bath is significantly higher in TRPV1(-/-), but not TRPA1(-/-), mice compared to respective wild-types. There was no difference between the noxious heat thresholds of the hind paw as measured by an increasing-temperature hot plate in TRPV1(-/-), TRPA1(-/-) and the corresponding wild-type mice. The withdrawal latency of the tail from 0°C water was prolonged in TRPA1(-/-), but not TRPV1(-/-), mice compared to respective wild-types. In wild-type animals, dipping the tail or paw into 1% AITC induced an 8-14°C drop of the noxious heat threshold (heat allodynia) of both the tail and paw, and 40-50% drop of the mechanonociceptive threshold (mechanical allodynia) of the paw measured by dynamic plantar esthesiometry. These AITC-evoked responses were diminished in TRPV1(-/-), but not TRPA1(-/-), mice. Tail withdrawal latency to 1% AITC was significantly prolonged in both gene-deleted strains. Different heat sensors determine the noxious heat threshold in distinct areas: a pivotal role for TRPV1 on the tail is contrasted with no involvement of either TRPV1 or TRPA1 on the hind paw. Noxious heat threshold measurement appears appropriate for preclinical screening of TRP channel ligands as novel analgesics. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of symbol type and numerical distance on the human event-related potential.

PubMed

Jiang, Ting; Qiao, Sibing; Li, Jin; Cao, Zhongyu; Gao, Xuefei; Song, Yan; Xue, Gui; Dong, Qi; Chen, Chuansheng

2010-01-01

This study investigated the influence of the symbol type and numerical distance of numbers on the amplitudes and peak latencies of event-related potentials (ERPs). Our aim was to (1) determine the point in time of magnitude information access in visual number processing; and (2) identify at what stage the advantage of Arabic digits over Chinese verbal numbers occur. ERPs were recorded from 64 scalp sites while subjects (n=26) performed a classification task. Results showed that larger ERP amplitudes were elicited by numbers with distance-close condition in comparison to distance-far condition in the VPP component over centro-frontal sites. Furthermore, the VPP latency varied as a function of the symbol type, but the N170 did not. Such results demonstrate that magnitude information access takes place as early as 150 ms after onset of visual number stimuli and the advantage of Arabic digits over verbal numbers should be localized to the VPP component. We establish the VPP component as a critical ERP component to report in studies of numerical cognition and our results call into question the N170/VPP association hypothesis and the serial-stage model of visual number comparison processing.

PAX3-FOXO1: Zooming in on an "undruggable" target.

PubMed

Wachtel, Marco; Schäfer, Beat W

2018-06-01

Driver oncogenes are prime targets for therapy in tumors many of which, including leukemias and sarcomas, express recurrent fusion transcription factors. One specific example for such a cancer type is alveolar rhabdomyosarcoma, which is associated in the majority of cases with the fusion protein PAX3-FOXO1. Since fusion transcription factors are challenging targets for development of small molecule inhibitors, indirect inhibitory strategies for this type of oncogenes represent a more promising approach. One can envision strategies at different molecular levels including upstream modifiers and activators, epigenetic and transcriptional co-regulators, and downstream effector targets. In this review, we will discuss the current knowledge regarding potential therapeutic targets that might contribute to indirect interference with PAX3-FOXO1 activity in alveolar rhabdomyosarcoma at the different molecular levels and extrapolate these findings to fusion transcription factors in general. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Functional Incompatibility between the Generic NF-κB Motif and a Subtype-Specific Sp1III Element Drives the Formation of the HIV-1 Subtype C Viral Promoter

PubMed Central

Verma, Anjali; Rajagopalan, Pavithra; Lotke, Rishikesh; Varghese, Rebu; Selvam, Deepak; Kundu, Tapas K.

2016-01-01

ABSTRACT Of the various genetic subtypes of human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) and simian immunodeficiency virus (SIV), only in subtype C of HIV-1 is a genetically variant NF-κB binding site found at the core of the viral promoter in association with a subtype-specific Sp1III motif. How the subtype-associated variations in the core transcription factor binding sites (TFBS) influence gene expression from the viral promoter has not been examined previously. Using panels of infectious viral molecular clones, we demonstrate that subtype-specific NF-κB and Sp1III motifs have evolved for optimal gene expression, and neither of the motifs can be replaced by a corresponding TFBS variant. The variant NF-κB motif binds NF-κB with an affinity 2-fold higher than that of the generic NF-κB site. Importantly, in the context of an infectious virus, the subtype-specific Sp1III motif demonstrates a profound loss of function in association with the generic NF-κB motif. An additional substitution of the Sp1III motif fully restores viral replication, suggesting that the subtype C-specific Sp1III has evolved to function with the variant, but not generic, NF-κB motif. A change of only two base pairs in the central NF-κB motif completely suppresses viral transcription from the provirus and converts the promoter into heterochromatin refractory to tumor necrosis factor alpha (TNF-α) induction. The present work represents the first demonstration of functional incompatibility between an otherwise functional NF-κB motif and a unique Sp1 site in the context of an HIV-1 promoter. Our work provides important leads as to the evolution of the HIV-1 subtype C viral promoter with relevance for gene expression regulation and viral latency. IMPORTANCE Subtype-specific genetic variations provide a powerful tool to examine how these variations offer a replication advantage to specific viral subtypes, if any. Only in subtype C of HIV-1 are two genetically distinct transcription factor binding sites positioned at the most critical location of the viral promoter. Since a single promoter regulates viral gene expression, the promoter variations can play a critical role in determining the replication fitness of the viral strains. Our work for the first time provides a scientific explanation for the presence of a unique NF-κB binding motif in subtype C, a major HIV-1 genetic family responsible for half of the global HIV-1 infections. The results offer compelling evidence that the subtype C viral promoter not only is stronger but also is endowed with a qualitative gain-of-function advantage. The genetically variant NF-κB and the Sp1III motifs may be respond differently to specific cell signal pathways, and these mechanisms must be examined. PMID:27194770

Transcriptional Pathways Altered in Response to Vibration in a Model of Hand-Arm Vibration Syndrome.

PubMed

Waugh, Stacey; Kashon, Michael L; Li, Shengqiao; Miller, Gerome R; Johnson, Claud; Krajnak, Kristine

2016-04-01

The aim of this study was to use an established model of vibration-induced injury to assess frequency-dependent changes in transcript expression in skin, artery, and nerve tissues. Transcript expression in tissues from control and vibration-exposed rats (4 h/day for 10 days at 62.5, 125, or 250 Hz; 49 m/s, rms) was measured. Transcripts affected by vibration were used in bioinformatics analyses to identify molecular- and disease-related pathways associated with exposure to vibration. Analyses revealed that cancer-related pathways showed frequency-dependent changes in activation or inhibition. Most notably, the breast-related cancer-1 pathway was affected. Other pathways associated with breast cancer type 1 susceptibility protein related signaling, or associated with cancer and cell cycle/cell survivability were also affected. Occupational exposure to vibration may result in DNA damage and alterations in cell signaling pathways that have significant effects on cellular division.

Herpes Simplex Virus 1 Tropism for Human Sensory Ganglion Neurons in the Severe Combined Immunodeficiency Mouse Model of Neuropathogenesis

PubMed Central

Che, Xibing; Reichelt, Mike; Qiao, Yanli; Gu, Haidong; Arvin, Ann

2013-01-01

The tropism of herpes simplex virus (HSV-1) for human sensory neurons infected in vivo was examined using dorsal root ganglion (DRG) xenografts maintained in mice with severe combined immunodeficiency (SCID). In contrast to the HSV-1 lytic infectious cycle in vitro, replication of the HSV-1 F strain was restricted in human DRG neurons despite the absence of adaptive immune responses in SCID mice, allowing the establishment of neuronal latency. At 12 days after DRG inoculation, 26.2% of human neurons expressed HSV-1 protein and 13.1% expressed latency-associated transcripts (LAT). Some infected neurons showed cytopathic changes, but HSV-1, unlike varicella-zoster virus (VZV), only rarely infected satellite cells and did not induce fusion of neuronal and satellite cell plasma membranes. Cell-free enveloped HSV-1 virions were observed, indicating productive infection. A recombinant HSV-1-expressing luciferase exhibited less virulence than HSV-1 F in the SCID mouse host, enabling analysis of infection in human DRG xenografts for a 61-day interval. At 12 days after inoculation, 4.2% of neurons expressed HSV-1 proteins; frequencies increased to 32.1% at 33 days but declined to 20.8% by 61 days. Frequencies of LAT-positive neurons were 1.2% at 12 days and increased to 40.2% at 33 days. LAT expression remained at 37% at 61 days, in contrast to the decline in neurons expressing viral proteins. These observations show that the progression of HSV-1 infection is highly restricted in human DRG, and HSV-1 genome silencing occurs in human neurons infected in vivo as a consequence of virus-host cell interactions and does not require adaptive immune control. PMID:23269807

The influence of target angular velocity on visual latency difference determined using the rotating Pulfrich effect.

PubMed

Nickalls, R W

1996-09-01

Visual latency difference was determined directly in normal volunteers, using the rotating Pulfrich technique described by Nickalls [Vision Research, 26, 367-372 (1986)]. Subjects fixated a black vertical rod rotating clockwise on a horizontal turntable turning with constant angular velocity (16.6,33.3 or 44.7 revs/min) with a neutral density filter (OD 0.7 or 1.5) in front of the right eye. For all subjects the latency difference associated with the 1.5 OD filter was significantly greater (P < 0.001) with the rod rotating at 16.6 rev/min than at 33.3 revs/min. The existence of an inverse relationship between latency difference and angular velocity is hypothesized.

Intranasal immunization with heat shock protein 60 induces CD4(+) CD25(+) GARP(+) and type 1 regulatory T cells and inhibits early atherosclerosis.

PubMed

Zhong, Y; Tang, H; Wang, X; Zeng, Q; Liu, Y; Zhao, X I; Yu, K; Shi, H; Zhu, R; Mao, X

2016-03-01

Atherosclerosis is an autoimmune inflammatory disease involving both innate and adaptive immune mechanisms. Immune tolerance induction may have therapeutic potential for the suppression of atherosclerosis. Current interest is directed towards mucosal tolerance induction, especially nasal tolerance. Previous studies have shown that heat shock protein 60 (HSP60) is recognized as an important autoantigen in atherosclerosis, and nasal or oral HSP60 can induce tolerance and ameliorate atherosclerosis by inducing several subsets of regulatory T cells (Tregs ) such as latency-associated peptide (LAP)(+) and forkhead box transcription factor 3 (FoxP3)(+) Tregs. However, little is known regarding the detailed mechanisms of nasal tolerance. Here, we again investigated the impact of nasal HSP60 on atherosclerosis and the mechanisms underlying the anti-atherosclerosis responses. We found that nasal HSP60 caused a significant 33·6% reduction in plaque size at the aortic root in the early stages of atherosclerosis (P < 0·001). Notably, a significant increase in activated CD4(+) CD25(+) glycoprotein A repetitions predominant (GARP)(+) Tregs, type 1 Tregs (Tr1 cells), and CD4(+) CD25(+) FoxP3(+) Tregs, as well as a marked decrease in the numbers of type 1 and 17 T helper cells was detected in the spleens and cervical lymph nodes of HSP60-treated mice. Moreover, nasal HSP60 increases the production of transforming growth factor (TGF)-β and interleukin (IL)-10 and decreases the secretion of IFN-γ and IL-17. Interestingly, the atheroprotective role of nasal HSP60 treatment was abrogated partly by the neutralization of IL-10. Our findings show that nasal administration of HSP60 can attenuate atherosclerotic formation by inducing GARP(+) Tregs, Tr1 cells and FoxP3(+) Tregs, and that these Tregs maintain immune homeostasis by secreting IL-10 and TGF-β. © 2015 British Society for Immunology.

Elevated expression of transient receptor potential vanilloid type 1 in dorsal root ganglia of rats with endometriosis

PubMed Central

Lian, Yu-Ling; Cheng, Ming-Jun; Zhang, Xian-Xia; Wang, Li

2017-01-01

Pain is the most pronounced complaint of women with endometriosis, however the underlying mechanism is still poorly understood. In the present study, the authors evaluate the effect of transient receptor potential vanilloid type 1 (TRPV1) of dorsal root ganglia (DRG) on endometriosis-associated pain. A total of 36 SD rats were randomly divided into a sham group (n=9) and a Model group (n=27), accepted auto-transplanted pieces of fat or uterus to the pelvic cavity. At 4 weeks, the Model group was randomly subdivided into the following groups: ENDO group (no treatment, n=9), BCTC group (Model + BCTC, an antagonist of TRPV1, n=9), Vehicle group (Model + cyclodextrin, the vehicle of BCTC, n=9). Tail-flick test was performed prior to surgery, 1 h prior to and following treatment of BCTC or cyclodextrin. The expression of TRPV1, substance P (SP), calcitonin gene-related peptide (CGRP) in L1-L6 DRG was measured via immunohistochemistry, western blotting and RT-qPCR. The results indicated that the Model group exhibited a significant decrease in tail flick latency compared to pre-surgical baseline, and the expression of TRPV1, SP, CGRP protein and mRNA in L1-L6 DRG significantly increased compared to the sham group. BCTC significantly improved tail flick latency, and downregulated the expression of TRPV1, SP and CGRP protein and mRNA levels in L1-L6 DRG compared to ENDO group. However, there were no significant differences of those in Vehicle group compared with the ENDO group. Taken together, the current study provides evidence that TRPV1 expressed in DRG may serve an important role in endometriosis-associated pain. PMID:28627595

Elevated expression of transient receptor potential vanilloid type 1 in dorsal root ganglia of rats with endometriosis.

PubMed

Lian, Yu-Ling; Cheng, Ming-Jun; Zhang, Xian-Xia; Wang, Li

2017-08-01

Pain is the most pronounced complaint of women with endometriosis, however the underlying mechanism is still poorly understood. In the present study, the authors evaluate the effect of transient receptor potential vanilloid type 1 (TRPV1) of dorsal root ganglia (DRG) on endometriosis-associated pain. A total of 36 SD rats were randomly divided into a sham group (n=9) and a Model group (n=27), accepted auto‑transplanted pieces of fat or uterus to the pelvic cavity. At 4 weeks, the Model group was randomly subdivided into the following groups: ENDO group (no treatment, n=9), BCTC group (Model + BCTC, an antagonist of TRPV1, n=9), Vehicle group (Model + cyclodextrin, the vehicle of BCTC, n=9). Tail‑flick test was performed prior to surgery, 1 h prior to and following treatment of BCTC or cyclodextrin. The expression of TRPV1, substance P (SP), calcitonin gene‑related peptide (CGRP) in L1‑L6 DRG was measured via immunohistochemistry, western blotting and RT‑qPCR. The results indicated that the Model group exhibited a significant decrease in tail flick latency compared to pre‑surgical baseline, and the expression of TRPV1, SP, CGRP protein and mRNA in L1‑L6 DRG significantly increased compared to the sham group. BCTC significantly improved tail flick latency, and downregulated the expression of TRPV1, SP and CGRP protein and mRNA levels in L1‑L6 DRG compared to ENDO group. However, there were no significant differences of those in Vehicle group compared with the ENDO group. Taken together, the current study provides evidence that TRPV1 expressed in DRG may serve an important role in endometriosis-associated pain.

Effects of troxerutin on cognitive deficits and glutamate cysteine ligase subunits in the hippocampus of streptozotocin-induced type 1 diabetes mellitus rats.

PubMed

Zhang, Songyun; Li, Hongyan; Zhang, Lihui; Li, Jie; Wang, Ruiying; Wang, Mian

2017-02-15

Increasing evidence demonstrates an association between diabetes and hippocampal neuron damage. This study aimed to determine the effects of troxerutin on cognitive deficits and glutamate cysteine ligase subunits (GCLM and GCLC) in the hippocampus of streptozotocin-induced type 1 diabetes mellitus (T1DM) rats. At 12weeks after streptozotocin injection, T1DM rats were randomly divided into 4 groups (n=15 each group) to receive no treatment (T1DM), saline (T1DM+saline), alpha-lipoic acid (T1DM+alpha-lipoic acid), and troxerutin (T1DM+troxerutin), respectively, for 6weeks. Meanwhile, 10 control animals (NC group) were assessed in parallel. Learning performance was evaluated by the Morris water maze. After treatment, hippocampi were collected for pathological examination by hematoxylin and eosin (H&E) staining. Next, hippocampal superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and glutathione (GSH) levels were assessed. Finally, glutamate cysteine ligase catalytic (GCLC) and glutamate cysteine ligase modifier (GCLM) subunit mRNA and protein levels were quantified by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. Compared with T1DM and T1DM+saline groups, escape latency was overtly reduced in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. Significantly increased GCLM and GCLC mRNA levels, GCLC protein amounts, SOD activity, and GSH levels, and reduced MDA amounts were observed in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. In T1DM and T1DM+saline groups, H&E staining showed less pyramidal cells in the hippocampus, with disorganized layers, karyopyknosis, decreased endochylema, and cavitation, effects relieved in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. Troxerutin alleviates oxidative stress and promotes learning in streptozotocin-induced T1DM rats, a process involving GCLC expression. Copyright © 2016 Elsevier B.V. All rights reserved.

The Human Papillomavirus Type 8 E6 Protein Interferes with NOTCH Activation during Keratinocyte Differentiation

PubMed Central

Meyers, Jordan M.; Spangle, Jennifer M.

2013-01-01

Cutaneous β-human papillomavirus (β-HPV) E6 proteins inhibit NOTCH signaling by associating with the transcriptional coactivator MAML1. NOTCH has tumor suppressor activities in epithelial cells and is activated during keratinocyte differentiation. Here we report that HPV type 8 (HPV8) E6 subverts NOTCH activation during keratinocyte differentiation by inhibiting RBPJ/MAML1 transcriptional activator complexes at NOTCH target DNA. NOTCH inhibition impairs epithelial differentiation and may thus contribute to β-HPV replication and viral oncogenesis. PMID:23365452

HTLV-1 Integration into Transcriptionally Active Genomic Regions Is Associated with Proviral Expression and with HAM/TSP

PubMed Central

Meekings, Kiran N.; Leipzig, Jeremy; Bushman, Frederic D.; Taylor, Graham P.; Bangham, Charles R. M.

2008-01-01

Human T-lymphotropic virus type 1 (HTLV-1) causes leukaemia or chronic inflammatory disease in ∼5% of infected hosts. The level of proviral expression of HTLV-1 differs significantly among infected people, even at the same proviral load (proportion of infected mononuclear cells in the circulation). A high level of expression of the HTLV-1 provirus is associated with a high proviral load and a high risk of the inflammatory disease of the central nervous system known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). But the factors that control the rate of HTLV-1 proviral expression remain unknown. Here we show that proviral integration sites of HTLV-1 in vivo are not randomly distributed within the human genome but are associated with transcriptionally active regions. Comparison of proviral integration sites between individuals with high and low levels of proviral expression, and between provirus-expressing and provirus non-expressing cells from within an individual, demonstrated that frequent integration into transcription units was associated with an increased rate of proviral expression. An increased frequency of integration sites in transcription units in individuals with high proviral expression was also associated with the inflammatory disease HAM/TSP. By comparing the distribution of integration sites in human lymphocytes infected in short-term cell culture with those from persistent infection in vivo, we infer the action of two selective forces that shape the distribution of integration sites in vivo: positive selection for cells containing proviral integration sites in transcriptionally active regions of the genome, and negative selection against cells with proviral integration sites within transcription units. PMID:18369476

Nimodipine-induced hypotension but not nitroglycerin-induced hypotension preserves long- and short-term memory in adult mice.

PubMed

Haile, Michael; Galoyan, Samuel; Li, Yong-Sheng; Cohen, Barry H; Quartermain, David; Blanck, Thomas; Bekker, Alex

2012-05-01

Acute hypotension may be implicated in cognitive dysfunction. L-type calcium channel blockers in the setting of hypoxia are protective of learning and memory. We tested the hypothesis that hypotension induced by nimodipine (NIMO) and nicardipine (NICA) would be protective of long- and short-term memory compared to hypotension induced by nitroglycerin (NTG). Forty Swiss-Webster mice (30 to 35 g, 6 to 8 weeks) were randomized into 4 groups for i.p. injection immediately after passive avoidance (PA) learning on day 0: (1) NTG (30 mg/kg); (2) NICA (40 mg/kg); (3) NIMO (40 mg/kg); and (4) saline. PA training latencies (seconds) were recorded for entry from a suspended platform into a Plexiglas tube where a shock (0.3 mA; 2-second duration) was automatically delivered. On day 2 latencies were recorded during a testing trial during which no shock was delivered. Latencies >900 seconds were assigned this value. Lower testing latency is indicative of an impairment of long-term associative memory. Forty-nine additional mice were randomized into similar groups for object recognition testing (ORT) and given i.p. injections on day 0. ORT measures short-term memory by exploiting the tendency of mice to prefer novel objects where a familiar object is present. On day 5 during training, 2 identical objects were placed in a circular arena and mice explored both for 15 minutes. A testing trial was conducted 1 hour later for 3 minutes after a novel object replaced a familiar one. Mice with intact memory spend about 65% of the time exploring the novel object. Mice with impaired memory devote equal time to each object. Recognition index (RI) is defined as the ratio of time spent exploring the novel object to time spent exploring both objects was the measure of memory. Mean arterial blood pressure (MAP), cerebral bloodflow, and body and brain oxygenation (PO(2)) studies were done in separate groups of mice to determine the dosages for matched degrees of hypotension and the physiological profile of each treatment. The median PA latencies for the different conditions were as follows: NTG (219.5 ± 93.5 second semi-interquartile range [SIQR]), NICA (372.5 ± 75.5 second SIQR), NIMO (540 ± 200 second SIQR) and saline (804 ± 257.5 second SIQR). Rank methods were used to analyze the PA latencies for significant differences. NTG latency was significantly shorter than NIMO latency (P = 0.012) and saline latency (P = 0.006), but not NICA latency (P = 0.126). ORT RI values showed a similar pattern. We found that NTG RI (47.2 ± 5.9% SEM) was different from NIMO RI (60.2 ± 4.6% SEM, P = 0.031) and different from saline RI (66.9 + 3.7% SEM, P = 0.006). Physiological experiments showed that MAP decreased to 45 to 50 mm Hg in all animals who became minimally responsive to external stimuli within 10 to 15 minutes of injection. Intergroup differences for MAP, body and brain oxygenation, and cerebral bloodflow were not statistically significant. Acute hypotension induced by NIMO was protective of 2 categories of memory formation relevant to the clinical posttreatment period. Both immediate long-term associative memory consolidation as measured by the PA learning paradigm and delayed short-term working memory function as measured by the ORT paradigm were significantly improved compared to matched levels of hypotension induced by NTG. These results indicate the utility of further investigation of l-type calcium channel blockers as a potential means of preserving cognition in the setting of hypotensive and low flow states.

Correlating Subjective and Objective Sleepiness: Revisiting the Association Using Survival Analysis

PubMed Central

Aurora, R. Nisha; Caffo, Brian; Crainiceanu, Ciprian; Punjabi, Naresh M.

2011-01-01

Study Objectives: The Epworth Sleepiness Scale (ESS) and multiple sleep latency test (MSLT) are the most commonly used measures of subjective and objective sleepiness, respectively. The strength of the association between these measures as well as the optimal ESS threshold that indicates objective sleepiness remains a topic of significant interest in the clinical and research arenas. The current investigation sought to: (a) examine the association between the ESS and the average sleep latency from the MSLT using the techniques of survival analysis; (b) determine whether specific patient factors influence the association; (c) examine the utility of each ESS question; and (d) identify the optimal ESS threshold that indicates objective sleepiness. Design: Cross-sectional study. Patients and Settings: Patients (N = 675) referred for polysomnography and MSLT. Measurements and Results: Using techniques of survival analysis, a significant association was noted between the ESS score and the average sleep latency. The adjusted hazard ratios for sleep onset during the MSLT for the ESS quartiles were 1.00 (ESS < 9), 1.32 (ESS: 10–13), 1.85 (ESS: 14-17), and 2.53 (ESS ≥ 18), respectively. The association was independent of several patient factors and was distinct for the 4 naps. Furthermore, most of the ESS questions were individually predictive of the average sleep latency except the tendency to doze off when lying down to rest in the afternoon, which was only predictive in patients with less than a college education. Finally, an ESS score ≥ 13 optimally predicted an average sleep latency < 8 minutes. Conclusions: In contrast to previous reports, the association between the ESS and the average sleep latency is clearly apparent when the data are analyzed by survival analysis, and most of the ESS questions are predictive of objective sleepiness. An ESS score ≥ 13 most effectively predicts objective sleepiness, which is higher than what has typically been used in clinical practice. Given the ease of administering the ESS, it represents a relatively simple and cost-effective method for identifying individuals at risk for daytime sleepiness. Citation: Aurora RN; Caffo B; Crainiceanu C; Punjabi NM. Correlating subjective and objective sleepiness: revisiting the association using survival analysis. SLEEP 2011;34(12):1707-1714. PMID:22131609

Behavioral disinhibition and reduced anxiety-like behaviors in monoamine oxidase B-deficient mice.

PubMed

Bortolato, Marco; Godar, Sean C; Davarian, Shieva; Chen, Kevin; Shih, Jean C

2009-12-01

Monoamine oxidase (MAO) B catalyzes the degradation of beta-phenylethylamine (PEA), a trace amine neurotransmitter implicated in mood regulation. Although several studies have shown an association between low MAO B activity in platelets and behavioral disinhibition in humans, the nature of this relation remains undefined. To investigate the impact of MAO B deficiency on the emotional responses elicited by environmental cues, we tested MAO B knockout (KO) mice in a set of behavioral assays capturing different aspects of anxiety-related manifestations, such as the elevated plus maze, defensive withdrawal, marble burying, and hole board. Furthermore, MAO B KO mice were evaluated for their exploratory patterns in response to unfamiliar objects and risk-taking behaviors. In comparison with their wild-type (WT) littermates, MAO B KO mice exhibited significantly lower anxiety-like responses and shorter latency to engage in risk-taking behaviors and exploration of unfamiliar objects. To determine the neurobiological bases of the behavioral differences between WT and MAO B KO mice, we measured the brain-regional levels of PEA in both genotypes. Although PEA levels were significantly higher in all brain regions of MAO B KO in comparison with WT mice, the most remarkable increments were observed in the striatum and prefrontal cortex, two key regions for the regulation of behavioral disinhibition. However, no significant differences in transcript levels of PEA's selective receptor, trace amine-associated receptor 1 (TAAR1), were detected in either region. Taken together, these results suggest that MAO B deficiency may lead to behavioral disinhibition and decreased anxiety-like responses partially through regional increases of PEA levels.

Fission yeast Tup1-like repressors repress chromatin remodeling at the fbp1+ promoter and the ade6-M26 recombination hotspot.

PubMed Central

Hirota, Kouji; Hoffman, Charles S; Shibata, Takehiko; Ohta, Kunihiro

2003-01-01

Chromatin remodeling plays crucial roles in the regulation of gene expression and recombination. Transcription of the fission yeast fbp1(+) gene and recombination at the meiotic recombination hotspot ade6-M26 (M26) are both regulated by cAMP responsive element (CRE)-like sequences and the CREB/ATF-type transcription factor Atf1*Pcr1. The Tup11 and Tup12 proteins, the fission yeast counterparts of the Saccharomyces cerevisiae Tup1 corepressor, are involved in glucose repression of the fbp1(+) transcription. We have analyzed roles of the Tup1-like corepressors in chromatin regulation around the fbp1(+) promoter and the M26 hotspot. We found that the chromatin structure around two regulatory elements for fbp1(+) was remodeled under derepressed conditions in concert with the robust activation of fbp1(+) transcription. Strains with tup11delta tup12delta double deletions grown in repressed conditions exhibited the chromatin state associated with wild-type cells grown in derepressed conditions. Interestingly, deletion of rst2(+), encoding a transcription factor controlled by the cAMP-dependent kinase, alleviated the tup11delta tup12delta defects in chromatin regulation but not in transcription repression. The chromatin at the M26 site in mitotic cultures of a tup11delta tup12delta mutant resembled that of wild-type meiotic cells. These observations suggest that these fission yeast Tup1-like corepressors repress chromatin remodeling at CRE-related sequences and that Rst2 antagonizes this function. PMID:14573465

Association of CD30 transcripts with Th1 responses and proinflammatory cytokines in patients with end-stage renal disease.

PubMed

Velásquez, Sonia Y; Opelz, Gerhard; Rojas, Mauricio; Süsal, Caner; Alvarez, Cristiam M

2016-05-01

High serum sCD30 levels are associated with inflammatory disorders and poor outcome in renal transplantation. The contribution to these phenomena of transcripts and proteins related to CD30-activation and -cleavage is unknown. We assessed in peripheral blood of end-stage renal disease patients (ESRDP) transcripts of CD30-activation proteins CD30 and CD30L, CD30-cleavage proteins ADAM10 and ADAM17, and Th1- and Th2-type immunity-related factors t-bet and GATA3. Additionally, we evaluated the same transcripts and release of sCD30 and 32 cytokines after allogeneic and polyclonal T-cell activation. In peripheral blood, ESRDP showed increased levels of t-bet and GATA3 transcripts compared to healthy controls (HC) (both P<0.01) whereas levels of CD30, CD30L, ADAM10 and ADAM17 transcripts were similar. Polyclonal and allogeneic stimulation induced higher levels of CD30 transcripts in ESRDP than in HC (both P<0.001). Principal component analysis (PCA) in allogeneic cultures of ESRDP identified two correlation clusters, one consisting of sCD30, the Th-1 cytokine IFN-γ, MIP-1α, RANTES, sIL-2Rα, MIP-1β, TNF-β, MDC, GM-CSF and IL-5, and another one consisting of CD30 and t-bet transcripts, IL-13 and proinflammatory proteins IP-10, IL-8, IL-1Rα and MCP-1. Reflecting an activated immune state, ESRDP exhibited after allostimulation upregulation of CD30 transcripts in T cells, which was associated with Th1 and proinflammatory responses. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Inhibition of CD1 antigen presentation by human cytomegalovirus.

PubMed

Raftery, Martin J; Hitzler, Manuel; Winau, Florian; Giese, Thomas; Plachter, Bodo; Kaufmann, Stefan H E; Schönrich, Günther

2008-05-01

The betaherpesvirus human cytomegalovirus (HCMV) encodes several molecules that block antigen presentation by the major histocompatibility complex (MHC) proteins. Humans also possess one other family of antigen-presenting molecules, the CD1 family; however, the effect of HCMV on CD1 expression is unknown. The majority of CD1 molecules are classified on the basis of homology as group 1 CD1 and are present almost exclusively on professional antigen-presenting cells such as dendritic cells, which are a major target for HCMV infection and latency. We have determined that HCMV encodes multiple blocking strategies targeting group 1 CD1 molecules. CD1 transcription is strongly inhibited by the HCMV interleukin-10 homologue cmvIL-10. HCMV also blocks CD1 antigen presentation posttranscriptionally by the inhibition of CD1 localization to the cell surface. This function is not performed by a known HCMV MHC class I-blocking molecule and is substantially stronger than the blockage induced by herpes simplex virus type 1. Antigen presentation by CD1 is important for the development of the antiviral immune response and the generation of mature antigen-presenting cells. HCMV present in antigen-presenting cells thus blunts the immune response by the blockage of CD1 molecules.

Decreased expression of ten-eleven translocation 1 protein is associated with some clinicopathological features in gastric cancer.

PubMed

Frycz, Bartosz Adam; Murawa, Dawid; Borejsza-Wysocki, Maciej; Marciniak, Ryszard; Murawa, Paweł; Drews, Michał; Kołodziejczak, Anna; Tomela, Katarzyna; Jagodziński, Paweł Piotr

2014-03-01

A decrease in ten-eleven translocation 1 (TET1) transcript and 5-Hydroxymethylcytosine (5hmC) levels has recently been demonstrated in primary gastric cancer (GC). However, little is known about TET1 protein levels in gastric tumoral and nontumoral tissue. Therefore, using reverse transcription, real-time quantitative polymerase chain reaction and western blotting analysis, we determined the TET1 transcript and protein levels in tumoral and nontumoral tissue from 38 patients with GC. We also assessed the association between the decrease in TET1 transcript and protein levels and some clinicopathological features in primary GC. We found significantly decreased levels of TET1 transcript (P=0.0023) and protein (P=0.00024) in primary tumoral tissues as compared to nontumoral tissues in patients with GC. Moreover, we also observed significantly lower amounts of TET1 transcript (P=0.03) and protein (P=0.00018) in tumoral tissues in patients aged>60. We also found significant lowered TET1 protein levels in male patients (P=0.0014), stomach (P=0.044) and cardia (P=0.013) tumor localization, T3 depth of invasion (P=0.019), N1 (P=0.012) and N3 lymph node metastasis (P=0.013) and G3 histological grade (P=0.0012). There were also significant decreases in TET1 transcript levels in female patients (P=0.042), intestinal histological types (P=0.0079) and T4 depth of invasion (P=0.037). Our results demonstrated that a decrease in TET1 transcript and protein levels is associated with some clinicopathological features in GC. Copyright © 2014. Published by Elsevier Masson SAS.

Identification of a Sjögren's syndrome susceptibility locus at OAS1 that influences isoform switching, protein expression, and responsiveness to type I interferons

PubMed Central

Li, He; Reksten, Tove Ragna; Ice, John A.; Kelly, Jennifer A.; Adrianto, Indra; Wang, Shaofeng; He, Bo; Grundahl, Kiely M.; Glenn, Stuart B.; Miceli-Richard, Corinne; Bowman, Simon; Lester, Sue; Eriksson, Per; Brun, Johan G.; Gøransson, Lasse G.; Harboe, Erna; Guthridge, Joel M.; Patel, Ketan; Adler, Adam J.; Farris, A. Darise; Brennan, Michael T.; Chodosh, James; Gopalakrishnan, Rajaram; Weisman, Michael H.; Venuturupalli, Swamy; Wallace, Daniel J.; Hefner, Kimberly S.; Houston, Glen D.; Hughes, Pamela J.; Lewis, David M.; Radfar, Lida; Vista, Evan S.; Rohrer, Michael D.; Stone, Donald U.; Vyse, Timothy J.; Harley, John B.; James, Judith A.; Turner, Sean; Alevizos, Ilias; Anaya, Juan-Manuel; Rhodus, Nelson L.; Segal, Barbara M.; Montgomery, Courtney G.; Scofield, R. Hal; Kovats, Susan; Mariette, Xavier; Witte, Torsten; Rischmueller, Maureen; Omdal, Roald; Lessard, Christopher J.; Sivils, Kathy L.

2017-01-01

Sjögren’s syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10−14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10−9; odds ratio = 0.75; 95% confidence interval = 0.66–0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease. PMID:28640813

Molecular mechanism of Spinocerebellar Ataxia type 6: glutamine repeat disorder, channelopathy and transcriptional dysregulation. The multifaceted aspects of a single mutation

PubMed Central

Giunti, Paola; Mantuano, Elide; Frontali, Marina; Veneziano, Liana

2015-01-01

Spinocerebellar Ataxia type 6 (SCA6) is an autosomal dominant neurodegenerative disease characterized by late onset, slowly progressive, mostly pure cerebellar ataxia. It is one of three allelic disorders associated to CACNA1A gene, coding for the Alpha1 A subunit of P/Q type calcium channel Cav2.1 expressed in the brain, particularly in the cerebellum. The other two disorders are Episodic Ataxia type 2 (EA2), and Familial Hemiplegic Migraine type 1 (FHM1). These disorders show distinct phenotypes that often overlap but have different pathogenic mechanisms. EA2 and FHM1 are due to mutations causing, respectively, a loss and a gain of channel function. SCA6, instead, is associated with short expansions of a polyglutamine stretch located in the cytoplasmic C-terminal tail of the protein. This domain has a relevant role in channel regulation, as well as in transcription regulation of other neuronal genes; thus the SCA6 CAG repeat expansion results in complex pathogenic molecular mechanisms reflecting the complex Cav2.1 C-terminus activity. We will provide a short review for an update on the SCA6 molecular mechanism. PMID:25762895

The Wnt signaling pathway is differentially expressed during the bovine herpesvirus 1 latency-reactivation cycle: evidence that two protein kinases associated with neuronal survival (Akt3 and bone morphogenetic protein....

USDA-ARS?s Scientific Manuscript database

Sensory neurons in trigeminal ganglia (TG) of calves latently infected with bovine herpesvirus 1 (BoHV-1) abundantly express latency-related (LR) gene products, including a protein (ORF2) and two micro-RNAs. Recent studies in mouse neuroblastoma cells (Neuro-2A) demonstrated ORF2 interacts with ß-ca...

Human Immunodeficiency Virus (HIV) Latency: The Major Hurdle in HIV Eradication

PubMed Central

Tyagi, Mudit; Bukrinsky, Michael

2012-01-01

Failure of highly active antiretroviral therapy to eradicate the human immunodeficiency virus (HIV), even in patients who suppress the virus to undetectable levels for many years, underscores the problems associated with fighting this infection. The existence of persistent infection in certain cellular and anatomical reservoirs appears to be the major hurdle in HIV eradication. The development of therapeutic interventions that eliminate or limit the latent viral pools or prevent the reemergence of the viruses from producing cells will therefore be required to enhance the effectiveness of current antiretroviral strategies. To achieve this goal, there is a pressing need to understand HIV latency at the molecular level to design novel and improved therapies to either eradicate HIV or find a functional cure in which patients could maintain a manageable viral pool without AIDS in the absence of antiretroviral therapy. The integrated proviral genome remains transcriptionally silent for a long period in certain subsets of T cells. This ability to infect cells latently helps HIV to establish a persistent infection despite strong humoral and cellular immune responses against the viral proteins. The main purpose of this report is to provide a general overview of the HIV latency. We will describe the hurdles being faced in eradicating latent HIV proviruses. We will also briefly discuss the ongoing strategies aimed toward curing HIV infection. PMID:22692576

An association of type 1 diabetes mellitus with auditory dysfunction: A systematic review and meta-analysis.

PubMed

Teng, Zhi-Pan; Tian, Rui; Xing, Fen-Li; Tang, Hui; Xu, Jin-Jing; Zhang, Bing-Wen; Qi, Jian-Wei

2017-07-01

To establish the relationship between the presence of type 1 diabetes mellitus (DM) and auditory dysfunction in clinical settings by a systematic review and meta-analysis of currently available published data. The electronic databases PubMed, Embase, and Wanfang Data were searched for eligible relevant studies up to May 2016, and the reference lists of the retrieved articles were used for additional manual search. All the articles included in this pooled analysis were determined according to the preset inclusion and exclusion criteria. Meta-analysis of pooled data was performed using Review Manager 5.3. A total of 15 studies were included for further combined analysis. The results showed that patients with type 1 diabetes had a significantly higher prevalence of hearing loss than controls (odds ratio = 49.08, 95% confidence interval = 12.03-200.31, P < 0.00001); standardized mean of differences (SMD) of pure tone audiometry at 4,000 Hz between diabetes and controls was 0.87 (Z = 2.22, P = 0.03, I 2 = 95%); SMD of the latency time was 0.54 (Z = 2.69, P = 0.007, I 2 = 78%) for waves III and 0.61 (Z = 2.38, P = 0.02, I 2 = 86%) for wave V, respectively; and SMD of the interpeak latency time was 0.41 (Z = 2.84, P = 0.005, I 2 = 39%) for waves I to III and 0.61 (Z = 2.67, P = 0.008, I 2 = 81%) for waves I to V, respectively, between diabetics and controls. Our study reveals that there is relationship between the presence of type 1 DM and an increased risk for developing mild and subclinical hearing impairment. NA. Laryngoscope, 127:1689-1697, 2017. © 2016 The Authors. The Laryngoscope published by Wiley Periodicals, Inc. on behalf of American Laryngological, Rhinological and Otological Society Inc, “The Triological Society” and American Laryngological Association (ALA).

Canine Sense and Sensibility: Tipping Points and Response Latency Variability as an Optimism Index in a Canine Judgement Bias Assessment

PubMed Central

Starling, Melissa J.; Branson, Nicholas; Cody, Denis; Starling, Timothy R.; McGreevy, Paul D.

2014-01-01

Recent advances in animal welfare science used judgement bias, a type of cognitive bias, as a means to objectively measure an animal's affective state. It is postulated that animals showing heightened expectation of positive outcomes may be categorised optimistic, while those showing heightened expectations of negative outcomes may be considered pessimistic. This study pioneers the use of a portable, automated apparatus to train and test the judgement bias of dogs. Dogs were trained in a discrimination task in which they learned to touch a target after a tone associated with a lactose-free milk reward and abstain from touching the target after a tone associated with water. Their judgement bias was then probed by presenting tones between those learned in the discrimination task and measuring their latency to respond by touching the target. A Cox's Proportional Hazards model was used to analyse censored response latency data. Dog and Cue both had a highly significant effect on latency and risk of touching a target. This indicates that judgement bias both exists in dogs and differs between dogs. Test number also had a significant effect, indicating that dogs were less likely to touch the target over successive tests. Detailed examination of the response latencies revealed tipping points where average latency increased by 100% or more, giving an indication of where dogs began to treat ambiguous cues as predicting more negative outcomes than positive ones. Variability scores were calculated to provide an index of optimism using average latency and standard deviation at cues after the tipping point. The use of a mathematical approach to assessing judgement bias data in animal studies offers a more detailed interpretation than traditional statistical analyses. This study provides proof of concept for the use of an automated apparatus for measuring cognitive bias in dogs. PMID:25229458

Comprehensive meta-analysis of Signal Transducers and Activators of Transcription (STAT) genomic binding patterns discerns cell-specific cis-regulatory modules

PubMed Central

2013-01-01

Background Cytokine-activated transcription factors from the STAT (Signal Transducers and Activators of Transcription) family control common and context-specific genetic programs. It is not clear to what extent cell-specific features determine the binding capacity of seven STAT members and to what degree they share genetic targets. Molecular insight into the biology of STATs was gained from a meta-analysis of 29 available ChIP-seq data sets covering genome-wide occupancy of STATs 1, 3, 4, 5A, 5B and 6 in several cell types. Results We determined that the genomic binding capacity of STATs is primarily defined by the cell type and to a lesser extent by individual family members. For example, the overlap of shared binding sites between STATs 3 and 5 in T cells is greater than that between STAT5 in T cells and non-T cells. Even for the top 1,000 highly enriched STAT binding sites, ~15% of STAT5 binding sites in mouse female liver are shared by other STATs in different cell types while in T cells ~90% of STAT5 binding sites are co-occupied by STAT3, STAT4 and STAT6. In addition, we identified 116 cis-regulatory modules (CRM), which are recognized by all STAT members across cell types defining a common JAK-STAT signature. Lastly, in liver STAT5 binding significantly coincides with binding of the cell-specific transcription factors HNF4A, FOXA1 and FOXA2 and is associated with cell-type specific gene transcription. Conclusions Our results suggest that genomic binding of STATs is primarily determined by the cell type and further specificity is achieved in part by juxtaposed binding of cell-specific transcription factors. PMID:23324445

Selective targeting of the repressive transcription factors YY1 and cMyc to disrupt quiescent human immunodeficiency viruses.

PubMed

Barton, Kirston; Margolis, David

2013-02-01

Quiescent HIV-1 infection of resting CD4(+) T cells is an obstacle to eradication of HIV-1 infection. These reservoirs are maintained, in part, by repressive complexes that bind to the HIV-1 long terminal repeat (LTR) and recruit histone deacetylases (HDACs). cMyc and YY1 are two transcription factors that are recruited as part of well-described, distinct complexes to the HIV-1 LTR and in turn recruit HDACs. In prior studies, depletion of single factors that recruit HDAC1 in various cell lines was sufficient to upregulate LTR activity. We used short hairpin RNAs (shRNAs) to test the effect of targeted disruption of a single transcription factor on quiescent proviruses in T cell lines. In this study, we found that depletion of YY1 significantly increases mRNA and protein expression from the HIV-1 promoter in some contexts, but does not affect HDAC1, HDAC2, HDAC3, or acetylated histone 3 occupancy of the HIV-1 LTR. Conversely, depletion of cMyc or cMyc and YY1 does not significantly alter the level of transcription from the LTR or affect recruitment of HDACs to the HIV-1 LTR. Furthermore, global inhibition of HDACs with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) enhanced the increase in LTR transcription in cells that were depleted of YY1.These findings show that despite prior isolated findings, redundancy in repressors of HIV-1 LTR expression will require selective targeting of multiple restrictive mechanisms to comprehensively induce the escape of quiescent proviruses from latency.

Proviral Latency, Persistent Human Immunodeficiency Virus Infection, and the Development of Latency Reversing Agents

PubMed Central

Archin, Nancie M.

2017-01-01

Abstract Quiescent proviral genomes that persist during human immunodeficiency virus type 1 (HIV-1) infection despite effective antiretroviral therapy (ART) can fuel rebound viremia after ART interruption and is a central obstacle to the cure of HIV infection. The induction of quiescent provirus is the goal of a new class of potential therapeutics, latency reversing agents (LRAs). The discovery, development, and testing of HIV LRAs is a key part of current efforts to develop latency reversal and viral clearance strategies to eradicate established HIV infection. The development of LRAs is burdened by many uncertainties that make drug discovery difficult. The biology of HIV latency is complex and incompletely understood. Potential targets for LRAs are host factors, and the potential toxicities of host-directed therapies in individuals that are otherwise clinically stable may be unacceptable. Assays to measure latency reversal and assess the effectiveness of potential therapeutics are complex and incompletely validated. Despite these obstacles, novel LRAs are under development and beginning to enter combination testing with viral clearance strategies. It is hoped that the steady advances in the development of LRAs now being paired with emerging immunotherapeutics to clear persistently infected cells will soon allow measurable clinical advances toward an HIV cure. PMID:28520964

TRACING THE DEVELOPMENT OF TYPEWRITING SKILLS IN AN ADAPTIVE E-LEARNING ENVIRONMENT.

PubMed

van den Bergh, Mattis; Hofman, Abe D; Schmittmann, Verena D; van der Maas, Han L J

2015-12-01

Typewriting studies which compare novice and expert typists have suggested that highly trained typing skills involve cognitive process with an inner and outer loop, which regulate keystrokes and words, respectively. The present study investigates these loops longitudinally, using multi-level modeling of 1,091,707 keystroke latencies from 62 children (M age=12.6 yr.) following an online typing course. Using finger movement repetition as indicator of the inner loop and words typed as indicator of the outer loop, practicing keystroke latencies resulted in different developmental curves for each loop. Moreover, based on plateaus in the developmental curves, the inner loop seemed to require less practice to develop than the outer loop.

Perceived ejaculatory latency and pleasure in different outlets.

PubMed

Corty, Eric W

2008-11-01

Ejaculatory latencies have been studied in coitus and with masturbation, but not with oral or manual stimulation by a partner. The present study extended research on ejaculatory latency to these outlets, and investigated the effect of perceived pleasure on self-reported ejaculatory latency. A convenience sample of male college students, not selected for sexual dysfunction, completed questionnaires assessing the outcome measures. Self-report measures of latency to ejaculation in, and perceived pleasure associated with, four different outlets (vaginal intercourse, oral intercourse, manual stimulation by a partner, and masturbation). Ejaculatory latencies in partnered activities were predictive of each other. Masturbatory latencies were predictive of coital latencies but not oral or manual stimulation latencies; all the partnered activities were predictive of each other. There was no difference in time to ejaculation among any of the partnered outlets, although ejaculation occurred more quickly with masturbation than with coitus or manual stimulation. In terms of pleasure associated with the outlets, vaginal and oral intercourse were perceived as equally pleasurable, and both were rated as more pleasurable than manual stimulation or masturbation, which did not differ from each other. These results suggest that rapidity of ejaculation is consistent across outlets for the partnered sexual activities, and that there is little unique-in terms of ejaculatory latency--about vaginal intercourse compared with oral or manual stimulation by a partner. Masturbation, however, does differ from the partnered activities. Although the average correlation, for individuals, between latency and pleasure for the different outlets is near zero, there are subgroups of men who have (i) a negative relation, (ii) a positive relation, or (iii) no relation. Results show that men, for whom greater pleasure is associated with shorter latency, are more likely to be dissatisfied with their intravaginal ejaculatory latencies, regardless of actual latency.

Reduced evolutionary rates in HIV-1 reveal extensive latency periods among replicating lineages.

PubMed

Immonen, Taina T; Leitner, Thomas

2014-10-16

HIV-1 can persist for the duration of a patient's life due in part to its ability to hide from the immune system, and from antiretroviral drugs, in long-lived latent reservoirs. Latent forms of HIV-1 may also be disproportionally involved in transmission. Thus, it is important to detect and quantify latency in the HIV-1 life cycle. We developed a novel molecular clock-based phylogenetic tool to investigate the prevalence of HIV-1 lineages that have experienced latency. The method removes alternative sources that may affect evolutionary rates, such as hypermutation, recombination, and selection, to reveal the contribution of generation-time effects caused by latency. Our method was able to recover latent lineages with high specificity and sensitivity, and low false discovery rates, even on relatively short branches on simulated phylogenies. Applying the tool to HIV-1 sequences from 26 patients, we show that the majority of phylogenetic lineages have been affected by generation-time effects in every patient type, whether untreated, elite controller, or under effective or failing treatment. Furthermore, we discovered extensive effects of latency in sequence data (gag, pol, and env) from reservoirs as well as in the replicating plasma population. To better understand our phylogenetic findings, we developed a dynamic model of virus-host interactions to investigate the proportion of lineages in the actively replicating population that have ever been latent. Assuming neutral evolution, our dynamic modeling showed that under most parameter conditions, it is possible for a few activated latent viruses to propagate so that in time, most HIV-1 lineages will have been latent at some time in their past. These results suggest that cycling in and out of latency plays a major role in the evolution of HIV-1. Thus, no aspect of HIV-1 evolution can be fully understood without considering latency - including treatment, drug resistance, immune evasion, transmission, and pathogenesis.

Primary display latency criteria based on flying qualities and performance data

NASA Technical Reports Server (NTRS)

Funk, John D., Jr.; Beck, Corin P.; Johns, John B.

1993-01-01

With a pilots' increasing use of visual cue augmentation, much requiring extensive pre-processing, there is a need to establish criteria for new avionics/display design. The timeliness and synchronization of the augmented cues is vital to ensure the performance quality required for precision mission task elements (MTEs) where augmented cues are the primary source of information to the pilot. Processing delays incurred while transforming sensor-supplied flight information into visual cues are unavoidable. Relationships between maximum control system delays and associated flying qualities levels are documented in MIL-F-83300 and MIL-F-8785. While cues representing aircraft status may be just as vital to the pilot as prompt control response for operations in instrument meteorological conditions, presently, there are no specification requirements on avionics system latency. To produce data relating avionics system latency to degradations in flying qualities, the Navy conducted two simulation investigations. During the investigations, flying qualities and performance data were recorded as simulated avionics system latency was varied. Correlated results of the investigation indicates that there is a detrimental impact of latency on flying qualities. Analysis of these results and consideration of key factors influencing their application indicate that: (1) Task performance degrades and pilot workload increases as latency is increased. Inconsistency in task performance increases as latency increases. (2) Latency reduces the probability of achieving Level 1 handling qualities with avionics system latency as low as 70 ms. (3) The data suggest that the achievement of desired performance will be ensured only at display latency values below 120 ms. (4) These data also suggest that avoidance of inadequate performance will be ensured only at display latency values below 150 ms.

Adenosine Deaminase Acting on RNA-1 (ADAR1) Inhibits HIV-1 Replication in Human Alveolar Macrophages

PubMed Central

Levy, David N.; Li, Yonghua; Kumar, Rajnish; Burke, Sean A.; Dawson, Rodney; Hioe, Catarina E.; Borkowsky, William; Rom, William N.; Hoshino, Yoshihiko

2014-01-01

While exploring the effects of aerosol IFN-γ treatment in HIV-1/tuberculosis co-infected patients, we observed A to G mutations in HIV-1 envelope sequences derived from bronchoalveolar lavage (BAL) of aerosol IFN-γ-treated patients and induction of adenosine deaminase acting on RNA 1 (ADAR1) in the BAL cells. IFN-γ induced ADAR1 expression in monocyte-derived macrophages (MDM) but not T cells. ADAR1 siRNA knockdown induced HIV-1 expression in BAL cells of four HIV-1 infected patients on antiretroviral therapy. Similar results were obtained in MDM that were HIV-1 infected in vitro. Over-expression of ADAR1 in transformed macrophages inhibited HIV-1 viral replication but not viral transcription measured by nuclear run-on, suggesting that ADAR1 acts post-transcriptionally. The A to G hyper-mutation pattern observed in ADAR1 over-expressing cells in vitro was similar to that found in the lungs of HIV-1 infected patients treated with aerosol IFN-γ suggesting the model accurately represented alveolar macrophages. Together, these results indicate that ADAR1 restricts HIV-1 replication post-transcriptionally in macrophages harboring HIV-1 provirus. ADAR1 may therefore contribute to viral latency in macrophages. PMID:25272020

The Pea light-independent photomorphogenesis1 Mutant Results from Partial Duplication of COP1 Generating an Internal Promoter and Producing Two Distinct Transcripts

PubMed Central

Sullivan, James A.; Gray, John C.

2000-01-01

The pea lip1 (light-independent photomorphogenesis1) mutant shows many of the characteristics of light-grown development when grown in continuous darkness. To investigate the identity of LIP1, cDNAs encoding the pea homolog of COP1, a repressor of photomorphogenesis identified in Arabidopsis, were isolated from wild-type and lip1 pea seedlings. lip1 seedlings contained a wild-type COP1 transcript as well as a larger COP1′ transcript that contained an internal in-frame duplication of 894 bp. The COP1′ transcript segregated with the lip1 phenotype in F2 seedlings and could be translated in vitro to produce a protein of ∼100 kD. The COP1 gene in lip1 peas contained a 7.5-kb duplication, consisting of exons 1 to 7 of the wild-type sequence, located 2.5 kb upstream of a region of genomic DNA identical to the wild-type COP1 DNA sequence. Transcription and splicing of the mutant COP1 gene was predicted to produce the COP1′ transcript, whereas transcription from an internal promoter in the 2.5-kb region of DNA located between the duplicated regions of COP1 would produce the wild-type COP1 transcript. The presence of small quantities of wild-type COP1 transcripts may reduce the severity of the phenotype produced by the mutated COP1′ protein. The genomic DNA sequences of the COP1 gene from wild-type and lip1 peas and the cDNA sequences of COP1 and COP1′ transcripts have been submitted to the EMBL database under the EMBL accession numbers AJ276591, AJ276592, AJ289773, and AJ289774, respectively. PMID:11041887

Acetylation of nucleosomal histones by p300 facilitates transcription from tax-responsive human T-cell leukemia virus type 1 chromatin template.

PubMed

Lu, Hanxin; Pise-Masison, Cynthia A; Fletcher, Terace M; Schiltz, R Louis; Nagaich, Akhilesh K; Radonovich, Michael; Hager, Gordon; Cole, Philip A; Brady, John N

2002-07-01

Expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated by the viral transcriptional activator Tax. Tax activates viral transcription through interaction with the cellular transcription factor CREB and the coactivators CBP/p300. One key property of the coactivators is the presence of histone acetyltransferase (HAT) activity, which enables p300/CBP to modify nucleosome structure. The data presented in this manuscript demonstrate that full-length p300 and CBP facilitate transcription of a reconstituted chromatin template in the presence of Tax and CREB. The ability of p300 and CBP to activate transcription from the chromatin template is dependent upon the HAT activity. Moreover, the coactivator HAT activity must be tethered to the template by Tax and CREB, since a p300 mutant that fails to interact with Tax did not facilitate transcription or acetylate histones. p300 acetylates histones H3 and H4 within nucleosomes located in the promoter and 5' proximal regions of the template. Nucleosome acetylation is accompanied by an increase in the level of binding of RNA polymerase II transcription factor TFIID and RNA polymerase II to the promoter. Interestingly, we found distinct transcriptional activities between CBP and p300. CBP, but not p300, possesses an N-terminal activation domain which directly activates Tax-mediated HTLV-1 transcription from a naked DNA template. Finally, using the chromatin immunoprecipitation assay, we provide the first direct experimental evidence that p300 and CBP are associated with the HTLV-1 long terminal repeat in vivo.

Non-singleton colors are not attended faster than categories, but they are encoded faster: A combined approach of behavior, modeling and ERPs.

PubMed

Callahan-Flintoft, Chloe; Wyble, Brad

2017-11-01

The visual system is able to detect targets according to a variety of criteria, such as by categorical (letter vs digit) or featural attributes (color). These criteria are often used interchangeably in rapid serial visual presentation (RSVP) studies but little is known about how rapidly they are processed. The aim of this work was to compare the time course of attentional selection and memory encoding for different types of target criteria. We conducted two experiments where participants reported one or two targets (T1, T2) presented in lateral RSVP streams. Targets were marked either by being a singleton color (red letter among black letters), being categorically distinct (digits among letters) or non-singleton color (target color letter among heterogeneously colored letters). Using event related potential (ERPs) associated with attention and memory encoding (the N2pc and the P3 respectively), we compared the relative latency of these two processing stages for these three kinds of targets. In addition to these ERP measures, we obtained convergent behavioral measures for attention and memory encoding by presenting two targets in immediate sequence and comparing their relative accuracy and proportion of temporal order errors. Both behavioral and EEG measures revealed that singleton color targets were attended much more quickly than either non-singleton color or categorical targets, and there was very little difference between attention latencies to non-singleton color and categorical targets. There was however a difference in the speed of memory encoding for non-singleton color and category latencies in both behavioral and EEG measures, which shows that encoding latency differences do not always mirror attention latency differences. Copyright © 2017 Elsevier Ltd. All rights reserved.

P3 event-related potential impairments in antisocial and psychopathic individuals: a meta-analysis.

PubMed

Gao, Yu; Raine, Adrian

2009-12-01

Prior findings on P3 event-related potential deficits in antisocial populations are mixed and it has been suggested that these abnormalities may not apply to psychopaths. A meta-analysis of 38 studies (total N=2616) was conducted to investigate the relationship of P3 measures to antisocial behavior. Reduced P3 amplitudes (d=0.252, p<.001) and longer P3 latencies (d=0.130, p=.019) were significantly associated with antisocial behavior across all electrode sites, and when using both normal and non-normal control groups. A significant moderating effect of electrode site indicated longer latencies at Fz but not Pz. Compared to non-psychopathic offenders, psychopathic offenders showed P3 amplitudes impairments in standard oddball tasks, but not other tasks. Findings suggest that reduced P3 amplitudes and prolonged P3 latencies may reflect inefficient deployment of neural resources in processing cognitive task-relevant information in individuals characterized with generic antisocial behavior (i.e., aggression, antisocial personality disorder, conduct disorder/oppositional-defiant disorder, and psychopathy), whereas this association in psychopaths may be moderated by the type of tasks.

LANP mediates neuritic pathology in Spinocerebellar ataxia type 1

PubMed Central

Cvetanovic, Marija; Kular, Rupinder K.; Opal, Puneet

2014-01-01

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disease that results from a pathogenic glutamine-repeat expansion in the protein ataxin-1 (ATXN1). Although the functions of ATXN1 are still largely unknown, there is evidence to suggest that ATXN1 plays a role in regulating gene expression, the earliest process known to go awry in SCA1 mouse models. In this study, we show that ATXN1 reduces histone acetylation, a post-translational modification of histones associated with enhanced transcription, and represses histone acetyl transferase-mediated transcription. In addition, we find that depleting the Leucine-rich Acidic Nuclear Protein (LANP)—an ATXN1 binding inhibitor of histone acetylation—reverses aspects of SCA1 neuritic pathology. PMID:22884877

Characterization of Neuronal Populations in the Human Trigeminal Ganglion and Their Association with Latent Herpes Simplex Virus-1 Infection

PubMed Central

Horn, Anja K. E.; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Theil, Diethilde; Hüfner, Katharina

2013-01-01

Following primary infection Herpes simplex virus-1 (HSV-1) establishes lifelong latency in the neurons of human sensory ganglia. Upon reactivation HSV-1 can cause neurological diseases such as facial palsy, vestibular neuritis or encephalitis. Certain populations of sensory neurons have been shown to be more susceptible to latent infection in the animal model, but this has not been addressed in human tissue. In the present study, trigeminal ganglion (TG) neurons expressing six neuronal marker proteins were characterized, based on staining with antibodies against the GDNF family ligand receptor Ret, the high-affinity nerve growth factor receptor TrkA, neuronal nitric oxide synthase (nNOS), the antibody RT97 against 200kDa neurofilament, calcitonin gene-related peptide and peripherin. The frequencies of marker-positive neurons and their average neuronal sizes were assessed, with TrkA-positive (61.82%) neurons being the most abundant, and Ret-positive (26.93%) the least prevalent. Neurons positive with the antibody RT97 (1253 µm2) were the largest, and those stained against peripherin (884 µm2) were the smallest. Dual immunofluorescence revealed at least a 4.5% overlap for every tested marker combination, with overlap for the combinations TrkA/Ret, TrkA/RT97 and Ret/nNOS lower, and the overlap between Ret/CGRP being higher than would be expected by chance. With respect to latent HSV-1 infection, latency associated transcripts (LAT) were detected using in situ hybridization (ISH) in neurons expressing each of the marker proteins. In contrast to the mouse model, co-localization with neuronal markers Ret or CGRP mirrored the magnitude of these neuron populations, whereas for the other four neuronal markers fewer marker-positive cells were also LAT-ISH+. Ret and CGRP are both known to label neurons related to pain signaling. PMID:24367603

PKCepsilon overexpression, irrespective of genetic background, sensitizes skin to UVR-induced development of squamous-cell carcinomas.

PubMed

Sand, Jordan M; Aziz, Moammir H; Dreckschmidt, Nancy E; Havighurst, Thomas C; Kim, KyungMann; Oberley, Terry D; Verma, Ajit K

2010-01-01

Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.

The Transcription Factor Rbf1 Is the Master Regulator for b-Mating Type Controlled Pathogenic Development in Ustilago maydis

PubMed Central

Vranes, Miroslav; Wahl, Ramon; Pothiratana, Chetsada; Schuler, David; Vincon, Volker; Finkernagel, Florian; Flor-Parra, Ignacio; Kämper, Jörg

2010-01-01

In the phytopathogenic basidiomycete Ustilago maydis, sexual and pathogenic development are tightly connected and controlled by the heterodimeric bE/bW transcription factor complex encoded by the b-mating type locus. The formation of the active bE/bW heterodimer leads to the formation of filaments, induces a G2 cell cycle arrest, and triggers pathogenicity. Here, we identify a set of 345 bE/bW responsive genes which show altered expression during these developmental changes; several of these genes are associated with cell cycle coordination, morphogenesis and pathogenicity. 90% of the genes that show altered expression upon bE/bW-activation require the zinc finger transcription factor Rbf1, one of the few factors directly regulated by the bE/bW heterodimer. Rbf1 is a novel master regulator in a multilayered network of transcription factors that facilitates the complex regulatory traits of sexual and pathogenic development. PMID:20700446

Coactivator-associated arginine methyltransferase 1 enhances transcriptional activity of the human T-cell lymphotropic virus type 1 long terminal repeat through direct interaction with Tax.

PubMed

Jeong, Soo-Jin; Lu, Hanxin; Cho, Won-Kyung; Park, Hyeon Ung; Pise-Masison, Cynthia; Brady, John N

2006-10-01

In this study, we demonstrate that the coactivator-associated arginine methyltransferase 1 (CARM1), which methylates histone H3 and other proteins such as p300/CBP, is positively involved in the regulation of Tax transactivation. First, transfection studies demonstrated that overexpression of CARM1 wild-type protein resulted in increased Tax transactivation of the human T-cell lymphotropic virus type 1 (HTLV-1) long terminal repeat (LTR). In contrast, transfection of a catalytically inactive CARM1 methyltransferase mutant did not enhance Tax transactivation. CARM1 facilitated Tax transactivation of the CREB-dependent cellular GEM promoter. A direct physical interaction between HTLV-1 Tax and CARM1 was demonstrated using in vitro glutathione S-transferase-Tax binding assays, in vivo coimmunoprecipitation, and confocal microscopy experiments. Finally, chromatin immunoprecipitation analysis of the activated HTLV-1 LTR promoter showed the association of CARM1 and methylated histone H3 with the template DNA. In vitro, Tax facilitates the binding of CARM1 to the transcription complex. Together, our data provide evidence that CARM1 enhances Tax transactivation of the HTLV-1 LTR through a direct interaction between CARM1 and Tax and this binding promotes methylation of histone H3 (R2, R17, and R26).

Transcriptional Pathways Altered in Response to Vibration in a Model of Hand-Arm Vibration Syndrome

PubMed Central

Waugh, Stacey; Kashon, Michael L.; Li, Shengqiao; Miller, Gerome R.; Johnson, Claud; Krajnak, Kristine

2016-01-01

Objective The aim of this study was to use an established model of vibration-induced injury to assess frequency-dependent changes in transcript expression in skin, artery, and nerve tissues. Methods Transcript expression in tissues from control and vibration-exposed rats (4 h/day for 10 days at 62.5, 125, or 250 Hz; 49 m/s2, rms) was measured. Transcripts affected by vibration were used in bioinformatics analyses to identify molecular- and disease-related pathways associated with exposure to vibration. Results Analyses revealed that cancer-related pathways showed frequency-dependent changes in activation or inhibition. Most notably, the breast-related cancer-1 pathway was affected. Other pathways associated with breast cancer type 1 susceptibility protein related signaling, or associated with cancer and cell cycle/cell survivability were also affected. Conclusion Occupational exposure to vibration may result in DNA damage and alterations in cell signaling pathways that have significant effects on cellular division. PMID:27058473

A Herpesviral Immediate Early Protein Promotes Transcription Elongation of Viral Transcripts.

PubMed

Fox, Hannah L; Dembowski, Jill A; DeLuca, Neal A

2017-06-13

Herpes simplex virus 1 (HSV-1) genes are transcribed by cellular RNA polymerase II (RNA Pol II). While four viral immediate early proteins (ICP4, ICP0, ICP27, and ICP22) function in some capacity in viral transcription, the mechanism by which ICP22 functions remains unclear. We observed that the FACT complex (comprised of SSRP1 and Spt16) was relocalized in infected cells as a function of ICP22. ICP22 was also required for the association of FACT and the transcription elongation factors SPT5 and SPT6 with viral genomes. We further demonstrated that the FACT complex interacts with ICP22 throughout infection. We therefore hypothesized that ICP22 recruits cellular transcription elongation factors to viral genomes for efficient transcription elongation of viral genes. We reevaluated the phenotype of an ICP22 mutant virus by determining the abundance of all viral mRNAs throughout infection by transcriptome sequencing (RNA-seq). The accumulation of almost all viral mRNAs late in infection was reduced compared to the wild type, regardless of kinetic class. Using chromatin immunoprecipitation sequencing (ChIP-seq), we mapped the location of RNA Pol II on viral genes and found that RNA Pol II levels on the bodies of viral genes were reduced in the ICP22 mutant compared to wild-type virus. In contrast, the association of RNA Pol II with transcription start sites in the mutant was not reduced. Taken together, our results indicate that ICP22 plays a role in recruiting elongation factors like the FACT complex to the HSV-1 genome to allow for efficient viral transcription elongation late in viral infection and ultimately infectious virion production. IMPORTANCE HSV-1 interacts with many cellular proteins throughout productive infection. Here, we demonstrate the interaction of a viral protein, ICP22, with a subset of cellular proteins known to be involved in transcription elongation. We determined that ICP22 is required to recruit the FACT complex and other transcription elongation factors to viral genomes and that in the absence of ICP22 viral transcription is globally reduced late in productive infection, due to an elongation defect. This insight defines a fundamental role of ICP22 in HSV-1 infection and elucidates the involvement of cellular factors in HSV-1 transcription. Copyright © 2017 Fox et al.

Identification and characterization of regulatory elements in the promoter of ACVR1, the gene mutated in Fibrodysplasia Ossificans Progressiva

PubMed Central

2013-01-01

Background The ACVR1 gene encodes a type I receptor for bone morphogenetic proteins (BMPs). Mutations in the ACVR1 gene are associated with Fibrodysplasia Ossificans Progressiva (FOP), a rare and extremely disabling disorder characterized by congenital malformation of the great toes and progressive heterotopic endochondral ossification in muscles and other non-skeletal tissues. Several aspects of FOP pathophysiology are still poorly understood, including mechanisms regulating ACVR1 expression. This work aimed to identify regulatory elements that control ACVR1 gene transcription. Methods and results We first characterized the structure and composition of human ACVR1 gene transcripts by identifying the transcription start site, and then characterized a 2.9 kb upstream region. This region showed strong activating activity when tested by reporter gene assays in transfected cells. We identified specific elements within the 2.9 kb region that are important for transcription factor binding using deletion constructs, co-transfection experiments with plasmids expressing selected transcription factors, site-directed mutagenesis of consensus binding-site sequences, and by protein/DNA binding assays. We also characterized a GC-rich minimal promoter region containing binding sites for the Sp1 transcription factor. Conclusions Our results showed that several transcription factors such as Egr-1, Egr-2, ZBTB7A/LRF, and Hey1, regulate the ACVR1 promoter by binding to the -762/-308 region, which is essential to confer maximal transcriptional activity. The Sp1 transcription factor acts at the most proximal promoter segment upstream of the transcription start site. We observed significant differences in different cell types suggesting tissue specificity of transcriptional regulation. These findings provide novel insights into the molecular mechanisms that regulate expression of the ACVR1 gene and that could be targets of new strategies for future therapeutic treatments. PMID:24047559

The Severity of Plasmodium falciparum Infection Is Associated with Transcript Levels of var Genes Encoding Endothelial Protein C Receptor-Binding P. falciparum Erythrocyte Membrane Protein 1.

PubMed

Mkumbaye, Sixbert I; Wang, Christian W; Lyimo, Eric; Jespersen, Jakob S; Manjurano, Alphaxard; Mosha, Jacklin; Kavishe, Reginald A; Mwakalinga, Steven B; Minja, Daniel T R; Lusingu, John P; Theander, Thor G; Lavstsen, Thomas

2017-04-01

By attaching infected erythrocytes to the vascular lining, Plasmodium falciparum parasites leave blood circulation and avoid splenic clearance. This sequestration is central to pathogenesis. Severe malaria is associated with parasites expressing an antigenically distinct P. falciparum erythrocyte membrane protein 1 (PfEMP1) subset mediating binding to endothelial receptors. Previous studies indicate that PfEMP1 adhesins with so-called CIDRα1 domains capable of binding endothelial protein C receptor (EPCR) constitute the PfEMP1 subset associated with severe pediatric malaria. To analyze the relative importance of different subtypes of CIDRα1 domains, we compared Pf emp1 transcript levels in children with severe malaria (including 9 fatal and 114 surviving cases), children hospitalized with uncomplicated malaria ( n = 42), children with mild malaria not requiring hospitalization ( n = 10), and children with parasitemia and no ongoing fever ( n = 12). High levels of transcripts encoding EPCR-binding PfEMP1 were found in patients with symptomatic infections, and the abundance of these transcripts increased with disease severity. The compositions of CIDRα1 subtype transcripts varied markedly between patients, and none of the subtypes were dominant. Transcript-level analyses targeting other domain types indicated that subtypes of DBLβ or DBLζ domains might mediate binding phenomena that, in conjunction with EPCR binding, could contribute to pathogenesis. These observations strengthen the rationale for targeting the PfEMP1-EPCR interaction by vaccines and adjunctive therapies. Interventions should target EPCR binding of all CIDRα1 subtypes. Copyright © 2017 American Society for Microbiology.

Auditory stimuli elicit hippocampal neuronal responses during sleep

PubMed Central

Vinnik, Ekaterina; Antopolskiy, Sergey; Itskov, Pavel M.; Diamond, Mathew E.

2012-01-01

To investigate how hippocampal neurons code behaviorally salient stimuli, we recorded from neurons in the CA1 region of hippocampus in rats while they learned to associate the presence of sound with water reward. Rats learned to alternate between two reward ports at which, in 50% of the trials, sound stimuli were presented followed by water reward after a 3-s delay. Sound at the water port predicted subsequent reward delivery in 100% of the trials and the absence of sound predicted reward omission. During this task, 40% of recorded neurons fired differently according to which of the two reward ports the rat was visiting. A smaller fraction of neurons demonstrated onset response to sound/nosepoke (19%) and reward delivery (24%). When the sounds were played during passive wakefulness, 8% of neurons responded with short latency onset responses; 25% of neurons responded to sounds when they were played during sleep. During sleep the short-latency responses in hippocampus are intermingled with long lasting responses which in the current experiment could last for 1–2 s. Based on the current findings and the results of previous experiments we described the existence of two types of hippocampal neuronal responses to sounds: sound-onset responses with very short latency and longer-lasting sound-specific responses that are likely to be present when the animal is actively engaged in the task. PMID:22754507

Context and the Spelling-to-Sound Regularity Effect in Pronunciation.

ERIC Educational Resources Information Center

Parkin, Alan J.; Ilett, Alison

1986-01-01

Examines how spelling-to-sound irregularity affects pronunciation latencies when words are presented in a sentence, and concludes that pronunciation latencies are strongly affected by the type of preceding sentence, with the specific sentences producing shorter latencies than the general sentences. (HOD)

Pathogenesis of cranial neuropathies in Moebius syndrome: Electrodiagnostic orofacial studies.

PubMed

Renault, Francis; Flores-Guevara, Roberto; Sergent, Bernard; Baudon, Jean Jacques; Aouizerate, Jessie; Vazquez, Marie-Paule; Gitiaux, Cyril

2018-02-09

We designed a retrospective study of 59 patients with congenital sporadic nonprogressive bilateral facial and abducens palsies. Examinations included needle electromyography (EMG) of facial and oral muscles, facial nerve motor latency and conduction velocity (FNCV), and blink responses (BR). Neurogenic EMG changes were found in 1 or more muscles in 55 of 59 patients, with no abnormal spontaneous activity. EMG changes were homogeneously neurogenic in 17 patients, homogeneously myopathic in 1 patient, and heterogeneous in 41 of 59 patients. Motor latency was increased according to recordings from 52 of 137 facial muscles. An increase of motor latency was not associated with neurogenic EMG (Fischer's test: right, P = 1; left, P = 0.76). FNCV was slowed in 19 of 36 patients. BR was absent bilaterally in 35 of 58 patients; when present, R1 and R2 latencies were normal. Our results support the hypothesis of an early developmental defect localized in motor cranial nerves with spared V-VII internuclear pathways. Muscle Nerve, 2018. © 2018 Wiley Periodicals, Inc.

The intracellular domain of teneurin-1 induces the activity of microphthalmia-associated transcription factor (MITF) by binding to transcriptional repressor HINT1.

PubMed

Schöler, Jonas; Ferralli, Jacqueline; Thiry, Stéphane; Chiquet-Ehrismann, Ruth

2015-03-27

Teneurins are large type II transmembrane proteins that are necessary for the normal development of the CNS. Although many studies highlight the significance of teneurins, especially during development, there is only limited information known about the molecular mechanisms of function. Previous studies have shown that the N-terminal intracellular domain (ICD) of teneurins can be cleaved at the membrane and subsequently translocates to the nucleus, where it can influence gene transcription. Because teneurin ICDs do not contain any intrinsic DNA binding sequences, interaction partners are required to affect transcription. Here, we identified histidine triad nucleotide binding protein 1 (HINT1) as a human teneurin-1 ICD interaction partner in a yeast two-hybrid screen. This interaction was confirmed in human cells, where HINT1 is known to inhibit the transcription of target genes by directly binding to transcription factors at the promoter. In a whole transcriptome analysis of BS149 glioblastoma cells overexpressing the teneurin-1 ICD, several microphthalmia-associated transcription factor (MITF) target genes were found to be up-regulated. Directly comparing the transcriptomes of MITF versus TEN1-ICD-overexpressing BS149 cells revealed 42 co-regulated genes, including glycoprotein non-metastatic b (GPNMB). Using real-time quantitative PCR to detect endogenous GPNMB expression upon overexpression of MITF and HINT1 as well as promoter reporter assays using GPNMB promoter constructs, we could demonstrate that the teneurin-1 ICD binds HINT1, thus switching on MITF-dependent transcription of GPNMB. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Orexin Receptor Antagonism Improves Sleep and Reduces Seizures in Kcna1-null Mice.

PubMed

Roundtree, Harrison M; Simeone, Timothy A; Johnson, Chaz; Matthews, Stephanie A; Samson, Kaeli K; Simeone, Kristina A

2016-02-01

Comorbid sleep disorders occur in approximately one-third of people with epilepsy. Seizures and sleep disorders have an interdependent relationship where the occurrence of one can exacerbate the other. Orexin, a wake-promoting neuropeptide, is associated with sleep disorder symptoms. Here, we tested the hypothesis that orexin dysregulation plays a role in the comorbid sleep disorder symptoms in the Kcna1-null mouse model of temporal lobe epilepsy. Rest-activity was assessed using infrared beam actigraphy. Sleep architecture and seizures were assessed using continuous video-electroencephalography-electromyography recordings in Kcna1-null mice treated with vehicle or the dual orexin receptor antagonist, almorexant (100 mg/kg, intraperitoneally). Orexin levels in the lateral hypothalamus/perifornical region (LH/P) and hypothalamic pathology were assessed with immunohistochemistry and oxygen polarography. Kcna1-null mice have increased latency to rapid eye movement (REM) sleep onset, sleep fragmentation, and number of wake epochs. The numbers of REM and non-REM (NREM) sleep epochs are significantly reduced in Kcna1-null mice. Severe seizures propagate to the wake-promoting LH/P where injury is apparent (indicated by astrogliosis, blood-brain barrier permeability, and impaired mitochondrial function). The number of orexin-positive neurons is increased in the LH/P compared to wild-type LH/P. Treatment with a dual orexin receptor antagonist significantly increases the number and duration of NREM sleep epochs and reduces the latency to REM sleep onset. Further, almorexant treatment reduces the incidence of severe seizures and overall seizure burden. Interestingly, we report a significant positive correlation between latency to REM onset and seizure burden in Kcna1-null mice. Dual orexin receptor antagonists may be an effective sleeping aid in epilepsy, and warrants further study on their somnogenic and ant-seizure effects in other epilepsy models. © 2016 Associated Professional Sleep Societies, LLC.

Transcriptional Mechanisms Underlying Hemoglobin Synthesis

PubMed Central

Katsumura, Koichi R.; DeVilbiss, Andrew W.; Pope, Nathaniel J.; Johnson, Kirby D.; Bresnick, Emery H.

2013-01-01

The physiological switch in expression of the embryonic, fetal, and adult β-like globin genes has garnered enormous attention from investigators interested in transcriptional mechanisms and the molecular basis of hemoglobinopathies. These efforts have led to the discovery of cell type-specific transcription factors, unprecedented mechanisms of transcriptional coregulator function, genome biology principles, unique contributions of nuclear organization to transcription and cell function, and promising therapeutic targets. Given the vast literature accrued on this topic, this article will focus on the master regulator of erythroid cell development and function GATA-1, its associated proteins, and its frontline role in controlling hemoglobin synthesis. GATA-1 is a crucial regulator of genes encoding hemoglobin subunits and heme biosynthetic enzymes. GATA-1-dependent mechanisms constitute an essential regulatory core that nucleates additional mechanisms to achieve the physiological control of hemoglobin synthesis. PMID:23838521

Metabolic Disruption Early in Life is Associated With Latent Carcinogenic Activity of Dichloroacetic Acid in Mice

EPA Science Inventory

Early-life environmental factors can influence later-life susceptibility to cancer. Recent evidence suggests that metabolic pathways may mediate this type of latency effect. Previously, we reported that short-term exposure to dichloroacetic acid (DCA) increased liver cancer in mi...

Intensive care unit robotic telepresence facilitates rapid physician response to unstable patients and decreased cost in neurointensive care.

PubMed

Vespa, Paul M; Miller, Chad; Hu, Xiao; Nenov, Val; Buxey, Farzad; Martin, Neil A

2007-04-01

The timely assessment and treatment of ICU patients is important for neurosurgeons and neurointensivists. We hypothesized that the use of RTP can improve physician rapid response to unstable ICU patients. This is a prospective study using a before-after, cohort-control design to test the effectiveness of RTP. Physicians used RTP to make rounds in the ICU in response to nursing pages. Data concerning several aspects of the RTP interaction including the latency of the response, the problem being treated, the intervention that was ordered, and the type of information gathered using the RTP were documented. The effect of RTP on ICU length of stay and cost was assessed. The use of RTP was associated with a reduction in latency of attending physician face-to-face response for routine and urgent pages compared to conventional care (RTP: 9.2 +/- 9.3 minutes vs conventional: 218 +/- 186 minutes). The response latencies to brain ischemia (7.8 +/- 2.8 vs 152 +/- 85 minutes) and elevated ICP (11 +/- 14 vs 108 +/- 55 minutes) were reduced (P < .001), as was the LOS for patients with SAH (2 days) and brain trauma (1 day). There was an increase in ICU occupancy by 11% compared with the prerobot era, and there was an ICU cost savings of $1.1 million attributable to the use of RTP. The use of RTP enabled rapid face-to-face attending physician response to ICU patients and resulted in decreased ICU cost and LOS.

Functional Interaction between Class II Histone Deacetylases and ICP0 of Herpes Simplex Virus Type 1

PubMed Central

Lomonte, Patrick; Thomas, Joëlle; Texier, Pascale; Caron, Cécile; Khochbin, Saadi; Epstein, Alberto L.

2004-01-01

This study describes the physical and functional interactions between ICP0 of herpes simplex virus type 1 and class II histone deacetylases (HDACs) 4, 5, and 7. Class II HDACs are mainly known for their participation in the control of cell differentiation through the regulation of the activity of the transcription factor MEF2 (myocyte enhancer factor 2), implicated in muscle development and neuronal survival. Immunofluorescence experiments performed on transfected cells showed that ICP0 colocalizes with and reorganizes the nuclear distribution of ectopically expressed class I and II HDACs. In addition, endogenous HDAC4 and at least one of its binding partners, the corepressor protein SMRT (for silencing mediator of retinoid and thyroid receptor), undergo changes in their nuclear distribution in ICP0-transfected cells. As a result, during infection endogenous HDAC4 colocalizes with ICP0. Coimmunoprecipitation and glutathione S-transferase pull-down assays confirmed that class II but not class I HDACs specifically interacted with ICP0 through their amino-terminal regions. This region, which is not conserved in class I HDACs but homologous to the MITR (MEF2-interacting transcription repressor) protein, is responsible for the repression, in a deacetylase-independent manner, of MEF2 by sequestering it under an inactive form in the nucleus. Consequently, we show that ICP0 is able to overcome the HDAC5 amino-terminal- and MITR-induced MEF2A repression in gene reporter assays. This is the first report of a viral protein interacting with and controlling the repressor activity of class II HDACs. We discuss the putative consequences of such an interaction for the biology of the virus both during lytic infection and reactivation from latency. PMID:15194749

Autophagy interaction with herpes simplex virus type-1 infection

PubMed Central

O'Connell, Douglas; Liang, Chengyu

2016-01-01

abstract More than 50% of the U.S. population is infected with herpes simplex virus type-I (HSV-1) and global infectious estimates are nearly 90%. HSV-1 is normally seen as a harmless virus but debilitating diseases can arise, including encephalitis and ocular diseases. HSV-1 is unique in that it can undermine host defenses and establish lifelong infection in neurons. Viral reactivation from latency may allow HSV-1 to lay siege to the brain (Herpes encephalitis). Recent advances maintain that HSV-1 proteins act to suppress and/or control the lysosome-dependent degradation pathway of macroautophagy (hereafter autophagy) and consequently, in neurons, may be coupled with the advancement of HSV-1-associated pathogenesis. Furthermore, increasing evidence suggests that HSV-1 infection may constitute a gradual risk factor for neurodegenerative disorders. The relationship between HSV-1 infection and autophagy manipulation combined with neuropathogenesis may be intimately intertwined demanding further investigation. PMID:26934628

Transcriptional analysis of exopolysaccharides biosynthesis gene clusters in Lactobacillus plantarum.

PubMed

Vastano, Valeria; Perrone, Filomena; Marasco, Rosangela; Sacco, Margherita; Muscariello, Lidia

2016-04-01

Exopolysaccharides (EPS) from lactic acid bacteria contribute to specific rheology and texture of fermented milk products and find applications also in non-dairy foods and in therapeutics. Recently, four clusters of genes (cps) associated with surface polysaccharide production have been identified in Lactobacillus plantarum WCFS1, a probiotic and food-associated lactobacillus. These clusters are involved in cell surface architecture and probably in release and/or exposure of immunomodulating bacterial molecules. Here we show a transcriptional analysis of these clusters. Indeed, RT-PCR experiments revealed that the cps loci are organized in five operons. Moreover, by reverse transcription-qPCR analysis performed on L. plantarum WCFS1 (wild type) and WCFS1-2 (ΔccpA), we demonstrated that expression of three cps clusters is under the control of the global regulator CcpA. These results, together with the identification of putative CcpA target sequences (catabolite responsive element CRE) in the regulatory region of four out of five transcriptional units, strongly suggest for the first time a role of the master regulator CcpA in EPS gene transcription among lactobacilli.

Thinking about False Belief: It's Not Just What Children Say, but How Long It Takes Them to Say It

ERIC Educational Resources Information Center

Atance, Cristina M.; Bernstein, Daniel M.; Meltzoff, Andrew N.

2010-01-01

We examined 240 children's (3.5-, 4.5-, and 5.5-year-olds) latency to respond to questions on a battery of false-belief tasks. Response latencies exhibited a significant cross-over interaction as a function of age and response type (correct vs. incorrect). 3.5-year-olds' "in"correct latencies were faster than their correct latencies, whereas the…

Transcriptional Elongation Regulator 1 Affects Transcription and Splicing of Genes Associated with Cellular Morphology and Cytoskeleton Dynamics and Is Required for Neurite Outgrowth in Neuroblastoma Cells and Primary Neuronal Cultures.

PubMed

Muñoz-Cobo, Juan Pablo; Sánchez-Hernández, Noemí; Gutiérrez, Sara; El Yousfi, Younes; Montes, Marta; Gallego, Carme; Hernández-Munain, Cristina; Suñé, Carlos

2017-12-01

TCERG1 is a highly conserved human protein implicated in interactions with the transcriptional and splicing machinery that is associated with neurodegenerative disorders. Biochemical, neuropathological, and genetic evidence suggests an important role for TCERG1 in Huntington's disease (HD) pathogenesis. At present, the molecular mechanism underlying TCERG1-mediated neuronal effects is unknown. Here, we show that TCERG1 depletion led to widespread alterations in mRNA processing that affected different types of alternative transcriptional or splicing events, indicating that TCERG1 plays a broad role in the regulation of alternative splicing. We observed considerable changes in the transcription and alternative splicing patterns of genes involved in cytoskeleton dynamics and neurite outgrowth. Accordingly, TCERG1 depletion in the neuroblastoma SH-SY5Y cell line and primary mouse neurons affected morphogenesis and resulted in reduced dendritic outgrowth, with a major effect on dendrite ramification and branching complexity. These defects could be rescued by ectopic expression of TCERG1. Our results indicate that TCERG1 affects expression of multiple mRNAs involved in neuron projection development, whose misregulation may be involved in TCERG1-linked neurological disorders.

Pathobiologic Roles of Epstein–Barr Virus-Encoded MicroRNAs in Human Lymphomas

PubMed Central

Navari, Mohsen; Etebari, Maryam; Ibrahimi, Mostafa; Leoncini, Lorenzo

2018-01-01

Epstein–Barr virus (EBV) is a human γ-herpesvirus implicated in several human malignancies, including a wide range of lymphomas. Several molecules encoded by EBV in its latent state are believed to be related to EBV-induced lymphomagenesis, among which microRNAs—small RNAs with a posttranscriptional regulating role—are of great importance. The genome of EBV encodes 44 mature microRNAs belonging to two different classes, including BamHI-A rightward transcript (BART) and Bam HI fragment H rightward open reading frame 1 (BHRF1), with different expression levels in different EBV latency types. These microRNAs might contribute to the pathogenetic effects exerted by EBV through targeting self mRNAs and host mRNAs and interfering with several important cellular mechanisms such as immunosurveillance, cell proliferation, and apoptosis. In addition, EBV microRNAs can regulate the surrounding microenvironment of the infected cells through exosomal transportation. Moreover, these small molecules could be potentially used as molecular markers. In this review, we try to present an updated and extensive view of the role of EBV-encoded miRNAs in human lymphomas. PMID:29649101

Associations between prenatal and recent postnatal methylmercury exposure and auditory function at age 19 years in the Seychelles Child Development Study.

PubMed

Orlando, Mark S; Dziorny, Adam C; Harrington, Donald; Love, Tanzy; Shamlaye, Conrad F; Watson, Gene E; van Wijngaarden, Edwin; Davidson, Philip W; Myers, Gary J

2014-01-01

The aim of this study was to determine if prenatal or recent postnatal methylmercury (MeHg) exposure from consuming ocean fish and seafood is associated with auditory deficits in young adults. Some investigators have reported adverse associations while others have found no associations. Ocean fish is an important nutrient source for billions of people around the world. Consequently, determining if there is an adverse association with objective auditory measures is important in assessing whether a risk is present or not. The peripheral and central auditory function of 534 subjects in the Seychelles Child Development Study (SCDS) Main Cohort was examined at age of 19 years. The auditory test battery included standard pure-tone audiometry, tympanometry, auditory brainstem response (ABR) latencies, and both click-evoked and distortion product otoacoustic emissions (OAE). Associations with MeHg were evaluated with multiple linear regression models, adjusting for sex, recent postnatal MeHg exposure, and hearing loss. Bilateral hearing loss (defined as a mean pure-tone threshold of greater than 25 dB) was present in 1.1%of the subjects and was not associated with prenatal or recent postnatal MeHg exposure. As expected, absolute and interwave ABR latencies were shorter for women as compared to men, as the stimulus presentation rate decreased from 69.9 to 19.9 clicks/s and as the stimulus intensity increased from 60 to 80 dBnHL. Similarly, larger OAE amplitudes were elicited in women as compared to men and in the right ears as compared to the left. There was no association of prenatal MeHg exposure with hearing loss, ABR absolute and interwave latencies or OAE amplitudes. As recent postnatal MeHg increased, some associations were found with a few ABR absolute and interwave latencies and a few OAE amplitudes. However, the direction of these associations was inconsistent. As recent postnatal MeHg levels increased the wave I absolute latencies were shorter at 80 dBnHL for all three click rates, but the interwave I–V latency was longer for males for the 80 dBnHL 19 clicks/s and for the III–V interwave latencies for males and females for the dBnHL 69 clicks/s. Similarly, smaller OAE amplitudes were found at 1500, 2000, and 4000 Hz for males while larger OAE amplitudes were found for females at 1500 and 2000 Hz as the recent postnatal MeHg levels increased. No consistent associations were present in this study between prenatal MeHg exposure from consumption of oceanic fish and seafood during pregnancy and auditory functions at 19 years of age. Given the level of prenatal exposure to MeHg, the number of audiologic measures tested, and the presence of the expected sex, click rate, and level dependent findings, it seems unlikely that an association was present and not detected. As recent postnatal MeHg exposure increased, a few associations with ABR latencies and OAE amplitudes were found. The direction of these associations was inconsistent as some showed improved performance as MeHg exposure levels increased while others showed poorer performance. The presence of the inconsistent postnatal MeHg exposure findings are intriguing and deserve further clarification.

Genetic regulation of adipose tissue transcript expression is involved in modulating serum triglyceride and HDL-cholesterol.

PubMed

Sajuthi, Satria P; Sharma, Neeraj K; Comeau, Mary E; Chou, Jeff W; Bowden, Donald W; Freedman, Barry I; Langefeld, Carl D; Parks, John S; Das, Swapan K

2017-10-20

Dyslipidemia is a major contributor to the increased cardiovascular disease and mortality associated with obesity and type 2 diabetes. We hypothesized that variation in expression of adipose tissue transcripts is associated with serum lipid concentrations in African Americans (AAs), and common genetic variants regulate expression levels of these transcripts. Fasting serum lipid levels, genome-wide transcript expression profiles of subcutaneous adipose tissue, and genome-wide SNP genotypes were analyzed in a cohort of non-diabetic AAs (N=250). Serum triglyceride (TRIG) and high density lipoprotein-cholesterol (HDL-C) levels were associated (FDR<0.01) with expression level of 1021 and 1875 adipose tissue transcripts, respectively, but none associated with total cholesterol or LDL-C levels. Serum HDL-C-associated transcripts were enriched for salient biological pathways, including branched-chain amino acid degradation, and oxidative phosphorylation. Genes in immuno-inflammatory pathways were activated among individuals with higher serum TRIG levels. We identified significant cis-regulatory SNPs (cis-eSNPs) for 449 serum lipid-associated transcripts in adipose tissue. The cis-eSNPs of 12 genes were nominally associated (p<0.001) with serum lipid level in genome wide association studies in Global Lipids Genetics Consortium (GLGC) cohorts. Allelic effect direction of cis-eSNPs on expression of MARCH2, BEST1 and TMEM258 matched with effect direction of these SNP alleles on serum TRIG or HDL-C levels in GLGC cohorts. These data suggest that expressions of serum lipid-associated transcripts in adipose tissue are dependent on common cis-eSNPs in African Americans. Thus, genetically-mediated transcriptional regulation in adipose tissue may play a role in reducing HDL-C and increasing TRIG in serum. Copyright © 2017 Elsevier B.V. All rights reserved.

Low-Dose Cannabinoid Type 2 Receptor Agonist Attenuates Tolerance to Repeated Morphine Administration via Regulating μ-Opioid Receptor Expression in Walker 256 Tumor-Bearing Rats.

PubMed

Zhang, Mingyue; Wang, Kun; Ma, Min; Tian, Songyu; Wei, Na; Wang, Guonian

2016-04-01

Morphine is widely used in patients with moderate and severe cancer pain, whereas the development of drug tolerance remains a major problem associated with opioid use. Previous studies have shown that cannabinoid type 2 (CB2) receptor agonists induce morphine analgesia, attenuate morphine tolerance in normal and neuropathic pain animals, induce transcription of the μ-opioid receptor (MOR) gene in Jurkat T cells, and increase morphine analgesia in cancer pain animals. However, no studies of the effects of CB2 receptor agonists on morphine tolerance in cancer pain have been performed. Therefore, we investigated the effect of repeated intrathecal (IT) injection of the low-dose CB2 receptor agonist AM1241 on the development of morphine tolerance in walker 256 tumor-bearing rats. We also tested the influence of the CB2 receptor agonist AM1241 on MOR protein and messenger ribonucleic acid (mRNA) expression in the rat spinal cord and dorsal root ganglia (DRG). Walker 256 cells were implanted into the plantar region of each rat's right hindpaw. Tumor-bearing rats received IT injection of the CB2 receptor agonist AM1241 or antagonist AM630 with or without morphine subcutaneously twice daily for 8 days. Rats receiving drug vehicle only served as the control group. Mechanical paw withdrawal threshold and thermal paw withdrawal latency were assessed by a von Frey test and hot plate test 30 minutes after drug administration every day. MOR protein and mRNA expression in the spinal cord and DRG were detected after the last day (day 8) of drug administration via Western blot and real-time reverse transcription polymerase chain reaction. The data were analyzed via analysis of variance followed by Student t test with Bonferroni correction for multiple comparisons. Repeated morphine treatments reduced the mechanical withdrawal threshold and thermal latency. Coadministration of a nonanalgetic dose of the CB2 receptor agonist AM1241 with morphine significantly inhibited the development of morphine tolerance and increased the MOR protein expression in the spinal cord and DRG and mRNA expression in the spinal cord in tumor-bearing rats. Our findings indicate that IT injection of a nonanalgetic dose of a CB2 receptor agonist increased the analgesia effect and alleviated tolerance to morphine in tumor-bearing rats, potentially by regulating MOR expression in the spinal cord and DRG. This receptor may be a new target for prevention of the development of opioid tolerance in cancer pain.

Novel kinase fusion transcripts found in endometrial cancer

PubMed Central

Tamura, Ryo; Yoshihara, Kosuke; Yamawaki, Kaoru; Suda, Kazuaki; Ishiguro, Tatsuya; Adachi, Sosuke; Okuda, Shujiro; Inoue, Ituro; Verhaak, Roel G. W.; Enomoto, Takayuki

2015-01-01

Recent advances in RNA-sequencing technology have enabled the discovery of gene fusion transcripts in the transcriptome of cancer cells. However, it remains difficult to differentiate the therapeutically targetable fusions from passenger events. We have analyzed RNA-sequencing data and DNA copy number data from 25 endometrial cancer cell lines to identify potential therapeutically targetable fusion transcripts, and have identified 124 high-confidence fusion transcripts, of which 69% are associated with gene amplifications. As targetable fusion candidates, we focused on three in-frame kinase fusion transcripts that retain a kinase domain (CPQ-PRKDC, CAPZA2-MET, and VGLL4-PRKG1). We detected only CPQ-PRKDC fusion transcript in three of 122 primary endometrial cancer tissues. Cell proliferation of the fusion-positive cell line was inhibited by knocking down the expression of wild-type PRKDC but not by blocking the CPQ-PRKDC fusion transcript expression. Quantitative real-time RT-PCR demonstrated that the expression of the CPQ-PRKDC fusion transcript was significantly lower than that of wild-type PRKDC, corresponding to a low transcript allele fraction of this fusion, based on RNA-sequencing read counts. In endometrial cancers, the CPQ-PRKDC fusion transcript may be a passenger aberration related to gene amplification. Our findings suggest that transcript allele fraction is a useful predictor to find bona-fide therapeutic-targetable fusion transcripts. PMID:26689674

Novel kinase fusion transcripts found in endometrial cancer.

PubMed

Tamura, Ryo; Yoshihara, Kosuke; Yamawaki, Kaoru; Suda, Kazuaki; Ishiguro, Tatsuya; Adachi, Sosuke; Okuda, Shujiro; Inoue, Ituro; Verhaak, Roel G W; Enomoto, Takayuki

2015-12-22

Recent advances in RNA-sequencing technology have enabled the discovery of gene fusion transcripts in the transcriptome of cancer cells. However, it remains difficult to differentiate the therapeutically targetable fusions from passenger events. We have analyzed RNA-sequencing data and DNA copy number data from 25 endometrial cancer cell lines to identify potential therapeutically targetable fusion transcripts, and have identified 124 high-confidence fusion transcripts, of which 69% are associated with gene amplifications. As targetable fusion candidates, we focused on three in-frame kinase fusion transcripts that retain a kinase domain (CPQ-PRKDC, CAPZA2-MET, and VGLL4-PRKG1). We detected only CPQ-PRKDC fusion transcript in three of 122 primary endometrial cancer tissues. Cell proliferation of the fusion-positive cell line was inhibited by knocking down the expression of wild-type PRKDC but not by blocking the CPQ-PRKDC fusion transcript expression. Quantitative real-time RT-PCR demonstrated that the expression of the CPQ-PRKDC fusion transcript was significantly lower than that of wild-type PRKDC, corresponding to a low transcript allele fraction of this fusion, based on RNA-sequencing read counts. In endometrial cancers, the CPQ-PRKDC fusion transcript may be a passenger aberration related to gene amplification. Our findings suggest that transcript allele fraction is a useful predictor to find bona-fide therapeutic-targetable fusion transcripts.

Nocturnal Sleep Dynamics Identify Narcolepsy Type 1.

PubMed

Pizza, Fabio; Vandi, Stefano; Iloti, Martina; Franceschini, Christian; Liguori, Rocco; Mignot, Emmanuel; Plazzi, Giuseppe

2015-08-01

To evaluate the reliability of nocturnal sleep dynamics in the differential diagnosis of central disorders of hypersomnolence. Cross-sectional. Sleep laboratory. One hundred seventy-five patients with hypocretin-deficient narcolepsy type 1 (NT1, n = 79), narcolepsy type 2 (NT2, n = 22), idiopathic hypersomnia (IH, n = 22), and "subjective" hypersomnolence (sHS, n = 52). None. Polysomnographic (PSG) work-up included 48 h of continuous PSG recording. From nocturnal PSG conventional sleep macrostructure, occurrence of sleep onset rapid eye movement period (SOREMP), sleep stages distribution, and sleep stage transitions were calculated. Patient groups were compared, and receiver operating characteristic (ROC) curve analysis was used to test the diagnostic utility of nocturnal PSG data to identify NT1. Sleep macrostructure was substantially stable in the 2 nights of each diagnostic group. NT1 and NT2 patients had lower latency to rapid eye movement (REM) sleep, and NT1 patients showed the highest number of awakenings, sleep stage transitions, and more time spent in N1 sleep, as well as most SOREMPs at daytime PSG and at multiple sleep latency test (MSLT) than all other groups. ROC curve analysis showed that nocturnal SOREMP (area under the curve of 0.724 ± 0.041, P < 0.0001), percent of total sleep time spent in N1 (0.896 ± 0.023, P < 0.0001), and the wakefulness-sleep transition index (0.796 ± 0.034, P < 0.0001) had a good sensitivity and specificity profile to identify NT1 sleep, especially when used in combination (0.903 ± 0.023, P < 0.0001), similarly to SOREMP number at continuous daytime PSG (0.899 ± 0.026, P < 0.0001) and at MSLT (0.956 ± 0.015, P < 0.0001). Sleep macrostructure (i.e. SOREMP, N1 timing) including stage transitions reliably identifies hypocretin-deficient narcolepsy type 1 among central disorders of hypersomnolence. © 2015 Associated Professional Sleep Societies, LLC.

Adaptive and Innate Transforming Growth Factor β Signaling Impact Herpes Simplex Virus 1 Latency and Reactivation▿

PubMed Central

Allen, Sariah J.; Mott, Kevin R.; Wechsler, Steven L.; Flavell, Richard A.; Town, Terrence; Ghiasi, Homayon

2011-01-01

Innate and adaptive immunity play important protective roles by combating herpes simplex virus 1 (HSV-1) infection. Transforming growth factor β (TGF-β) is a key negative cytokine regulator of both innate and adaptive immune responses. Yet, it is unknown whether TGF-β signaling in either immune compartment impacts HSV-1 replication and latency. We undertook genetic approaches to address these issues by infecting two different dominant negative TGF-β receptor type II transgenic mouse lines. These mice have specific TGF-β signaling blockades in either T cells or innate cells. Mice were ocularly infected with HSV-1 to evaluate the effects of restricted innate or adaptive TGF-β signaling during acute and latent infections. Limiting innate cell but not T cell TGF-β signaling reduced virus replication in the eyes of infected mice. On the other hand, blocking TGF-β signaling in either innate cells or T cells resulted in decreased latency in the trigeminal ganglia of infected mice. Furthermore, inhibiting TGF-β signaling in T cells reduced cell lysis and leukocyte infiltration in corneas and trigeminal ganglia during primary HSV-1 infection of mice. These findings strongly suggest that TGF-β signaling, which generally functions to dampen immune responses, results in increased HSV-1 latency. PMID:21880769

Transcription of the Epstein-Barr virus nuclear antigen 1 (EBNA1) gene occurs before induction of the BCR2 (Cp) EBNA gene promoter during the initial stages of infection in B cells.

PubMed

Schlager, S; Speck, S H; Woisetschläger, M

1996-06-01

The purpose of this study was to gain insights into the regulation of Epstein-Barr virus (EBV) gene transcription during the establishment of viral latency in B cells. During the early stages of EBV infection in B lymphocytes, transcription of six viral nuclear antigens (EBNAs) is initiated from an early promoter (Wp). This is followed by a switch of promoter usage to an upstream promoter, Cp, whose activity is autoregulated by both EBNA1 and EBNA2. Previously it was demonstrated that infection of primary B cells with EBNA2-negative (EBNA2-) EBNA4-mutant (EBNA4mut) virus resulted only in the expression of mutant EBNA4 protein and failure to express the other EBNA gene products (C. Rooney H. G. Howe, S. H. Speck, and G. Miller, J. Virol. 63:1531-1539, 1989). We extended this research to demonstrate that Wp-to-Cp switching did not occur upon infection of primary B cells with an EBNA2- EBNA4mut virus (M. Woisetschlaeger, X. W. Jin, C. N. Yandara, L. A. Furmanski, J. L. Strominger, and S. H. Speck, Proc. Natl. Acad. Sci. USA 88:3942-3946, 1991). Further characterization of this phenomenon led to the identification of an EBNA2-dependent enhancer upstream of Cp. On the basis of these data, a model was proposed in which initial transcription from Wp gives rise to the expression of EBNA2 and EBNA4, and then transcription is upregulated from Cp via the EBNA2- dependent enhancer (Woisetschlaeger et al., as noted above). Implicit in this model is that transcription of the EBNA1 and EBNA3a to -3c genes is dependent on the switch from Wp to Cp, since primary cells infected with EBNA2- EBNA4mut virus fail to switch and also fail to express these viral antigens. Here we critically evaluate this model and demonstrate, in contrast to the predictions of the model, that transcription of both the EBNA1 and EBNA2 genes precedes activation of Cp. Furthermore, the level of EBNA1 gene transcription was strongly reduced in primary B cells infected with EBNA2- EBNA4mut virus compared with that of cells infected with wild-type virus. Switching to Cp, as well as EBNA1 gene transcription, was observed upon infection of EBV-negative Burkitt's lymphoma (BL) cell lines with EBNA2- EBNA4mut virus, thus establishing a correlation between early EBNA1 gene transcription and upregulation of transcription initiation from Cp. However, in EBV-negative BL cell lines infected with EBNA2- EBNA4mut virus, transcription of the EBNA1 gene at early time points postinfection initiated from Qp, the EBNA1 gene promoter active in group I BL cells (B. C. Schaefer, J. L. Strominger, and S. H. Speck, Proc. Natl. Acad. Sci. USA 92:10565-10569, 1995), rather than from Wp. The data support a model in which EBNA1 plays an important role in the cascade of events leading to successful switching from Wp to Cp and subsequent immortalization of the infected B cell.

Nuclear sequestration of COL1A1 mRNA transcript associated with type I osteogenesis imperfecta (OI)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Primorac, D.; Stover, M.L.; McKinstry, M.B.

Previously we identified an OI type I patient with a splice donor mutation that resulted in intron 26 retention instead of exon skipping and sequestration of normal levels of the mutant transcript in the nuclear compartment. Intron retention was consistent with the exon definition hypothesis for splice site selection since the size of the exon-intron-exon unit was less than 300 bp. Furthermore, the retained intron contained in-frame stop codons which is thought to cause the mutant RNA to remain within the nucleus rather than appearing in the cytoplasm. To test these hypotheses, genomic fragments containing the normal sequence or themore » donor mutation were cloned into a collagen minigene and expressed in stably tansfected NIH 3T3 cells. None of the modifications to the normal intron altered the level of RNA that accumulated in the cytoplasm, as expected. However none of the modifications to the mutant intron allowed accumulation of normal levels of mRNA in the cytoplasm. Moreover, in contrast to our findings in the patient`s cells only low levels of mutant transcript were found in the nucleus; a fraction of the transcript did appear in the cytoplasm which had spliced the mutant donor site correctly. Nuclear run-on experiments demonstrated equal levels of transcription from each transgene. Expression of another donor mutation known to cause in-frame exon skipping in OI type IV was accurately reproduced in the minigene in transfected 3T3 cells. Our experience suggests that either mechanism can lead to formation of a null allele possibly related to the type of splicing events surrounding the potential stop codons. Understanding the rules governing inactivation of a collagen RNA transcript may be important in designing a strategy to inactivate a dominate negative mutation associated with the more severe forms of OI.« less

c-Fos-activated synthesis of nuclear phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P₂] promotes global transcriptional changes.

PubMed

Ferrero, Gabriel O; Renner, Marianne L; Gil, Germán A; Rodríguez-Berdini, Lucia; Caputto, Beatriz L

2014-08-01

c-Fos is a well-recognized member of the AP-1 (activator protein-1) family of transcription factors. In addition to this canonical activity, we previously showed that cytoplasmic c-Fos activates phospholipid synthesis through a mechanism independent of its genomic AP-1 activity. c-Fos associates with particular enzymes of the lipid synthesis pathway at the endoplasmic reticulum and increases the Vmax of the reactions without modifying the Km values. This lipid synthesis activation is associated with events of differentiation and proliferation that require high rates of membrane biogenesis. Since lipid synthesis also occurs in the nucleus, and different phospholipids have been assigned transcription regulatory functions, in the present study we examine if c-Fos also acts as a regulator of phospholipid synthesis in the nucleus. Furthermore, we examine if c-Fos modulates transcription through its phospholipid synthesis activator capacity. We show that nuclear-localized c-Fos associates with and activates PI4P5K (phosphatidylinositol-4-monophosphate 5-kinase), but not with PI4KIIIβ (type IIIβ phosphatidylinositol 4-kinase) thus promoting PtdIns(4,5)P₂ (phosphatidylinositol 4,5-bisphosphate) formation, which, in turn, promotes transcriptional changes. We propose c-Fos as a key regulator of nuclear PtdIns(4,5)P₂ synthesis in response to growth signals that results in c-Fos-dependent transcriptional changes promoted by the newly synthesized lipids.

Transcriptional analysis of Volvox photoreceptors suggests the existence of different cell-type specific light-signaling pathways.

PubMed

Kianianmomeni, Arash; Hallmann, Armin

2015-02-01

Photosynthetic organisms, e.g., plants including green algae, use a sophisticated light-sensing system, composed of primary photoreceptors and additional downstream signaling components, to monitor changes in the ambient light environment towards adjust their growth and development. Although a variety of cellular processes, e.g., initiation of cleavage division and final cellular differentiation, have been shown to be light-regulated in the green alga Volvox carteri, little is known about the underlying light perception and signaling pathways. This multicellular alga possesses at least 12 photoreceptors, i.e., one phototropin (VcPhot), four cryptochromes (VcCRYa, VcCRYp, VcCRYd1, and VcCRYd2), and seven members of rhodopsin-like photoreceptors (VR1, VChR1, VChR2, VcHKR1, VcHKR2, VcHKR3, and VcHKR4), which display distinct light-dependent chemical processes based on their protein architectures and associated chromophores. Gene expression analyses could show that the transcript levels of some of the photoreceptor genes (e.g., VChR1 and VcHKR1) accumulate during division cleavages, while others (e.g., VcCRYa, VcCRYp, and VcPhot) accumulate during final cellular differentiation. However, the pattern of transcript accumulation changes when the alga switches to the sexual development. Eight photoreceptor genes, e.g., VcPhot, VcCRYp, and VcHKR1, are highly expressed in the somatic cells, while only the animal-type rhodopsin VR1 was found to be highly expressed in the reproductive cells/embryos during both asexual and sexual life cycles. Moreover, accumulation of VChR1 and VcCRYa transcripts is more sensitive to light and changes in response to more than one light quality. Obviously, different regulatory mechanisms underlying gene expression control transcript accumulation of photoreceptors not only during development, but also in a cell-type specific way and in response to various external signals such as light quality. The transcriptional patterns described in this study show that Volvox photoreceptors are mostly expressed in a cell-type specific manner. This gives reason to believe that cell-type specific light-signaling pathways allow differential regulation of cellular and developmental processes in response to the environmental light cues.

Is There a Relation between Reticular Formation and Storage Symptoms in Men.

PubMed

Zorba, Orhan Ü; Kirbaş, Serkan; Uzun, Hakkı; Önem, Kadir; Çetinkaya, Mehmet; Rifaioğlu, Mehmet M

2014-01-01

To reveal brainstem originated pathology in men with different types of lower urinary tract symptoms blink reflex latency times were assessed. A total of 32 men, 16 with storage and 16 with voiding symptoms, were enrolled in the study. Blink reflex latency times were analyzed through electrical stimulation of the supraorbital nerve. Two responses in the orbicularis oculi muscle were recorded: the latency times for the early ipsilateral response, R1, and the late bilateral responses, R2. The mean ages of the patients with storage and voiding symptoms were 57.31 ± 6.87 and 58.06 ± 6.29 years, respectively. The R2 latency times were significantly longer in men with storage symptoms. However, the R1 latency times were similar for the two groups. Late blink latency times were long only in patients who had storage symptoms. An oligosynaptic path through the trigeminal nuclei, which includes one or two interneurons, is responsible for early response; however, late response is relayed through a polysynaptic path, including neurons in the reticular formation. It has also been shown that stimulation of the pontine reticular formation inhibits the micturition contraction. In some patients, storage symptoms may result from pathology that originates with the reticular formation and this pathology may lead to increases in late blink latency times. Additional studies are needed on other reflexes that are mediated through reticular formation, in order to show the possible dysfunction of the reticular formation in men with storage symptoms. © 2013 Wiley Publishing Asia Pty Ltd.

Enhanced Fine-Form Perception Does Not Contribute to Gestalt Face Perception in Autism Spectrum Disorder

PubMed Central

Maekawa, Toshihiko; Miyanaga, Yuka; Takahashi, Kenji; Takamiya, Naomi; Ogata, Katsuya; Tobimatsu, Shozo

2017-01-01

Individuals with autism spectrum disorder (ASD) show superior performance in processing fine detail, but often exhibit impaired gestalt face perception. The ventral visual stream from the primary visual cortex (V1) to the fusiform gyrus (V4) plays an important role in form (including faces) and color perception. The aim of this study was to investigate how the ventral stream is functionally altered in ASD. Visual evoked potentials were recorded in high-functioning ASD adults (n = 14) and typically developing (TD) adults (n = 14). We used three types of visual stimuli as follows: isoluminant chromatic (red/green, RG) gratings, high-contrast achromatic (black/white, BW) gratings with high spatial frequency (HSF, 5.3 cycles/degree), and face (neutral, happy, and angry faces) stimuli. Compared with TD controls, ASD adults exhibited longer N1 latency for RG, shorter N1 latency for BW, and shorter P1 latency, but prolonged N170 latency, for face stimuli. Moreover, a greater difference in latency between P1 and N170, or between N1 for BW and N170 (i.e., the prolongation of cortico-cortical conduction time between V1 and V4) was observed in ASD adults. These findings indicate that ASD adults have enhanced fine-form (local HSF) processing, but impaired color processing at V1. In addition, they exhibit impaired gestalt face processing due to deficits in integration of multiple local HSF facial information at V4. Thus, altered ventral stream function may contribute to abnormal social processing in ASD. PMID:28146575

Enhancer Activation Requires Trans-Recruitment of a Mega Transcription Factor Complex

PubMed Central

Liu, Zhijie; Merkurjev, Daria; Yang, Feng; Li, Wenbo; Oh, Soohwan; Friedman, Meyer J.; Song, Xiaoyuan; Zhang, Feng; Ma, Qi; Ohgi, Kenneth; Krones, Anna; Rosenfeld, Michael G.

2014-01-01

Summary Enhancers provide critical information directing cell-type specific transcriptional programs, regulated by binding of signal-dependent transcription factors and their associated cofactors. Here we report that the most strongly activated estrogen (E2)-responsive enhancers are characterized by trans-recruitment and in situ assembly of a large 1-2 MDa complex of diverse DNA-binding transcription factors by ERα at ERE-containing enhancers. We refer to enhancers recruiting these factors as mega transcription factor-bound in trans (MegaTrans) enhancers. The MegaTrans complex is a signature of the most potent functional enhancers and is required for activation of enhancer RNA transcription and recruitment of coactivators, including p300 and Med1. The MegaTrans complex functions, in part, by recruiting specific enzymatic machinery, exemplified by DNA-dependent protein kinase. Thus, MegaTrans-containing enhancers represent a cohort of functional enhancers that mediate a broad and important transcriptional program and provide a molecular explanation for transcription factor clustering and hotspots noted in the genome. PMID:25303530

Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

PubMed

Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

2015-12-01

Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

A Transcriptional Regulatory Role for the Membrane Type-1 Matrix Metalloproteinase in Carcinogen-Induced Inflammasome Gene Expression.

PubMed

Sheehy, Samuel; Annabi, Borhane

2017-01-01

Signal-transducing functions driven by the cytoplasmic domain of membrane type-1 matrix metalloproteinase (MT1-MMP) are believed to regulate many inflammation-associated cancer cell functions including migration, proliferation, and survival. Aside from upregulation of the inflammation biomarker cyclooxygenase-2 (COX-2) expression, MT1-MMP's role in relaying intracellular signals triggered by extracellular pro-inflammatory cues remains poorly understood. Here, we triggered inflammation in HT1080 fibrosarcoma cells with phorbol-12-myristate-13-acetate (PMA), an inducer of COX-2 and of MT1-MMP. To assess the global transcriptional regulatory role that MT1-MMP may exert on inflammation biomarkers, we combined gene array screens with a transient MT1-MMP gene silencing strategy. Expression of MT1-MMP was found to exert both stimulatory and repressive transcriptional control of several inflammasome-related biomarkers such as interleukin (IL)-1B, IL-6, IL-12A, and IL-33, as well as of transcription factors such as EGR1, ELK1, and ETS1/2 in PMA-treated cells. Among the signal-transducing pathways explored, the silencing of MT1-MMP prevented PMA from phosphorylating extracellular signal-regulated kinase, inhibitor of κB, and p105 nuclear factor κB (NF-κB) intermediates. We also found a signaling axis linking MT1-MMP to MMP-9 transcriptional regulation. Altogether, our data indicate a significant involvement of MT1-MMP in the transcriptional regulation of inflammatory biomarkers consolidating its contribution to signal transduction functions in addition to its classical hydrolytic activity.

Kaposi's Sarcoma-Associated Herpesvirus Utilizes and Manipulates RNA N6-Adenosine Methylation To Promote Lytic Replication

PubMed Central

Chen, E. Ricky; Nilsen, Timothy W.

2017-01-01

ABSTRACT N6-adenosine methylation (m6A) is the most common posttranscriptional RNA modification in mammalian cells. We found that most transcripts encoded by the Kaposi's sarcoma-associated herpesvirus (KSHV) genome undergo m6A modification. The levels of m6A-modified mRNAs increased substantially upon stimulation for lytic replication. The blockage of m6A inhibited splicing of the pre-mRNA encoding the replication transcription activator (RTA), a key KSHV lytic switch protein, and halted viral lytic replication. We identified several m6A sites in RTA pre-mRNA crucial for splicing through interactions with YTH domain containing 1 (YTHDC1), an m6A nuclear reader protein, in conjunction with serine/arginine-rich splicing factor 3 (SRSF3) and SRSF10. Interestingly, RTA induced m6A and enhanced its own pre-mRNA splicing. Our results not only demonstrate an essential role of m6A in regulating RTA pre-mRNA splicing but also suggest that KSHV has evolved a mechanism to manipulate the host m6A machinery to its advantage in promoting lytic replication. IMPORTANCE KSHV productive lytic replication plays a pivotal role in the initiation and progression of Kaposi's sarcoma tumors. Previous studies suggested that the KSHV switch from latency to lytic replication is primarily controlled at the chromatin level through histone and DNA modifications. The present work reports for the first time that KSHV genome-encoded mRNAs undergo m6A modification, which represents a new mechanism at the posttranscriptional level in the control of viral replication. PMID:28592530

LKB1 tumor suppressor and salt-inducible kinases negatively regulate human T-cell leukemia virus type 1 transcription

PubMed Central

2013-01-01

Background Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL). Treatment options are limited and prophylactic agents are not available. We have previously demonstrated an essential role for CREB-regulating transcriptional coactivators (CRTCs) in HTLV-1 transcription. Results In this study we report on the negative regulatory role of LKB1 tumor suppressor and salt-inducible kinases (SIKs) in the activation of HTLV-1 long terminal repeats (LTR) by the oncoprotein Tax. Activation of LKB1 and SIKs effectively blunted Tax activity in a phosphorylation-dependent manner, whereas compromising these kinases, but not AMP-dependent protein kinases, augmented Tax function. Activated LKB1 and SIKs associated with Tax and suppressed Tax-induced LTR activation by counteracting CRTCs and CREB. Enforced expression of LKB1 or SIK1 in cells transfected with HTLV-1 molecular clone pX1MT repressed proviral transcription. On the contrary, depletion of LKB1 in pX1MT-transfected cells and in HTLV-1-transformed T cells boosted the expression of Tax. Treatment of HTLV-1 transformed cells with metformin led to LKB1/SIK1 activation, reduction in Tax expression, and inhibition of cell proliferation. Conclusions Our findings revealed a new function of LKB1 and SIKs as negative regulators of HTLV-1 transcription. Pharmaceutical activation of LKB1 and SIKs might be considered as a new strategy in anti-HTLV-1 and anti-ATL therapy. PMID:23577667

Pooled analysis of two Swedish case-control studies on the use of mobile and cordless telephones and the risk of brain tumours diagnosed during 1997-2003.

PubMed

Mild, Kjell Hansson; Hardell, Lennart; Carlberg, Michael

2007-01-01

Here we present the pooled analysis of 2 case-control studies on the association of brain tumours with mobile phone use. Use of analogue cellular phones increased the risk for acoustic neuroma by 5%, 95% confidence interval (CI) = 2-9% per 100 hrs of use. The risk increased for astrocytoma grade III-IV with latency period with highest estimates using >10-year time period from first use of these phone types. The risk increased per one year of use of analogue phones by 10%, 95% CI = 6-14%, digital phones by 11%, 95% CI = 6-16%, and cordless phones by 8%, 95% CI = 5-12%. For all studied phone types OR for brain tumours, mainly acoustic neuroma and malignant brain tumours, increased with latency period, especially for astrocytoma grade III-IV.

Teaching resources. Model of the TIR1 pathway for auxin-mediated gene expression.

PubMed

Laskowski, Marta

2006-02-14

Auxin mediates numerous plant responses, some of which have been shown to require transcriptional regulation. One auxin response pathway, which depends on the relief of transcriptional repression, is mediated by TIR1 (transport inhibitor response protein 1). TIR1 is an auxin receptor and also a subunit of an SCF-type ubiquitin ligase. In the presence of a low concentration of auxin in the nucleus, members of the Aux/IAA family of transcriptional repressors bind to ARF proteins and inhibit the transcription of specific auxin response genes. Increased nuclear concentrations of auxin promote auxin binding to TIR1, causing the Aux/IAA proteins to associate with TIR1 and leading to their degradation by a proteasome-mediated pathway. This decreases the concentration of Aux/IAA proteins in the nucleus and thereby enables the expression of certain auxin response genes.

Increased excitability of spinal pain reflexes and altered frequency-dependent modulation in the dopamine D3-receptor knockout mouse.

PubMed

Keeler, Benjamin E; Baran, Christine A; Brewer, Kori L; Clemens, Stefan

2012-12-01

Frequency-dependent modulation and dopamine (DA) receptors strongly modulate neural circuits in the spinal cord. Of the five known DA receptor subtypes, the D3 receptor has the highest affinity to DA, and D3-mediated actions are mainly inhibitory. Using an animal model of spinal sensorimotor dysfunction, the D3 receptor knockout mouse (D3KO), we investigated the physiological consequences of D3 receptor dysfunction on pain-associated signaling pathways in the spinal cord, the initial integration site for the processing of pain signaling. In the D3KO spinal cord, inhibitory actions of DA on the proprioceptive monosynaptic stretch reflex are converted from depression to facilitation, but its effects on longer-latency and pain-associated reflex responses and the effects of FM have not been studied. Using behavioral approaches in vivo, we found that D3KO animals exhibit reduced paw withdrawal latencies to thermal pain stimulation (Hargreaves' test) over wild type (WT) controls. Electrophysiological and pharmacological approaches in the isolated spinal cord in vitro showed that constant current stimulation of dorsal roots at a pain-associated frequency was associated with a significant reduction in the frequency-dependent modulation of longer-latency reflex (LLRs) responses but not monosynaptic stretch reflexes (MSRs) in D3KO. Application of the D1 and D2 receptor agonists and the voltage-gated calcium-channel ligand, pregabalin, but not DA, was able to restore the frequency-dependent modulation of the LLR in D3KO to WT levels. Thus we demonstrate that nociception-associated LLRs and proprioceptive MSRs are differentially modulated by frequency, dopaminergics and the Ca(2+) channel ligand, pregabalin. Our data suggest a role for the DA D3 receptor in pain modulation and identify the D3KO as a possible model for increased nociception. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of hypoglycaemia, with or without caffeine ingestion, on visual sensation and performance.

PubMed

Owen, G; Watson, J; McGown, A; Sharma, S; Deary, I; Kerr, D; Barrett, G

2001-06-01

Full-field visual evoked potentials and visual information processing were measured in 16 normal, healthy subjects during a hyperinsulinaemic clamp. A randomized cross-over design was used across three conditions: hypoglycaemia and caffeine; hypoglycaemia and placebo; and euglycaemia and caffeine. The latency of the P100 component of the pattern-reversal visual evoked potential increased significantly from rest to hypoglycaemia, but no effect of caffeine was found. Subjects were subsequently divided into two median groups based on the increase in P100 latency in the placebo condition (Group 1, +0.5 ms; Group 2, +5.6 ms). In the absence of caffeine, an inverse correlation between the increase in P100 latency from rest and a deterioration in visual movement detection was found for Group 2, but not for Group 1. Caffeine ingestion resulted in a further increase in P100 latency, from rest to hypoglycaemia, for subjects in Group 2. Hypoglycaemia in the absence of caffeine produces changes in visual sensation from rest to hypoglycaemia. In those subjects most sensitive to the effects of hypoglycaemia (Group 2), the increase in P100 latency was associated with poorer performance in tests of visual information processing. Caffeine ingestion produced further increases in P100 latency in these subjects.

Narcolepsy in a three-year-old girl: A case report.

PubMed

Park, Eu Gene; Lee, Jiwon; Joo, Eun Yeon; Lee, Munhyang; Lee, Jeehun

2016-01-01

Narcolepsy is characterized by excessive daytime somnolence associated with sleep paralysis, hallucinations when falling asleep or awakening, and cataplexy. Early recognition of pediatric narcolepsy is essential for growth and development. We experienced a case of narcolepsy in a three-year-old girl. The patient underwent brain MRI and 24h video-electroencephalogram (EEG) monitoring. Polysomnography (PSG) with multiple sleep latency test (MSLT) and human leukocyte antigen (HLA) DQ typing was performed. The brain MRI was normal. 24h video-EEG monitoring revealed no abnormal slow or epileptiform discharge on interictal EEG, and no EEG change during tongue thrusting, dropping head with laughter, or flopping down, which was consistent with cataplexy associated with narcolepsy. A mean sleep latency of 2.5 min and four episodes of sleep-onset REM periods in five naps were observed in PSG with MSLT. She was positive in HLA-DQB1*0602. Based on these findings, she was diagnosed as narcoleptic with cataplexy. The history, combined with PSG and MSLT, was helpful in the diagnosis of narcolepsy. We report a case of early-onset narcolepsy presenting with excessive sleepiness and cataplexy. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Human T Cell Leukemia Virus Type I Tax-Induced IκB-ζ Modulates Tax-Dependent and Tax-Independent Gene Expression in T Cells1

PubMed Central

Kimura, Ryuichiro; Senba, Masachika; Cutler, Samuel J; Ralph, Stephen J; Xiao, Gutian; Mori, Naoki

2013-01-01

Human T cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T cell leukemia (ATL) and various inflammatory disorders including HTLV-I-associated myelopathy/tropical spastic paraparesis. HTLV-I oncoprotein Tax is known to cause permanent activation of many cellular transcription factors including nuclear factor-κB (NF-κB), cyclic adenosine 3′,5′-monophosphate response element-binding protein, and activator protein 1 (AP-1). Here, we show that NF-κB-binding cofactor inhibitor of NF-κB-ζ (IκB-ζ) is constitutively expressed in HTLV-I-infected T cell lines and ATL cells, and Tax transactivates the IκB-ζ gene, mainly through NF-κB. Microarray analysis of IκB-ζ-expressing uninfected T cells demonstrated that IκB-ζ induced the expression of NF-κB. and interferon-regulatory genes such as B cell CLL/lymphoma 3 (Bcl3), guanylate-binding protein 1, and signal transducer and activator of transcription 1. The transcriptional activation domain, nuclear localization signal, and NF-κB-binding domain of IκB-ζ were required for Bcl3 induction, and IκB-ζ synergistically enhanced Tax-induced Bcl3 transactivation in an NF-κB-dependent manner. Interestingly, IκB-ζ inhibited Tax-induced NF-κB, AP-1 activation, and HTLV-I transcription. Furthermore, IκB-ζ interacted with Tax in vitro and this interaction was also observed in an HTLV-I-transformed T cell line. These results suggest that IκB-ζ modulates Tax-dependent and Tax-independent gene transcription in T cells. The function of IκB-ζ may be of significance in ATL genesis and pathogenesis of HTLV-I-associated diseases. PMID:24027435

Cellular corepressor TLE2 inhibits replication-and-transcription- activator-mediated transactivation and lytic reactivation of Kaposi's sarcoma-associated herpesvirus.

PubMed

He, Zhiheng; Liu, Yunhua; Liang, Deguang; Wang, Zhuo; Robertson, Erle S; Lan, Ke

2010-02-01

Replication and transcription activator (RTA) encoded by open reading frame 50 (ORF50) of Kaposi's sarcoma-associated herpesvirus (KSHV) is essential and sufficient to initiate lytic reactivation. RTA activates its target genes through direct binding with high affinity to its responsive elements or by interaction with cellular factors, such as RBP-Jkappa, Ap-1, C/EBP-alpha, and Oct-1. In this study, we identified transducin-like enhancer of split 2 (TLE2) as a novel RTA binding protein by using yeast two-hybrid screening of a human spleen cDNA library. The interaction between TLE2 and RTA was confirmed by glutathione S-transferase (GST) binding and coimmunoprecipitation assays. Immunofluorescence analysis showed that TLE2 and RTA were colocalized in the same nuclear compartment in KSHV-infected cells. This interaction recruited TLE2 to RTA bound to its recognition sites on DNA and repressed RTA auto-activation and transactivation activity. Moreover, TLE2 also inhibited the induction of lytic replication and virion production driven by RTA. We further showed that the Q (Gln-rich), SP (Ser-Pro-rich), and WDR (Trp-Asp repeat) domains of TLE2 and the Pro-rich domain of RTA were essential for this interaction. RBP-Jkappa has been shown previously to bind to the same Pro-rich domain of RTA, and this binding can be subject to competition by TLE2. In addition, TLE2 can form a complex with RTA to access the cognate DNA sequence of the RTA-responsive element at different promoters. Intriguingly, the transcription level of TLE2 could be upregulated by RTA during the lytic reactivation process. In conclusion, we identified a new RTA binding protein, TLE2, and demonstrated that TLE2 inhibited replication and transactivation mediated by RTA. This provides another potentially important mechanism for maintenance of KSHV viral latency through interaction with a host protein.

Normal sensorimotor plasticity in complex regional pain syndrome with fixed posture of the hand.

PubMed

Morgante, Francesca; Naro, Antonino; Terranova, Carmen; Russo, Margherita; Rizzo, Vincenzo; Risitano, Giovanni; Girlanda, Paolo; Quartarone, Angelo

2017-01-01

Movement disorders associated with complex regional pain syndrome type I have been a subject of controversy over the last 10 years regarding their nature and pathophysiology, with an intense debate about the functional (psychogenic) nature of this disorder. The aim of this study was to test sensorimotor plasticity and cortical excitability in patients with complex regional pain syndrome type I who developed a fixed posture of the hand. Ten patients with complex regional pain syndrome type I in the right upper limb and a fixed posture of the hand (disease duration less than 24 months) and 10 age-matched healthy subjects were enrolled. The following parameters of corticospinal excitability were recorded from the abductor pollicis brevis muscle of both hands by transcranial magnetic stimulation: resting and active motor thresholds, short-interval intracortical inhibition and facilitation, cortical silent period, and short- and long-latency afferent inhibition. Sensorimotor plasticity was tested using the paired associative stimulation protocol. Short-interval intracortical inhibition and long-latency afferent inhibition were reduced only in the affected right hand of patients compared with control subjects. Sensorimotor plasticity was comparable to normal subjects, with a preserved topographic specificity. Our data support the view that motor disorder in complex regional pain syndrome type I is not associated with abnormal sensorimotor plasticity, and it shares pathophysiological abnormalities with functional (psychogenic) dystonia rather than with idiopathic dystonia. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Transcription of two adjacent carbohydrate utilization gene clusters in Bifidobacterium breve UCC2003 is controlled by LacI- and repressor open reading frame kinase (ROK)-type regulators.

PubMed

O'Connell, Kerry Joan; Motherway, Mary O'Connell; Liedtke, Andrea; Fitzgerald, Gerald F; Paul Ross, R; Stanton, Catherine; Zomer, Aldert; van Sinderen, Douwe

2014-06-01

Members of the genus Bifidobacterium are commonly found in the gastrointestinal tracts of mammals, including humans, where their growth is presumed to be dependent on various diet- and/or host-derived carbohydrates. To understand transcriptional control of bifidobacterial carbohydrate metabolism, we investigated two genetic carbohydrate utilization clusters dedicated to the metabolism of raffinose-type sugars and melezitose. Transcriptomic and gene inactivation approaches revealed that the raffinose utilization system is positively regulated by an activator protein, designated RafR. The gene cluster associated with melezitose metabolism was shown to be subject to direct negative control by a LacI-type transcriptional regulator, designated MelR1, in addition to apparent indirect negative control by means of a second LacI-type regulator, MelR2. In silico analysis, DNA-protein interaction, and primer extension studies revealed the MelR1 and MelR2 operator sequences, each of which is positioned just upstream of or overlapping the correspondingly regulated promoter sequences. Similar analyses identified the RafR binding operator sequence located upstream of the rafB promoter. This study indicates that transcriptional control of gene clusters involved in carbohydrate metabolism in bifidobacteria is subject to conserved regulatory systems, representing either positive or negative control.

Developmental disorders of the hypothalamus and pituitary gland associated with congenital hypopituitarism.

PubMed

Mehta, Ameeta; Dattani, Mehul T

2008-02-01

The pituitary gland is a complex organ secreting six hormones from five different cell types. It is the end product of a carefully orchestrated pattern of expression of signalling molecules and transcription factors. Naturally occurring and transgenic murine models have demonstrated a role for many of these molecules in the aetiology of congenital hypopituitarism. These include the transcription factors HESX1, PROP1, POU1F1, LHX3, LHX4, PITX1, PITX2, SOX2 and SOX3. The expression pattern of these transcription factors dictates the phenotype that results when the gene encoding the relevant transcription factor is mutated. The highly variable phenotype may consist of isolated hypopituitarism or more complex disorders such as septo-optic dysplasia and holoprosencephaly. However, the overall incidence of mutations in known transcription factors in patients with hypopituitarism is low, indicating that many genes remain to be identified; characterization of these will further elucidate the pathogenesis of this complex condition and also shed light on normal pituitary development and function.

Obesity-Mediated Regulation of HGF/c-Met Is Associated with Reduced Basal-Like Breast Cancer Latency in Parous Mice

PubMed Central

Sundaram, Sneha; Freemerman, Alex J.; Galanko, Joseph A.; McNaughton, Kirk K.; Bendt, Katharine M.; Darr, David B.; Troester, Melissa A.; Makowski, Liza

2014-01-01

It is widely thought that pregnancy reduces breast cancer risk, but this lacks consideration of breast cancer subtypes. While a full term pregnancy reduces risk for estrogen receptor positive (ER+) and luminal breast cancers, parity is associated with increased risk of basal-like breast cancer (BBC) subtype. Basal-like subtypes represent less than 10% of breast cancers and are highly aggressive, affecting primarily young, African American women. Our previous work demonstrated that high fat diet-induced obesity in nulliparous mice significantly blunted latency in C3(1)-TAg mice, a model of BBC, potentially through the hepatocyte growth factor (HGF)/c-Met oncogenic pathway. Experimental studies have examined parity and obesity individually, but to date, the joint effects of parity and obesity have not been studied. We investigated the role of obesity in parous mice on BBC. Parity alone dramatically blunted tumor latency compared to nulliparous controls with no effects on tumor number or growth, while obesity had only a minor role in further reducing latency. Obesity-associated metabolic mediators and hormones such as insulin, estrogen, and progesterone were not significantly regulated by obesity. Plasma IL-6 was also significantly elevated by obesity in parous mice. We have previously reported a potential role for stromal-derived hepatocyte growth factor (HGF) via its cognate receptor c-Met in the etiology of obesity-induced BBC tumor onset and in both human and murine primary coculture models of BBC-aggressiveness. Obesity-associated c-Met concentrations were 2.5-fold greater in normal mammary glands of parous mice. Taken together, our studies demonstrate that, parity in C3(1)-TAg mice dramatically reduced BBC latency compared to nulliparous mice. In parous mice, c-Met is regulated by obesity in unaffected mammary gland and is associated with tumor onset. C3(1)-TAg mice recapitulate epidemiologic findings such that parity drives increased BBC risk and potential microenvironmental alterations in c-Met signaling may play a role in etiology. PMID:25354395

Ectopic expression of a wheat WRKY transcription factor gene TaWRKY71-1 results in hyponastic leaves in Arabidopsis thaliana.

PubMed

Qin, Zhen; Lv, Hongjun; Zhu, Xinlei; Meng, Chen; Quan, Taiyong; Wang, Mengcheng; Xia, Guangmin

2013-01-01

Leaf type is an important trait that closely associates with crop yield. WRKY transcription factors exert diverse regulatory effects in plants, but their roles in the determination of leaf type have not been reported so far. In this work, we isolated a WRKY transcription factor gene TaWRKY71-1 from a wheat introgression line SR3, which has larger leaves, superior growth capacity and higher yield than its parent common wheat JN177. TaWRKY71-1 specifically expressed in leaves, and produced more mRNA in SR3 than in JN177. TaWRKY71-1 localized in the nucleus and had no transcriptional activation activity. TaWRKY71-1 overexpression in Arabidopsis resulted in hyponastic rosette leaves, and the hyponastic strength was closely correlative with the transcription level of the transgene. The spongy mesophyll cells at abaxial side of leaves were drastically compacted by TaWRKY71-1 overexpression. In TaWRKY71-1 overexpression Arabidopsis, the expression of IAMT1 that encodes a methyltransferase converting free indole-3-acetic acid (IAA) to methyl-IAA ester (MeIAA) to alter auxin homeostatic level was induced, and the induction level was dependent on the abundance of TaWRKY71-1 transcripts. Besides, several TCP genes that had found to be restricted by IAMT1 had lower expression levels as well. Our results suggest that TaWRKY71-1 causes hyponastic leaves through altering auxin homeostatic level by promoting the conversion of IAA to MeIAA.

Stimulation of Pol III-dependent 5S rRNA and U6 snRNA gene expression by AP-1 transcription factors.

PubMed

Ahuja, Richa; Kumar, Vijay

2017-07-01

RNA polymerase III transcribes structurally diverse group of essential noncoding RNAs including 5S ribosomal RNA (5SrRNA) and U6 snRNA. These noncoding RNAs are involved in RNA processing and ribosome biogenesis, thus, coupling Pol III activity to the rate of protein synthesis, cell growth, and proliferation. Even though a few Pol II-associated transcription factors have been reported to participate in Pol III-dependent transcription, its activation by activator protein 1 (AP-1) factors, c-Fos and c-Jun, has remained unexplored. Here, we show that c-Fos and c-Jun bind to specific sites in the regulatory regions of 5S rRNA (type I) and U6 snRNA (type III) gene promoters and stimulate their transcription. Our chromatin immunoprecipitation studies suggested that endogenous AP-1 factors bind to their cognate promoter elements during the G1/S transition of cell cycle apparently synchronous with Pol III transcriptional activity. Furthermore, the interaction of c-Jun with histone acetyltransferase p300 promoted the recruitment of p300/CBP complex on the promoters and facilitated the occupancy of Pol III transcriptional machinery via histone acetylation and chromatin remodeling. The findings of our study, together, suggest that AP-1 factors are novel regulators of Pol III-driven 5S rRNA and U6 snRNA expression with a potential role in cell proliferation. © 2017 Federation of European Biochemical Societies.

The Transcription Profile of Tax-3 Is More Similar to Tax-1 than Tax-2: Insights into HTLV-3 Potential Leukemogenic Properties

PubMed Central

Chevalier, Sébastien A.; Durand, Stéphanie; Dasgupta, Arindam; Radonovich, Michael; Cimarelli, Andrea; Brady, John N.

2012-01-01

Human T-cell Lymphotropic Viruses type 1 (HTLV-1) is the etiological agent of Adult T-cell Leukemia/Lymphoma. Although associated with lymphocytosis, HTLV-2 infection is not associated with any malignant hematological disease. Similarly, no infection-related symptom has been detected in HTLV-3-infected individuals studied so far. Differences in individual Tax transcriptional activity might account for these distinct physiopathological outcomes. Tax-1 and Tax-3 possess a PDZ binding motif in their sequence. Interestingly, this motif, which is critical for Tax-1 transforming activity, is absent from Tax-2. We used the DNA microarray technology to analyze and compare the global gene expression profiles of different T- and non T-cell types expressing Tax-1, Tax-2 or Tax-3 viral transactivators. In a T-cell line, this analysis allowed us to identify 48 genes whose expression is commonly affected by all Tax proteins and are hence characteristic of the HTLV infection, independently of the virus type. Importantly, we also identified a subset of genes (n = 70) which are specifically up-regulated by Tax-1 and Tax-3, while Tax-1 and Tax-2 shared only 1 gene and Tax-2 and Tax-3 shared 8 genes. These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation. Analysis of the molecular interactions existing between those Tax-1/Tax-3 deregulated genes then allowed us to highlight biological networks of genes characteristic of HTLV-1 and HTLV-3 infection. The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation. In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo. PMID:22911729

PCAF interacts with tax and stimulates tax transactivation in a histone acetyltransferase-independent manner.

PubMed

Jiang, H; Lu, H; Schiltz, R L; Pise-Masison, C A; Ogryzko, V V; Nakatani, Y; Brady, J N

1999-12-01

Recent studies have shown that the p300/CREB binding protein (CBP)-associated factor (PCAF) is involved in transcriptional activation. PCAF activity has been shown strongly associated with histone acetyltransferase (HAT) activity. In this report, we present evidence for a HAT-independent transcription function that is activated in the presence of the human T-cell leukemia virus type 1 (HTLV-1) Tax protein. In vitro and in vivo GST-Tax pull-down and coimmunoprecipitation experiments demonstrate that there is a direct interaction between Tax and PCAF, independent of p300/CBP. PCAF can be recruited to the HTLV-1 Tax responsive element in the presence of Tax, and PCAF cooperates with Tax in vivo to activate transcription from the HTLV-1 LTR over 10-fold. Point mutations at Tax amino acid 318 (TaxS318A) or 319 to 320 (Tax M47), which have decreased or no activity on the HTLV-1 promoter, are defective for PCAF binding. Strikingly, the ability of PCAF to stimulate Tax transactivation is not solely dependent on the PCAF HAT domain. Two independent PCAF HAT mutants, which knock out acetyltransferase enzyme activity, activate Tax transactivation to approximately the same level as wild-type PCAF. In contrast, p300 stimulation of Tax transactivation is HAT dependent. These studies provide experimental evidence that PCAF contains a coactivator transcription function independent of the HAT activity on the viral long terminal repeat.

PCAF Interacts with Tax and Stimulates Tax Transactivation in a Histone Acetyltransferase-Independent Manner

PubMed Central

Jiang, Hua; Lu, Hanxin; Schiltz, R. Louis; Pise-Masison, Cynthia A.; Ogryzko, Vasily V.; Nakatani, Yoshihiro; Brady, John N.

1999-01-01

Recent studies have shown that the p300/CREB binding protein (CBP)-associated factor (PCAF) is involved in transcriptional activation. PCAF activity has been shown strongly associated with histone acetyltransferase (HAT) activity. In this report, we present evidence for a HAT-independent transcription function that is activated in the presence of the human T-cell leukemia virus type 1 (HTLV-1) Tax protein. In vitro and in vivo GST-Tax pull-down and coimmunoprecipitation experiments demonstrate that there is a direct interaction between Tax and PCAF, independent of p300/CBP. PCAF can be recruited to the HTLV-1 Tax responsive element in the presence of Tax, and PCAF cooperates with Tax in vivo to activate transcription from the HTLV-1 LTR over 10-fold. Point mutations at Tax amino acid 318 (TaxS318A) or 319 to 320 (Tax M47), which have decreased or no activity on the HTLV-1 promoter, are defective for PCAF binding. Strikingly, the ability of PCAF to stimulate Tax transactivation is not solely dependent on the PCAF HAT domain. Two independent PCAF HAT mutants, which knock out acetyltransferase enzyme activity, activate Tax transactivation to approximately the same level as wild-type PCAF. In contrast, p300 stimulation of Tax transactivation is HAT dependent. These studies provide experimental evidence that PCAF contains a coactivator transcription function independent of the HAT activity on the viral long terminal repeat. PMID:10567539

Accumulation of unstable promoter-associated transcripts upon loss of the nuclear exosome subunit Rrp6p in Saccharomyces cerevisiae

PubMed Central

Davis, Carrie Anne; Ares, Manuel

2006-01-01

Mutations in RRP6 result in the accumulation of aberrant polyadenylated transcripts from small nucleolar RNA genes. We exploited this observation to search for novel noncoding RNA genes in the yeast genome. When RNA from rrp6Δ yeast is compared with wild-type on whole-genome microarrays, numerous intergenic loci exhibit an increased mutant/wild type signal ratio. Among these loci, we found one encoding a new C/D box small nucleolar RNA, as well as a surprising number that gave rise to heterogeneous Trf4p-polyadenylated RNAs with lengths of ≈250–500 nt. This class of RNAs is not easily detected in wild-type cells and appears associated with promoters. Fine mapping of several such transcripts shows they originate near known promoter elements but do not usually extend far enough to act as mRNAs, and may regulate the transcription of downstream mRNAs. Rather than being uninformative transcriptional “noise,” we hypothesize that these transcripts reflect important features of RNA polymerase activity at the promoter. This activity is normally undetectable in wild-type cells because the transcripts are somehow distinguished from true mRNAs and are degraded in an Rrp6p-dependent fashion in the nucleus. PMID:16484372

Functional relevance for type 1 diabetes mellitus-associated genetic variants by using integrative analyses.

PubMed

Qiu, Ying-Hua; Deng, Fei-Yan; Tang, Zai-Xiang; Jiang, Zhen-Huan; Lei, Shu-Feng

2015-10-01

Type 1 diabetes mellitus (type 1 DM) is an autoimmune disease. Although genome-wide association studies (GWAS) and meta-analyses have successfully identified numerous type 1 DM-associated susceptibility loci, the underlying mechanisms for these susceptibility loci are currently largely unclear. Based on publicly available datasets, we performed integrative analyses (i.e., integrated gene relationships among implicated loci, differential gene expression analysis, functional prediction and functional annotation clustering analysis) and combined with expression quantitative trait loci (eQTL) results to further explore function mechanisms underlying the associations between genetic variants and type 1 DM. Among a total of 183 type 1 DM-associated SNPs, eQTL analysis showed that 17 SNPs with cis-regulated eQTL effects on 9 genes. All the 9 eQTL genes enrich in immune-related pathways or Gene Ontology (GO) terms. Functional prediction analysis identified 5 SNPs located in transcription factor (TF) binding sites. Of the 9 eQTL genes, 6 (TAP2, HLA-DOB, HLA-DQB1, HLA-DQA1, HLA-DRB5 and CTSH) were differentially expressed in type 1 DM-associated related cells. Especially, rs3825932 in CTSH has integrative functional evidence supporting the association with type 1 DM. These findings indicated that integrative analyses can yield important functional information to link genetic variants and type 1 DM. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Spam1-associated transmission ratio distortion in mice: Elucidating the mechanism

PubMed Central

Martin-DeLeon, Patricia A; Zhang, Hong; Morales, Carlos R; Zhao, Yutong; Rulon, Michelle; Barnoski, Barry L; Chen, Hong; Galileo, Deni S

2005-01-01

Background While transmission ratio distortion, TRD, (a deviation from Mendelian ratio) is extensive in humans and well-documented in mice, the underlying mechanisms are unknown. Our earlier studies on carriers of spontaneous mutations of mouse Sperm Adhesion Molecule 1 (Spam1) suggested that TRD results from biochemically different sperm, due to a lack of transcript sharing through the intercellular cytoplasmic bridges of spermatids. These bridges usually allow transcript sharing among genetically different spermatids which develop into biochemically and functionally equivalent sperm. Objectives The goals of the study were to provide support for the lack of sharing (LOS) hypothesis, using transgene and null carriers of Spam1, and to determine the mechanism of Spam1-associated TRD. Methods Carriers of Spam1-Hyal5 BAC transgenes were mated with wild-type female mice and the progeny analyzed for TRD by PCR genotyping. Sperm from transgene and Spam1 null carriers were analyzed using flow cytometry and immunocytochemistry to detect quantities of Spam1 and/or Hyal5. Transgene-bearing sperm with Spam1 overexpression were detected by fluorescence in situ hybridization. In wild-type animals, EM studies of in situ transcript hybridization of testis sections and Northern analysis of biochemically fractionated testicular RNA were performed to localize Spam1 transcript. Finally, AU-rich motifs identified in the 3' UTR of Spam1 RNA were assayed by UV cross-linking to determine their ability to interact with testicular RNA binding proteins. Results The Tg8 line of transgene carriers had a significant (P < 0.001) TRD, due to reduced fertilizing ability of transgene-bearing sperm. These sperm retained large cytoplasmic droplets engorged with overexpressed Spam1 or Hyal5 protein. Caudal sperm from transgene carriers and caput sperm of null carriers showed a bimodal distribution of Spam1, indicating that the sperm in a male were biochemically different with respect to Spam1 quantities. Spam1 RNA was absent from the bridges, associated exclusively with the ER, and was shown to be anchored to the cytoskeleton. This compartmentalization of the transcript, mediated by cytoskeletal binding, occurs via protein interactions with 3' UTR AU-rich sequences that are likely involved in its stabilization. Conclusion We provide strong support for the LOS hypothesis, and have elucidated the mechanism of Spam1-associated TRD. PMID:16092963

When Wine and Apple Both Help the Production of Grapes: ERP Evidence for Post-lexical Semantic Facilitation in Picture Naming

PubMed Central

Python, Grégoire; Fargier, Raphaël; Laganaro, Marina

2018-01-01

Background: Producing a word in referential naming requires to select the right word in our mental lexicon among co-activated semantically related words. The mechanisms underlying semantic context effects during speech planning are still controversial, particularly for semantic facilitation which investigation remains under-represented in contrast to the plethora of studies dealing with interference. Our aim is to study the time-course of semantic facilitation in picture naming, using a picture-word “interference” paradigm and event-related potentials (ERPs). Methods: We compared two different types of semantic relationships, associative and categorical, in a single word priming and a double word priming paradigm. The primes were presented visually with a long negative Stimulus Onset Asynchrony (SOA), which is expected to cause facilitation. Results: Shorter naming latencies were observed after both associative and categorical primes, as compared to unrelated primes, and even shorter latencies after two primes. Electrophysiological results showed relatively late modulations of waveform amplitudes for both types of primes (beginning ~330 ms post picture onset with a single prime and ~275 ms post picture onset with two primes), corresponding to a shift in latency of similar topographic maps across conditions. Conclusion: The present results are in favor of a post-lexical locus of semantic facilitation for associative and categorical priming in picture naming and confirm that semantic facilitation is as relevant as semantic interference to inform on word production. The post-lexical locus argued here might be related to self-monitoting or/and to modulations at the level of word-form planning, without excluding the participation of strategic processes. PMID:29692716

Song matching, overlapping, and switching in the banded wren: the sender’s perspective

PubMed Central

Vehrencamp, Sandra L.; Hall, Michelle L.; Bohman, Erin R.; Depeine, Catherine D.; Dalziell, Anastasia H.

2008-01-01

Interpreting receiver responses to on-territory playback of aggressive signals is problematic. One solution is to combine such receiver-perspective experiments with a sender-perspective experiment that allows subjects to demonstrate how their choice of singing strategies is associated with their approach behavior. Here we report the results of a sender-perspective study on the banded wren (Thryothorus pleurostictus), and combine information on context and results of previous receiver-perspective experiments to clarify function. Territorial males were presented with a 5-min playback consisting of song types present in their repertoire. We assessed the degree to which the subjects’ song matching rate, overlapping rate, and song-type versatility were correlated with their approach latency, closeness of approach, latency to first retreat, and time spent close to the speaker. Male age, breeding stage, and features of the playback stimuli were also considered. Song matching was associated with rapid and close approach, consistent with the receiver-perspective interpretation of type matching as a conventional signal of aggressive motivation. Overlapping was associated with earlier retreat, and together with the aversive receiver response to our previous overlapping playback experiment suggests that overlapping is a defensive withdrawal signal. High versatility was associated with slower first retreat from the speaker and high levels of reciprocal matching between subject and playback. Males with fledglings sang with particularly low versatility and approached the speaker aggressively, whereas males with nestlings overlapped more and retreated quickly. Finally, older males matched more but overlapped less. PMID:18392112

Data Latency Characteristics Observed Through Diverse Communication Links by the EarthScope USArray Transportable Array

NASA Astrophysics Data System (ADS)

Vernon, F. L.; Eakins, J. A.; Busby, R.

2008-12-01

The USArray Transportable Array has deployed over 600 stations in aggregate over the past four years. All stations communicate in near-real time using ip protocols over a variety of communication links including satellite, cell phone, and DSL. Several different communication providers have been used for each type of communication links. In addition, data are being acquired from several regional networks either directly from a data server or after passing through the IRIS DMC BUD system. We will present results about the latency of data arriving at the UCSD Array Network Facility where the real time data are acquired. Under normal operating conditions the median data latency is several seconds. We will also examine the data return rates through the near-real time systems. In addition we will examine the statistics of over 36,000 events which have automatic event locations and associations. We evaluate the timeliness of these results in the context of seismic early warning systems.

EBNA-2 of herpesvirus papio diverges significantly from the type A and type B EBNA-2 proteins of Epstein-Barr virus but retains an efficient transactivation domain with a conserved hydrophobic motif.

PubMed Central

Ling, P D; Ryon, J J; Hayward, S D

1993-01-01

EBNA-2 contributes to the establishment of Epstein-Barr virus (EBV) latency in B cells and to the resultant alterations in B-cell growth pattern by up-regulating expression from specific viral and cellular promoters. We have taken a comparative approach toward characterizing functional domains within EBNA-2. To this end, we have cloned and sequenced the EBNA-2 gene from the closely related baboon virus herpesvirus papio (HVP). All human EBV isolates have either a type A or type B EBNA-2 gene. However, the HVP EBNA-2 gene falls into neither the type A category nor the type B category, suggesting that the separation into these two subtypes may have been a recent evolutionary event. Comparison of the predicted amino acid sequences indicates 37% amino acid identity with EBV type A EBNA-2 and 35% amino acid identity with type B EBNA-2. To define the domains of EBNA-2 required for transcriptional activation, the DNA binding domain of the GAL4 protein was fused to overlapping segments of EBV EBNA-2. This approach identified a 40-amino-acid (40-aa) EBNA-2 activation domain located between aa 437 and 477. Transactivation ability was completely lost when the amino-terminal boundary of this domain was moved to aa 441, indicating that the motif at aa 437 to 440, Pro-Ile-Leu-Phe, contains residues critical for function. The aa 437 boundary identified in these experiments coincides precisely with a block of conserved sequences in HVP EBNA-2, and the comparable carboxy-terminal region of HVP EBNA-2 also functioned as a strong transcriptional activation domain when fused to the Gal4(1-147) protein. The EBV and HVP EBNA-2 activation domains share a mixed proline-rich, negatively charged character with a striking conservation of positionally equivalent hydrophobic residues. The importance of the individual amino acids making up the Pro-Ile-Leu-Phe motif was examined by mutagenesis. Any alteration of these residues was found to reduce transactivation efficiency, with changes at the Pro-437 and Phe-440 positions producing the most deleterious effects. Activation of the EBV latency C promoter by EBNA-2 was shown to be dependent on the presence of the carboxy-terminal activation domain. However, this requirement was generic, rather than specific, since the EBNA-2 activation domain could be replaced with those from the herpes simplex virus (HSV) VP16 protein or the EBV Rta protein. Potential karyophilic signals within EBNA-2 were examined by introducing oligonucleotides encoding positively charged amino acid groupings that might serve in this capacity into a cytoplasmic test protein, HSV delta IE175, and by examining the intracellular localization of the resulting proteins. This assay identified a strong nuclear localization signal between EBV amino acids (aa) 478 to 485, which was conserved in HVP, and a weaker noncanonical signal between EBV aa 341 to 355, which was not conserved in HVP. Images PMID:8388484

EBNA-2 of herpesvirus papio diverges significantly from the type A and type B EBNA-2 proteins of Epstein-Barr virus but retains an efficient transactivation domain with a conserved hydrophobic motif.

PubMed

Ling, P D; Ryon, J J; Hayward, S D

1993-06-01

EBNA-2 contributes to the establishment of Epstein-Barr virus (EBV) latency in B cells and to the resultant alterations in B-cell growth pattern by up-regulating expression from specific viral and cellular promoters. We have taken a comparative approach toward characterizing functional domains within EBNA-2. To this end, we have cloned and sequenced the EBNA-2 gene from the closely related baboon virus herpesvirus papio (HVP). All human EBV isolates have either a type A or type B EBNA-2 gene. However, the HVP EBNA-2 gene falls into neither the type A category nor the type B category, suggesting that the separation into these two subtypes may have been a recent evolutionary event. Comparison of the predicted amino acid sequences indicates 37% amino acid identity with EBV type A EBNA-2 and 35% amino acid identity with type B EBNA-2. To define the domains of EBNA-2 required for transcriptional activation, the DNA binding domain of the GAL4 protein was fused to overlapping segments of EBV EBNA-2. This approach identified a 40-amino-acid (40-aa) EBNA-2 activation domain located between aa 437 and 477. Transactivation ability was completely lost when the amino-terminal boundary of this domain was moved to aa 441, indicating that the motif at aa 437 to 440, Pro-Ile-Leu-Phe, contains residues critical for function. The aa 437 boundary identified in these experiments coincides precisely with a block of conserved sequences in HVP EBNA-2, and the comparable carboxy-terminal region of HVP EBNA-2 also functioned as a strong transcriptional activation domain when fused to the Gal4(1-147) protein. The EBV and HVP EBNA-2 activation domains share a mixed proline-rich, negatively charged character with a striking conservation of positionally equivalent hydrophobic residues. The importance of the individual amino acids making up the Pro-Ile-Leu-Phe motif was examined by mutagenesis. Any alteration of these residues was found to reduce transactivation efficiency, with changes at the Pro-437 and Phe-440 positions producing the most deleterious effects. Activation of the EBV latency C promoter by EBNA-2 was shown to be dependent on the presence of the carboxy-terminal activation domain. However, this requirement was generic, rather than specific, since the EBNA-2 activation domain could be replaced with those from the herpes simplex virus (HSV) VP16 protein or the EBV Rta protein. Potential karyophilic signals within EBNA-2 were examined by introducing oligonucleotides encoding positively charged amino acid groupings that might serve in this capacity into a cytoplasmic test protein, HSV delta IE175, and by examining the intracellular localization of the resulting proteins. This assay identified a strong nuclear localization signal between EBV amino acids (aa) 478 to 485, which was conserved in HVP, and a weaker noncanonical signal between EBV aa 341 to 355, which was not conserved in HVP.

Transcriptional activation of the suppressor of cytokine signaling-3 (SOCS-3) gene via STAT3 is increased in F9 REX1 (ZFP-42) knockout teratocarcinoma stem cells relative to wild-type cells.

PubMed

Xu, Juliana; Sylvester, Renia; Tighe, Ann P; Chen, Siming; Gudas, Lorraine J

2008-03-14

Rex1 (Zfp42), first identified as a gene that is transcriptionally repressed by retinoic acid (RA), encodes a zinc finger transcription factor expressed at high levels in F9 teratocarcinoma stem cells, embryonic stem cells, and other stem cells. Loss of both alleles of Rex1 by homologous recombination alters the RA-induced differentiation of F9 cells, a model of pluripotent embryonic stem cells. We identified Suppressor of Cytokine Signaling-3 (SOCS-3) as a gene that exhibits greatly increased transcriptional activation in RA, cAMP, and theophylline (RACT)-treated F9 Rex1(-/-) cells (approximately 25-fold) as compared to wild-type (WT) cells ( approximately 2.5-fold). By promoter deletion, mutation, and transient transfection analyses, we have shown that this transcriptional increase is mediated by the STAT3 DNA-binding elements located between -99 to -60 in the SOCS-3 promoter. Overexpression of STAT3 dominant-negative mutants greatly diminishes this SOCS-3 transcriptional increase in F9 Rex1(-/-) cells. This increase in SOCS-3 transcription is associated with a four- to fivefold higher level of tyrosine-phosphorylated STAT3 in the RACT-treated F9 Rex1(-/-) cells as compared to WT. Dominant-negative Src tyrosine kinase, Jak2, and protein kinase A partially reduce the transcriptional activation of the SOCS 3 gene in RACT-treated F9 Rex1 null cells. In contrast, parathyroid hormone peptide enhances the effect of RA in F9 Rex1(-/-) cells, but not in F9 WT. Thus, Rex1, which is highly expressed in stem cells, inhibits signaling via the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, thereby modulating the differentiation of F9 cells.

Does vitamin C and vitamin E supplementation prolong the latency period before delivery following the preterm premature rupture of membranes? A randomized controlled study.

PubMed

Gungorduk, Kemal; Asicioglu, Osman; Gungorduk, Ozgu Celikkol; Yildirim, Gokhan; Besimoğlu, Berhan; Ark, Cemal

2014-03-01

To determine whether maternal vitamin C and vitamin E supplementation after the premature rupture of membranes is associated with an increase in the latency period before delivery. In the present prospective open randomized trial, 229 pregnant women with preterm premature rupture of membranes (PPROM) at ≥ 24.0 and < 34.0 weeks' gestation were randomly assigned to receive either 1,000 mg of vitamin C and 400 IU of vitamin E (n = 126) or a placebo (n = 123). The primary outcome was the latency period until delivery. Analysis was performed on an intention-to-treat basis. No significant differences in demographic or clinical characteristics were observed between the groups. Latency period until delivery was significantly higher in the group that received vitamins compared with the control group (11.2 ± 6.3 days versus 6.2 ± 4.0 days; p < 0.001). Gestational age at delivery was also significantly higher in the vitamin group compared with the control group (31.9 ± 2.6 weeks versus 31.0 ± 2.6 weeks; p = 0.01). No significant differences in adverse maternal outcome (i.e., chorioamnionitis or endometritis) or neonatal outcome (i.e., neonatal sepsis, neonatal death, necrotizing enterocolitis, or grade 3 to 4 intraventricular hemorrhage) were noted between groups. The findings of the present study suggest that the use of vitamins C and E in women with PPROM is associated with a longer latency period before delivery. Moreover, adverse neonatal and maternal outcomes, which are often associated with prolonged latency periods, were similar between the groups. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Effects of aging and involuntary capture of attention on event-related potentials associated with the processing of and the response to a target stimulus

PubMed Central

Cid-Fernández, Susana; Lindín, Mónica; Díaz, Fernando

2014-01-01

The main aim of the present study was to assess whether aging modulates the effects of involuntary capture of attention by novel stimuli on performance, and on event-related potentials (ERPs) associated with target processing (N2b and P3b) and subsequent response processes (stimulus-locked Lateralized Readiness Potential -sLRP- and response-locked Lateralized Readiness Potential -rLRP-). An auditory-visual distraction-attention task was performed by 77 healthy participants, divided into three age groups (Young: 21–29, Middle-aged: 51–64, Old: 65–84 years old). Participants were asked to attend to visual stimuli and to ignore auditory stimuli. Aging was associated with slowed reaction times, target stimulus processing in working memory (WM, longer N2b and P3b latencies) and selection and preparation of the motor response (longer sLRP and earlier rLRP onset latencies). In the novel relative to the standard condition we observed, in the three age groups: (1) a distraction effect, reflected in a slowing of reaction times, of stimuli categorization in WM (longer P3b latency), and of motor response selection (longer sLRP onset latency); (2) a facilitation effect on response preparation (later rLRP onset latency), and (3) an increase in arousal (larger amplitudes of all ERPs evaluated, except for N2b amplitude in the Old group). A distraction effect on the stimulus evaluation processes (longer N2b latency) were also observed, but only in middle-aged and old participants, indicating that the attentional capture slows the stimulus evaluation in WM from early ages (from 50 years onwards, without differences between middle-age and older adults), but not in young adults. PMID:25294999

Predictive Compensator Optimization for Head Tracking Lag in Virtual Environments

NASA Technical Reports Server (NTRS)

Adelstein, Barnard D.; Jung, Jae Y.; Ellis, Stephen R.

2001-01-01

We examined the perceptual impact of plant noise parameterization for Kalman Filter predictive compensation of time delays intrinsic to head tracked virtual environments (VEs). Subjects were tested in their ability to discriminate between the VE system's minimum latency and conditions in which artificially added latency was then predictively compensated back to the system minimum. Two head tracking predictors were parameterized off-line according to cost functions that minimized prediction errors in (1) rotation, and (2) rotation projected into translational displacement with emphasis on higher frequency human operator noise. These predictors were compared with a parameterization obtained from the VE literature for cost function (1). Results from 12 subjects showed that both parameterization type and amount of compensated latency affected discrimination. Analysis of the head motion used in the parameterizations and the subsequent discriminability results suggest that higher frequency predictor artifacts are contributory cues for discriminating the presence of predictive compensation.

Abnormal motor phenotype at adult stages in mice lacking type 2 deiodinase.

PubMed

Bárez-López, Soledad; Bosch-García, Daniel; Gómez-Andrés, David; Pulido-Valdeolivas, Irene; Montero-Pedrazuela, Ana; Obregon, Maria Jesus; Guadaño-Ferraz, Ana

2014-01-01

Thyroid hormones have a key role in both the developing and adult central nervous system and skeletal muscle. The thyroid gland produces mainly thyroxine (T4) but the intracellular concentrations of 3,5,3'-triiodothyronine (T3; the transcriptionally active hormone) in the central nervous system and skeletal muscle are modulated by the activity of type 2 deiodinase (D2). To date no neurological syndrome has been associated with mutations in the DIO2 gene and previous studies in young and juvenile D2-knockout mice (D2KO) did not find gross neurological alterations, possibly due to compensatory mechanisms. This study aims to analyze the motor phenotype of 3-and-6-month-old D2KO mice to evaluate the role of D2 on the motor system at adult stages in which compensatory mechanisms could have failed. Motor abilities were explored by validated tests. In the footprint test, D2KO showed an altered global gait pattern (mice walked slower, with shorter strides and with a hindlimb wider base of support than wild-type mice). No differences were detected in the balance beam test. However, a reduced latency to fall was found in the rotarod, coat-hanger and four limb hanging wire tests indicating impairment on coordination and prehensile reflex and a reduction of muscle strength. In histological analyses of cerebellum and skeletal muscle, D2KO mice did not present gross structural abnormalities. Thyroid hormones levels and deiodinases activities were also determined. In D2KO mice, despite euthyroid T3 and high T4 plasma levels, T3 levels were significantly reduced in cerebral cortex (48% reduction) and skeletal muscle (33% reduction), but not in the cerebellum where other deiodinase (type 1) is expressed. The motor alterations observed in D2KO mice indicate an important role for D2 in T3 availability to maintain motor function and muscle strength. Our results suggest a possible implication of D2 in motor disorders.

Tax Abolishes Histone H1 Repression of p300 Acetyltransferase Activity at the Human T-Cell Leukemia Virus Type 1 Promoter▿

PubMed Central

Konesky, Kasey L.; Nyborg, Jennifer K.; Laybourn, Paul J.

2006-01-01

Upon infection of human T-cell leukemia virus type 1 (HTLV-1), the provirus is integrated into the host cell genome and subsequently packaged into chromatin that contains histone H1. Consequently, transcriptional activation of the virus requires overcoming the environment of chromatin and H1. To efficiently activate transcription, HTLV-1 requires the virally encoded protein Tax and cellular transcription factor CREB. Together Tax and CREB interact with three cis-acting promoter elements called viral cyclic-AMP response elements (vCREs). Binding of Tax and CREB to the vCREs promotes association of p300/CBP into the complex and leads to transcriptional activation. Therefore, to fully understand the mechanism of Tax transactivation, it is necessary to examine transcriptional activation from chromatin assembled with H1. Using a DNA template harboring the complete HTLV-1 promoter sequence and a highly defined recombinant assembly system, we demonstrate proper incorporation of histone H1 into chromatin. Addition of H1 to the chromatin template reduces HTLV-1 transcriptional activation through a novel mechanism. Specifically, H1 does not inhibit CREB or Tax binding to the vCREs or p300 recruitment to the promoter. Rather, H1 directly targets p300 acetyltransferase activity. Interestingly, in determining the mechanism of H1 repression, we have discovered a previously undefined function of Tax, overcoming the repressive effects of H1-chromatin. Tax specifically abrogates the H1 repression of p300 enzymatic activity in a manner independent of p300 recruitment and without displacement of H1 from the promoter. PMID:16943293

Test Operations Procedure (TOP) 02-2-546 Teleoperated Unmanned Ground Vehicle (UGV) Latency Measurements

DTIC Science & Technology

2017-01-11

discrete system components or measurements of latency in autonomous systems. 15. SUBJECT TERMS Unmanned Ground Vehicles, Basic Video Latency, End-to... discrete system components or measurements of latency in autonomous systems. 1.1 Basic Video Latency. Teleoperation latency, or lag, describes

Mapping Adipose and Muscle Tissue Expression Quantitative Trait Loci in African Americans to Identify Genes for Type 2 Diabetes and Obesity

PubMed Central

Sajuthi, Satria P.; Sharma, Neeraj K.; Chou, Jeff W.; Palmer, Nicholette D.; McWilliams, David R.; Beal, John; Comeau, Mary E.; Ma, Lijun; Calles-Escandon, Jorge; Demons, Jamehl; Rogers, Samantha; Cherry, Kristina; Menon, Lata; Kouba, Ethel; Davis, Donna; Burris, Marcie; Byerly, Sara J.; Ng, Maggie C.Y.; Maruthur, Nisa M.; Patel, Sanjay R.; Bielak, Lawrence F.; Lange, Leslie; Guo, Xiuqing; Sale, Michèle M.; Chan, Kei Hang; Monda, Keri L.; Chen, Gary K.; Taylor, Kira; Palmer, Cameron; Edwards, Todd L; North, Kari E.; Haiman, Christopher A.; Bowden, Donald W.; Freedman, Barry I.; Langefeld, Carl D.; Das, Swapan K.

2016-01-01

Relative to European Americans, type 2 diabetes (T2D) is more prevalent in African Americans (AAs). Genetic variation may modulate transcript abundance in insulin-responsive tissues and contribute to risk; yet published studies identifying expression quantitative trait loci (eQTLs) in African ancestry populations are restricted to blood cells. This study aims to develop a map of genetically regulated transcripts expressed in tissues important for glucose homeostasis in AAs, critical for identifying the genetic etiology of T2D and related traits. Quantitative measures of adipose and muscle gene expression, and genotypic data were integrated in 260 non-diabetic AAs to identify expression regulatory variants. Their roles in genetic susceptibility to T2D, and related metabolic phenotypes were evaluated by mining GWAS datasets. eQTL analysis identified 1,971 and 2,078 cis-eGenes in adipose and muscle, respectively. Cis-eQTLs for 885 transcripts including top cis-eGenes CHURC1, USMG5, and ERAP2, were identified in both tissues. 62.1% of top cis-eSNPs were within ±50kb of transcription start sites and cis-eGenes were enriched for mitochondrial transcripts. Mining GWAS databases revealed association of cis-eSNPs for more than 50 genes with T2D (e.g. PIK3C2A, RBMS1, UFSP1), gluco-metabolic phenotypes, (e.g. INPP5E, SNX17, ERAP2, FN3KRP), and obesity (e.g. POMC, CPEB4). Integration of GWAS meta-analysis data from AA cohorts revealed the most significant association for cis-eSNPs of ATP5SL and MCCC1 genes, with T2D and BMI, respectively. This study developed the first comprehensive map of adipose and muscle tissue eQTLs in AAs (publically accessible at https://mdsetaa.phs.wakehealth.edu) and identified genetically-regulated transcripts for delineating genetic causes of T2D, and related metabolic phenotypes. PMID:27193597

Transcranial magnetic stimulation over the cerebellum delays predictive head movements in the coordination of gaze.

PubMed

Zangemeister, W H; Nagel, M

2001-01-01

We investigated coordinated saccadic eye and head movements following predictive horizontal visual targets at +/- 30 degrees by applying transcranial magnetic stimulation (TMS) over the cerebellum before the start of the gaze movement in 10 young subjects. We found three effects of TMS on eye-head movements: 1. Saccadic latency effect. When stimulation took place shortly before movements commenced (75-25 ms before), significantly shorter latencies were found between predictive target presentation and initiation of saccades. Eye latencies were significantly decreased by 45 ms on average, but head latencies were not. 2. Gaze amplitude effect. Without TMS, for the 60 degrees target amplitudes, head movements usually preceded eye movements, as expected (predictive gaze type 3). With TMS 5-75 ms before the gaze movement, the number of eye movements preceding head movements by 20-50 ms was significantly increased (p < 0.001) and the delay between eye and head movements was reversed (p < 0.001), i.e. we found eye-predictive gaze type 1. 3. Saccadic peak velocity effect. For TMS 5-25 s before the start of head movement, mean peak velocity of synkinetic eye saccades increased by 20-30% up to 600 degrees/s, compared to 350-400 degrees/s without TMS. We conclude that transient functional cerebellar deficits exerted by means of TMS can change the central synkinesis of eye-head coordination, including the preprogramming of the saccadic pulse and step of a coordinated gaze movement.

An Alternative Splice Product of IκB Kinase (IKKγ), IKKγ-Δ, Differentially Mediates Cytokine and Human T-Cell Leukemia Virus Type 1 Tax-Induced NF-κB Activation

PubMed Central

Hai, Tao; Yeung, Man-Lung; Wood, Thomas G.; Wei, Yuanfen; Yamaoka, Shoji; Gatalica, Zoran; Jeang, Kuan-Teh; Brasier, Allan R.

2006-01-01

NF-κB is an inducible transcription factor mediating innate immune responses whose activity is controlled by the multiprotein IκB kinase (IKK) “signalsome”. The core IKK consists of two catalytic serine kinases, IKKα and IKKβ, and a noncatalytic subunit, IKKγ. IKKγ is required for IKK activity by mediating kinase oligomerization and serving to couple the core catalytic subunits to upstream mitogen-activated protein 3-kinase cascades. We have discovered an alternatively spliced IKKγ mRNA isoform, encoding an in-frame deletion of exon 5, termed IKKγ-Δ. Using a specific reverse transcription-PCR assay, we find that IKKγ-Δ is widely expressed in cultured human cells and normal human tissues. Because IKKγ-Δ protein is lacking a critical coiled-coil domain important in protein-protein interactions, we sought to determine its signaling properties by examining its ability to self associate, couple to activators of the canonical pathway, and mediate human T-cell leukemia virus type 1 (HTLV-1) Tax-induced NF-κB activity. Coimmunoprecipitation and confocal colocalization assays indicate IKKγ-Δ has strong homo- and heterotypic association with wild-type (WT) IKKγ and, like IKKγ WT, associates with the IKKβ kinase. Similarly, IKKγ-Δ mediates IKK kinase activity and downstream NF-κB-dependent transcription in response to tumor necrosis factor (TNF) and the NF-κB-inducing kinase-IKKα signaling pathway. Surprisingly, however, in contrast to IKKγ WT, IKKγ-Δ is not able to mediate HTLV-1 Tax-induced NF-κB-dependent transcription, even though IKKγ-Δ binds and colocalizes with Tax. These observations suggest that IKKγ-Δ is a functionally distinct alternatively spliced mRNA product differentially mediating TNF-induced, but not Tax-induced, signals converging on the IKK signalsome. Differing levels of IKKγ-Δ expression, therefore, may affect signal transduction cascades coupling to IKK. PMID:16611882

Genomic signatures characterize leukocyte infiltration in myositis muscles.

PubMed

Zhu, Wei; Streicher, Katie; Shen, Nan; Higgs, Brandon W; Morehouse, Chris; Greenlees, Lydia; Amato, Anthony A; Ranade, Koustubh; Richman, Laura; Fiorentino, David; Jallal, Bahija; Greenberg, Steven A; Yao, Yihong

2012-11-21

Leukocyte infiltration plays an important role in the pathogenesis and progression of myositis, and is highly associated with disease severity. Currently, there is a lack of: efficacious therapies for myositis; understanding of the molecular features important for disease pathogenesis; and potential molecular biomarkers for characterizing inflammatory myopathies to aid in clinical development. In this study, we developed a simple model and predicted that 1) leukocyte-specific transcripts (including both protein-coding transcripts and microRNAs) should be coherently overexpressed in myositis muscle and 2) the level of over-expression of these transcripts should be correlated with leukocyte infiltration. We applied this model to assess immune cell infiltration in myositis by examining mRNA and microRNA (miRNA) expression profiles in muscle biopsies from 31 myositis patients and 5 normal controls. Several gene signatures, including a leukocyte index, type 1 interferon (IFN), MHC class I, and immunoglobulin signature, were developed to characterize myositis patients at the molecular level. The leukocyte index, consisting of genes predominantly associated with immune function, displayed strong concordance with pathological assessment of immune cell infiltration. This leukocyte index was subsequently utilized to differentiate transcriptional changes due to leukocyte infiltration from other alterations in myositis muscle. Results from this differentiation revealed biologically relevant differences in the relationship between the type 1 IFN pathway, miR-146a, and leukocyte infiltration within various myositis subtypes. Results indicate that a likely interaction between miR-146a expression and the type 1 IFN pathway is confounded by the level of leukocyte infiltration into muscle tissue. Although the role of miR-146a in myositis remains uncertain, our results highlight the potential benefit of deconvoluting the source of transcriptional changes in myositis muscle or other heterogeneous tissue samples. Taken together, the leukocyte index and other gene signatures developed in this study may be potential molecular biomarkers to help to further characterize inflammatory myopathies and aid in clinical development. These hypotheses need to be confirmed in separate and sufficiently powered clinical trials.

Deletion of Fmr1 Alters Function and Synaptic Inputs in the Auditory Brainstem

PubMed Central

Rotschafer, Sarah E.; Marshak, Sonya; Cramer, Karina S.

2015-01-01

Fragile X Syndrome (FXS), a neurodevelopmental disorder, is the most prevalent single-gene cause of autism spectrum disorder. Autism has been associated with impaired auditory processing, abnormalities in the auditory brainstem response (ABR), and reduced cell number and size in the auditory brainstem nuclei. FXS is characterized by elevated cortical responses to sound stimuli, with some evidence for aberrant ABRs. Here, we assessed ABRs and auditory brainstem anatomy in Fmr1 -/- mice, an animal model of FXS. We found that Fmr1 -/- mice showed elevated response thresholds to both click and tone stimuli. Amplitudes of ABR responses were reduced in Fmr1 -/- mice for early peaks of the ABR. The growth of the peak I response with sound intensity was less steep in mutants that in wild type mice. In contrast, amplitudes and response growth in peaks IV and V did not differ between these groups. We did not observe differences in peak latencies or in interpeak latencies. Cell size was reduced in Fmr1 -/- mice in the ventral cochlear nucleus (VCN) and in the medial nucleus of the trapezoid body (MNTB). We quantified levels of inhibitory and excitatory synaptic inputs in these nuclei using markers for presynaptic proteins. We measured VGAT and VGLUT immunolabeling in VCN, MNTB, and the lateral superior olive (LSO). VGAT expression in MNTB was significantly greater in the Fmr1 -/- mouse than in wild type mice. Together, these observations demonstrate that FXS affects peripheral and central aspects of hearing and alters the balance of excitation and inhibition in the auditory brainstem. PMID:25679778

Interference resolution in major depression.

PubMed

Joormann, Jutta; Nee, Derek Evan; Berman, Marc G; Jonides, John; Gotlib, Ian H

2010-03-01

In two experiments, we investigated individual differences in the ability to resolve interference in participants diagnosed with major depressive disorder (MDD). Participants were administered the "Ignore/Suppress" task, a short-term memory task composed of two steps. In Step 1 ("ignore"), participants were instructed to memorize a set of stimuli while ignoring simultaneously presented irrelevant material. In Step 2 ("suppress"), participants were instructed to forget a subset of the previously memorized material. The ability to resolve interference was indexed by response latencies on two recognition tasks in which participants decided whether a probe was a member of the target set. In Step 1, we compared response latencies to probes from the to-be-ignored list with response latencies to nonrecently presented items. In Step 2, we compared response latencies to probes from the to-be-suppressed list with response latencies to nonrecently presented items. The results indicate that, compared with control participants, depressed participants exhibited increased interference in the "suppress" but not in the "ignore" step of the task, when the stimuli were negative words. No group differences were obtained when we presented letters instead of emotional words. These findings indicate that depression is associated with difficulty in removing irrelevant negative material from short-term memory.

HuR interacts with human immunodeficiency virus type 1 reverse transcriptase, and modulates reverse transcription in infected cells

PubMed Central

Lemay, Julie; Maidou-Peindara, Priscilla; Bader, Thomas; Ennifar, Eric; Rain, Jean-Christophe; Benarous, Richard; Liu, Lang Xia

2008-01-01

Reverse transcription of the genetic material of human immunodeficiency virus type 1 (HIV-1) is a critical step in the replication cycle of this virus. This process, catalyzed by reverse transcriptase (RT), is well characterized at the biochemical level. However, in infected cells, reverse transcription occurs in a multiprotein complex – the reverse transcription complex (RTC) – consisting of viral genomic RNA associated with viral proteins (including RT) and, presumably, as yet uncharacterized cellular proteins. Very little is known about the cellular proteins interacting with the RTC, and with reverse transcriptase in particular. We report here that HIV-1 reverse transcription is affected by the levels of a nucleocytoplasmic shuttling protein – the RNA-binding protein HuR. A direct protein-protein interaction between RT and HuR was observed in a yeast two-hybrid screen and confirmed in vitro by homogenous time-resolved fluorescence (HTRF). We mapped the domain interacting with HuR to the RNAse H domain of RT, and the binding domain for RT to the C-terminus of HuR, partially overlapping the third RRM RNA-binding domain of HuR. HuR silencing with specific siRNAs greatly impaired early and late steps of reverse transcription, significantly inhibiting HIV-1 infection. Moreover, by mutagenesis and immunoprecipitation studies, we could not detect the binding of HuR to the viral RNA. These results suggest that HuR may be involved in and may modulate the reverse transcription reaction of HIV-1, by an as yet unknown mechanism involving a protein-protein interaction with HIV-1 RT. PMID:18544151

An In Vitro Model of Latency and Reactivation of Varicella Zoster Virus in Human Stem Cell-Derived Neurons

PubMed Central

Markus, Amos; Lebenthal-Loinger, Ilana; Yang, In Hong; Kinchington, Paul R.; Goldstein, Ronald S.

2015-01-01

Varicella zoster virus (VZV) latency in sensory and autonomic neurons has remained enigmatic and difficult to study, and experimental reactivation has not yet been achieved. We have previously shown that human embryonic stem cell (hESC)-derived neurons are permissive to a productive and spreading VZV infection. We now demonstrate that hESC-derived neurons can also host a persistent non-productive infection lasting for weeks which can subsequently be reactivated by multiple experimental stimuli. Quiescent infections were established by exposing neurons to low titer cell-free VZV either by using acyclovir or by infection of axons in compartmented microfluidic chambers without acyclovir. VZV DNA and low levels of viral transcription were detectable by qPCR for up to seven weeks. Quiescently-infected human neuronal cultures were induced to undergo renewed viral gene and protein expression by growth factor removal or by inhibition of PI3-Kinase activity. Strikingly, incubation of cultures induced to reactivate at a lower temperature (34°C) resulted in enhanced VZV reactivation, resulting in spreading, productive infections. Comparison of VZV genome transcription in quiescently-infected to productively-infected neurons using RNASeq revealed preferential transcription from specific genome regions, especially the duplicated regions. These experiments establish a powerful new system for modeling the VZV latent state, and reveal a potential role for temperature in VZV reactivation and disease. PMID:26042814

Interval dosing with the HDAC inhibitor vorinostat effectively reverses HIV latency

PubMed Central

Archin, Nancie M.; Kirchherr, Jennifer L.; Sung, Julia A.M.; Clutton, Genevieve; Sholtis, Katherine; Xu, Yinyan; Allard, Brigitte; Stuelke, Erin; Kashuba, Angela D.; Kuruc, Joann D.; Gay, Cynthia L.; Goonetilleke, Nilu

2017-01-01

BACKGROUND. The histone deacetylase (HDAC) inhibitor vorinostat (VOR) can increase HIV RNA expression in vivo within resting CD4+ T cells of aviremic HIV+ individuals. However, while studies of VOR or other HDAC inhibitors have reported reversal of latency, none has demonstrated clearance of latent infection. We sought to identify the optimal dosing of VOR for effective serial reversal of HIV latency. METHODS. In a study of 16 HIV-infected, aviremic individuals, we measured resting CD4+ T cell–associated HIV RNA ex vivo and in vivo following a single exposure to VOR, and then in vivo after a pair of doses separated by 48 or 72 hours, and finally following a series of 10 doses given at 72-hour intervals. RESULTS. Serial VOR exposures separated by 72 hours most often resulted in an increase in cell-associated HIV RNA within circulating resting CD4+ T cells. VOR was well tolerated by all participants. However, despite serial reversal of latency over 1 month of VOR dosing, we did not observe a measurable decrease (>0.3 log10) in the frequency of latent infection within resting CD4+ T cells. CONCLUSIONS. These findings outline parameters for the experimental use of VOR to clear latent infection. Latency reversal can be achieved by VOR safely and repeatedly, but effective depletion of persistent HIV infection will require additional advances. In addition to improvements in latency reversal, these advances may include the sustained induction of potent antiviral immune responses capable of recognizing and clearing the rare cells in which HIV latency has been reversed. TRIAL REGISTRATION. Clinicaltrials.gov NCT01319383. FUNDING. NIH grants U01 AI095052, AI50410, and P30 CA016086 and National Center for Advancing Translational Sciences grant KL2 TR001109. PMID:28714868

[Prediction of the latency period by cervical ultrasonography in premature rupture of the membranes before term].

PubMed

Gabriel, R; Morille, C; Drieux, L; Bige, V; Leymarie, F; Quereux, C

2002-11-01

To assess the value of ultrasonographic measurement of cervical length for predicting the duration of the latency period from admission to delivery in women with preterm premature rupture of the membranes (PROM). Prospective study in 88 women with preterm PROM before 34 weeks of amenorrhea. The median gestational age at admission was of 30.1 weeks. The clinical management included: no digital examination of the uterine cervix, antenatal corticosteroids, antibiotics (amoxicillin & clavulanic acid) for 7 days, and hoding back until 34 weeks. Cervical length at admission was determined with transvaginal ultrasonography. The duration of the latency period was studied in relation with cervical length, serum C-reactive protein (CRP) level and white blood cell (WBC) count at admission. The median latency period was longer in women with a cervical length > or = 25 mm (10 vs 5 days; p = 0.04), but this was not associated with a significant increase in birth weight. The median latency period was also longer in women with CRP < 20 mg/l (10 vs 3 days; p < 0.001) and this was associated with a significant increase in birth weight (1716 +/- 549 vs 1201 +/- 485 g; p < 0.01). Moreover, increased CRP levels were more frequent in women with a cervical length < 25 mm, and cervical length was no more predictive of the duration of the latency period in the subgroup of women with CRP < 20 mg/l and WBC < 20,000 cells/mm3. In women with preterm PROM, the latency period from admission to delivery is shorter when cervical length is < 25 mm. However, the clinical value of transvaginal ultrasonography is limited in comparison with serum CRP.

The Canonical Immediate Early 3 Gene Product pIE611 of Mouse Cytomegalovirus Is Dispensable for Viral Replication but Mediates Transcriptional and Posttranscriptional Regulation of Viral Gene Products.

PubMed

Rattay, Stephanie; Trilling, Mirko; Megger, Dominik A; Sitek, Barbara; Meyer, Helmut E; Hengel, Hartmut; Le-Trilling, Vu Thuy Khanh

2015-08-01

Transcription of mouse cytomegalovirus (MCMV) immediate early ie1 and ie3 is controlled by the major immediate early promoter/enhancer (MIEP) and requires differential splicing. Based on complete loss of genome replication of an MCMV mutant carrying a deletion of the ie3-specific exon 5, the multifunctional IE3 protein (611 amino acids; pIE611) is considered essential for viral replication. Our analysis of ie3 transcription resulted in the identification of novel ie3 isoforms derived from alternatively spliced ie3 transcripts. Construction of an IE3-hemagglutinin (IE3-HA) virus by insertion of an in-frame HA epitope sequence allowed detection of the IE3 isoforms in infected cells, verifying that the newly identified transcripts code for proteins. This prompted the construction of an MCMV mutant lacking ie611 but retaining the coding capacity for the newly identified isoforms ie453 and ie310. Using Δie611 MCMV, we demonstrated the dispensability of the canonical ie3 gene product pIE611 for viral replication. To determine the role of pIE611 for viral gene expression during MCMV infection in an unbiased global approach, we used label-free quantitative mass spectrometry to delineate pIE611-dependent changes of the MCMV proteome. Interestingly, further analysis revealed transcriptional as well as posttranscriptional regulation of MCMV gene products by pIE611. Cytomegaloviruses are pathogenic betaherpesviruses persisting in a lifelong latency from which reactivation can occur under conditions of immunosuppression, immunoimmaturity, or inflammation. The switch from latency to reactivation requires expression of immediate early genes. Therefore, understanding of immediate early gene regulation might add insights into viral pathogenesis. The mouse cytomegalovirus (MCMV) immediate early 3 protein (611 amino acids; pIE611) is considered essential for viral replication. The identification of novel protein isoforms derived from alternatively spliced ie3 transcripts prompted the construction of an MCMV mutant lacking ie611 but retaining the coding capacity for the newly identified isoforms ie453 and ie310. Using Δie611 MCMV, we demonstrated the dispensability of the canonical ie3 gene product pIE611 for viral replication and delineated pIE611-dependent changes of the MCMV proteome. Our findings have fundamental implications for the interpretation of earlier studies on pIE3 functions and highlight the complex orchestration of MCMV gene regulation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Integrated Genome-wide association and hypothalamus eQTL studies indicate a link between the circadian rhythm-related gene PER1 and coping behavior

PubMed Central

Ponsuksili, Siriluck; Zebunke, Manuela; Murani, Eduard; Trakooljul, Nares; Krieter, Joachim; Puppe, Birger; Schwerin, Manfred; Wimmers, Klaus

2015-01-01

Animal personality and coping styles are basic concepts for evaluating animal welfare. Struggling response of piglets in so-called backtests early in life reflects their coping strategy. Behavioral reactions of piglets in backtests have a moderate heritability, but their genetic basis largely remains unknown. Here, latency, duration and frequency of struggling attempts during one-minute backtests were repeatedly recorded of piglets at days 5, 12, 19, and 26. A genome-wide association study for backtest traits revealed 465 significant SNPs (FDR ≤ 0.05) mostly located in QTL (quantitative trait locus) regions on chromosome 3, 5, 12 and 16. In order to capture genes in these regions, 37 transcripts with significant SNPs were selected for expressionQTL analysis in the hypothalamus. Eight genes (ASGR1, CPAMD8, CTC1, FBXO39, IL19, LOC100511790, RAD51B, UBOX5) had cis- and five (RANGRF, PER1, PDZRN3, SH2D4B, LONP2) had trans-expressionQTL. In particular, for PER1, with known physiological implications for maintenance of circadian rhythms, a role in coping behavior was evidenced by confirmed association in an independent population. For CTC1 a cis-expression QTL and the consistent relationship of gene polymorphism, mRNA expression level and backtest traits promoted its link to coping style. GWAS and eQTL analyses uncovered positional and functional gene candidates for coping behavior. PMID:26537429

Integrated Genome-wide association and hypothalamus eQTL studies indicate a link between the circadian rhythm-related gene PER1 and coping behavior.

PubMed

Ponsuksili, Siriluck; Zebunke, Manuela; Murani, Eduard; Trakooljul, Nares; Krieter, Joachim; Puppe, Birger; Schwerin, Manfred; Wimmers, Klaus

2015-11-05

Animal personality and coping styles are basic concepts for evaluating animal welfare. Struggling response of piglets in so-called backtests early in life reflects their coping strategy. Behavioral reactions of piglets in backtests have a moderate heritability, but their genetic basis largely remains unknown. Here, latency, duration and frequency of struggling attempts during one-minute backtests were repeatedly recorded of piglets at days 5, 12, 19, and 26. A genome-wide association study for backtest traits revealed 465 significant SNPs (FDR ≤ 0.05) mostly located in QTL (quantitative trait locus) regions on chromosome 3, 5, 12 and 16. In order to capture genes in these regions, 37 transcripts with significant SNPs were selected for expressionQTL analysis in the hypothalamus. Eight genes (ASGR1, CPAMD8, CTC1, FBXO39, IL19, LOC100511790, RAD51B, UBOX5) had cis- and five (RANGRF, PER1, PDZRN3, SH2D4B, LONP2) had trans-expressionQTL. In particular, for PER1, with known physiological implications for maintenance of circadian rhythms, a role in coping behavior was evidenced by confirmed association in an independent population. For CTC1 a cis-expression QTL and the consistent relationship of gene polymorphism, mRNA expression level and backtest traits promoted its link to coping style. GWAS and eQTL analyses uncovered positional and functional gene candidates for coping behavior.

The A- and B-type nuclear lamin networks: microdomains involved in chromatin organization and transcription

PubMed Central

Shimi, Takeshi; Pfleghaar, Katrin; Kojima, Shin-ichiro; Pack, Chan-Gi; Solovei, Irina; Goldman, Anne E.; Adam, Stephen A.; Shumaker, Dale K.; Kinjo, Masataka; Cremer, Thomas; Goldman, Robert D.

2008-01-01

The nuclear lamins function in the regulation of replication, transcription, and epigenetic modifications of chromatin. However, the mechanisms responsible for these lamin functions are poorly understood. We demonstrate that A- and B-type lamins form separate, but interacting, stable meshworks in the lamina and have different mobilities in the nucleoplasm as determined by fluorescence correlation spectroscopy (FCS). Silencing lamin B1 (LB1) expression dramatically increases the lamina meshwork size and the mobility of nucleoplasmic lamin A (LA). The changes in lamina mesh size are coupled to the formation of LA/C-rich nuclear envelope blebs deficient in LB2. Comparative genomic hybridization (CGH) analyses of microdissected blebs, fluorescence in situ hybridization (FISH), and immunofluorescence localization of modified histones demonstrate that gene-rich euchromatin associates with the LA/C blebs. Enrichment of hyperphosphorylated RNA polymerase II (Pol II) and histone marks for active transcription suggest that blebs are transcriptionally active. However, in vivo labeling of RNA indicates that transcription is decreased, suggesting that the LA/C-rich microenvironment induces promoter proximal stalling of Pol II. We propose that different lamins are organized into separate, but interacting, microdomains and that LB1 is essential for their organization. Our evidence suggests that the organization and regulation of chromatin are influenced by interconnections between these lamin microdomains. PMID:19141474

SCF(KMD) controls cytokinin signaling by regulating the degradation of type-B response regulators.

PubMed

Kim, Hyo Jung; Chiang, Yi-Hsuan; Kieber, Joseph J; Schaller, G Eric

2013-06-11

Cytokinins are plant hormones that play critical roles in growth and development. In Arabidopsis, the transcriptional response to cytokinin is regulated by action of type-B Arabidopsis response regulators (ARRs). Although central elements in the cytokinin signal transduction pathway have been identified, mechanisms controlling output remain to be elucidated. Here we demonstrate that a family of F-box proteins, called the kiss me deadly (KMD) family, targets type-B ARR proteins for degradation. KMD proteins form an S-phase kinase-associated PROTEIN1 (SKP1)/Cullin/F-box protein (SCF) E3 ubiquitin ligase complex and directly interact with type-B ARR proteins. Loss-of-function KMD mutants stabilize type-B ARRs and exhibit an enhanced cytokinin response. In contrast, plants with elevated KMD expression destabilize type-B ARR proteins leading to cytokinin insensitivity. Our results support a model in which an SCF(KMD) complex negatively regulates cytokinin responses by controlling levels of a key family of transcription factors.

Compensatory Saccades Are Associated With Physical Performance in Older Adults: Data From the Baltimore Longitudinal Study of Aging.

PubMed

Xie, Yanjun; Anson, Eric R; Simonsick, Eleanor M; Studenski, Stephanie A; Agrawal, Yuri

2017-03-01

To determine whether compensatory saccade metrics observed in the video head impulse test, specifically saccade amplitude and latency, predict physical performance. Cross-sectional analysis of the Baltimore Longitudinal Study of Aging, a prospective cohort study. National Institute on Aging Intramural Research Program Clinical Research Unit in Baltimore, Maryland. Community-dwelling older adults. Video head impulse testing was performed, and compensatory saccades and horizontal vestibulo-ocular reflex (VOR) gain were measured. Physical performance was assessed using the Short Physical Performance Battery (SPPB), which included the feet side-by-side, semitandem, tandem, and single-leg stance; repeated chair stands; and usual gait speed measurements. Compensatory saccade amplitude and latency, VOR gain, and SPPB performance. In 183 participants who underwent vestibular and SPPB testing (mean age 71.8 yr; 53% females), both higher mean saccade amplitude (odds ratio [OR] =1.62, p = 0.010) and shorter mean saccade latency (OR = 0.88, p = 0.004) were associated with a higher odds of failing the tandem stand task. In contrast, VOR gain was not associated with any physical performance measure. We observed in a cohort of healthy older adults that compensatory saccade amplitude and latency were associated with tandem stance performance. Compensatory saccade metrics may provide insights into capturing the impact of vestibular loss on physical function in older adults.

Molecular targets for the therapy of cancer associated with metabolic syndrome (transcription and growth factors).

PubMed

Yunusova, Natalia V; Kondakova, Irina V; Kolomiets, Larisa A; Afanas'ev, Sergey G; Chernyshova, Alena L; Kudryavtsev, Igor V; Tsydenova, Anastasia A

2018-06-01

Metabolic syndrome (MS) is one of the leading risk factors for the development of cardiovascular diseases, type II diabetes mellitus and reproductive system diseases. Currently, not only cardiovascular disease and reproductive history risks related with MS are frequently discussed, but it has been also shown that MS is associated with increased risk of some common cancers (endometrial cancer, postmenopausal breast cancer, colorectal cancer, biliary tract cancers and liver cancer for men). Further studies are required to understand the mechanisms of the involvement of MS components in the pathogenesis of malignant neoplasms. Changes in the expression of transcription and growth factors in the peripheral tissues as well as in cancer tissues of patients with MS were revealed. Transcription factors (AMP-activated protein kinase-1, STAT3, sterol regulatory element-binding protein-1 and peroxisome proliferator-activated receptor-γ), leptin and adiponectin receptors seem to be the most promising molecular targets for the therapy of cancers associated with MS. © 2017 John Wiley & Sons Australia, Ltd.

The gene for a lectin-like protein is transcriptionally activated during sexual development, but is not essential for fruiting body formation in the filamentous fungus Sordaria macrospora.

PubMed

Nowrousian, Minou; Cebula, Patricia

2005-11-03

The filamentous fungus Sordaria macrospora forms complex three-dimensional fruiting bodies called perithecia that protect the developing ascospores and ensure their proper discharge. In previous microarray analyses, several genes have been identified that are downregulated in sterile mutants compared to the wild type. Among these genes was tap1 (transcript associated with perithecial development), a gene encoding a putative lectin homolog. Analysis of tap1 transcript levels in the wild type under conditions allowing only vegetative growth compared to conditions that lead to fruiting body development showed that tap1 is not only downregulated in developmental mutants but is also upregulated in the wild type during fruiting body development. We have cloned and sequenced a 3.2 kb fragment of genomic DNA containing the tap1 open reading frame and adjoining sequences. The genomic region comprising tap1 is syntenic to its homologous region in the closely related filamentous fungus Neurospora crassa. To determine whether tap1 is involved in fruiting body development in S. macrospora, a knockout construct was generated in which the tap1 open reading frame was replaced by the hygromycin B resistance gene hph under the control of fungal regulatory regions. Transformation of the S. macrospora wild type with this construct resulted in a tap1 deletion strain where tap1 had been replaced by the hph cassette. The knockout strain displayed no phenotypic differences under conditions of vegetative growth and sexual development when compared to the wild type. Double mutants carrying the Deltatap1 allele in several developmental mutant backgrounds were phenotypically similar to the corresponding developmental mutant strains. The tap1 transcript is strongly upregulated during sexual development in S. macrospora; however, analysis of a tap1 knockout strain shows that tap1 is not essential for fruiting body formation in S. macrospora.

The gene for a lectin-like protein is transcriptionally activated during sexual development, but is not essential for fruiting body formation in the filamentous fungus Sordaria macrospora

PubMed Central

Nowrousian, Minou; Cebula, Patricia

2005-01-01

Background The filamentous fungus Sordaria macrospora forms complex three-dimensional fruiting bodies called perithecia that protect the developing ascospores and ensure their proper discharge. In previous microarray analyses, several genes have been identified that are downregulated in sterile mutants compared to the wild type. Among these genes was tap1 (transcript associated with perithecial development), a gene encoding a putative lectin homolog. Results Analysis of tap1 transcript levels in the wild type under conditions allowing only vegetative growth compared to conditions that lead to fruiting body development showed that tap1 is not only downregulated in developmental mutants but is also upregulated in the wild type during fruiting body development. We have cloned and sequenced a 3.2 kb fragment of genomic DNA containing the tap1 open reading frame and adjoining sequences. The genomic region comprising tap1 is syntenic to its homologous region in the closely related filamentous fungus Neurospora crassa. To determine whether tap1 is involved in fruiting body development in S. macrospora, a knockout construct was generated in which the tap1 open reading frame was replaced by the hygromycin B resistance gene hph under the control of fungal regulatory regions. Transformation of the S. macrospora wild type with this construct resulted in a tap1 deletion strain where tap1 had been replaced by the hph cassette. The knockout strain displayed no phenotypic differences under conditions of vegetative growth and sexual development when compared to the wild type. Double mutants carrying the Δtap1 allele in several developmental mutant backgrounds were phenotypically similar to the corresponding developmental mutant strains. Conclusion The tap1 transcript is strongly upregulated during sexual development in S. macrospora; however, analysis of a tap1 knockout strain shows that tap1 is not essential for fruiting body formation in S. macrospora. PMID:16266439

Cell Type-Specific Chromatin Signatures Underline Regulatory DNA Elements in Human Induced Pluripotent Stem Cells and Somatic Cells.

PubMed

Zhao, Ming-Tao; Shao, Ning-Yi; Hu, Shijun; Ma, Ning; Srinivasan, Rajini; Jahanbani, Fereshteh; Lee, Jaecheol; Zhang, Sophia L; Snyder, Michael P; Wu, Joseph C

2017-11-10

Regulatory DNA elements in the human genome play important roles in determining the transcriptional abundance and spatiotemporal gene expression during embryonic heart development and somatic cell reprogramming. It is not well known how chromatin marks in regulatory DNA elements are modulated to establish cell type-specific gene expression in the human heart. We aimed to decipher the cell type-specific epigenetic signatures in regulatory DNA elements and how they modulate heart-specific gene expression. We profiled genome-wide transcriptional activity and a variety of epigenetic marks in the regulatory DNA elements using massive RNA-seq (n=12) and ChIP-seq (chromatin immunoprecipitation combined with high-throughput sequencing; n=84) in human endothelial cells (CD31 + CD144 + ), cardiac progenitor cells (Sca-1 + ), fibroblasts (DDR2 + ), and their respective induced pluripotent stem cells. We uncovered 2 classes of regulatory DNA elements: class I was identified with ubiquitous enhancer (H3K4me1) and promoter (H3K4me3) marks in all cell types, whereas class II was enriched with H3K4me1 and H3K4me3 in a cell type-specific manner. Both class I and class II regulatory elements exhibited stimulatory roles in nearby gene expression in a given cell type. However, class I promoters displayed more dominant regulatory effects on transcriptional abundance regardless of distal enhancers. Transcription factor network analysis indicated that human induced pluripotent stem cells and somatic cells from the heart selected their preferential regulatory elements to maintain cell type-specific gene expression. In addition, we validated the function of these enhancer elements in transgenic mouse embryos and human cells and identified a few enhancers that could possibly regulate the cardiac-specific gene expression. Given that a large number of genetic variants associated with human diseases are located in regulatory DNA elements, our study provides valuable resources for deciphering the epigenetic modulation of regulatory DNA elements that fine-tune spatiotemporal gene expression in human cardiac development and diseases. © 2017 American Heart Association, Inc.

Subclinical vestibular dysfunction in migraine patients: a preliminary study of ocular and rectified cervical vestibular evoked myogenic potentials.

PubMed

Kim, Chul-Ho; Jang, Min-Uk; Choi, Hui-Chul; Sohn, Jong-Hee

2015-01-01

Many studies have identified various vestibular symptoms and laboratory abnormalities in migraineurs. Although the vestibular tests may be abnormal, the changes may exist without vestibular symptoms. To date, vestibular-evoked myogenic potential (VEMP) has been the easiest and simplest test for measuring vestibular function in clinical practice. Cervical VEMP (cVEMP) represents a vestibulo-collic reflex, whereas ocular VEMP (oVEMP) reflects a vestibulo-ocular pathway. Therefore, we determined whether ocular and rectified cervical VEMPs differed in patients with migraine or tension type headache (TTH) and compared the results to controls with no accompanying vestibular symptoms. The present study included 38 females with migraine without aura, 30 with episodic TTH, and 50 healthy controls without vestibular symptoms. oVEMP and cVEMP using a blood pressure manometer were recorded during a headache-free period. From the VEMP graphs, latency and amplitude parameters were analyzed, especially following EMG rectification in cVEMP. With respect to oVEMP, the migraine group exhibited significantly longer mean latencies of bilateral n1 and left p1 than the other groups (p < 0.05). Amplitudes of n1-p1 were lower than in other groups, but the difference did not reach statistical significance. In regards to cVEMP, p13 and n23 latencies and amplitudes after rectification did not differ significantly among groups. An abnormal interictal oVEMP profile was associated with subclinical vestibular dysfunction in migraineurs, suggesting pathology within the vestibulo-ocular reflex. oVEMP is a more reliable measure than cVEMP to evaluate vestibular function in migraineurs, although results from the two tests in patients with migraine are complementary.

Increased reaction time variability in attention-deficit hyperactivity disorder as a response-related phenomenon: evidence from single-trial event-related potentials.

PubMed

Saville, Christopher W N; Feige, Bernd; Kluckert, Christian; Bender, Stephan; Biscaldi, Monica; Berger, Andrea; Fleischhaker, Christian; Henighausen, Klaus; Klein, Christoph

2015-07-01

Increased intra-subject variability (ISV) in reaction times (RTs) is a promising endophenotype for attention-deficit hyperactivity disorder (ADHD) and among the most robust hallmarks of the disorder. ISV has been assumed to represent an attentional deficit, either reflecting lapses in attention or increased neural noise. Here, we use an innovative single-trial event-related potential approach to assess whether the increased ISV associated with ADHD is indeed attributable to attention, or whether it is related to response-related processing. We measured electroencephalographic responses to working memory oddball tasks in patients with ADHD (N = 20, aged 11.3 ± 1.1) and healthy controls (N = 25, aged 11.7 ± 1.1), and analysed these data with a recently developed method of single-trial event-related potential analysis. Estimates of component latency variability were computed for the stimulus-locked and response-locked forms of the P3b and the lateralised readiness potential (LRP). ADHD patients showed significantly increased ISV in behavioural ISV. This increased ISV was paralleled by an increase in variability in response-locked event-related potential latencies, while variability in stimulus-locked latencies was equivalent between groups. This result held across the P3b and LRP. Latency of all components predicted RTs on a single-trial basis, confirming that all were relevant for speed of processing. These data suggest that the increased ISV found in ADHD could be associated with response-end, rather than stimulus-end processes, in contrast to prevailing conceptions about the endophenotype. This mental chronometric approach may also be useful for exploring whether the existing lack of specificity of ISV to particular psychiatric conditions can be improved upon. © 2014 Association for Child and Adolescent Mental Health.

A cross-sectional observation of the factors associated with deliberate self-poisoning with acetaminophen: impact of gender differences and psychiatric intervention.

PubMed

Zyoud, Sa'ed H; Awang, Rahmat; Sulaiman, Syed Azhar Syed; Al-Jabi, Samah W

2010-08-01

The objectives of this study were to determine the risk factors and life stressors that are prevalent among the acetaminophen deliberate self-poisoning (DSP) cases, to identify gender differences in the associated factors, and to determine the prevalence of psychiatric diagnosis and the patterns and types of psychotherapeutic interventions provided by psychiatrists. This is a cross-sectional study, a retrospective descriptive case review of hospital admissions for acetaminophen DSP. There were 177 incidences of DSP during the study period. The mean age of the cases was 23.1 +/- 7.3 years and 84.1% of them were females. The risk factors were more significantly associated with males: chronic ethanol intake (p = 0.04), higher reported dose ingested (p = 0.01), higher latency time (p = 0.04) and longer hospital stay (p = 0.03). The most commonly reported psychotherapeutic interventions used by psychiatrists were psychoeducation of the patient, followed by referral to a psychiatric clinic, family psychoeducation and psychotropic medication. Sertraline (SSRI) was the most frequently prescribed antidepressant. Males have been shown to use more toxic doses and to delay treatment due to high latency time. Most DSP patients have different life stressors and psychiatric diagnoses that may be associated with varying degrees of suicidal intent. All patients presenting following DSP need to be carefully screened for psychiatric illness. Randomized controlled studies need to be conducted on DSP patients with psychiatric illness to determine which treatments are effective. Copyright 2010 John Wiley & Sons, Ltd.

Radiation associated tumors following therapeutic cranial radiation

PubMed Central

Chowdhary, Abhineet; Spence, Alex M.; Sales, Lindsay; Rostomily, Robert C.; Rockhill, Jason K.; Silbergeld, Daniel L.

2012-01-01

Background: A serious, albeit rare, sequel of therapeutic ionizing radiotherapy is delayed development of a new, histologically distinct neoplasm within the radiation field. Methods: We identified 27 cases, from a 10-year period, of intracranial tumors arising after cranial irradiation. The original lesions for which cranial radiation was used for treatment included: tinea capitis (1), acute lymphoblastic leukemia (ALL; 5), sarcoma (1), scalp hemangioma (1), cranial nerve schwannoma (1) and primary (13) and metastatic (1) brain tumors, pituitary tumor (1), germinoma (1), pinealoma (1), and unknown histology (1). Dose of cranial irradiation ranged from 1800 to 6500 cGy, with a mean of 4596 cGy. Age at cranial irradiation ranged from 1 month to 43 years, with a mean of 13.4 years. Results: Latency between radiotherapy and diagnosis of a radiation-induced neoplasm ranged from 4 to 47 years (mean 18.8 years). Radiation-induced tumors included: meningiomas (14), sarcomas (7), malignant astrocytomas (4), and medulloblastomas (2). Data were analyzed to evaluate possible correlations between gender, age at irradiation, dose of irradiation, latency, use of chemotherapy, and radiation-induced neoplasm histology. Significant correlations existed between age at cranial irradiation and development of either a benign neoplasm (mean age 8.5 years) versus a malignant neoplasm (mean age 20.3; P = 0.012), and development of either a meningioma (mean age 7.0 years) or a sarcoma (mean age 27.4 years; P = 0.0001). There was also a significant positive correlation between latency and development of either a meningioma (mean latency 21.8 years) or a sarcoma (mean latency 7.7 years; P = 0.001). The correlation between dose of cranial irradiation and development of either a meningioma (mean dose 4128 cGy) or a sarcoma (mean dose 5631 cGy) approached significance (P = 0.059). Conclusions: Our study is the first to show that younger patients had a longer latency period and were more likely to have lower-grade lesions (e.g. meningiomas) as a secondary neoplasm, while older patients had a shorter latency period and were more likely to have higher-grade lesions (e.g. sarcomas). PMID:22629485

Transcription-associated processes cause DNA double-strand breaks and translocations in neural stem/progenitor cells.

PubMed

Schwer, Bjoern; Wei, Pei-Chi; Chang, Amelia N; Kao, Jennifer; Du, Zhou; Meyers, Robin M; Alt, Frederick W

2016-02-23

High-throughput, genome-wide translocation sequencing (HTGTS) studies of activated B cells have revealed that DNA double-strand breaks (DSBs) capable of translocating to defined bait DSBs are enriched around the transcription start sites (TSSs) of active genes. We used the HTGTS approach to investigate whether a similar phenomenon occurs in primary neural stem/progenitor cells (NSPCs). We report that breakpoint junctions indeed are enriched around TSSs that were determined to be active by global run-on sequencing analyses of NSPCs. Comparative analyses of transcription profiles in NSPCs and B cells revealed that the great majority of TSS-proximal junctions occurred in genes commonly expressed in both cell types, possibly because this common set has higher transcription levels on average than genes transcribed in only one or the other cell type. In the latter context, among all actively transcribed genes containing translocation junctions in NSPCs, those with junctions located within 2 kb of the TSS show a significantly higher transcription rate on average than genes with junctions in the gene body located at distances greater than 2 kb from the TSS. Finally, analysis of repair junction signatures of TSS-associated translocations in wild-type versus classical nonhomologous end-joining (C-NHEJ)-deficient NSPCs reveals that both C-NHEJ and alternative end-joining pathways can generate translocations by joining TSS-proximal DSBs to DSBs on other chromosomes. Our studies show that the generation of transcription-associated DSBs is conserved across divergent cell types.

Transcription factor 19 interacts with histone 3 lysine 4 trimethylation and controls gluconeogenesis via the nucleosome-remodeling-deacetylase complex.

PubMed

Sen, Sabyasachi; Sanyal, Sulagna; Srivastava, Dushyant Kumar; Dasgupta, Dipak; Roy, Siddhartha; Das, Chandrima

2017-12-15

Transcription factor 19 (TCF19) has been reported as a type 1 diabetes-associated locus involved in maintenance of pancreatic β cells through a fine-tuned regulation of cell proliferation and apoptosis. TCF19 also exhibits genomic association with type 2 diabetes, although the precise molecular mechanism remains unknown. It harbors both a plant homeodomain and a forkhead-associated domain implicated in epigenetic recognition and gene regulation, a phenomenon that has remained unexplored. Here, we show that TCF19 selectively interacts with histone 3 lysine 4 trimethylation through its plant homeodomain finger. Knocking down TCF19 under high-glucose conditions affected many metabolic processes, including gluconeogenesis. We found that TCF19 overexpression represses de novo glucose production in HepG2 cells. The transcriptional repression of key genes, induced by TCF19, coincided with NuRD (nucleosome-remodeling-deacetylase) complex recruitment to the promoters of these genes. TCF19 interacted with CHD4 (chromodomain helicase DNA-binding protein 4), which is a part of the NuRD complex, in a glucose concentration-independent manner. In summary, our results show that TCF19 interacts with an active transcription mark and recruits a co-repressor complex to regulate gluconeogenic gene expression in HepG2 cells. Our study offers critical insights into the molecular mechanisms of transcriptional regulation of gluconeogenesis and into the roles of chromatin readers in metabolic homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Interleukin-1 antagonism moderates the inflammatory state associated with Type 1 diabetes during clinical trials conducted at disease onset

PubMed Central

Cabrera, Susanne M.; Wang, Xujing; Chen, Yi-Guang; Jia, Shuang; Kaldunski, Mary L.; Greenbaum, Carla J.; Mandrup-Poulsen, Thomas; Hessner, Martin J.

2016-01-01

IL-1 antagonism has been hypothesized to preserve β-cell function in new onset Type 1 diabetes (T1D). However, the Anti-Interleukin-1 in Diabetes Action (AIDA) and TrialNet Canakinumab (TN-14) trials failed to show efficacy of IL-1 receptor antagonist (IL-1Ra) or canakinumab, as measured by stimulated C-peptide response. Additional measures are needed to define immune state changes associated with therapeutic responses. Here, we studied these trial participants with transcriptional analysis of plasma-induced PBMCs. In blinded analyses, 70.2% of AIDA and 68.9% of TN-14 participants were correctly called to their treatment arm. While the PBMC transcriptional signatures from the two groups were distinct, both therapies achieved varying immunomodulation consistent with IL-1 inhibition. On average, IL-1 antagonism resulted in modest normalization relative to healthy controls. At endpoint, signatures were quantified using a gene ontology-based inflammatory index, and an inverse relationship was observed between measured inflammation and stimulated C-peptide response in IL-1Ra- and canakinumab-treated patients. Cytokine neutralization studies showed that IL-1α and IL-1β additively contribute to the T1D inflammatory state. Finally, analyses of baseline signatures were indicative of later therapeutic response. Despite the absence of clinical efficacy by IL-1 antagonist therapy, transcriptional analysis detected immunomodulation and may yield new insight when applied to other clinical trials. PMID:26692253

Interleukin-1 antagonism moderates the inflammatory state associated with Type 1 diabetes during clinical trials conducted at disease onset.

PubMed

Cabrera, Susanne M; Wang, Xujing; Chen, Yi-Guang; Jia, Shuang; Kaldunski, Mary L; Greenbaum, Carla J; Mandrup-Poulsen, Thomas; Hessner, Martin J

2016-04-01

It was hypothesized that IL-1 antagonism would preserve β-cell function in new onset Type 1 diabetes (T1D). However, the Anti-Interleukin-1 in Diabetes Action (AIDA) and TrialNet Canakinumab (TN-14) trials failed to show efficacy of IL-1 receptor antagonist (IL-1Ra) or canakinumab, as measured by stimulated C-peptide response. Additional measures are needed to define immune state changes associated with therapeutic responses. Here, we studied these trial participants with plasma-induced transcriptional analysis. In blinded analyses, 70.2% of AIDA and 68.9% of TN-14 participants were correctly called to their treatment arm. While the transcriptional signatures from the two trials were distinct, both therapies achieved varying immunomodulation consistent with IL-1 inhibition. On average, IL-1 antagonism resulted in modest normalization relative to healthy controls. At endpoint, signatures were quantified using a gene ontology-based inflammatory index, and an inverse relationship was observed between measured inflammation and stimulated C-peptide response in IL-1Ra- and canakinumab-treated patients. Cytokine neutralization studies showed that IL-1α and IL-1β additively contribute to the T1D inflammatory state. Finally, analyses of baseline signatures were indicative of later therapeutic response. Despite the absence of clinical efficacy by IL-1 antagonist therapy, transcriptional analysis detected immunomodulation and may yield new insight when applied to other clinical trials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subjective and Objective Measures of Hypersomnolence Demonstrate Divergent Associations with Depression among Participants in the Wisconsin Sleep Cohort Study.

PubMed

Plante, David T; Finn, Laurel A; Hagen, Erika W; Mignot, Emmanuel; Peppard, Paul E

2016-04-15

To examine associations of depression with habitual sleep duration, daytime sleepiness, and objective sleep propensity in a nonclinical population. Data from adults participating in the Wisconsin Sleep Cohort Study were utilized in analyses. There were 1,287 adults (3,324 observations) who were used in the analysis of subjective hypersomnolence measures; 1,155 adults (2,981 observations) were used in the analysis of objective sleep propensity assessed by the multiple sleep latency test (MSLT). Repeated-measures logistic regression estimated associations between presence of depression (defined as modified Zung Self-Rating Depression Scale ≥ 50 or use of antidepressant medications) and three primary hypersomnolence measures: subjective excessive daytime sleepiness (Epworth Sleepiness Scale [ESS] ≥ 11), self-reported sleep duration ≥ 9 h/d, and objective sleep propensity (MSLT mean sleep latency < 8 min). After adjusting for age, sex, body mass index, chronic medical conditions, sedative hypnotic medication use, caffeine, tobacco, and alcohol use, sleep disordered breathing, as well as insomnia and sleep duration when appropriate, estimated odd ratios (95% confidence interval) for depression were: 1.56 (1.31,1.86) for ESS ≥ 11; 2.01 (1.49, 2.72) for habitual sleep time ≥ 9 h; and 0.76 (0.63-0.92) for MSLT mean sleep latency < 8 min. Our results demonstrate divergent associations between subjective and objective symptoms of hypersomnolence and depression, with subjective sleepiness and excessive sleep duration associated with increased odds of depression, but objective sleep propensity as measured by the MSLT associated with decreased odds of depression. Further research is indicated to explain this paradox and the impact of different hypersomnolence measures on the course of mood disorders. A commentary on this article appears in this issue on page 467. © 2016 American Academy of Sleep Medicine.

Early life stress and later peer distress on depressive behavior in adolescent female rats: Effects of a novel intervention on GABA and D2 receptors.

PubMed

Lukkes, Jodi L; Meda, Shirisha; Thompson, Britta S; Freund, Nadja; Andersen, Susan L

2017-07-14

Early life adversity (ELA) increases the risk of depression during adolescence that may result from a decline in parvalbumin (PVB) secondary to increased neuroinflammation. In this study, we investigated depressive-like behavior following exposure to two different types of stressors that are relevant for their developmental period: 1) chronic ELA (maternal separation; MS) and 2) an acute emotional stressor during adolescence (witnessing their peers receive multiple shocks; WIT), and their interaction. We also determined whether reducing inflammation by cyclooxygenase-2 (COX-2) inhibition would prevent the onset of depressive-like behavior. Female Sprague-Dawley rat pups underwent MS for four-hours/day or received typical care (CON) between postnatal days (P) 2 and P20. A COX-2 inhibitor (COX-2I) or vehicle was administered every other day between P30 and P38. Subjects were tested for learned helplessness to assess depressive-like behavior at P40 (adolescence). MS females demonstrated increased escape latency and decreased PVB in the prefrontal cortex (PFC) and dorsal raphe that were attenuated by COX-2I intervention. Helplessness was also associated with an increase in D2 receptors in the accumbens. In contrast, WIT elevated escape latency in CON, but reduced latency in MS females. Furthermore, COX-2I intervention decreased escape latency in both CON and MS after WIT. WIT reduced PVB levels in the basolateral amygdala and increased PFC levels to CON levels. Our data suggest that decreased PVB in the PFC is important for the expression of depressive-like behavior and suggest that COX-2I intervention may provide a novel prevention for depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Adenovirus E1a prevents the retinoblastoma gene product from repressing the activity of a cellular transcription factor.

PubMed Central

Zamanian, M; La Thangue, N B

1992-01-01

The retinoblastoma (Rb) gene product forms a complex with the cellular transcription factor DRTF1, a property assumed to be important for mediating negative growth control because certain viral oncogenes, such as adenovirus E1a, prevent this interaction and mutant Rb alleles, which have lost the capacity to regulate growth, encode proteins that fail to associate with DRTF1. In this study, we show that the wild-type Rb protein can specifically repress transcription from promoters driven by DRTF1 whereas a naturally occurring mutant Rb protein cannot. Furthermore, Rb-mediated transcriptional repression can be overridden by adenovirus E1a; this requires regions in E1a necessary for cellular transformation. The Rb protein therefore acts in trans to repress the transcriptional activity of DRTF1 whereas adenovirus E1a prevents this interaction and thus maintains DRTF1 in a constitutively active state. The Rb protein and adenovirus E1a therefore have opposite effects on the activity of a common molecular target. Transcriptional repression mediated by the Rb protein and inactivation of repression by the E1a protein are likely to play an important role in mediating their biological effects. Images PMID:1385776

Detection of asymptomatic cranial neuropathies in patients with systemic lupus erythematosus and their relation to antiribosomal P antibody levels and disease activity.

PubMed

Gaber, Wafaa; Ezzat, Yasser; El Fayoumy, Neveen M; Helmy, Hanan; Mohey, Abeer M

2014-01-01

The objectives of this study are to assess the risk of asymptomatic cranial neuropathy among patients with systemic lupus erythematosus (SLE) and find any association with disease activity and antiribosomal P antibodies. This study is a case-control study including 60 female patients and 30 healthy female controls. Disease activity was measured with the SLE disease activity index (SLEDAI). All patients were evaluated using evoked potentials, blink reflex, and levels of antiribosomal P antibodies. Patients with abnormal electrophysiological parameters had significantly higher levels of antiribosomal P antibodies (P = 0.034) and secondary antiphospholipid syndrome (P = 0.044). Antiribosomal P antibodies (odds ratio 5.4, 95 % confidence interval 1.002-1.03, P = 0.002) and presence of anti-DNA antibodies (odds ratio 1.01, 95 % confidence interval 1.2-24.8, P = 0.032) were independent risk factors for the presence of the abnormal electrophysiological parameters. Disease duration was positively correlated with wave 1 of the auditory brain reflex (P < 0.001) and a latency of the evoked blink reflex (component R1, P = 0.013). SLEDAI scores were positively correlated with latencies of the visually evoked potential (P100, P = 0.02), wave 1 of the auditory brain reflex (P < 0.001), and a latency of the evoked blink reflex (R2c, P = 0.005). Steroid dosage was negatively correlated with P100 latencies (P = 0.042) and components of the evoked blink reflex (R1, P = 0.042; R2i, P = 0.041; R2c, P < 0.001). Because abnormalities in the visually evoked potential and blink reflex were associated with antiribosomal P antibodies, they can be useful for detecting asymptomatic cranial neuropathy. Further studies on large number of patients should be done to determine any association.

Pattern Visual Evoked Potential as a Predictor of Occlusion Therapy for Amblyopia

PubMed Central

Chung, Woosuk; Hong, Samin; Lee, Jong Bok

2008-01-01

Purpose This study was conducted to investigate the role of the pattern visual evoked potential (pVEP) as a predictor of occlusion therapy for patients with strabismic, anisometropic, and isometropic amblyopia. The secondary aim was to compare the characteristics of pVEP between strabismic and anisometropic amblyopia. Methods This retrospective comparative case series included 120 patients who had received occlusion therapy or a glasses prescription for correction of strabismic, anisometropic, and isometropic amblyopia (20 patients had strabismic amblyopia, 41 patients had anisometropic amblyopia, and 59 patients had isometropic amblyopia). For each patient, the value of the P100 latency on pVEP at the time of the initial diagnosis of amblyopia was collected. Subsequently, the P100 latency was compared according to types of amblyopia. Fifty of 120 patients (7 patients with strabismic amblyopia, 21 patients with anisometropic amblyopia, and 22 patients with isometropic amblyopia) who were followed-up for longer than 6 months were divided into two groups based on the value of their P100 latency (Group 1, P100 latency 120 msec or less; Group 2, P100 latency longer than 120 msec.) The amount of visual improvement after occlusion therapy or glasses was compared between two study groups. Results The mean P100 latency was 119.7±25.2 msec in eyes with strabismic amblyopia and 111.9±17.8 msec in eyes with non-strabismic (anisometropic or isometropic) amblyopia (p=0.213). In Group 1, the mean visual improvement after occlusion therapy or glasses was 3.69±2.14 lines on Dr. Hahn's standard test chart; in Group 2, the mean improvement was 2.27±2.21 lines (p=0.023). Conclusions The P100 latency on pVEP at the time of initial diagnosis was significantly related to the visual improvement after occlusion therapy or glasses in patients with strabismic, anisometropic, and isometropic amblyopia. Therefore, it was presumed that patients with a delayed P100 latency might have less visual improvement after occlusion therapy or glasses. In addition, there was no apparent difference in P100 latency between patients with strabismic and non-strabismic (anisometropic or isometropic) amblyopia. PMID:19096243

Pattern visual evoked potential as a predictor of occlusion therapy for amblyopia.

PubMed

Chung, Woosuk; Hong, Samin; Lee, Jong Bok; Han, Sueng-Han

2008-12-01

This study was conducted to investigate the role of the pattern visual evoked potential (pVEP) as a predictor of occlusion therapy for patients with strabismic, anisometropic, and isometropic amblyopia. The secondary aim was to compare the characteristics of pVEP between strabismic and anisometropic amblyopia. This retrospective comparative case series included 120 patients who had received occlusion therapy or a glasses prescription for correction of strabismic, anisometropic, and isometropic amblyopia (20 patients had strabismic amblyopia, 41 patients had anisometropic amblyopia, and 59 patients had isometropic amblyopia). For each patient, the value of the P100 latency on pVEP at the time of the initial diagnosis of amblyopia was collected. Subsequently, the P100 latency was compared according to types of amblyopia. Fifty of 120 patients (7 patients with strabismic amblyopia, 21 patients with anisometropic amblyopia, and 22 patients with isometropic amblyopia) who were followed-up for longer than 6 months were divided into two groups based on the value of their P100 latency (Group 1, P100 latency 120 msec or less; Group 2, P100 latency longer than 120 msec.) The amount of visual improvement after occlusion therapy or glasses was compared between two study groups. The mean P100 latency was 119.7+/-25.2 msec in eyes with strabismic amblyopia and 111.9+/-17.8 msec in eyes with non-strabismic (anisometropic or isometropic) amblyopia (p=0.213). In Group 1, the mean visual improvement after occlusion therapy or glasses was 3.69+/-2.14 lines on Dr. Hahn's standard test chart; in Group 2, the mean improvement was 2.27+/-2.21 lines (p=0.023). The P100 latency on pVEP at the time of initial diagnosis was significantly related to the visual improvement after occlusion therapy or glasses in patients with strabismic, anisometropic, and isometropic amblyopia. Therefore, it was presumed that patients with a delayed P100 latency might have less visual improvement after occlusion therapy or glasses. In addition, there was no apparent difference in P100 latency between patients with strabismic and non-strabismic (anisometropic or isometropic) amblyopia.

Transcription of Two Adjacent Carbohydrate Utilization Gene Clusters in Bifidobacterium breve UCC2003 Is Controlled by LacI- and Repressor Open Reading Frame Kinase (ROK)-Type Regulators

PubMed Central

O'Connell, Kerry Joan; O'Connell Motherway, Mary; Liedtke, Andrea; Fitzgerald, Gerald F.; Ross, R. Paul; Stanton, Catherine; Zomer, Aldert

2014-01-01

Members of the genus Bifidobacterium are commonly found in the gastrointestinal tracts of mammals, including humans, where their growth is presumed to be dependent on various diet- and/or host-derived carbohydrates. To understand transcriptional control of bifidobacterial carbohydrate metabolism, we investigated two genetic carbohydrate utilization clusters dedicated to the metabolism of raffinose-type sugars and melezitose. Transcriptomic and gene inactivation approaches revealed that the raffinose utilization system is positively regulated by an activator protein, designated RafR. The gene cluster associated with melezitose metabolism was shown to be subject to direct negative control by a LacI-type transcriptional regulator, designated MelR1, in addition to apparent indirect negative control by means of a second LacI-type regulator, MelR2. In silico analysis, DNA-protein interaction, and primer extension studies revealed the MelR1 and MelR2 operator sequences, each of which is positioned just upstream of or overlapping the correspondingly regulated promoter sequences. Similar analyses identified the RafR binding operator sequence located upstream of the rafB promoter. This study indicates that transcriptional control of gene clusters involved in carbohydrate metabolism in bifidobacteria is subject to conserved regulatory systems, representing either positive or negative control. PMID:24705323

Wheat bHLH-type transcription factor gene TabHLH1 is crucial in mediating osmotic stresses tolerance through modulating largely the ABA-associated pathway.

PubMed

Yang, Tongren; Yao, Sufei; Hao, Lin; Zhao, Yuanyuan; Lu, Wenjing; Xiao, Kai

2016-11-01

Wheat bHLH family gene TabHLH1 is responsive to drought and salt stresses, and it acts as one crucial regulator in mediating tolerance to aforementioned stresses largely through an ABA-associated pathway. Osmotic stresses are adverse factors for plant growth and crop productivity. In this study, we characterized TabHLH1, a gene encoding wheat bHLH-type transcription factor (TF) protein, in mediating plant adaptation to osmotic stresses. TabHLH1 protein contains a conserved basic-helix-loop-helix (bHLH) domain shared by its plant counterparts. Upon PEG-simulated drought stress, salt stress, and exogenous abscisic acid (ABA), the TabHLH1 transcripts in roots and leaves were induced. Under PEG-simulated drought stress and salt stress treatments, the tobacco seedlings with TabHLH1 overexpression exhibited improved growth and osmotic stress-associated traits, showing increased biomass and reduced leaf water loss rate (WLR) relative to wild type (WT). The transgenic lines also possessed promoted stomata closure under drought stress, salt stress, and exogenous ABA and increased proline and soluble sugar contents and reduced hydrogen peroxide (H 2 O 2 ) amount under osmotic stress conditions, indicating that TabHLH1-mediated osmolyte accumulation and cellular ROS homeostasis contributed to the drought stress and salt stress tolerance. NtPYL12 and NtSAPK2;1, the genes encoding ABA receptor and SnRK2 family kinase, respectively, showed up-regulated expression in lines overexpressing TabHLH1 under osmotic stress and exogenous ABA conditions; overexpression of them conferred plants modified stomata movement, leaf WLR, and growth feature under drought and high salinity, suggesting that these ABA-signaling genes are mediated by wheat TabHLH1 gene and involved in regulating plant responses to simulated drought and salt stresses. Our investigation indicates that the TabHLH1 gene plays critical roles in plant tolerance to osmotic stresses largely through an ABA-dependent pathway.

Expression of an Intestine-Specific Transcription Factor (CDX1) in Intestinal Metaplasia and in Subsequently Developed Intestinal Type of Cholangiocarcinoma in Rat Liver

PubMed Central

Ren, Ping; Silberg, Debra G.; Sirica, Alphonse E.

2000-01-01

CDX1 is a caudal-type homeobox intestine-specific transcription factor that has been shown to be selectively expressed in epithelial cells in intestinal metaplasia of the human stomach and esophagus and variably expressed in human gastric and esophageal adenocarcinomas (Silberg DG, Furth EE, Taylor JK, Schuck T, Chiou T, Traber PG: Gastroenterology 1997, 113: 478–486). Through the use of immunohistochemistry and Western blotting, we investigated whether CDX1 is also uniquely associated with the intestinal metaplasia associated with putative precancerous cholangiofibrosis induced in rat liver during furan cholangiocarcinogenesis, as well as expressed in neoplastic glands in a subsequently developed intestinal type of cholangiocarcinoma. In normal, control adult rat small intestine, specific nuclear immunoreactivity for CDX1 was most prominent in enterocytes lining the crypts. In comparison, epithelium from intestinal metaplastic glands within furan-induced hepatic cholangiofibrosis and neoplastic epithelium from later developed primary intestinal-type cholangiocarcinoma each demonstrated strong nuclear immunoreactivity for CDX1. CDX1-positive cells were detected in hepatic cholangiofibrotic tissue as early as 3 weeks after the start of chronic furan treatment. We further determined that the percentages of CDX1-positive neoplastic glands and glandular nuclei are significantly higher in primary tumors than in a derived, transplantable cholangiocarcinoma serially-propagated in vivo. Western blotting confirmed our immunohistochemical results, and no CDX1 immunoreactivity was detected in normal adult rat liver or in hyperplastic biliary epithelial cells. These findings indicate that CDX1 is specifically associated with early intestinal metaplasia and a later developed intestinal-type of cholangiocarcinoma induced in the liver of furan-treated rats. PMID:10666391

Expression of an intestine-specific transcription factor (CDX1) in intestinal metaplasia and in subsequently developed intestinal type of cholangiocarcinoma in rat liver.

PubMed

Ren, P; Silberg, D G; Sirica, A E

2000-02-01

CDX1 is a caudal-type homeobox intestine-specific transcription factor that has been shown to be selectively expressed in epithelial cells in intestinal metaplasia of the human stomach and esophagus and variably expressed in human gastric and esophageal adenocarcinomas (Silberg DG, Furth EE, Taylor JK, Schuck T, Chiou T, Traber PG: Gastroenterology 1997, 113: 478-486). Through the use of immunohistochemistry and Western blotting, we investigated whether CDX1 is also uniquely associated with the intestinal metaplasia associated with putative precancerous cholangiofibrosis induced in rat liver during furan cholangiocarcinogenesis, as well as expressed in neoplastic glands in a subsequently developed intestinal type of cholangiocarcinoma. In normal, control adult rat small intestine, specific nuclear immunoreactivity for CDX1 was most prominent in enterocytes lining the crypts. In comparison, epithelium from intestinal metaplastic glands within furan-induced hepatic cholangiofibrosis and neoplastic epithelium from later developed primary intestinal-type cholangiocarcinoma each demonstrated strong nuclear immunoreactivity for CDX1. CDX1-positive cells were detected in hepatic cholangiofibrotic tissue as early as 3 weeks after the start of chronic furan treatment. We further determined that the percentages of CDX1-positive neoplastic glands and glandular nuclei are significantly higher in primary tumors than in a derived, transplantable cholangiocarcinoma serially-propagated in vivo. Western blotting confirmed our immunohistochemical results, and no CDX1 immunoreactivity was detected in normal adult rat liver or in hyperplastic biliary epithelial cells. These findings indicate that CDX1 is specifically associated with early intestinal metaplasia and a later developed intestinal-type of cholangiocarcinoma induced in the liver of furan-treated rats.

A sugar transporter from Medicago truncatula: altered expression pattern in roots during vesicular-arbuscular (VA) mycorrhizal associations.

PubMed

Harrison, M J

1996-04-01

A cDNA clone encoding a hexose transporter has been isolated from a library prepared from Medicago truncatula roots colonized by the mycorrhizal fungus Glomus versiforme. The clone (Mtst1) represents a M. truncatula gene and expression studies in yeast indicate that the encoded protein transports glucose and fructose but not sucrose. Transcripts corresponding to Mtst1 are expressed in leaves, stems and roots of M. truncatula, with the highest levels of expression in roots. In the roots, Mtst1 transcripts were detected in two distinct locations; the phloem fiber cells of the vascular tissue, and the cells of the root tip. Mtst1 expression in the roots is regulated in response to colonization by G. versiforme; transcript levels increased two- to fourfold in both M. truncatula and M. sativa following colonization by G. versiforme but did not increase during the unsuccessful interaction between G. versiforme and a M. sativa myc- mutant, suggesting that the increase in Mtst1 transcripts in the successful mycorrhizal interaction is correlated with internal growth of the fungus and potentially with a functioning symbiosis. Mtst1 transcripts were also detected in the cortical cells of the mycorrhizal root, specifically in areas of the root that were highly colonized by the mycorrhizal fungus. Thus, the formation of a symbiotic association with a VA mycorrhizal fungus is accompanied by a change in the cell type-specific expression of a transporter that potentially functions to supply sugars to root cells critically involved in the symbiotic association.

A PAX3 polymorphism (T315K) in a family exhibiting Waardenburg Syndrome type 2.

PubMed

Wang, C; Kim, E; Attaie, A; Smith, T N; Wilcox, E R; Lalwani, A K

1998-02-01

Waardenburg Syndrome (WS) is an autosomal-dominant disorder phenotypically characterized by sensorineural hearing loss and pigmentary disturbances. Presence of dystopia canthorum is indicative of WS type 1 and results from defects in the PAX3 gene, whereas normally located medial canthi is characteristic of type 2 WS (WS2) and is associated with defects in the microphthalmia-associated transcription factor (MIFT) gene. Here a neutral polymorphism is reported in the PAX3 gene (T315K) in a family with WS2. Copyright 1998 Academic Press Limited

Evasion of Early Antiviral Responses by Herpes Simplex Viruses

PubMed Central

Suazo, Paula A.; Ibañez, Francisco J.; Retamal-Díaz, Angello R.; Paz-Fiblas, Marysol V.; Bueno, Susan M.; Kalergis, Alexis M.; González, Pablo A.

2015-01-01

Besides overcoming physical constraints, such as extreme temperatures, reduced humidity, elevated pressure, and natural predators, human pathogens further need to overcome an arsenal of antimicrobial components evolved by the host to limit infection, replication and optimally, reinfection. Herpes simplex virus-1 (HSV-1) and herpes simplex virus-2 (HSV-2) infect humans at a high frequency and persist within the host for life by establishing latency in neurons. To gain access to these cells, herpes simplex viruses (HSVs) must replicate and block immediate host antiviral responses elicited by epithelial cells and innate immune components early after infection. During these processes, infected and noninfected neighboring cells, as well as tissue-resident and patrolling immune cells, will sense viral components and cell-associated danger signals and secrete soluble mediators. While type-I interferons aim at limiting virus spread, cytokines and chemokines will modulate resident and incoming immune cells. In this paper, we discuss recent findings relative to the early steps taking place during HSV infection and replication. Further, we discuss how HSVs evade detection by host cells and the molecular mechanisms evolved by these viruses to circumvent early antiviral mechanisms, ultimately leading to neuron infection and the establishment of latency. PMID:25918478

Low-dose radiation from 18F-FDG PET does not increase cancer frequency or shorten latency but reduces kidney disease in cancer-prone Trp53+/- mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Kristina; Lemon, Jennifer A.; Phan, Nghi

There is considerable interest in the health effects associated with low-level radiation exposure from medical imaging procedures. Concerns in the medical community that increased radiation exposure from imaging procedures may increase cancer risk among patients are confounded by research showing that low-dose radiation exposure can extend lifespan by increasing the latency period of some types of cancer. The most commonly used radiopharmaceutical for positron emission tomography (PET) scans is 2-[ 18F] fluoro-2-deoxy-d-glucose ( 18F-FDG), which exposes tissue to a low-dose, mixed radiation quality: 634 keV β+ and 511 keV γ-rays. The goal of this research was to investigate how modificationmore » of cancer risk associated with exposure to low-dose ionising radiation in cancer-prone Trp53+/- mice is influenced by radiation quality from PET. At 7-8 weeks of age, Trp53+/- female mice were exposed to one of five treatments: 0 Gy, 10 mGy γ-rays, 10 mGy 18F-FDG, 4 Gy γ-rays, 10 mGy 18F-FDG + 4 Gy γ-rays (n > 185 per group). The large 4-Gy radiation dose significantly reduced the lifespan by shortening the latency period of cancer and significantly increasing the number of mice with malignancies, compared with unirradiated controls. The 10 mGy γ-rays and 10 mGy PET doses did not significantly modify the frequency or latency period of cancer relative to unirradiated mice. Similarly, the PET scan administered prior to a large 4-Gy dose did not significantly modify the latency or frequency of cancer relative to mice receiving a dose of only 4 Gy. The relative biological effectiveness of radiation quality from 18F-FDG, with respect to malignancy, is approximately 1. Furthermore, when non-cancer endpoints were studied, it was found that the 10-mGy PET group had a significant reduction in kidney lesions (P < 0.021), indicating that a higher absorbed dose (20 ± 0.13 mGy), relative to the whole-body average, which occurs in specific tissues, may not be detrimental.« less

Low-dose radiation from 18F-FDG PET does not increase cancer frequency or shorten latency but reduces kidney disease in cancer-prone Trp53+/- mice

DOE PAGES

Taylor, Kristina; Lemon, Jennifer A.; Phan, Nghi; ...

2014-05-28

There is considerable interest in the health effects associated with low-level radiation exposure from medical imaging procedures. Concerns in the medical community that increased radiation exposure from imaging procedures may increase cancer risk among patients are confounded by research showing that low-dose radiation exposure can extend lifespan by increasing the latency period of some types of cancer. The most commonly used radiopharmaceutical for positron emission tomography (PET) scans is 2-[ 18F] fluoro-2-deoxy-d-glucose ( 18F-FDG), which exposes tissue to a low-dose, mixed radiation quality: 634 keV β+ and 511 keV γ-rays. The goal of this research was to investigate how modificationmore » of cancer risk associated with exposure to low-dose ionising radiation in cancer-prone Trp53+/- mice is influenced by radiation quality from PET. At 7-8 weeks of age, Trp53+/- female mice were exposed to one of five treatments: 0 Gy, 10 mGy γ-rays, 10 mGy 18F-FDG, 4 Gy γ-rays, 10 mGy 18F-FDG + 4 Gy γ-rays (n > 185 per group). The large 4-Gy radiation dose significantly reduced the lifespan by shortening the latency period of cancer and significantly increasing the number of mice with malignancies, compared with unirradiated controls. The 10 mGy γ-rays and 10 mGy PET doses did not significantly modify the frequency or latency period of cancer relative to unirradiated mice. Similarly, the PET scan administered prior to a large 4-Gy dose did not significantly modify the latency or frequency of cancer relative to mice receiving a dose of only 4 Gy. The relative biological effectiveness of radiation quality from 18F-FDG, with respect to malignancy, is approximately 1. Furthermore, when non-cancer endpoints were studied, it was found that the 10-mGy PET group had a significant reduction in kidney lesions (P < 0.021), indicating that a higher absorbed dose (20 ± 0.13 mGy), relative to the whole-body average, which occurs in specific tissues, may not be detrimental.« less

Narcolepsy Type 1 and Idiopathic Generalized Epilepsy: Diagnostic and Therapeutic Challenges in Dual Cases.

PubMed

Baiardi, Simone; Vandi, Stefano; Pizza, Fabio; Alvisi, Lara; Toscani, Lucia; Zambrelli, Elena; Tinuper, Paolo; Mayer, Geert; Plazzi, Giuseppe

2015-11-15

The aim of this study is to describe the possible co-occurrence of narcolepsy type 1 and generalized epilepsy, focusing on diagnostic challenge and safety of dual treatments. Four patients with comorbidity for narcolepsy type 1 and idiopathic generalized epilepsy are reported: in three cases the onset of epilepsy preceded narcolepsy type 1 appearance, whereas in one case epileptic spells onset was subsequent. Patients presented with absences, myoclonic and tonic-clonic seizure type: in the patient with tonic-clonic seizures the dual pathology was easily recognized, in the other cases the first diagnosis caused the comorbid disease to be overlooked, independent of the time-course sequence. All four patients underwent neurological examination, video-electroencephalogram during which ictal and interictal epileptic discharges were recorded, and sleep polysomnographic studies. Repeated sleep onset rapid eye movement periods (SOREMPs) were documented with the multiple sleep latency test (MLST) in all the four cases. All patients had unremarkable brain magnetic resonance imaging studies and cerebrospinal hypocretin-1 was assessed in two patients, revealing undetectable levels. The association of antiepileptic drugs and substances currently used to treat narcolepsy type 1, including sodium oxybate, was effective in improving seizures, sleep disturbance, and cataplexy. Narcolepsy type 1 may occur in association with idiopathic generalized epilepsy, leading to remarkable diagnostic and therapeutic challenges. Electrophysiological studies as well as a comprehensive somnologic interview can help confirm the diagnosis in patients with ambiguous neurological history. Sodium oxybate in combination with antiepileptic drugs is safe and effective in treating cataplexy and excessive daytime sleepiness. © 2015 American Academy of Sleep Medicine.

Tissue–selective effects of nucleolar stress and rDNA damage in developmental disorders

PubMed Central

Calo, Eliezer; Gu, Bo; Bowen, Margot E.; Aryan, Fardin; Zalc, Antoine; Liang, Jialiang; Flynn, Ryan A.; Swigut, Tomek; Chang, Howard Y.; Attardi, Laura D.; Wysocka, Joanna

2018-01-01

Many craniofacial disorders are caused by heterozygous mutations in general regulators of housekeeping cellular functions such as transcription or ribosome biogenesis1,2. Although it is understood that many of these malformations are a consequence of defects in cranial neural crest cells, a cell type that gives rise to most of the facial structures during embryogenesis3,4, the mechanism underlying cell-type selectivity of these defects remains largely unknown. By exploring molecular functions of DDX21, a DEAD-box RNA helicase involved in control of both RNA polymerase (Pol) I- and II-dependent transcriptional arms of ribosome biogenesis5, we uncovered a previously unappreciated mechanism linking nucleolar dysfunction, ribosomal DNA (rDNA) damage, and craniofacial malformations. Here we demonstrate that genetic perturbations associated with Treacher Collins syndrome, a craniofacial disorder caused by heterozygous mutations in components of the Pol I transcriptional machinery or its cofactor TCOF1 (ref. 1), lead to relocalization of DDX21 from the nucleolus to the nucleoplasm, its loss from the chromatin targets, as well as inhibition of rRNA processing and downregulation of ribosomal protein gene transcription. These effects are cell-type-selective, cell-autonomous, and involve activation of p53 tumour-suppressor protein. We further show that cranial neural crest cells are sensitized to p53-mediated apoptosis, but blocking DDX21 loss from the nucleolus and chromatin rescues both the susceptibility to apoptosis and the craniofacial phenotypes associated with Treacher Collins syndrome. This mechanism is not restricted to cranial neural crest cells, as blood formation is also hypersensitive to loss of DDX21 functions. Accordingly, ribosomal gene perturbations associated with Diamond-Blackfan anaemia disrupt DDX21 localization. At the molecular level, we demonstrate that impaired rRNA synthesis elicits a DNA damage response, and that rDNA damage results in tissue-selective and dosage-dependent effects on craniofacial development. Taken together, our findings illustrate how disruption in general regulators that compromise nucleolar homeostasis can result in tissue-selective malformations. PMID:29364875

Typing is writing: Linguistic properties modulate typing execution.

PubMed

Pinet, Svetlana; Ziegler, Johannes C; Alario, F-Xavier

2016-12-01

Typing is becoming our preferred way of writing. Perhaps because of the relative recency of this change, very few studies have investigated typing from a psycholinguistic perspective. In addition, and despite obvious similarities between typing and handwriting, typing research has remained rather disconnected from handwriting research. The current study aimed at bridging this gap by evaluating how typing is affected by a number of psycholinguistic variables defined at the word, syllable, and letter levels. In a writing-to-dictation task, we assessed typing performance by measuring response accuracy, onset latencies - an index of response preparation and initiation - and interkeystroke intervals (IKIs) - an index of response execution processes. The lexical and sublexical factors revealed a composite pattern of effects. Lexical frequency improved response latencies and accuracy, while bigram frequency speeded up IKIs. Sound-spelling consistency improved latencies, but had an inhibitory effect on IKI. IKIs were also longer at syllable boundaries. Together, our findings can be fit within a framework for typed production that combines the previously developed theories of spelling and typing execution. At their interface, we highlight the need for an intermediate hierarchical stage, perhaps in the form of a graphemic buffer for typing.

Simian Varicella Virus Infection of Rhesus Macaques Recapitulates Essential Features of Varicella Zoster Virus Infection in Humans

PubMed Central

Messaoudi, Ilhem; Barron, Alexander; Wellish, Mary; Engelmann, Flora; Legasse, Alfred; Planer, Shannon; Gilden, Don; Nikolich-Zugich, Janko; Mahalingam, Ravi

2009-01-01

Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation. PMID:19911054

Simian varicella virus infection of rhesus macaques recapitulates essential features of varicella zoster virus infection in humans.

PubMed

Messaoudi, Ilhem; Barron, Alexander; Wellish, Mary; Engelmann, Flora; Legasse, Alfred; Planer, Shannon; Gilden, Don; Nikolich-Zugich, Janko; Mahalingam, Ravi

2009-11-01

Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

Complex and Simple Clinical Reaction Times Are Associated with Gait, Balance, and Major Fall Injury in Older Subjects with Diabetic Peripheral Neuropathy

PubMed Central

Richardson, James K.; Eckner, James T.; Allet, Lara; Kim, Hogene; Ashton-Miller, James

2016-01-01

Objective To identify relationships between complex and simple clinical measures of reaction time (RTclin), and indicators of balance in older subjects with and without diabetic peripheral neuropathy (DPN). Design Prospective cohort design. Complex RTclin Accuracy, Simple RTclin Latency, and their ratio were determined using a novel device in 42 subjects (age = 69.1 ± 8.3 yrs), 26 with DPN and 16 without. Dependent variables included unipedal stance time (UST), step width variability and range on an uneven surface, and major fall-related injury over 12 months. Results In the DPN subjects the ratio of Complex RTclin Accuracy:Simple RTclin Latency was strongly associated with longer UST (r/p = .653/.004), and decreased step width variability and range (r/p = −.696/.001 and −.782/<.001, respectively) on an uneven surface. Additionally, the two DPN subjects sustaining major injuries had lower Complex RTclin Accuracy:Simple: RTclin Latency than those without. Conclusions The ratio of Complex RTclin Accuracy:Simple RTclin Latency is a potent predictor of UST and frontal plane gait variability in response to perturbations, and may predict major fall injury in older subjects with DPN. These short latency neurocognitive measures may compensate for lower limb neuromuscular impairments, and provide a more comprehensive understanding of balance and fall risk. PMID:27552354

An Implicit Measure of Associations with Mental Illness versus Physical Illness: Response Latency Decomposition and Stimuli Differential Functioning in Relation to IAT Order of Associative Conditions and Accuracy

PubMed Central

Mannarini, Stefania; Boffo, Marilisa

2014-01-01

The present study aimed at the definition of a latent measurement dimension underlying an implicit measure of automatic associations between the concept of mental illness and the psychosocial and biogenetic causal explanatory attributes. To this end, an Implicit Association Test (IAT) assessing the association between the Mental Illness and Physical Illness target categories to the Psychological and Biologic attribute categories, representative of the causal explanation domains, was developed. The IAT presented 22 stimuli (words and pictures) to be categorized into the four categories. After 360 university students completed the IAT, a Many-Facet Rasch Measurement (MFRM) modelling approach was applied. The model specified a person latency parameter and a stimulus latency parameter. Two additional parameters were introduced to denote the order of presentation of the task associative conditions and the general response accuracy. Beyond the overall definition of the latent measurement dimension, the MFRM was also applied to disentangle the effect of the task block order and the general response accuracy on the stimuli response latency. Further, the MFRM allowed detecting any differential functioning of each stimulus in relation to both block ordering and accuracy. The results evidenced: a) the existence of a latency measurement dimension underlying the Mental Illness versus Physical Illness - Implicit Association Test; b) significant effects of block order and accuracy on the overall latency; c) a differential functioning of specific stimuli. The results of the present study can contribute to a better understanding of the functioning of an implicit measure of semantic associations with mental illness and give a first blueprint for the examination of relevant issues in the development of an IAT. PMID:25000406

An implicit measure of associations with mental illness versus physical illness: response latency decomposition and stimuli differential functioning in relation to IAT order of associative conditions and accuracy.

PubMed

Mannarini, Stefania; Boffo, Marilisa

2014-01-01

The present study aimed at the definition of a latent measurement dimension underlying an implicit measure of automatic associations between the concept of mental illness and the psychosocial and biogenetic causal explanatory attributes. To this end, an Implicit Association Test (IAT) assessing the association between the Mental Illness and Physical Illness target categories to the Psychological and Biologic attribute categories, representative of the causal explanation domains, was developed. The IAT presented 22 stimuli (words and pictures) to be categorized into the four categories. After 360 university students completed the IAT, a Many-Facet Rasch Measurement (MFRM) modelling approach was applied. The model specified a person latency parameter and a stimulus latency parameter. Two additional parameters were introduced to denote the order of presentation of the task associative conditions and the general response accuracy. Beyond the overall definition of the latent measurement dimension, the MFRM was also applied to disentangle the effect of the task block order and the general response accuracy on the stimuli response latency. Further, the MFRM allowed detecting any differential functioning of each stimulus in relation to both block ordering and accuracy. The results evidenced: a) the existence of a latency measurement dimension underlying the Mental Illness versus Physical Illness - Implicit Association Test; b) significant effects of block order and accuracy on the overall latency; c) a differential functioning of specific stimuli. The results of the present study can contribute to a better understanding of the functioning of an implicit measure of semantic associations with mental illness and give a first blueprint for the examination of relevant issues in the development of an IAT.

Basic Helix-Loop-Helix Transcription Factors JASMONATE-ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3 Are Negative Regulators of Jasmonate Responses in Arabidopsis1[W][OPEN

PubMed Central

Sasaki-Sekimoto, Yuko; Jikumaru, Yusuke; Obayashi, Takeshi; Saito, Hikaru; Masuda, Shinji; Kamiya, Yuji; Ohta, Hiroyuki; Shirasu, Ken

2013-01-01

Jasmonates regulate transcriptional reprogramming during growth, development, and defense responses. Jasmonoyl-isoleucine, an amino acid conjugate of jasmonic acid (JA), is perceived by the protein complex composed of the F-box protein CORONATINE INSENSITIVE1 (COI1) and JASMONATE ZIM DOMAIN (JAZ) proteins, leading to the ubiquitin-dependent degradation of JAZ proteins. This activates basic helix-loop-helix-type MYC transcription factors to regulate JA-responsive genes. Here, we show that the expression of genes encoding other basic helix-loop-helix transcription factors, JASMONATE ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3, is positively regulated in a COI1- and MYC2-dependent manner in Arabidopsis (Arabidopsis thaliana). However, contrary to myc2, the jam1jam2jam3 triple mutant exhibited shorter roots when treated with methyl jasmonate (MJ), indicating enhanced responsiveness to JA. Our genome-wide expression analyses revealed that key jasmonate metabolic genes as well as a set of genes encoding transcription factors that regulate the JA-responsive metabolic genes are negatively regulated by JAMs after MJ treatment. Consistently, loss of JAM genes resulted in higher accumulation of anthocyanin in MJ-treated plants as well as higher accumulation of JA and 12-hydroxyjasmonic acid in wounded plants. These results show that JAMs negatively regulate the JA responses in a manner that is mostly antagonistic to MYC2. PMID:23852442

Nucleus accumbens cocaine-amphetamine regulated transcript mediates food intake during novelty conflict

PubMed Central

Burghardt, PR; Krolewski, DM; Dykhuis, KE; Ching, J; Pinawin, AM; Britton, SL; Koch, LG; Watson, SJ; Akil, H.

2016-01-01

Obesity is a persistent and pervasive problem, particularly in industrialized nations. It has come to be appreciated that the metabolic health of an individual can influence brain function and subsequent behavioral patterns. To examine the relationship between metabolic phenotype and central systems that regulate behavior, we tested rats with divergent metabolic phenotypes (Low Capacity Runner: LCR vs. High Capacity Runner: HCR) for behavioral responses to the conflict between hunger and environmental novelty using the novelty suppressed feeding (NSF) paradigm. Additionally, we measured expression of mRNA, for peptides involved in energy management, in response to fasting. Following a 24-h fast, LCR rats showed lower latencies to begin eating in a novel environment compared to HCR rats. A 48-h fast equilibrated the latency to begin eating in the novel environment. A 24-h fast differentially affected expression of cocaine-amphetamine regulated transcript (CART) mRNA in the nucleus accumbens (NAc), where 24-h of fasting reduced CART mRNA in LCR rats. Bilateral microinjections of CART 55–102 peptide into the NAc increased the latency to begin eating in the NSF paradigm following a 24-h fast in LCR rats. These results indicate that metabolic phenotype influences how animals cope with the conflict between hunger and novelty, and that these differences are at least partially mediated by CART signaling in the NAc. For individuals with poor metabolic health who have to navigate food-rich and stressful environments, changes in central systems that mediate conflicting drives may feed into the rates of obesity and exacerbate the difficulty individuals have in maintaining weight loss. PMID:26926827

Crystal structure of extracellular domain of human lectin-like transcript 1 (LLT1), the ligand for natural killer receptor-P1A.

PubMed

Kita, Shunsuke; Matsubara, Haruki; Kasai, Yoshiyuki; Tamaoki, Takaharu; Okabe, Yuki; Fukuhara, Hideo; Kamishikiryo, Jun; Krayukhina, Elena; Uchiyama, Susumu; Ose, Toyoyuki; Kuroki, Kimiko; Maenaka, Katsumi

2015-06-01

Emerging evidence has revealed the pivotal roles of C-type lectin-like receptors (CTLRs) in the regulation of a wide range of immune responses. Human natural killer cell receptor-P1A (NKRP1A) is one of the CTLRs and recognizes another CTLR, lectin-like transcript 1 (LLT1) on target cells to control NK, NKT and Th17 cells. The structural basis for the NKRP1A-LLT1 interaction was limitedly understood. Here, we report the crystal structure of the ectodomain of LLT1. The plausible receptor-binding face of the C-type lectin-like domain is flat, and forms an extended β-sheet. The residues of this face are relatively conserved with another CTLR, keratinocyte-associated C-type lectin, which binds to the CTLR member, NKp65. A LLT1-NKRP1A complex model, prepared using the crystal structures of LLT1 and the keratinocyte-associated C-type lectin-NKp65 complex, reasonably satisfies the charge consistency and the conformational complementarity to explain a previous mutagenesis study. Furthermore, crystal packing and analytical ultracentrifugation revealed dimer formation, which supports a complex model. Our results provide structural insights for understanding the binding modes and signal transduction mechanisms, which are likely to be conserved in the CTLR family, and for further rational drug design towards regulating the LLT1 function. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sleepiness in sleepwalking and sleep terrors: a higher sleep pressure?

PubMed

Carrillo-Solano, Marisol; Leu-Semenescu, Smaranda; Golmard, Jean-Louis; Groos, Elisabeth; Arnulf, Isabelle

2016-10-01

To identify the determinants of excessive daytime sleepiness in adults with sleepwalking or sleep terrors (SW/ST). We collected the charts of all consecutive adult patients admitted from 2012 to 2014 for SW/ST. They had completed the Paris Arousal Disorders Severity Scale and the Epworth Sleepiness Scale, and had undergone one (n = 34) or two consecutive (n = 124) nocturnal videopolysomnographies. The demographic, clinical, and sleep determinants of excessive daytime sleepiness (defined as an Epworth Sleepiness Scale score of greater than 10) were analyzed. Almost half (46.8%) of the 158 adult patients with SW/ST reported excessive daytime sleepiness. They had shorter sleep onset latencies (in night 1 and night 2), shorter REM sleep latencies, longer total sleep time, and higher REM sleep percentages in night 2, but no greater clinical severity of the parasomnia than patients without sleepiness. The level of sleepiness correlated with the same measures (sleep onset latency on both nights, REM sleep onset latency, and total sleep time in night 2), plus the latency to N3. In the regression model, higher sleepiness was determined by shorter sleep onset latency on night 1, lower number of awakenings in N3 on night 1, and higher total sleep time on night 2. Daytime sleepiness in patients with SW/ST is not the consequence of disturbed sleep but is associated with a specific polygraphic phenotype (rapid sleep onset, long sleep time, lower numbers of awakenings on N3) that is suggestive of a higher sleep pressure that may contribute to incomplete arousal from N3. Copyright © 2015 Elsevier B.V. All rights reserved.

Modulation of transcription factor binding and epigenetic regulation of the MLH1 CpG island and shore by polymorphism rs1800734 in colorectal cancer

PubMed Central

Savio, Andrea J.; Bapat, Bharati

2017-01-01

ABSTRACT The MLH1 promoter polymorphism rs1800734 is associated with MLH1 CpG island hypermethylation and expression loss in colorectal cancer (CRC). Conversely, variant rs1800734 is associated with MLH1 shore, but not island, hypomethylation in peripheral blood mononuclear cell DNA. To explore these distinct patterns, MLH1 CpG island and shore methylation was assessed in CRC cell lines stratified by rs1800734 genotype. Cell lines containing the variant A allele demonstrated MLH1 shore hypomethylation compared to wild type (GG). There was significant enrichment of transcription factor AP4 at the MLH1 promoter in GG and GA cell lines, but not the AA cell line, by chromatin immunoprecipitation studies. Preferential binding to the G allele was confirmed by sequencing in the GA cell line. The enhancer-associated histone modification H3K4me1 was enriched at the MLH1 shore; however, H3K27ac was not, indicating the shore is an inactive enhancer. These results demonstrate the role of variant rs1800734 in altering transcription factor binding as well as epigenetics at regions beyond the MLH1 CpG island in which it is located. PMID:28304185

Modulation of transcription factor binding and epigenetic regulation of the MLH1 CpG island and shore by polymorphism rs1800734 in colorectal cancer.

PubMed

Savio, Andrea J; Bapat, Bharati

2017-06-03

The MLH1 promoter polymorphism rs1800734 is associated with MLH1 CpG island hypermethylation and expression loss in colorectal cancer (CRC). Conversely, variant rs1800734 is associated with MLH1 shore, but not island, hypomethylation in peripheral blood mononuclear cell DNA. To explore these distinct patterns, MLH1 CpG island and shore methylation was assessed in CRC cell lines stratified by rs1800734 genotype. Cell lines containing the variant A allele demonstrated MLH1 shore hypomethylation compared to wild type (GG). There was significant enrichment of transcription factor AP4 at the MLH1 promoter in GG and GA cell lines, but not the AA cell line, by chromatin immunoprecipitation studies. Preferential binding to the G allele was confirmed by sequencing in the GA cell line. The enhancer-associated histone modification H3K4me1 was enriched at the MLH1 shore; however, H3K27ac was not, indicating the shore is an inactive enhancer. These results demonstrate the role of variant rs1800734 in altering transcription factor binding as well as epigenetics at regions beyond the MLH1 CpG island in which it is located.

[Relationships between electrophysiological characteristic of speech evoked auditory brainstem response and Mandarin monosyllable discriminative ability at different hearing impairment].

PubMed

Fu, Q Y; Liang, Y; Zou, A; Wang, T; Zhao, X D; Wan, J

2016-04-07

To investigate the relationships between electrophysiological characteristic of speech evoked auditory brainstem response(s-ABR) and Mandarin phonetically balanced maximum(PBmax) at different hearing impairment, so as to provide more clues for the mechanism of speech cognitive behavior. Forty-one ears in 41 normal hearing adults(NH), thirty ears in 30 conductive hearing loss patients(CHL) and twenty-seven ears in 27 sensorineural hearing loss patients(SNHL) were included in present study. The speech discrimination scores were obtained by Mandarin phonemic-balanced monosyllable lists via speech audiometric software. Their s-ABRs were recorded with speech syllables /da/ with the intensity of phonetically balanced maximum(PBmax). The electrophysiological characteristic of s-ABR, as well as the relationships between PBmax and s-ABR parameters including latency in time domain, fundamental frequency(F0) and first formant(F1) in frequency domain were analyzed statistically. All subjects completed good speech perception tests and PBmax of CHL and SNHL had no significant difference (P>0.05), but both significantly less than that of NH (P<0.05). While divided the subjects into three groups by 90%

The Hippo signal transduction network for exercise physiologists

PubMed Central

Hamilton, D. Lee; Tremblay, Annie M.

2016-01-01

The ubiquitous transcriptional coactivators Yap (gene symbol Yap1) and Taz (gene symbol Wwtr1) regulate gene expression mainly by coactivating the Tead transcription factors. Being at the center of the Hippo signaling network, Yap and Taz are regulated by the Hippo kinase cassette and additionally by a plethora of exercise-associated signals and signaling modules. These include mechanotransduction, the AKT-mTORC1 network, the SMAD transcription factors, hypoxia, glucose homeostasis, AMPK, adrenaline/epinephrine and angiotensin II through G protein-coupled receptors, and IL-6. Consequently, exercise should alter Hippo signaling in several organs to mediate at least some aspects of the organ-specific adaptations to exercise. Indeed, Tead1 overexpression in muscle fibers has been shown to promote a fast-to-slow fiber type switch, whereas Yap in muscle fibers and cardiomyocytes promotes skeletal muscle hypertrophy and cardiomyocyte adaptations, respectively. Finally, genome-wide association studies in humans have linked the Hippo pathway members LATS2, TEAD1, YAP1, VGLL2, VGLL3, and VGLL4 to body height, which is a key factor in sports. PMID:26940657

Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root.

PubMed

Carvalho, Luiz Jcb; Agustini, Marco Av; Anderson, James V; Vieira, Eduardo A; de Souza, Claudia Rb; Chen, Songbi; Schaal, Barbara A; Silva, Joseane P

2016-06-10

Cassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality. Among the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total β-carotene, containing all-E-, 9-Z-, and 13-Z-β-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no α-carotene was observed, variable amounts of a α-ring derived xanthophyll, lutein, was detected; with greater accumulation of α-ring xanthophylls than of β-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total β-carotene accumulation. Among the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low LYCb transcript abundance, whereas landrace Cas64 (intense yellow storage root) had decreased HYb transcript abundance. These results may explain the increased amounts of lycopene and total β-carotene observed in landraces Cas51 and Cas64, respectively. Overall, total carotenoid content in cassava storage root of color class representatives were associated with spatial patterns of secondary growth, color, and abundance of transcripts linked to plastid division. Finally, a partial carotenoid biosynthesis pathway is proposed.

When does word frequency influence written production?

PubMed

Baus, Cristina; Strijkers, Kristof; Costa, Albert

2013-01-01

The aim of the present study was to explore the central (e.g., lexical processing) and peripheral processes (motor preparation and execution) underlying word production during typewriting. To do so, we tested non-professional typers in a picture typing task while continuously recording EEG. Participants were instructed to write (by means of a standard keyboard) the corresponding name for a given picture. The lexical frequency of the words was manipulated: half of the picture names were of high-frequency while the remaining were of low-frequency. Different measures were obtained: (1) first keystroke latency and (2) keystroke latency of the subsequent letters and duration of the word. Moreover, ERPs locked to the onset of the picture presentation were analyzed to explore the temporal course of word frequency in typewriting. The results showed an effect of word frequency for the first keystroke latency but not for the duration of the word or the speed to which letter were typed (interstroke intervals). The electrophysiological results showed the expected ERP frequency effect at posterior sites: amplitudes for low-frequency words were more positive than those for high-frequency words. However, relative to previous evidence in the spoken modality, the frequency effect appeared in a later time-window. These results demonstrate two marked differences in the processing dynamics underpinning typing compared to speaking: First, central processing dynamics between speaking and typing differ already in the manner that words are accessed; second, central processing differences in typing, unlike speaking, do not cascade to peripheral processes involved in response execution.

When does word frequency influence written production?

PubMed Central

Baus, Cristina; Strijkers, Kristof; Costa, Albert

2013-01-01

The aim of the present study was to explore the central (e.g., lexical processing) and peripheral processes (motor preparation and execution) underlying word production during typewriting. To do so, we tested non-professional typers in a picture typing task while continuously recording EEG. Participants were instructed to write (by means of a standard keyboard) the corresponding name for a given picture. The lexical frequency of the words was manipulated: half of the picture names were of high-frequency while the remaining were of low-frequency. Different measures were obtained: (1) first keystroke latency and (2) keystroke latency of the subsequent letters and duration of the word. Moreover, ERPs locked to the onset of the picture presentation were analyzed to explore the temporal course of word frequency in typewriting. The results showed an effect of word frequency for the first keystroke latency but not for the duration of the word or the speed to which letter were typed (interstroke intervals). The electrophysiological results showed the expected ERP frequency effect at posterior sites: amplitudes for low-frequency words were more positive than those for high-frequency words. However, relative to previous evidence in the spoken modality, the frequency effect appeared in a later time-window. These results demonstrate two marked differences in the processing dynamics underpinning typing compared to speaking: First, central processing dynamics between speaking and typing differ already in the manner that words are accessed; second, central processing differences in typing, unlike speaking, do not cascade to peripheral processes involved in response execution. PMID:24399980

Altered Sleep Stage Transitions of REM Sleep: A Novel and Stable Biomarker of Narcolepsy.

PubMed

Liu, Yaping; Zhang, Jihui; Lam, Venny; Ho, Crover Kwok Wah; Zhou, Junying; Li, Shirley Xin; Lam, Siu Ping; Yu, Mandy Wai Man; Tang, Xiangdong; Wing, Yun-Kwok

2015-08-15

To determine the diagnostic values, longitudinal stability, and HLA association of the sleep stage transitions in narcolepsy. To compare the baseline differences in the sleep stage transition to REM sleep among 35 patients with type 1 narcolepsy, 39 patients with type 2 narcolepsy, 26 unaffected relatives, and 159 non-narcoleptic sleep patient controls, followed by a reassessment at a mean duration of 37.4 months. The highest prevalence of altered transition from stage non-N2/N3 to stage R in multiple sleep latency test (MSLT) and nocturnal polysomnography (NPSG) was found in patients with type 1 narcolepsy (92.0% and 57.1%), followed by patients with type 2 narcolepsy (69.4% and 12.8%), unaffected relatives (46.2% and 0%), and controls (39.3% and 1.3%). Individual sleep variables had varied sensitivity and specificity in diagnosing narcolepsy. By incorporating a combination of sleep variables, the decision tree analysis improved the sensitivity to 94.3% and 82.1% and enhanced specificity to 82.4% and 83% for the diagnosis of type 1 and type 2 narcolepsy, respectively. There was a significant association of DBQ1*0602 with the altered sleep stage transition (OR = 16.0, 95% CI: 1.7-149.8, p = 0.015). The persistence of the altered sleep stage transition in both MSLT and NPSG was high for both type 1 (90.5% and 64.7%) and type 2 narcolepsy (92.3% and 100%), respectively. Altered sleep stage transition is a significant and stable marker of narcolepsy, which suggests a vulnerable wake-sleep dysregulation trait in narcolepsy. Altered sleep stage transition has a significant diagnostic value in the differential diagnosis of hypersomnias, especially when combined with other diagnostic sleep variables in decision tree analysis. © 2015 American Academy of Sleep Medicine.

Effects of paroxetine on intravaginal ejaculatory latency time in Egyptian patients with lifelong premature ejaculation as a function of serotonin transporter polymorphism.

PubMed

Salem, A M; Kamel, I I; Rashed, L A; GamalEl Din, S F

2017-01-01

Premature ejaculation (PE) is a common ejaculatory complaint. The estimated rates among Turkish men reached 20%, although the severest type of PE (lifelong PE) usually does not exceed 2.3%. This could be seen in line with two survey studies involving five nations. They revealed that 2.5% of men had an intravaginal ejaculation latency time of <1 min and 6% of <2 min. Rapid ejaculation may be treated pharmacologically with a variety of different medications that act either centrally or locally to delay ejaculation and subsequent orgasm. Antidepressants, particularly members of the selective serotonin reuptake inhibitor class, retard ejaculation significantly. Recently, it was postulated that men with lifelong PE might result from a combination of polymorphisms of the serotonergic transporter and receptors, and other neurotransmitters and/or receptors. Our findings augment the significant effect of paroxetine in delaying ejaculation in the responders (P<0.001). Meanwhile, the findings do not suggest a positive association between such response and serotonin transporter gene promoter polymorphism.

Basic helix-loop-helix transcription factors JASMONATE-ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3 are negative regulators of jasmonate responses in Arabidopsis.

PubMed

Sasaki-Sekimoto, Yuko; Jikumaru, Yusuke; Obayashi, Takeshi; Saito, Hikaru; Masuda, Shinji; Kamiya, Yuji; Ohta, Hiroyuki; Shirasu, Ken

2013-09-01

Jasmonates regulate transcriptional reprogramming during growth, development, and defense responses. Jasmonoyl-isoleucine, an amino acid conjugate of jasmonic acid (JA), is perceived by the protein complex composed of the F-box protein CORONATINE INSENSITIVE1 (COI1) and JASMONATE ZIM DOMAIN (JAZ) proteins, leading to the ubiquitin-dependent degradation of JAZ proteins. This activates basic helix-loop-helix-type MYC transcription factors to regulate JA-responsive genes. Here, we show that the expression of genes encoding other basic helix-loop-helix transcription factors, JASMONATE ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3, is positively regulated in a COI1- and MYC2-dependent manner in Arabidopsis (Arabidopsis thaliana). However, contrary to myc2, the jam1jam2jam3 triple mutant exhibited shorter roots when treated with methyl jasmonate (MJ), indicating enhanced responsiveness to JA. Our genome-wide expression analyses revealed that key jasmonate metabolic genes as well as a set of genes encoding transcription factors that regulate the JA-responsive metabolic genes are negatively regulated by JAMs after MJ treatment. Consistently, loss of JAM genes resulted in higher accumulation of anthocyanin in MJ-treated plants as well as higher accumulation of JA and 12-hydroxyjasmonic acid in wounded plants. These results show that JAMs negatively regulate the JA responses in a manner that is mostly antagonistic to MYC2.

IFP35 Is Involved in the Antiviral Function of Interferon by Association with the Viral Tas Transactivator of Bovine Foamy Virus▿

PubMed Central

Tan, Juan; Qiao, Wentao; Wang, Jian; Xu, Fengwen; Li, Yue; Zhou, Jun; Chen, Qimin; Geng, Yunqi

2008-01-01

Interferon-induced proteins (IFPs) exert multiple functions corresponding to diverse interferon signals. However, the intracellular functions of many IFPs are not fully characterized. Here, we report that IFP35, a member of the IFP family with a molecular mass of 35 kDa, can interact with the bovine Tas (BTas) regulatory protein of bovine foamy virus (BFV). The interaction involves NID2 (IFP35/Nmi homology domain) of IFP35 and the central domain of BTas. The overexpression of IFP35 disturbs the ability of BTas to activate viral-gene transcription and inhibits viral replication. The depletion of endogenous IFP35 by interfering RNA can promote the activation of BFV, suggesting an inhibitory function of IFP35 in viral-gene expression. In addition, IFP35 can interact with the homologous regulatory protein of prototype FV and arrest viral replication and repress viral transcription. Our study suggests that IFP35 may represent a novel pathway of interferon-mediated antiviral activity in host organisms that plays a role in the maintenance of FV latency. PMID:18305040

Insomnia and Sleepiness in Parkinson Disease: Associations with Symptoms and Comorbidities

PubMed Central

Chung, Seockhoon; Bohnen, Nicolaas I.; Albin, Roger L.; Frey, Kirk A.; Müller, Martijn L. T. M.; Chervin, Ronald D.

2013-01-01

Study Objectives: Insomnia and daytime sleepiness are common complaints in Parkinson disease (PD), but the main causes remain unclear. We examined the potential impact of both motor and non-motor symptoms of PD on sleep problems. Methods: Patients with PD (n = 128) were assessed using the Insomnia Severity Index, Epworth Sleepiness Scale, Unified Parkinson Disease Rating Scale, Beck Depression Inventory, Fatigue Severity Scale, Survey of Autonomic Symptoms, and the 39-item Parkinson Disease Questionnaire. A subset of subjects (n = 38, 30%) also completed nocturnal polysomnography and a multiple sleep latency test (MSLT). Results: Multivariate stepwise logistic regression models revealed that subjective insomnia was independently associated with depressed mood (odds ratio [OR] = 1.79; 95% confidence interval (CI) [1.01-3.19]), autonomic symptoms (1.77 [1.08-2.90]), fatigue (1.19 [1.02-1.38]), and age (0.61 [0.39-0.96]). Subjective daytime sleepiness was associated with dosage of dopaminergic medication (1.74 [1.08-2.80]) and fatigue (1.14 [1.02-1.28]). On polysomnography, longer sleep latency correlated with autonomic symptoms (rho = 0.40, p = 0.01) and part I (non-motor symptoms) of the Unified PD Rating Scale (rho = 0.38, p = 0.02). Decreased sleep efficiency correlated with autonomic symptoms (rho = -0.42, p < 0.0001). However, no significant difference emerged on polysomnography and MSLTs between patients with or without insomnia or daytime sleepiness. Higher rates of apneic events did predict shorter sleep latencies on the MSLTs. Conclusions: Non-motor symptoms appear to be associated with subjective insomnia, whereas fatigue and dopaminergic medication are associated with subjective daytime sleepiness. Objective sleep laboratory data provided little insight into complaints of insomnia and sleepiness, though obstructive sleep apnea predicted worsened sleepiness when measured objectively. Citation: Chung S; Bohnen NI; Albin RL; Frey KA; Müller MLTM; Chervin RD. Insomnia and sleepiness in Parkinson disease: associations with symptoms and comorbidities. J Clin Sleep Med 2013;9(11):1131-1137. PMID:24235893

Modes of Human T Cell Leukemia Virus Type 1 Transmission, Replication and Persistence

PubMed Central

Carpentier, Alexandre; Barez, Pierre-Yves; Hamaidia, Malik; Gazon, Hélène; de Brogniez, Alix; Perike, Srikanth; Gillet, Nicolas; Willems, Luc

2015-01-01

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that causes cancer (Adult T cell Leukemia, ATL) and a spectrum of inflammatory diseases (mainly HTLV-associated myelopathy—tropical spastic paraparesis, HAM/TSP). Since virions are particularly unstable, HTLV-1 transmission primarily occurs by transfer of a cell carrying an integrated provirus. After transcription, the viral genomic RNA undergoes reverse transcription and integration into the chromosomal DNA of a cell from the newly infected host. The virus then replicates by either one of two modes: (i) an infectious cycle by virus budding and infection of new targets and (ii) mitotic division of cells harboring an integrated provirus. HTLV-1 replication initiates a series of mechanisms in the host including antiviral immunity and checkpoint control of cell proliferation. HTLV-1 has elaborated strategies to counteract these defense mechanisms allowing continuous persistence in humans. PMID:26198240

THRAP3 interacts with and inhibits the transcriptional activity of SOX9 during chondrogenesis.

PubMed

Sono, Takashi; Akiyama, Haruhiko; Miura, Shigenori; Deng, Jian Min; Shukunami, Chisa; Hiraki, Yuji; Tsushima, Yu; Azuma, Yoshiaki; Behringer, Richard R; Matsuda, Shuichi

2018-07-01

Sex-determining region Y (Sry)-box (Sox)9 is required for chondrogenesis as a transcriptional activator of genes related to chondrocyte proliferation, differentiation, and cartilage-specific extracellular matrix. Although there have been studies investigating the Sox9-dependent transcriptional complexes, not all their components have been identified. In the present study, we demonstrated that thyroid hormone receptor-associated protein (THRAP)3 is a component of a SOX9 transcriptional complex by liquid chromatography mass spectrometric analysis of FLAG-tagged Sox9-binding proteins purified from FLAG-HA-tagged Sox9 knock-in mice. Thrap3 knockdown in ATDC5 chondrogenic cells increased the expression of Collagen type II alpha 1 chain (Col2a1) without affecting Sox9 expression. THRAP3 and SOX9 overexpression reduced Col2a1 levels to a greater degree than overexpression of SOX9 alone. The negative regulation of SOX9 transcriptional activity by THRAP3 was mediated by interaction between the proline-, glutamine-, and serine-rich domain of SOX9 and the innominate domain of THRAP3. These results indicate that THRAP3 negatively regulates SOX9 transcriptional activity as a cofactor of a SOX9 transcriptional complex during chondrogenesis.

Small Changes in the Regulation of One Arabidopsis Profilin Isovariant, PRF1, Alter Seedling Development

PubMed Central

McKinney, Elizabeth Cohen; Kandasamy, Muthugapatti K.; Meagher, Richard B.

2001-01-01

Profilin (PRF) is a low-molecular-weight actin binding protein encoded by a diverse gene family in plants. Arabidopsis PRF1 transcripts are moderately well expressed in all vegetative organs. A regulatory mutant in PRF1, prf1-1, was isolated from a library of T-DNA insertions. The insertion disrupted the promoter region of PRF1 100 bp upstream from the transcriptional start site. Although steady state levels of PRF1 transcripts appeared normal in mature prf1-1 plants, the levels in young seedlings were only one-half those observed in wild type. Reactions with a PRF1 isovariant–specific monoclonal antiserum and general anti-profilin antisera demonstrated that PRF1 protein levels also were one-half those found in wild-type seedlings, although total profilin levels were unaffected. Mutant seedlings no longer could downregulate PRF1 levels in the light, as did wild type. Consistent with their molecular phenotypes, young mutant seedlings displayed several morphological phenotypes but developed into apparently normal adult plants. Their initial germination rate and development were slow, and they produced excessive numbers of root hairs. Mutant seedlings had abnormally raised cotyledons, elongated hypocotyls, and elongated cells in the hypocotyl, typical of phenotypes associated with some defects in light and circadian responses. A wild-type PRF1 transgene fully complements the hypocotyl phenotypes in the prf1-1 mutant. The ability of profilin to regulate actin polymerization and participate directly in signal transduction pathways is discussed in light of the prf1-1 phenotypes. PMID:11340190

Quantitative analysis of Epstein-Barr virus (EBV)-related gene expression in patients with chronic active EBV infection.

PubMed

Iwata, Seiko; Wada, Kaoru; Tobita, Satomi; Gotoh, Kensei; Ito, Yoshinori; Demachi-Okamura, Ayako; Shimizu, Norio; Nishiyama, Yukihiro; Kimura, Hiroshi

2010-01-01

Chronic active Epstein-Barr virus (CAEBV) infection is a systemic Epstein-Barr virus (EBV)-positive lymphoproliferative disorder characterized by persistent or recurrent infectious mononucleosis-like symptoms in patients with no known immunodeficiency. The detailed pathogenesis of the disease is unknown and no standard treatment regimen has been developed. EBV gene expression was analysed in peripheral blood samples collected from 24 patients with CAEBV infection. The expression levels of six latent and two lytic EBV genes were quantified by real-time RT-PCR. EBV-encoded small RNA 1 and BamHI-A rightward transcripts were abundantly detected in all patients, and latent membrane protein (LMP) 2 was observed in most patients. EBV nuclear antigen (EBNA) 1 and LMP1 were detected less frequently and were expressed at lower levels. EBNA2 and the two lytic genes were not detected in any of the patients. The pattern of latent gene expression was determined to be latency type II. EBNA1 was detected more frequently and at higher levels in the clinically active patients. Quantifying EBV gene expression is useful in clarifying the pathogenesis of CAEBV infection and may provide information regarding a patient's disease prognosis, as well as possible therapeutic interventions.

The AP-1 Transcription Factor c-Jun Promotes Arthritis by Regulating Cyclooxygenase-2 and Arginase-1 Expression in Macrophages.

PubMed

Hannemann, Nicole; Jordan, Jutta; Paul, Sushmita; Reid, Stephen; Baenkler, Hanns-Wolf; Sonnewald, Sophia; Bäuerle, Tobias; Vera, Julio; Schett, Georg; Bozec, Aline

2017-05-01

Activation of proinflammatory macrophages is associated with the inflammatory state of rheumatoid arthritis. Their polarization and activation are controlled by transcription factors such as NF-κB and the AP-1 transcription factor member c-Fos. Surprisingly, little is known about the role of the AP-1 transcription factor c-Jun in macrophage activation. In this study, we show that mRNA and protein levels of c-Jun are increased in macrophages following pro- or anti-inflammatory stimulations. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment cluster analyses of microarray data using wild-type and c-Jun-deleted macrophages highlight the central function of c-Jun in macrophages, in particular for immune responses, IL production, and hypoxia pathways. Mice deficient for c-Jun in macrophages show an amelioration of inflammation and bone destruction in the serum-induced arthritis model. In vivo and in vitro gene profiling, together with chromatin immunoprecipitation analysis of macrophages, revealed direct activation of the proinflammatory factor cyclooxygenase-2 and indirect inhibition of the anti-inflammatory factor arginase-1 by c-Jun. Thus, c-Jun regulates the activation state of macrophages and promotes arthritis via differentially regulating cyclooxygenase-2 and arginase-1 levels. Copyright © 2017 by The American Association of Immunologists, Inc.

No evidence for the presence of Epstein-Barr virus in squamous cell carcinoma of the mobile tongue.

PubMed

Wilms, Torben; Khan, Gulfaraz; Coates, Philip J; Sgaramella, Nicola; Fåhraeus, Robin; Hassani, Asma; Philip, Pretty S; Norberg Spaak, Lena; Califano, Luigi; Colella, Giuseppe; Olofsson, Katarina; Loizou, Christos; Franco, Renato; Nylander, Karin

2017-01-01

Squamous cell carcinoma of the head and neck (SCCHN) comprises a large group of cancers in the oral cavity and nasopharyngeal area that typically arise in older males in association with alcohol/tobacco usage. Within the oral cavity, the mobile tongue is the most common site for tumour development. The incidence of tongue squamous cell carcinoma (TSCC) is increasing in younger people, which has been suggested to associate with a viral aetiology. Two common human oncogenic viruses, human papilloma virus (HPV) and Epstein-Barr virus (EBV) are known causes of certain types of SCCHN, namely the oropharynx and nasopharynx, respectively. EBV infects most adults worldwide through oral transmission and establishes a latent infection, with sporadic productive viral replication and release of virus in the oral cavity throughout life. In view of the prevalence of EBV in the oral cavity and recent data indicating that it infects tongue epithelial cells and establishes latency, we examined 98 cases of primary squamous cell carcinoma of the mobile tongue and 15 cases of tonsillar squamous cell carcinoma for the presence of EBV-encoded RNAs (EBERs), EBV DNA and an EBV-encoded protein, EBNA-1. A commercially available in situ hybridisation kit targeting EBER transcripts (EBER-ISH) showed a positive signal in the cytoplasm and/or nuclei of tumour cells in 43% of TSCCs. However, application of control probes and RNase A digestion using in-house developed EBER-ISH showed identical EBER staining patterns, indicating non-specific signals. PCR analysis of the BamH1 W repeat sequences did not identify EBV genomes in tumour samples. Immunohistochemistry for EBNA-1 was also negative. These data exclude EBV as a potential player in TSCC in both old and young patients and highlight the importance of appropriate controls for EBER-ISH in investigating EBV in human diseases.

No evidence for the presence of Epstein-Barr virus in squamous cell carcinoma of the mobile tongue

PubMed Central

Wilms, Torben; Khan, Gulfaraz; Coates, Philip J.; Sgaramella, Nicola; Fåhraeus, Robin; Hassani, Asma; Philip, Pretty S.; Norberg Spaak, Lena; Califano, Luigi; Colella, Giuseppe; Olofsson, Katarina; Loizou, Christos; Franco, Renato

2017-01-01

Squamous cell carcinoma of the head and neck (SCCHN) comprises a large group of cancers in the oral cavity and nasopharyngeal area that typically arise in older males in association with alcohol/tobacco usage. Within the oral cavity, the mobile tongue is the most common site for tumour development. The incidence of tongue squamous cell carcinoma (TSCC) is increasing in younger people, which has been suggested to associate with a viral aetiology. Two common human oncogenic viruses, human papilloma virus (HPV) and Epstein-Barr virus (EBV) are known causes of certain types of SCCHN, namely the oropharynx and nasopharynx, respectively. EBV infects most adults worldwide through oral transmission and establishes a latent infection, with sporadic productive viral replication and release of virus in the oral cavity throughout life. In view of the prevalence of EBV in the oral cavity and recent data indicating that it infects tongue epithelial cells and establishes latency, we examined 98 cases of primary squamous cell carcinoma of the mobile tongue and 15 cases of tonsillar squamous cell carcinoma for the presence of EBV-encoded RNAs (EBERs), EBV DNA and an EBV-encoded protein, EBNA-1. A commercially available in situ hybridisation kit targeting EBER transcripts (EBER-ISH) showed a positive signal in the cytoplasm and/or nuclei of tumour cells in 43% of TSCCs. However, application of control probes and RNase A digestion using in-house developed EBER-ISH showed identical EBER staining patterns, indicating non-specific signals. PCR analysis of the BamH1 W repeat sequences did not identify EBV genomes in tumour samples. Immunohistochemistry for EBNA-1 was also negative. These data exclude EBV as a potential player in TSCC in both old and young patients and highlight the importance of appropriate controls for EBER-ISH in investigating EBV in human diseases. PMID:28926591

Posterior cricoarytenoid muscle electrophysiologic changes are predictive of vocal cord paralysis with recurrent laryngeal nerve compressive injury in a canine model.

PubMed

Puram, Sidharth V; Chow, Harold; Wu, Che-Wei; Heaton, James T; Kamani, Dipti; Gorti, Gautham; Chiang, Feng Yu; Dionigi, Gianlorenzo; Barczynski, Marcin; Schneider, Rick; Dralle, Henning; Lorenz, Kerstin; Randolph, Gregory W

2016-12-01

Injury to the recurrent laryngeal nerve (RLN) is a dreaded complication of endocrine surgery. Intraoperative neural monitoring (IONM) has been increasingly utilized to assess the functional status of the RLN. Although the posterior cricoarytenoid muscle (PCA) is innervated by the RLN as the abductor of the larynx, PCA electromyography (EMG) is infrequently recorded during IONM and PCA activity after RLN compressive injury remains poorly characterized. Single-subject prospective animal study. We employed a canine model to identify postcricoid EMG correlates of postoperative vocal cord paralysis (VCP). Postcricoid electrode recordings were obtained before and after compressive RLN injury associated with VCP. Normative postcricoid recordings revealed mean amplitude of 1288 microvolt (μV) and latency of 8.2 millisecond (ms) with maximum (1 milliamp [mA]) vagal stimulation, and mean amplitude of 1807 μV and latency of 3.5 ms with maximum (1 mA) RLN stimulation. Following injury that was associated with VCP, there was 62.1% decrement in postcricoid EMG amplitude with maximum vagal stimulation and 80% decrement with maximum RLN stimulation. Threshold stimulation of the vagus increased by 23%, and there was a corresponding 42% decrease in amplitude. For RLN stimulation, latency increased by 17.3% following injury, whereas threshold stimulation increased by 61% with 35.5% decrement in EMG amplitude. Thus, if RLN amplitude decreases by ≥ 80%, with absolute amplitude of ≤ 300 μV or less and latency increase of ≥ 10%, RLN injury is likely associated with VCP. Our results predict postoperative VCP based on postcricoid electromyographic IONM and may guide surgical decision making. NA Laryngoscope, 126:2744-2751, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Long Noncoding RNA uc002yug.2 Activates HIV-1 Latency through Regulation of mRNA Levels of Various RUNX1 Isoforms and Increased Tat Expression.

PubMed

Huan, Chen; Li, Zhaolong; Ning, Shanshan; Wang, Hong; Yu, Xiao-Fang; Zhang, Wenyan

2018-05-01

The HIV-1 reservoir is a major obstacle to complete eradication of the virus. Although many proteins and RNAs have been characterized as regulators in HIV-1/AIDS pathogenesis and latency, only a few long noncoding RNAs (lncRNAs) have been shown to be closely associated with HIV-1 replication and latency. In this study, we demonstrated that lncRNA uc002yug.2 plays a key role in HIV-1 replication and latency. uc002yug.2 potentially enhances HIV-1 replication, long terminal repeat (LTR) activity, and the activation of latent HIV-1 in both cell lines and CD4 + T cells from patients. Further investigation revealed that uc002yug.2 activates latent HIV-1 through downregulating RUNX1b and -1c and upregulating Tat protein expression. The accumulated evidence supports our model that the Tat protein has the key role in the uc002yug.2-mediated regulatory effect on HIV-1 reactivation. Moreover, uc002yug.2 showed an ability to activate HIV-1 similar to that of suberoylanilide hydroxamic acid or phorbol 12-myristate 13-acetate using latently infected cell models. These findings improve our understanding of lncRNA regulation of HIV-1 replication and latency, providing new insights into potential targeted therapeutic interventions. IMPORTANCE The latent viral reservoir is the primary obstacle to curing HIV-1 disease. To date, only a few lncRNAs, which play major roles in various biological processes, including viral infection, have been identified as regulators in HIV-1 latency. In this study, we demonstrated that lncRNA uc002yug.2 is important for both HIV-1 replication and activation of latent viruses. Moreover, uc002yug.2 was shown to activate latent HIV-1 through regulating alternative splicing of RUNX1 and increasing the expression of Tat protein. These findings highlight the potential merit of targeting lncRNA uc002yug.2 as an activating agent for latent HIV-1. Copyright © 2018 American Society for Microbiology.

The Epidemiology of Human Immunodeficiency Virus Infection.

ERIC Educational Resources Information Center

Glasner, Peter D.; Kaslow, Richard A.

1990-01-01

Reviews epidemiology and natural history of human immunodeficiency virus-Type 1 (HIV-1) infection. Discusses early and late clinical manifestations, diagnosis of infection, incubation and latency periods, and survival time. Reviews data from published literature on distribution of HIV infection in adult United States population and factors that…

Discordance between bovine leukemia virus tax immortalization in vitro and oncogenicity in vivo.

PubMed

Twizere, J C; Kerkhofs, P; Burny, A; Portetelle, D; Kettmann, R; Willems, L

2000-11-01

Bovine leukemia virus (BLV) Tax protein, a transcriptional activator of viral expression, is essential for viral replication in vivo. Tax is believed to be involved in leukemogenesis because of its second function, immortalization of primary cells in vitro. These activities of Tax can be dissociated on the basis of point mutations within specific regions of the protein. For example, mutation of the phosphorylation sites at serines 106 and 293 abrogates immortalization potential in vitro but maintains transcriptional activity. This type of mutant is thus particularly useful for unraveling the role of Tax immortalization activity during leukemogenesis independently of viral replication. In this report, we describe the biological properties of BLV recombinant proviruses mutated in the Tax phosphorylation sites (BLVTax106+293). Titration of the proviral loads by semiquantitative PCR revealed that the BLV mutants propagated at wild-type levels in vivo. Furthermore, two animals (sheep 480 and 296) infected with BLVTax106+293 developed leukemia or lymphosarcoma after 16 and 36 months, respectively. These periods of time are within the normal range of latencies preceding the onset of pathogenesis induced by wild-type viruses. The phenotype of the mutant-infected cells was characteristic of a B lymphocyte (immunoglobulin M positive) expressing CD11b and CD5 (except at the final stage for the latter marker), a pattern that is typical of wild-type virus-infected target cells. Interestingly, the transformed B lymphocytes from sheep 480 also coexpressed the CD8 marker, a phenotype rarely observed in tumor biopsies from chronic lymphocytic leukemia patients. Finally, direct sequencing of the tax gene demonstrated that the leukemic cells did not harbor revertant proviruses. We conclude that viruses expressing a Tax mutant unable to transform primary cells in culture are still pathogenic in the sheep animal model. Our data thus provide a clear example of the discordant conclusions that can be drawn from in vitro immortalization assays and in vivo experiments. These observations could be of interest for other systems, such as the related human T-cell leukemia virus type 1, which currently lack animal models allowing the study of the leukemogenic process.

Decreased HIV Type 1 Transcription in CCR5-Δ32 Heterozygotes During Suppressive Antiretroviral Therapy

PubMed Central

Wang, Charlene; Abdel-Mohsen, Mohamed; Strain, Matthew C.; Lada, Steven M.; Yukl, Steven; Cockerham, Leslie R.; Pilcher, Christopher D.; Hecht, Frederick M.; Sinclair, Elizabeth; Liegler, Teri; Richman, Douglas D.; Deeks, Steven G.; Pillai, Satish K.

2014-01-01

Individuals who are heterozygous for the CCR5-Δ32 mutation provide a natural model to examine the effects of reduced CCR5 expression on human immunodeficiency virus (HIV) persistence. We evaluated the HIV reservoir in 18 CCR5-Δ32 heterozygotes and 54 CCR5 wild-type individuals during suppressive antiretroviral therapy. Cell-associated HIV RNA levels (P = .035), RNA to DNA transcriptional ratios (P = .013), and frequency of detectable HIV 2–long terminal repeat circular DNA (P = .013) were significantly lower in CD4+ T cells from CCR5-Δ32 heterozygotes. Cell-associated HIV RNA was significantly correlated with CCR5 surface expression on CD4+ T cells (r2 = 0.136; P = .002). Our findings suggest that curative strategies should further explore manipulation of CCR5. PMID:24935955

Does Noise From Shipping and Boat Traffic Affect Predator Vigilance in the European Common Hermit Crab?

PubMed

Nousek-McGregor, Anna E; Mei, Francesca Tee Liang

2016-01-01

The effect of noise on predator vigilance in Pagurus bernhardus was explored in this study. Latency of the first response, emergence time, and response type were measured from hermit crabs during continuous and variable vessel noise and two controls. The mean (±SE) response latency was longer for the noise treatments (continuous, 18.19 ± 2.78 s; variable, 11.39 ± 1.48 s) than for the controls (ambient, 7.21 ± 0.82 s; silent, 6.66 ± 0.95 s). Response type and emergence time were not significantly affected but were more variable during the noise treatments than during the controls. Noisy conditions may increase predation risk, suggesting potential fitness consequences for invertebrates.

[Transcription of protein arginine N-methyltransferase genes in mouse dorsal root ganglia following peripheral nerve injury].

PubMed

Xu, Hua-Li; Xu, Shi-Yuan; Mo, Kai

2017-12-20

To investigate the changes in the transcription of protein arginine methylation enzyme family genes in the dorsal root ganglia (DRG) following peripheral nerve injury in mice. C57BL6 mouse models of neuropathic pain induced by peripheral nerve injury were established by bilateral L4 spinal nerve ligation (SNL). At 7 days after SNL or sham operation, the DRG tissue was collected for transcriptional analysis of 9 protein arginine methylation enzyme genes (Prmt1?3, Carm1, and Prmt5?9) using RNA?Seq to identify the differentially expressed genes in the injured DRGs. We also established mouse models of lateral L4 SNL and models of chronic constriction injury (CCI) of the sciatic nerve and tested the paw withdrawal frequency (PWF) in response to mechanical stimulation and paw withdrawal latency (PWL) in response to thermal stimulation on 0, 3, 7 and 14 days after SNL or CCI; the expressions of the differentially expressed genes in the injured DRGs were verified in the two models using RT?qPCR. Among the 9 protein arginine methylation enzyme family genes that were tissue?specifically expressed in the DRG, Prmt2 and Prmt3 showed the highest and Prmt6 showed the lowest basal expression. Compared with the sham?operated mice group, the mice receiving SNL exhibited upregulated Carm1 gene transcription (by 1.7 folds) but downregulated Prmt5, Prmt8 and Prmt9 transcription in the injured DRG (Prmt8 gene showed the most significant down?regulation by 16.3 folds). In mouse models of SNL and CCI, Carm1 gene expression increased progressively with time while Prmt8 transcription was obviously lowered on days 3, 7 and 14 after the injury; the transcription levels of Prmt1, Prmt5 and Prmt9 presented with no significant changes following the injuries. Both SNL and CCI induced mechanical allodynia and thermal hypersensitivities in the mice shown by increased PWF and decreased PWL on days 3, 7 and 14 after the injuries. Periphery nerve injury induces Carm1 upregulation and Prmt8 downregulation in the injured DRG in mice, which sheds light on new targets for treatment of neuropathic pain.

Early nodule senescence is activated in symbiotic mutants of pea (Pisum sativum L.) forming ineffective nodules blocked at different nodule developmental stages.

PubMed

Serova, Tatiana A; Tsyganova, Anna V; Tsyganov, Viktor E

2018-04-03

Plant symbiotic mutants are useful tool to uncover the molecular-genetic mechanisms of nodule senescence. The pea (Pisum sativum L.) mutants SGEFix - -1 (sym40), SGEFix - -3 (sym26), and SGEFix - -7 (sym27) display an early nodule senescence phenotype, whereas the mutant SGEFix - -2 (sym33) does not show premature degradation of symbiotic structures, but its nodules show an enhanced immune response. The nodules of these mutants were compared with each other and with those of the wild-type SGE line using seven marker genes that are known to be activated during nodule senescence. In wild-type SGE nodules, transcript levels of all of the senescence-associated genes were highest at 6 weeks after inoculation (WAI). The senescence-associated genes showed higher transcript abundance in mutant nodules than in wild-type nodules at 2 WAI and attained maximum levels in the mutant nodules at 4 WAI. Immunolocalization analyses showed that the ethylene precursor 1-aminocyclopropane-1-carboxylate accumulated earlier in the mutant nodules than in wild-type nodules. Together, these results showed that nodule senescence was activated in ineffective nodules blocked at different developmental stages in pea lines that harbor mutations in four symbiotic genes.

Typing pictures: Linguistic processing cascades into finger movements.

PubMed

Scaltritti, Michele; Arfé, Barbara; Torrance, Mark; Peressotti, Francesca

2016-11-01

The present study investigated the effect of psycholinguistic variables on measures of response latency and mean interkeystroke interval in a typewritten picture naming task, with the aim to outline the functional organization of the stages of cognitive processing and response execution associated with typewritten word production. Onset latencies were modulated by lexical and semantic variables traditionally linked to lexical retrieval, such as word frequency, age of acquisition, and naming agreement. Orthographic variables, both at the lexical and sublexical level, appear to influence just within-word interkeystroke intervals, suggesting that orthographic information may play a relevant role in controlling actual response execution. Lexical-semantic variables also influenced speed of execution. This points towards cascaded flow of activation between stages of lexical access and response execution. Copyright © 2016 Elsevier B.V. All rights reserved.

Mapping Mammalian Cell-type-specific Transcriptional Regulatory Networks Using KD-CAGE and ChIP-seq Data in the TC-YIK Cell Line

PubMed Central

Lizio, Marina; Ishizu, Yuri; Itoh, Masayoshi; Lassmann, Timo; Hasegawa, Akira; Kubosaki, Atsutaka; Severin, Jessica; Kawaji, Hideya; Nakamura, Yukio; Suzuki, Harukazu; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R. R.

2015-01-01

Mammals are composed of hundreds of different cell types with specialized functions. Each of these cellular phenotypes are controlled by different combinations of transcription factors. Using a human non islet cell insulinoma cell line (TC-YIK) which expresses insulin and the majority of known pancreatic beta cell specific genes as an example, we describe a general approach to identify key cell-type-specific transcription factors (TFs) and their direct and indirect targets. By ranking all human TFs by their level of enriched expression in TC-YIK relative to a broad collection of samples (FANTOM5), we confirmed known key regulators of pancreatic function and development. Systematic siRNA mediated perturbation of these TFs followed by qRT-PCR revealed their interconnections with NEUROD1 at the top of the regulation hierarchy and its depletion drastically reducing insulin levels. For 15 of the TF knock-downs (KD), we then used Cap Analysis of Gene Expression (CAGE) to identify thousands of their targets genome-wide (KD-CAGE). The data confirm NEUROD1 as a key positive regulator in the transcriptional regulatory network (TRN), and ISL1, and PROX1 as antagonists. As a complimentary approach we used ChIP-seq on four of these factors to identify NEUROD1, LMX1A, PAX6, and RFX6 binding sites in the human genome. Examining the overlap between genes perturbed in the KD-CAGE experiments and genes with a ChIP-seq peak within 50 kb of their promoter, we identified direct transcriptional targets of these TFs. Integration of KD-CAGE and ChIP-seq data shows that both NEUROD1 and LMX1A work as the main transcriptional activators. In the core TRN (i.e., TF-TF only), NEUROD1 directly transcriptionally activates the pancreatic TFs HSF4, INSM1, MLXIPL, MYT1, NKX6-3, ONECUT2, PAX4, PROX1, RFX6, ST18, DACH1, and SHOX2, while LMX1A directly transcriptionally activates DACH1, SHOX2, PAX6, and PDX1. Analysis of these complementary datasets suggests the need for caution in interpreting ChIP-seq datasets. (1) A large fraction of binding sites are at distal enhancer sites and cannot be directly associated to their targets, without chromatin conformation data. (2) Many peaks may be non-functional: even when there is a peak at a promoter, the expression of the gene may not be affected in the matching perturbation experiment. PMID:26635867

Shikimate Induced Transcriptional Activation of Protocatechuate Biosynthesis Genes by QuiR, a LysR-Type Transcriptional Regulator, in Listeria monocytogenes.

PubMed

Prezioso, Stephanie M; Xue, Kevin; Leung, Nelly; Gray-Owen, Scott D; Christendat, Dinesh

2018-04-27

Listeria monocytogenes is a common foodborne bacterial pathogen that contaminates plant and animal consumable products. The persistent nature of L. monocytogenes is associated with millions of dollars in food recalls annually. Here, we describe the role of shikimate in directly modulating the expression of genes encoding enzymes for the conversion of quinate and shikimate metabolites to protocatechuate. In L. monocytogenes, these genes are found within two operons, named qui1 and qui2. In addition, a gene named quiR, encoding a LysR-Type Transcriptional Regulator (QuiR), is located immediately upstream of the qui1 operon. Transcriptional lacZ-promoter fusion experiments show that QuiR induces gene expression of both qui1 and qui2 operons in the presence of shikimate. Furthermore, co-crystallization of the QuiR effector binding domain in complex with shikimate provides insights into the mechanism of activation of this regulator. Together these data show that upon shikimate accumulation, QuiR activates the transcription of genes encoding enzymes involved in shikimate and quinate utilization for the production of protocatechuate. Furthermore, the accumulation of protocatechuate leads to the inhibition of Listeria growth. Since protocatechuate is not known to be utilized by Listeria, its role is distinct from those established in other bacteria. Copyright © 2018 Elsevier Ltd. All rights reserved.

HDAC inhibition induces HIV-1 protein and enables immune-based clearance following latency reversal

PubMed Central

Wu, Guoxin; Swanson, Michael; Talla, Aarthi; Graham, Donald; Strizki, Julie; Gorman, Daniel; Barnard, Richard J.O.; Blair, Wade; Søgaard, Ole S.; Tolstrup, Martin; Østergaard, Lars; Rasmussen, Thomas A.; Sekaly, Rafick-Pierre; Archin, Nancie M.; Hazuda, Daria J.; Howell, Bonnie J.

2017-01-01

Promising therapeutic approaches for eradicating HIV include transcriptional activation of provirus from latently infected cells using latency-reversing agents (LRAs) and immune-mediated clearance to purge reservoirs. Accurate detection of cells capable of producing viral antigens and virions, and the measurement of clearance of infected cells, is essential to assessing therapeutic efficacy. Here, we apply enhanced methodology extending the sensitivity limits for the rapid detection of subfemtomolar HIV gag p24 capsid protein in CD4+ T cells from ART-suppressed HIV+ individuals, and we show viral protein induction following treatment with LRAs. Importantly, we demonstrate that clinical administration of histone deacetylase inhibitors (HDACis; vorinostat and panobinostat) induced HIV gag p24, and ex vivo stimulation produced sufficient viral antigen to elicit immune-mediated cell killing using anti-gp120/CD3 bispecific antibody. These findings extend beyond classical nucleic acid endpoints, which are confounded by the predominance of mutated, defective proviruses and, of paramount importance, enable assessment of cells making HIV protein that can now be targeted by immunological approaches. PMID:28814661

SWI/SNF Associates with Nascent Pre-mRNPs and Regulates Alternative Pre-mRNA Processing

PubMed Central

Tyagi, Anu; Ryme, Jessica; Brodin, David; Östlund Farrants, Ann Kristin; Visa, Neus

2009-01-01

The SWI/SNF chromatin remodeling complexes regulate the transcription of many genes by remodeling nucleosomes at promoter regions. In Drosophila, SWI/SNF plays an important role in ecdysone-dependent transcription regulation. Studies in human cells suggest that Brahma (Brm), the ATPase subunit of SWI/SNF, regulates alternative pre-mRNA splicing by modulating transcription elongation rates. We describe, here, experiments that study the association of Brm with transcribed genes in Chironomus tentans and Drosophila melanogaster, the purpose of which was to further elucidate the mechanisms by which Brm regulates pre-mRNA processing. We show that Brm becomes incorporated into nascent Balbiani ring pre-mRNPs co-transcriptionally and that the human Brm and Brg1 proteins are associated with RNPs. We have analyzed the expression profiles of D. melanogaster S2 cells in which the levels of individual SWI/SNF subunits have been reduced by RNA interference, and we show that depletion of SWI/SNF core subunits changes the relative abundance of alternative transcripts from a subset of genes. This observation, and the fact that a fraction of Brm is not associated with chromatin but with nascent pre-mRNPs, suggest that SWI/SNF affects pre-mRNA processing by acting at the RNA level. Ontology enrichment tests indicate that the genes that are regulated post-transcriptionally by SWI/SNF are mostly enzymes and transcription factors that regulate postembryonic developmental processes. In summary, the data suggest that SWI/SNF becomes incorporated into nascent pre-mRNPs and acts post-transcriptionally to regulate not only the amount of mRNA synthesized from a given promoter but also the type of alternative transcript produced. PMID:19424417

Connective Tissue Growth Factor (CTGF) as a Regulator of Lactogenic Differentiation

DTIC Science & Technology

2009-06-09

1 1.62 Myeloid leukemia factor 1, Mlf1 1.57 ADAMTS-l4 1.55 E2F transcription factor, E2F2 1.44 Tensin 4 -1.5 BCL2/adenovirus E1B interacting... Mlf1 1.57 ADAMTS-l4 1.55 Ras homolog gene family, member B, RhoB 1.48 Cell Differentiation-associated Wingless-type MMTV integration site family...B, relB 1.92 Myeloid leukemia factor 1, Mlf1 1.57 Growth Factor, Catalytic Activity-associated Dual specificity protein phosphatase 8, Dusp8

Tissue and cell-type co-expression networks of transcription factors and wood component genes in Populus trichocarpa.

PubMed

Shi, Rui; Wang, Jack P; Lin, Ying-Chung; Li, Quanzi; Sun, Ying-Hsuan; Chen, Hao; Sederoff, Ronald R; Chiang, Vincent L

2017-05-01

Co-expression networks based on transcriptomes of Populus trichocarpa major tissues and specific cell types suggest redundant control of cell wall component biosynthetic genes by transcription factors in wood formation. We analyzed the transcriptomes of five tissues (xylem, phloem, shoot, leaf, and root) and two wood forming cell types (fiber and vessel) of Populus trichocarpa to assemble gene co-expression subnetworks associated with wood formation. We identified 165 transcription factors (TFs) that showed xylem-, fiber-, and vessel-specific expression. Of these 165 TFs, 101 co-expressed (correlation coefficient, r > 0.7) with the 45 secondary cell wall cellulose, hemicellulose, and lignin biosynthetic genes. Each cell wall component gene co-expressed on average with 34 TFs, suggesting redundant control of the cell wall component gene expression. Co-expression analysis showed that the 101 TFs and the 45 cell wall component genes each has two distinct groups (groups 1 and 2), based on their co-expression patterns. The group 1 TFs (44 members) are predominantly xylem and fiber specific, and are all highly positively co-expressed with the group 1 cell wall component genes (30 members), suggesting their roles as major wood formation regulators. Group 1 TFs include a lateral organ boundary domain gene (LBD) that has the highest number of positively correlated cell wall component genes (36) and TFs (47). The group 2 TFs have 57 members, including 14 vessel-specific TFs, and are generally less correlated with the cell wall component genes. An exception is a vessel-specific basic helix-loop-helix (bHLH) gene that negatively correlates with 20 cell wall component genes, and may function as a key transcriptional suppressor. The co-expression networks revealed here suggest a well-structured transcriptional homeostasis for cell wall component biosynthesis during wood formation.