bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteasome InhibitionIn VivoPromotes Survival in a Lethal Murine Model of Severe Acute Respiratory Syndrome
Authors: Ma Xue-Zhong , Bartczak Agata , Zhang Jianhua , Khattar Ramzi , Chen Limin , Liu Ming Feng , Edwards Aled , Levy Gary , McGilvray Ian D. 
Published: September 2010

ABSTRACTUbiquitination is a critical regulator of the host immune response to viral infection, and many viruses, including coronaviruses, encode proteins that target the ubiquitination system. To explore the link between coronavirus infection and the ubiquitin system, we asked whether protein degradation by the 26S proteasome plays a role in severe coronavirus infections using a murine model of SARS-like pneumonitis induced by murine hepatitis virus strain 1 (MHV-1).In vitro, the pretreatment of peritoneal macrophages with inhibitors of the proteasome (pyrrolidine dithiocarbamate [PDTC], MG132, and PS-341) markedly inhibited MHV-1 replication at an early step in its replication cycle, as evidenced by inhibition of viral RNA production. Proteasome inhibition also blocked viral cytotoxicity in macrophages, as well as the induction of inflammatory mediators such as IP-10, gamma interferon (IFN-γ), and monocyte chemoattractant protein 1 (MCP-1).In vivo, intranasal inoculation of MHV-1 results in a lethal pneumonitis in A/J mice. Treatment of A/J mice with the proteasome inhibitor PDTC, MG132, or PS-341 led to 40% survival (P< 0.01), with a concomitant improvement of lung histology, reduced pulmonary viral replication, decreased pulmonary STAT phosphorylation, and reduced pulmonary inflammatory cytokine expression. These data demonstrate that inhibition of the cellular proteasome attenuates pneumonitis and cytokine gene expressionin vivoby reducing MHV-1 replication and the resulting inflammatory response. The results further suggest that targeting the proteasome may be an effective new treatment for severe coronavirus infections.
Role of Erythropoietin Receptor Signaling in Parvovirus B19 Replication in Human Erythroid Progenitor Cells
Authors: Chen Aaron Yun , Guan Wuxiang , Lou Sai , Liu Zhengwen , Kleiboeker Steve , Qiu Jianming 
Published: September 2010

ABSTRACT

Parvovirus B19 (B19V) infection is highly restricted to human erythroid progenitor cells. Although previous studies have led to the theory that the basis of this tropism is receptor expression, this has been questioned by more recent observation. In the study reported here, we have investigated the basis of this tropism, and a potential role of erythropoietin (Epo) signaling, in erythroid progenitor cells (EPCs) expanded
ex vivo
from CD34
+
hematopoietic cells in the absence of Epo (CD36
+
/Epo
−
EPCs). We show, first, that CD36
+
/Epo
−
EPCs do not support B19V replication, in spite of B19V entry, but Epo exposure either prior to infection or after virus entry enabled active B19V replication. Second, when Janus kinase 2 (Jak2) phosphorylation was inhibited using the inhibitor AG490, phosphorylation of the Epo receptor (EpoR) was also inhibited, and B19V replication in
ex vivo
-expanded erythroid progenitor cells exposed to Epo (CD36
+
/Epo
+
EPCs) was abolished. Third, expression of constitutively active EpoR in CD36
+
/Epo
−
EPCs led to efficient B19V replication. Finally, B19V replication in CD36
+
/Epo
+
EPCs required Epo, and the replication response was dose dependent. Our findings demonstrate that EpoR signaling is absolutely required for B19V replication in
ex vivo
-expanded erythroid progenitor cells after initial virus entry and at least partly accounts for the remarkable tropism of B19V infection for human erythroid progenitors.
Crystal Structure of a Virus-Encoded Putative Glycosyltransferase
Authors: Xiang Ye , Baxa Ulrich , Zhang Ying , Steven Alasdair C. , Lewis Gentry L. , Van Etten James L. , Rossmann Michael G. 
Published: September 2010

ABSTRACT

The chloroviruses (family
Phycodnaviridae
), unlike most viruses, encode some, if not most, of the enzymes involved in the glycosylation of their structural proteins. Annotation of the gene product B736L from chlorovirus NY-2A suggests that it is a glycosyltransferase. The structure of the recombinantly expressed B736L protein was determined by X-ray crystallography to 2.3-Å resolution, and the protein was shown to have two nucleotide-binding folds like other glycosyltransferase type B enzymes. This is the second structure of a chlorovirus-encoded glycosyltransferase and the first structure of a chlorovirus type B enzyme to be determined. B736L is a retaining enzyme and belongs to glycosyltransferase family 4. The donor substrate was identified as GDP-mannose by isothermal titration calorimetry and was shown to bind into the cleft between the two domains in the protein. The active form of the enzyme is probably a dimer in which the active centers are separated by about 40 Å.
Vaccinia Virus D4 Mutants Defective in Processive DNA Synthesis Retain Binding to A20 and DNA
Authors: Druck Shudofsky Abigail M. , Silverman Janice Elaine Y. , Chattopadhyay Debasish , Ricciardi Robert P. 
Published: September 2010

ABSTRACT
Genome replication is inefficient without processivity factors, which tether DNA polymerases to their templates. The vaccinia virus DNA polymerase E9 requires two viral proteins, A20 and D4, for processive DNA synthesis, yet the mechanism of how this tricomplex functions is unknown. This study confirms that these three proteins are necessary and sufficient for processivity, and it focuses on the role of D4, which also functions as a uracil DNA glycosylase (UDG) repair enzyme. A series of D4 mutants was generated to discover which sites are important for processivity. Three point mutants (K126V, K160V, and R187V) which did not function in processive DNA synthesis, though they retained UDG catalytic activity, were identified. The mutants were able to compete with wild-type D4 in processivity assays and retained binding to both A20 and DNA. The crystal structure of R187V was resolved and revealed that the local charge distribution around the substituted residue is altered. However, the mutant protein was shown to have no major structural distortions. This suggests that the positive charges of residues 126, 160, and 187 are required for D4 to function in processive DNA synthesis. Consistent with this is the ability of the conserved mutant K126R to function in processivity. These mutants may help unlock the mechanism by which D4 contributes to processive DNA synthesis.
Kaposi's Sarcoma-Associated Herpesvirus Viral Interferon Regulatory Factor 4 (vIRF4/K10) Is a Novel Interaction Partner of CSL/CBF1, the Major Downstream Effector of Notch Signaling
Authors: Heinzelmann Katharina , Scholz Barbara A. , Nowak Agnes , Fossum Even , Kremmer Elisabeth , Haas Juergen , Frank Ronald , Kempkes Bettina 
Published: September 2010

ABSTRACT
In cells infected with the Kaposi's sarcoma-associated herpesvirus (KSHV), CSL/CBF1 signaling is essential for viral replication and promotes the survival of KSHV-infected cells. CSL/CBF1 is a DNA adaptor molecule which recruits coactivator and corepressor complexes to regulate viral and cellular gene transcription and which is a major downstream effector molecule of activated Notch. The interaction of KSHV RTA and LANA with CSL/CBF1 has been shown to balance the lytic and latent viral life cycle. Here we report that a third KSHV protein, viral interferon regulatory factor 4 (vIRF4/K10), but none of the three other KSHV-encoded vIRFs, interacts with CSL/CBF1. Two regions of vIRF4 with dissimilar affinities contribute to CSL/CBF1 binding. Similar to Notch, vIRF4 targets the hydrophobic pocket in the beta trefoil domain of CSL/CBF1 through a short peptide motif which closely resembles a motif found in Notch but does not strictly follow the ΦWΦP consensus conserved in human and mouse Notch proteins. Our results suggest that vIRF4 might compete with Notch for CSL/CBF1 binding and signaling.
Autographa californica
Multiple Nucleopolyhedrovirus Ac92 (ORF92, P33) Is Required for Budded Virus Production and Multiply Enveloped Occlusion-Derived Virus Formation
Authors: Wu Wenbi , Passarelli A. Lorena 
Published: September 2010

ABSTRACT

The
Autographa californica
multiple nucleopolyhedrovirus
orf92
(
p33
),
ac92
, is one of 31 genes carried in all sequenced baculovirus genomes, thus suggesting an essential function. Ac92 has homology to the family of flavin adenine dinucleotide-linked sulfhydryl oxidases and is related to the ERV/ALR family of sulfhydryl oxidases. The role of
ac92
during virus replication is unknown. Ac92 was associated with the envelope of both budded and occlusion-derived virus (ODV). To investigate the role of Ac92 during virus replication, an
ac92
-knockout bacmid was generated through homologous recombination in
Escherichia coli
. Titration and plaque assays showed no virus spread in
ac92
-knockout bacmid DNA-transfected insect cells. Deletion of
ac92
did not affect viral DNA replication. However,
ac92
-knockout bacmid DNA-transfected cells lacked multiply enveloped occlusion-derived nucleocapsids; instead, singly enveloped nucleocapsids were detected. To gain insight into the requirement for sulfhydryl oxidation during virus replication, a virus was constructed in which the Ac92 C
155
XXC
158
amino acids, important for sulfhydryl oxidase activity, were mutated to A
155
XXA
158
. The mutant virus exhibited a phenotype similar to that of the knockout virus, suggesting that the C-X-X-C motif was essential for sulfhydryl oxidase activity and responsible for the altered ODV phenotype.
Immunization with Different Viral Antigens Alters the Pattern of T Cell Exhaustion and Latency in Herpes Simplex Virus Type 1-Infected Mice
Authors: Allen Sariah J. , Mott Kevin R. , Zandian Mandana , Ghiasi Homayon 
Published: September 2010

ABSTRACT

We have shown previously that immunization with herpes simplex virus type 1 (HSV-1) glycoprotein K (gK) exacerbated corneal scarring (CS) in ocularly infected mice. In this study, we investigated whether higher levels of CS were correlated with higher levels of latency and T cell exhaustion in gK-immunized mice. BALB/c mice were vaccinated with baculovirus-expressed gK or gD or mock immunized. Twenty-one days after the third immunization, mice were ocularly infected with 2 × 10
4
PFU/eye of virulent HSV-1 strain McKrae. On day 5 postinfection, virus replication in the eye was measured, and on day 30 postinfection, infiltration of the trigeminal ganglia (TG) by CD4, CD8, programmed death 1 (PD-1), and T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) was monitored by immunohistochemistry and quantitative real-time PCR (qRT-PCR). This study demonstrated that higher levels of CS were correlated with higher levels of latency, and this was associated with the presence of significantly higher numbers of CD4
+
PD-1
+
and CD8
+
PD-1
+
cells in the TG of the gK-immunized group than in both the gD- and mock-immunized groups. Levels of exhaustion associated with Tim-3 were the same among gK- and mock-vaccinated groups but higher than levels in the gD-vaccinated group. In this study, we have shown for the first time that both PD-1 and Tim-3 contribute to T cell exhaustion and an increase of latency in the TG of latently infected mice.
High Natural Permissivity of Primary Rabbit Cells for HIV-1, with a Virion Infectivity Defect in Macrophages as the Final Replication Barrier
Authors: Tervo Hanna-Mari , Keppler Oliver T. 
Published: September 2010

ABSTRACT

An immunocompetent, permissive, small-animal model would be valuable for the study of human immunodeficiency virus type 1 (HIV-1) pathogenesis and for the testing of drug and vaccine candidates. However, the development of such a model has been hampered by the inability of primary rodent cells to efficiently support several steps of the HIV-1 replication cycle. Although transgenesis of the HIV receptor complex and human cyclin T1 have been beneficial, additional late-phase blocks prevent robust replication of HIV-1 in rodents and limit the range of
in vivo
applications. In this study, we explored the HIV-1 susceptibility of rabbit primary T cells and macrophages. Envelope-specific and coreceptor-dependent entry of HIV-1 was achieved by expressing human CD4 and CCR5. A block of HIV-1 DNA synthesis, likely mediated by TRIM5, was overcome by limited changes to the HIV-1
gag
gene. Unlike with mice and rats, primary cells from rabbits supported the functions of the regulatory viral proteins Tat and Rev, Gag processing, and the release of HIV-1 particles at levels comparable to those in human cells. While HIV-1 produced by rabbit T cells was highly infectious, a macrophage-specific infectivity defect became manifest by a complex pattern of mutations in the viral genome, only part of which were deamination dependent. These results demonstrate a considerable natural HIV-1 permissivity of the rabbit species and suggest that receptor complex transgenesis combined with modifications in
gag
and possibly
vif
of HIV-1 to evade species-specific restriction factors might render lagomorphs fully permissive to infection by this pathogenic human lentivirus.
Sequences from Ancestral Single-Stranded DNA Viruses in Vertebrate Genomes: the
Parvoviridae
and
Circoviridae
Are More than 40 to 50 Million Years Old
Authors: Belyi Vladimir A. , Levine Arnold J. , Skalka Anna Marie 
Published: September 2010

ABSTRACT

Vertebrate genomic assemblies were analyzed for endogenous sequences related to any known viruses with single-stranded DNA genomes. Numerous high-confidence examples related to the
Circoviridae
and two genera in the family
Parvoviridae
, the parvoviruses and dependoviruses, were found and were broadly distributed among 31 of the 49 vertebrate species tested. Our analyses indicate that the ages of both virus families may exceed 40 to 50 million years. Shared features of the replication strategies of these viruses may explain the high incidence of the integrations.
Assessment of tobacco control advocacy behavioural capacity among students at schools of public health in China
Authors: Yang Tingzhong , Abdullah Abu S , Rockett Ian R H , Li Mu , Zhou Yuhua , Ma Jun , Ji Huaping , Zheng Jianzhong , Zhang Yuhong , Wang Liming 
Published: September 2010

ObjectivesTo evaluate student tobacco control advocacy behavioural capacity using longitudinal trace data.MethodsA tobacco control advocacy curriculum was developed and implemented at schools of public health (SPH) or departments of public health in seven universities in China. Participants comprised undergraduate students studying the public health curriculum in these 13 Universities. A standardised assessment tool was used to evaluate their tobacco control advocacy behavioural capacity. Repeated measures analysis of variance, paired t tests and paired χ2tests were used to determine differences between dependent variables across time. Multivariate analysis of variance (MANOVA) and multivariate logistic regression were used to assess treatment effects between intervention and control sites.ResultsRespective totals of 426 students in the intervention group and 338 in the control group were available for the evaluation. Approximately 90% of respondents were aged 21 years or older and 56% were women. Findings show that the capacity building program significantly improved public health student advocacy behavioural capacity, including advocacy attitude, interest, motivation and anti-secondhand smoke behaviours. The curriculum did not impact student smoking behaviour.ConclusionsThis study provides sufficient evidence to support the implementation of tobacco control advocacy training at Chinese schools of public health.
A publish-subscribe architecture and component-based programming model for medical device interoperability
Authors: King Andrew , Procter Sam , Andresen Dan , Hatcliff John , Warren Steve , Spees William , Jetley Raoul , Jones Paul , Weininger Sandy 
Published: September 2010

Medical devices historically have been monolithic units --- developed, validated, and approved by regulatory authorities as standalone entities. Modern medical devices increasingly incorporate connectivity mechanisms that offer the potential to stream device data into electronic health records, integrate information from multiple devices into single customizable displays, and coordinate the actions of groups of cooperating devices to realize "closed loop" scenarios and automate clinical workflows.
In this paper, we describe a publish-subscribe architecture for medical device integration based on the Java Messaging Service. We provide a overview of a model-based development environment that we have built for rapidly programming device coordination scenarios. We assess the extent to which this framework is capable of supporting and complementing the Integrated Clinical Environment that has been proposed by the Medical Device Plug and Play Interoperability Project The implementation of this framework is freely available and open source. One of the primary goals of the framework is to provide researchers in acadaemia, industry, and government with an open test bed for exploring development, quality assurance, and regulatory issues related to medical device interoperability.
Hyperpolarized 13C Spectroscopic Imaging Informs on Hypoxia-Inducible Factor-1 and Myc Activity Downstream of Platelet-Derived Growth Factor Receptor
Authors: Dafni Hagit , Larson Peder E.Z. , Hu Simon , Yoshihara Hikari A.I. , Ward Christopher S. , Venkatesh Humsa S. , Wang Chunsheng , Zhang Xiaoliang , Vigneron Daniel B. , Ronen Sabrina M. 
Published: September 2010

Abstract
The recent development of hyperpolarized 13C magnetic resonance spectroscopic imaging provides a novel method for in vivo metabolic imaging with potential applications for detection of cancer and response to treatment. Chemotherapy-induced apoptosis was shown to decrease the flux of hyperpolarized 13C label from pyruvate to lactate due to depletion of NADH, the coenzyme of lactate dehydrogenase. In contrast, we show here that in PC-3MM2 tumors, inhibition of platelet-derived growth factor receptor with imatinib reduces the conversion of hyperpolarized pyruvate to lactate by lowering the expression of lactate dehydrogenase itself. This was accompanied by reduced expression of vascular endothelial growth factor and glutaminase, and is likely mediated by reduced expression of their transcriptional factors hypoxia-inducible factor-1 and c-Myc. Our results indicate that hyperpolarized 13C MRSI could potentially detect the molecular effect of various cell signaling inhibitors, thus providing a radiation-free method to predict tumor response. Cancer Res; 70(19); 7400–10. ©2010 AACR.
Evidence of an Adaptive Response Targeting DNA Nonhomologous End Joining and Its Transmission to Bystander Cells
Authors: Klammer Holger , Kadhim Munira , Iliakis George 
Published: September 2010

Abstract
Adaptive response (AR) is a term describing resistance to ionizing radiation–induced killing or formation of aberrant chromosomes that is mediated by pre-exposure to low ionizing radiation doses. The mechanism of AR remains elusive. Because cell killing and chromosome aberration formation derive from erroneous processing of DNA double-strand breaks (DSB), AR may reflect a modulation of DSB processing by nonhomologous end joining (NHEJ) or homologous recombination repair. Here, we use plasmid end-joining assays to quantify modulations induced by low ionizing radiation doses to NHEJ, the dominant pathway of DSB repair in higher eukaryotes, and investigate propagation of this response through medium transfer to nonirradiated bystander cells. Mouse embryo fibroblasts were conditioned with 10 to 1000 mGy and NHEJ quantified at different times thereafter by challenging with reporter plasmids containing a DSB. We show robust increases in NHEJ efficiency in mouse embryo fibroblasts exposed to ionizing radiation &gt;100 mGy, irrespective of reporter plasmid used. Human tumor cells also show AR of similar magnitude that is compromised by caffeine, an inhibitor of DNA damage signaling acting by inhibiting ATM, ATR, and DNA-PKcs. Growth medium from pre-irradiated cells induces a caffeine-sensitive AR in nonirradiated cells, similar in magnitude to that seen in irradiated cells. In bystander cells, γH2AX foci are specifically detected in late S-G2 phase and are associated with Rad51 foci that signify the function of homologous recombination repair, possibly on DNA replication–mediated DSBs. The results point to enhanced NHEJ as a mechanism of AR and suggest that AR may be transmitted to bystander cells through factors generating replication-mediated DSBs. Cancer Res; 70(21); 8498–506. ©2010 AACR.
AXL Is an Essential Factor and Therapeutic Target for Metastatic Ovarian Cancer
Authors: Rankin Erinn B. , Fuh Katherine C. , Taylor Tiffany E. , Krieg Adam J. , Musser Margaret , Yuan Jenny , Wei Kevin , Kuo Calvin J. , Longacre Teri A. , Giaccia Amato J. 
Published: September 2010

Abstract
The receptor tyrosine kinase AXL is thought to play a role in metastasis; however, the therapeutic efficacy of an AXL-targeting agent remains largely untested in metastatic disease. In this study, we defined AXL as a therapeutic target for metastatic ovarian cancer. AXL is primarily expressed in metastases and advanced-stage human ovarian tumors but not in normal ovarian epithelium. Genetic inhibition of AXL in human metastatic ovarian tumor cells is sufficient to prevent the initiation of metastatic disease in vivo. Mechanistically, inhibition of AXL signaling in animals with metastatic disease results in decreased invasion and matrix metalloproteinase activity. Most importantly, soluble human AXL receptors that imposed a specific blockade of the GAS6/AXL pathway had a profound inhibitory effect on progression of established metastatic ovarian cancer without normal tissue toxicity. These results offer the first genetic validation of GAS6/AXL targeting as an effective strategy for inhibition of metastatic tumor progression in vivo. Furthermore, this study defines the soluble AXL receptor as a therapeutic candidate agent for treatment of metastatic ovarian cancer, for which current therapies are ineffective. Cancer Res; 70(19); 7570–9. ©2010 AACR.
Metabolic Aggressiveness in Benign Meningiomas with Chromosomal Instabilities
Authors: Monleón Daniel , Morales José Manuel , Gonzalez-Segura Ana , Gonzalez-Darder José Manuel , Gil-Benso Rosario , Cerdá-Nicolás Miguel , López-Ginés Concepción 
Published: September 2010

Abstract
Meningiomas are often considered benign tumors curable by surgery, but most recurrent meningiomas correspond to histologic benign tumors. Because alterations in chromosome 14 among others have suggested clinical aggressiveness and recurrence, determining both the molecular phenotype and the genetic profile may help distinguish tumors with aggressive metabolism. The aim of this study was to achieve higher specificity in the detection of meningioma subgroups by measuring chromosomal instabilities by fluorescence in situ hybridization and cytogenetics and metabolic phenotypes by high-resolution magic angle spinning spectroscopy. We studied 46 meningioma biopsies with these methodologies. Of these, 34 were of WHO grade 1 and 12 were of WHO grade 2. Genetic analysis showed a subgroup of histologic benign meningioma with chromosomal instabilities. The metabolic phenotype of this subgroup indicated an aggressive metabolism resembling that observed for atypical meningioma. According to the metabolic profiles, these tumors had increased energy demand, higher hypoxic conditions, increased membrane turnover and cell proliferation, and possibly increased resistance to apoptosis. Taken together, our results identify distinct metabolic phenotypes for otherwise benign meningiomas based on cytogenetic studies and global metabolic profiles of intact tumors. Measuring the metabolic phenotype of meningioma intact biopsies at the same time as histopathologic analysis may allow the early detection of clinically aggressive tumors. Cancer Res; 70(21); 8426–34. ©2010 AACR.