bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relevance of insulin‐like growth factor 2 in the etiopathophysiology of diabetic nephropathy: Possible roles of phosphatase and tensin homolog on chromosome 10 and secreted protein acidic and rich in cysteine as regulators of repair
Authors: SIREESHA Movva , SAMBASIVAN Venkatasubramanian , KUMAR Vattam Kiran , RADHA Sistla , RAJ Ahuja Yog , QURRATULAIN Hasan 
Published: March 2009

AbstractBackground: Diabetic nephropathy (DN) is a devastating complication of diabetes, the exact molecular pathophysiology of which is not well established. Hyperglycemia increases insulin‐like growth factors (IGFs), especially IGF2, which acts via the IGF1 receptor present on renal cells. Elevated glucose levels damage the kidney, which is repaired by modulators such as secreted protein acidic and rich in cysteine (SPARC). Hence, it was hypothesized that IGF2 and SPARC may have an important role in the etiology of DN.Methods: Human renal biopsies, histopathologically categorized as normal, early Type 2 diabetes mellitus (T2DM), or established DN, were analyzed for the localization and expression of IGF2, its negative regulator phosphatase and tensin homolog on chromosome 10 (PTEN), and SPARC.Results: Expression of IGF2, PTEN, and SPARC was increased in renal biopsies from T2DM patients compared with normal samples. Although IGF2 protein was increased in biopsies from DN patients, PTEN and SPARC levels were decreased. Real‐time reverse transcription–polymerase chain reaction indicated that transcript levels of IGF2 and PTEN were greater than those of β‐actin in all human renal biopsy samples.Conclusion: The results suggest the following molecular etiopathophysiology of DN: (i) hyperglycemia upregulates IGF2, which initiates PTEN, a regulator of IGF2 signaling; (ii) loss of this IGF2–PTEN feedback loop causes changes that are characteristic of DN; and (iii) lowered expression of the repair modulator SPARC results in the development and/or progression of DN. Hence, targeting relevant modulators, such as like IGF2, PTEN, and SPARC, may be important in the management of DN.
Identification of Domains of the Hag/MID Surface Protein Recognized by Systemic and Mucosal Antibodies in Adults with Chronic Obstructive Pulmonary Disease following Clearance of
Moraxella catarrhalis
Authors: LaFontaine Eric R. , Snipes Lauren E. , Bullard Brian , Brauer Aimee L. , Sethi Sanjay , Murphy Timothy F. 
Published: March 2009

ABSTRACT

Moraxella catarrhalis
is a common cause of respiratory tract infection in the setting of chronic obstructive pulmonary disease (COPD). Adults with COPD acquire and clear strains of
M. catarrhalis
from the respiratory tract continuously and develop strain-specific protection following clearance of a strain. In previous work, we identified Hag/MID (
Moraxella
immunoglobulin D-binding protein), a large multifunctional surface protein that acts as an adhesin and hemagglutinin, as a target of antibody responses in adults with COPD after clearance of
M. catarrhalis
. The goal of the present study was to characterize the domains of Hag/MID to which humans make antibodies, including both systemic and mucosal antibody responses. Analysis of recombinant peptide constructs, which spanned the
M. catarrhalis
strain O35E Hag/MID protein, with well-characterized serum and sputum samples revealed that most adults with COPD made antibodies directed toward a region of the molecule bounded by amino acids 706 to 863. Serum immunoglobulin G (IgG) and IgA purified from sputum both recognized the same domain. Some flanking sequence of this fragment was necessary for the epitope(s) in this region to maintain its conformation to bind human antibodies. These results reveal that humans consistently generate both systemic and mucosal antibody responses to an immunodominant region of the Hag/MID molecule, which was previously shown to overlap with several biologically relevant domains, including epithelial cell adherence, IgD binding, collagen binding, and hemagglutination.
Development of Loop-Mediated Isothermal Amplification Assay for Detection of
Entamoeba histolytica
Authors: Liang Shih-Yu , Chan Yun-Hsien , Hsia Kan-Tai , Lee Jing-Lun , Kuo Ming-Chu , Hwa Kuo-Yuan , Chan Chi-Wen , Chiang Ting-Yi , Chen Jung-Sheng , Wu Fang-Tzy , Ji Dar-Der 
Published: March 2009

ABSTRACT

A novel one-step, closed-tube, loop-mediated isothermal amplification (LAMP) assay for detecting
Entamoeba histolytica
, one of the leading causes of morbidity in developing countries, was developed. The sensitivity of the LAMP assay is 1 parasite per reaction. A total of 130 clinical samples were analyzed, and the results compared with those of conventional nested PCR to validate the practicability of this assay. No DNA was amplified from other diarrheal pathogens, such as other
Entamoeba
species, bacteria, and viruses. These results indicate that LAMP is a rapid, simple, and valuable diagnostic tool for epidemiological studies of amebiasis.
Ezrin-Radixin-Moesin Family Proteins Are Involved in Parvovirus Replication and Spreading
Authors: Nüesch Jürg P. F. , Bär Séverine , Lachmann Sylvie , Rommelaere Jean 
Published: March 2009

ABSTRACT
The propagation of autonomous parvoviruses is strongly dependent on the phosphorylation of the major nonstructural protein NS1 by members of the protein kinase C (PKC) family. Minute virus of mice (MVM) replication is accompanied by changes in the overall phosphorylation pattern of NS1, which is newly modified at consensus PKC sites. These changes result, at least in part, from the ability of MVM to modulate the PDK-1/PKC pathway, leading to activation and redistribution of both PDK-1 and PKCη. We show that proteins of the ezrin-radixin-moesin (ERM) family are essential for virus propagation and spreading through their functions as adaptors for PKCη. MVM infection led to redistribution of radixin and moesin in the cell, resulting in increased colocalization of these proteins with PKCη. Radixin was found to control the PKCη-driven phosphorylation of NS1 and newly synthesized capsids in vivo. Conversely, radixin phosphorylation and activation were driven by the NS1/CKIIα complex. Altogether, these data argue for ERM proteins being both targets and modulators of parvovirus infection.
Role of Untranslated Regions of the Hemagglutinin-Neuraminidase Gene in Replication and Pathogenicity of Newcastle Disease Virus
Authors: Yan Yongqi , Rout Subrat N. , Kim Shin-Hee , Samal Siba K. 
Published: March 2009

ABSTRACT
To determine the role of untranslated regions (UTRs) in replication and pathogenesis of Newcastle disease virus (NDV), we generated recombinant viruses with deletions in 5′ and 3′ UTRs of the HN mRNA. Deletion of any HN UTR did not noticeably affect in vitro replication of these viruses. However, complete deletion of the 5′ UTR of the HN gene decreased the HN mRNA levels and HN protein contents in virus particles, resulting in attenuation of the virus in chickens. This indicates that the 5′ UTR of HN mRNA plays an important role in replication and pathogenicity of NDV in vivo.
Intranasal Vaccination with 1918 Influenza Virus-Like Particles Protects Mice and Ferrets from Lethal 1918 and H5N1 Influenza Virus Challenge
Authors: Perrone Lucy A. , Ahmad Attiya , Veguilla Vic , Lu Xiuhua , Smith Gale , Katz Jacqueline M. , Pushko Peter , Tumpey Terrence M. 
Published: March 2009

ABSTRACTInfluenza vaccines capable of inducing cross-reactive or heterotypic immunity could be an important first line of prevention against a novel subtype virus. Influenza virus-like particles (VLPs) displaying functional viral proteins are effective vaccines against replication-competent homologous virus, but their ability to induce heterotypic immunity has not been adequately tested. To measure VLP vaccine efficacy against a known influenza pandemic virus, recombinant VLPs were generated from structural proteins of the 1918 H1N1 virus. Mucosal and traditional parenteral administrations of H1N1 VLPs were compared for the ability to protect against the reconstructed 1918 virus and a highly pathogenic avian H5N1 virus isolated from a fatal human case. Mice that received two intranasal immunizations of H1N1 VLPs were largely protected against a lethal challenge with both the 1918 virus and the H5N1 virus. In contrast, mice that received two intramuscular immunizations of 1918 VLPs were only protected against a homologous virus challenge. Mucosal vaccination of mice with 1918 VLPs induced higher levels of cross-reactive immunoglobulin G (IgG) and IgA antibodies than did parenteral vaccination. Similarly, ferrets mucosally vaccinated with 1918 VLPs completely survived a lethal challenge with the H5N1 virus, while only a 50% survival rate was observed in parenterally vaccinated animals. These results suggest a strategy of VLP vaccination against a pandemic virus and one that stimulates heterotypic immunity against an influenza virus strain with threatening pandemic potential.
Regulation of Histone Deposition on the Herpes Simplex Virus Type 1 Genome during Lytic Infection
Authors: Kutluay Sebla B. , Triezenberg Steven J. 
Published: March 2009

ABSTRACT
During lytic infection by herpes simplex virus type 1 (HSV-1), histones are present at relatively low levels on the viral genome. However, the mechanisms that account for such low levels—how histone deposition on the viral genome is blocked or how histones are removed from the genome—are not yet defined. In this study, we show that histone occupancy on the viral genome gradually increased with time when transcription of the viral immediate-early (IE) genes was inhibited either by deletion of the VP16 activation domain or by chemical inhibition of RNA polymerase II (RNAP II). Inhibition of IE protein synthesis by cycloheximide did not affect histone occupancy on most IE promoters and coding regions but did cause an increase at delayed-early and late gene promoters. IE gene transcription from HSV-1 genomes associated with high levels of histones was stimulated by superinfection with HSV-2 without altering histone occupancy or covalent histone modifications at IE gene promoters. Moreover, RNAP II and histones cooccupied the viral genome in this context, indicating that RNAP II does not preferentially associate with viral genomes that are devoid of histones. These results suggest that during lytic infection, VP16, RNAP II, and IE proteins may all contribute to the low levels of histones on the viral genome, and yet the dearth of histones is neither a prerequisite for nor a necessary result of VP16-dependent transcription of nucleosomal viral genomes.
Protein Kinase PKR-Dependent Activation of Mitogen-Activated Protein Kinases Occurs through Mitochondrial Adapter IPS-1 and Is Antagonized by Vaccinia Virus E3L
Authors: Zhang Ping , Langland Jeffrey O. , Jacobs Bertram L. , Samuel Charles E. 
Published: March 2009

ABSTRACT

The p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) play important roles in the host innate immune response. The protein kinase regulated by RNA (PKR) is implicated in p38 MAPK activation in response to proinflammatory signals in mouse embryonic fibroblasts. To test the role of PKR in the activation of p38 and JNK MAPKs in human cells following viral infection, HeLa cells made stably deficient in PKR by using an RNA interference strategy were compared to cells with sufficient PKR. The phosphorylation of both p38 and JNK in cells with sufficient PKR was activated following either infection with an E3L deletion (ΔE3L) mutant of vaccinia virus or transfection with double-stranded RNA (dsRNA) in the absence of infection with wild-type vaccinia virus. The depletion of PKR by stable knockdown impaired the phosphorylation of both p38 and JNK induced by either the ΔE3L mutant virus or dsRNA but not that induced by tumor necrosis factor alpha. The PKR-dependent activation of MAPKs in ΔE3L mutant-infected cells was abolished by treatment with cytosine β-
d
-arabinoside. The complementation of PKR-deficient cells with the human PKR wild-type protein, but not with the PKR catalytic mutant (K296R) protein, restored p38 and JNK phosphorylation following ΔE3L mutant virus infection. Transient small interfering RNA knockdown established that the p38 and JNK kinase activation following ΔE3L infection was dependent upon RIG-I-like receptor signal transduction pathway components, including the mitochondrial adapter IPS-1 protein.
Dimerization and a Novel Tax Speckled Structure Localization Signal Are Required for Tax Nuclear Localization
Authors: Fryrear Kimberly A. , Durkin Sarah S. , Gupta Saurabh K. , Tiedebohl Jessica B. , Semmes O. John 
Published: March 2009

ABSTRACT
The human T-cell leukemia virus type 1 oncoprotein Tax has pleiotropic activities, a subset of which likely leads to immortalization of T cells. Tax is expressed and known to function in both the cell nucleus and the cytoplasm. Tax has defined nuclear localization (NLS) and nuclear export signals that enable shuttling between the two compartments. In this study, we identified a novel region in Tax that targets the protein to discrete nuclear foci that we have previously termed Tax speckled structures (TSS). We demonstrated that the identified region is both necessary and sufficient for directing proteins to TSS. This novel TSS localization signal (TSLS), spanning amino acids 50 to 75, is separable from and adjacent to the NLS of Tax. Coexpression of a Tax NLS mutant and a Tax TSLS mutant rescued the nuclear entry and subnuclear TSS targeting of both proteins, demonstrating that these signals are independent domains. Our analysis also revealed that Tax proteins deficient for dimerization fail to localize to the nucleus. Consequently, when we restored dimerization via induction of a heterologous “dimerizer” domain, nuclear localization was rescued. Thus, we defined additional domains in Tax specific for nuclear localization and subnuclear targeting. Our results reveal a more complex network for regulation of Tax subcellular localization and subsequent function.
Plant Virus Cell-to-Cell Movement Is Not Dependent on the Transmembrane Disposition of Its Movement Protein
Authors: Martínez-Gil Luis , Sánchez-Navarro Jesús A. , Cruz Antonio , Pallás Vicente , Pérez-Gil Jesús , Mingarro Ismael 
Published: March 2009

ABSTRACT

The cell-to-cell transport of plant viruses depends on one or more virus-encoded movement proteins (MPs). Some MPs are integral membrane proteins that interact with the membrane of the endoplasmic reticulum, but a detailed understanding of the interaction between MPs and biological membranes has been lacking. The cell-to-cell movement of the
Prunus necrotic ringspot virus
(PNRSV) is facilitated by a single MP of the 30K superfamily. Here, using a myriad of biochemical and biophysical approaches, we show that the PNRSV MP contains only one hydrophobic region (HR) that interacts with the membrane interface, as opposed to being a transmembrane protein. We also show that a proline residue located in the middle of the HR constrains the structural conformation of this region at the membrane interface, and its replacement precludes virus movement.
Virion Stability Is Important for the Circulative Transmission of
Tomato Yellow Leaf Curl Sardinia Virus
by
Bemisia tabaci
, but Virion Access to Salivary Glands Does Not Guarantee Transmissibility
Authors: Caciagli Piero , Medina Piles Vicente , Marian Daniele , Vecchiati Manuela , Masenga Vera , Mason Giovanna , Falcioni Tania , Noris Emanuela 
Published: March 2009

ABSTRACT

The capsid protein (CP) of the monopartite begomovirus
Tomato yellow leaf curl Sardinia virus
(TYLCSV), family
Geminiviridae
, is indispensable for plant infection and vector transmission. A region between amino acids 129 and 152 is critical for virion assembly and insect transmissibility. Two previously described mutants, one with a double Q129P Q134H mutation (PNHD) and another with a further D152E change (PNHE), were found nontransmissible (NT). Another NT mutant with a single N130D change (QDQD) was retrieved from a new mutational analysis. In this study, these three NT mutants and the wild-type (wt) virus were compared in their relationships with the whitefly vector
Bemisia tabaci
and the nonvector
Trialeurodes vaporariorum
. Retention kinetics of NT mutants were analyzed by quantitative dot blot hybridization in whiteflies fed on infected plants. The QDQD mutant, whose virions appeared nongeminate following purification, was hardly detectable in either whitefly species at any sampling time. The PNHD mutant was acquired and circulated in both whitefly species for up to 10 days, like the wt virus, while PNHE circulated in
B. tabaci
only. Using immunogold labeling, both PNHD and PNHE CPs were detected in
B. tabaci
salivary glands (SGs) like the wt virus, while no labeling was found in any whitefly tissue with the QDQD mutant. Significant inhibition of transmission of the wt virus was observed after prior feeding of the insects on plants infected with the PNHE mutant, but not on plants infected with the other mutants. Virion stability and ability to cross the SG barrier are necessary for TYLCSV transmission, but interactions with molecular components inside the SGs are also critical for transmissibility.
Single-Amino-Acid Alterations in a Highly Conserved Central Region of Vesicular Stomatitis Virus N Protein Differentially Affect the Viral Nucleocapsid Template Functions
Authors: Nayak Debasis , Panda Debasis , Das Subash C. , Luo Ming , Pattnaik Asit K. 
Published: March 2009

ABSTRACT
The nucleocapsid protein (N) of vesicular stomatitis virus and other rhabdoviruses plays a central role in the assembly and template functions of the viral N-RNA complex. The crystal structure of the viral N-RNA complex suggests that the central region of the N protein interacts with the viral RNA. Sequence alignment of rhabdovirus N proteins revealed several highly conserved regions, one of which spanned residues 282 to 291 (GLSSKSPYSS) in the central region of the molecule. Alanine-scanning mutagenesis of this region suggested that replacement of the tyrosine residue at position 289 (Y289) with alanine resulted in an N-RNA template that is nonfunctional in viral genome replication and transcription. To establish the molecular basis of this defect, our further studies revealed that the Y289A mutant maintained its interaction with other N protein molecules but that its interactions with the P protein or with the viral RNA were defective. Replacement of Y289 with other aromatic, polar, or large amino acids indicated that the hydrophobic and aromatic nature of this position in the N protein is functionally important and that a larger aromatic residue is less favorable. Interestingly, we have observed that several single-amino-acid substitutions in this highly conserved region of the molecule rendered the nucleocapsid template nonfunctional in transcription without adversely affecting the replication functions. These results suggest that the structure of the N protein and the resulting N-RNA complex, in part, regulate the viral template functions in transcription and replication.
Fas-Mediated Apoptotic Signaling in the Mouse Brain following Reovirus Infection
Authors: Clarke Penny , Beckham J. David , Leser J. Smith , Hoyt Cristen C. , Tyler Kenneth L. 
Published: March 2009

ABSTRACTType 3 (T3) reovirus strains induce apoptotic neuronal cell death and lethal encephalitis in infected mice. T3 strain Dearing (T3D)-induced apoptosis in primary neuronal cultures occurs by a Fas-mediated mechanism and requires the activation of caspase 8. We now show that Fas mRNA is upregulated in the brains of mice infected with encephalitic reovirus T3D and T3 strain Abney (T3A) but not following infection with nonencephalitic reovirus type 1 strain Lang. Fas is upregulated in regions of the brain that are injured during infection with T3 reovirus strains and colocalizes with virus antigen in individual neurons. In contrast, levels of FasL mRNA induced by encephalitic and nonencephalitic reovirus strains do not differ significantly. Caspase 8, the initiator caspase associated with Fas-mediated apoptosis, is activated in the cortex and hippocampal regions of both T3D- and T3A-infected mice. Furthermore, Bid cleavage and the activation of caspase 9 in the brains of T3D-infected mice suggest that the caspase 8-dependent activation of mitochondrial apoptotic signaling contributes to virus-induced apoptosis. We have previously shown that the inhibition of c-Jun N-terminal kinase (JNK) signaling blocks T3D-induced apoptosis and improves the outcome of virus-induced encephalitis. We now show that the reovirus-induced upregulation of Fas requires JNK signaling, thereby providing a link between reovirus-induced death receptor signaling and mitogen-activated protein kinase pathways and a potential mechanism for the therapeutic action of JNK inhibition.
Tissue-Specific Sequence Alterations in the Human Immunodeficiency Virus Type 1 Envelope Favoring CCR5 Usage Contribute to Persistence of Dual-Tropic Virus in the Brain
Authors: Gray Lachlan , Roche Michael , Churchill Melissa J. , Sterjovski Jasminka , Ellett Anne , Poumbourios Pantelis , Sheffief Shameem , Wang Bin , Saksena Nitin , Purcell Damian F. J. , Wesselingh Steven , Cunningham Anthony L. , Brew Bruce J. , Gabuzda Dana , Gorry Paul R. 
Published: March 2009

ABSTRACT
Most human immunodeficiency virus type 1 (HIV-1) strains isolated from the brain use CCR5 for entry into macrophages and microglia. Strains that use both CCR5 and CXCR4 for entry (R5X4 strains) have been identified in the brains of some individuals, but mechanisms underlying the persistence of R5X4 viruses compartmentalized between the brain and other tissue reservoirs are unknown. Here, we characterized changes in the HIV-1 envelope (Env) that enhance the tropism of R5X4 variants for brain or lymphoid tissue. R5X4 Envs derived from the brains of two individuals had enhanced CCR5 usage in fusion assays compared to R5X4 Envs derived from matched spleen or blood, which was associated with reduced dependence on specific residues in the CCR5 N terminus and extracellular loop 1 (ECL1) and ECL3 regions. In contrast, spleen/blood-derived Envs had enhanced CXCR4 usage compared to brain-derived Envs, which was associated with reduced dependence on residues in the CXCR4 N terminus and ECL2 region. Consequently, brain-derived Envs had preferential CCR5 usage for HIV-1 entry into the JC53 cell line, could use either CCR5 or CXCR4 for entry into monocyte-derived macrophages (MDM), and could use CCR5 (albeit inefficiently) for entry into peripheral blood mononuclear cells (PBMC), whereas the entry of spleen-derived Envs was CXCR4 dependent in all three cell types. Mutagenesis studies of Env amino acid variants influencing coreceptor usage showed that S306 in the gp120 V3 region of brain-derived Envs reduces dependence on the CCR5 N terminus and enhances CCR5 usage for HIV-1 entry into PBMC and MDM, whereas R306 in spleen-derived Envs reduces dependence on the CXCR4 N terminus and confers the CXCR4 restricted phenotype. These results identify mechanisms underlying R5X4 HIV-1 persistence in different tissue reservoirs. Tissue-specific changes in the gp120 V3 region that increase the efficiency of CCR5 or CXCR4 usage, and thereby influence coreceptor preference, may enhance the tropism of R5X4 strains for CCR5-expressing macrophage lineage cells in the brain and CXCR4-expressing T cells in lymphoid tissues, respectively.