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Query: EC:2.7.7.6 (
RNA polymerase
)
34,946
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Cynomolgus macaques (Macaca fascicularis) infected with influenza virus A/HongKong/156/97 (H5N1) developed acute respiratory distress syndrome (ARDS) with fever. Reverse
transcriptase
/polymerase chain reaction (RT/PCR) and virus isolation showed that the respiratory tract is the major target of the virus. The main lesion observed upon necropsy, performed 4 or 7 days postinfection, was a necrotizing bronchointerstitial
pneumonia
, similar to that found in primary influenza
pneumonia
in human beings. By immunohistochemistry, influenza virus antigen proved to be limited to pulmonary tissue and tonsils. The data indicate that ARDS and multiple organ dysfunction syndrome (MODS), observed in both humans and monkeys infected with this virus, are caused by diffuse alveolar damage from virus replication in the lungs alone.
...
PMID:A primate model to study the pathogenesis of influenza A (H5N1) virus infection. 1457 89
During the past years, human coronaviruses (HCoVs) have been increasingly identified as pathogens associated with more-severe respiratory tract infection (RTI). Diagnostic tests for HCoVs are not frequently used in the routine setting. It is likely that, as a result, the precise role that HCoVs play in RTIs is greatly underestimated. We describe a rapid, sensitive, and highly specific quantitative real-time reverse-
transcriptase
polymerase chain reaction (RT-PCR) for the detection of HCoV that can easily be implemented in the routine diagnostic setting. HCoV was detected in 28 (11%) of the 261 clinical specimens obtained from patients presenting with symptoms of RTI ranging from common cold to severe
pneumonia
. Only 1 (0.4%) of the 243 control specimens obtained from patients without symptoms of RTI showed the presence of HCoV. We conclude that HCoVs can be frequently detected in patients presenting with RTI. Real-time RT-PCR provides a tool for large-scale epidemiological studies to further clarify the role that coronavirus infection plays in RTI in humans.
...
PMID:Frequent detection of human coronaviruses in clinical specimens from patients with respiratory tract infection by use of a novel real-time reverse-transcriptase polymerase chain reaction. 1476 19
Streptococcus pneumoniae is the major cause of community-acquired
pneumonia
and one of the most common causes of death by infectious disease in industrialized countries. Little is known concerning the mechanisms of target cell activation in this disease. The present study shows that NF-kappaB and p38 MAPK signaling pathways contribute to chemokine synthesis by lung epithelial cells in response to pneumococci. In infected lungs of mice pneumococci stimulate expression of the interleukin (IL)-8 homolog keratinocyte-derived chemokine and granulocyte-macrophage colony-stimulating factor, as well as activate p38 MAPK. Human bronchial epithelium was chosen as a cellular model, because it establishes the first barrier against pathogens, and little is known about its function in innate immunity. Pneumococci infection induces expression of IL-8 and granulocyte-macrophage colony-stimulating factor as well as activation of p38 MAPK in human bronchial epithelial cells (BEAS-2B). Inhibition of p38 MAPK activity by SB202190 and SB203580 blocks pneumococci-induced cytokine release. In mouse lungs in vivo as well as in cultured cells, pneumococci activate NF-kappaBinanIkappaB kinase-dependent manner. Inhibition of p38 MAPK by chemical inhibitors or by RNA interference targeting p38alpha reduces pneumococci-induced NF-kappaB-dependent gene transcription. Blockade of p38 activity did not affect inducible nuclear translocation and recruitment of NF-kappaB/RelA to the IL-8 promotor but did reduce the level of phosphorylated RelA (serine 536) at IL-8 promotor and inhibited pneumococci-mediated recruitment of
RNA polymerase II
to IL-8 promotor. Thus, p38 MAPK contributes to pneumococci-induced chemokine transcription by modulating p65 NF-kappaB-mediated transactivation.
...
PMID:Streptococcus pneumoniae-induced p38 MAPK-dependent phosphorylation of RelA at the interleukin-8 promotor. 1548 52
Streptococcus pneumoniae is a major cause of community-acquired
pneumonia
and death from infectious diseases in industrialized countries. Lung airway and alveolar epithelial cells comprise an important barrier against airborne pathogens. Cyclooxygenase (COX)-derived prostaglandins, such as PGE(2), are considered to be important regulators of lung function. Herein, we tested the hypothesis that pneumococci induced COX-2-dependent PGE(2) production in pulmonary epithelial cells. Pneumococci-infected human pulmonary epithelial BEAS-2B cells released PGE(2). Expression of COX-2 but not COX-1 was dose and time dependently increased in S. pneumoniae-infected BEAS-2B cells as well as in lungs of mice with pneumococcal
pneumonia
. S. pneumoniae induced degradation of IkappaBalpha and DNA binding of NF-kappaB. A specific peptide inhibitor of the IkappaBalpha kinase complex blocked pneumococci-induced PGE(2) release and COX-2 expression. In addition, we noted activation of p38 MAPK and JNK in pneumococci-infected BEAS-2B cells. PGE(2) release and COX-2 expression were reduced by p38 MAPK inhibitor SB-202190 but not by JNK inhibitor SP-600125. We analyzed interaction of kinase pathways and NF-kappaB activation: dominant-negative mutants of p38 MAPK isoforms alpha, beta(2), gamma, and delta blocked S. pneumoniae-induced NF-kappaB activation. In addition, recruitment of NF-kappaB subunit p65/RelA and
RNA polymerase II
to the cox2 promoter depended on p38 MAPK but not on JNK activity. In summary, p38 MAPK- and NF-kappaB-controlled COX-2 expression and subsequent PGE(2) release by lung epithelial cells may contribute significantly to the host response in pneumococcal
pneumonia
.
...
PMID:Streptococcus pneumoniae induced p38 MAPK- and NF-kappaB-dependent COX-2 expression in human lung epithelium. 1641 78
Legionella pneumophila causes community-acquired
pneumonia
with high mortality, but little is known about its interaction with the alveolar epithelium. The aim of this study was to investigate whether L. pneumophila infection of lung epithelial cells (A549) resulted in pro-inflammatory activation. L. pneumophila infection induced liberation of interleukin (IL)-2, -4, -6, -8 and -17, monocyte chemoattractant protein-1, tumour necrosis factor-alpha, IL-1beta, interferon-gamma and granulocyte colony-stimulating factor, but not of IL-5, -7, -10, -12 (p70) or -13 or granulocyte-macrophage colony-stimulating factor. The present study focused on IL-8 and found induction by L. pneumophila strains 130b, Philadelphia 1, Corby and, to a lesser extent, JR32. Knockout of dotA, a central gene involved in type IVB secretion, did not alter IL-8 induction, whereas lack of flagellin significantly reduced IL-8 release by Legionella. Moreover, p38 mitogen-activated protein kinase (MAPK) was activated and kinase inhibition reduced secretion of induced cytokines, with the exception of IL-2 and granulocyte colony-stimulating factor. In contrast, inhibition of the MAPK kinase 1/extracellular signal-regulated kinase pathway only reduced the expression of a few cytokines. L. pneumophila also induced binding of nuclear factor-kappaB subunit RelA/p65 and
RNA polymerase II
to the il8 promoter, and a specific inhibitor of the inhibitor of nuclear factor-kappaB complex dose-dependently lowered IL-8 expression. Taken together, Legionella pneumophila activated p38 mitogen-activated protein kinase- and nuclear factor-kappaB/RelA pathway-dependent expression of a complex pattern of cytokines by human alveolar epithelial cells, presumably contributing to the immune response in legionellosis.
...
PMID:Legionella pneumophila-induced NF-kappaB- and MAPK-dependent cytokine release by lung epithelial cells. 1697 6
Respiratory syncytial virus (RSV) is a common winter time respiratory virus that affects persons of all ages and is the major cause of serious lower respiratory tract infections in young children. However, RSV is also an important pathogen in adults, particularly in the elderly, patients with chronic lung disease, or those with impaired immunity. Clinical features of RSV infections overlap with other respiratory viruses, so laboratory tests are required to establish the diagnosis. Reverse
transcriptase
polymerase chain reaction (RT-PCR) of samples from nasal swabs, sputum, or bronchoalveolar lavage is a sensitive test to substantiate the diagnosis. Serologies are useful in epidemiological surveys. The clinical course of RSV infections is variable. In infants, RSV presents as bronchiolitis. In adults, mild to moderate upper respiratory tract illness is characteristic. However, severe
pneumonia
can occur, particularly in the elderly with comorbidities or compromised immune status. Humoral antibodies confer partial immunity to RSV infection and disease severity; cellular immunity is important to eradicate RSV in established infections. Treatment of RSV infections is often supportive. Aerosolized ribavirin is approved for RSV infections in infants; its role in adults is controversial. Infection control measures are critical to limit spread of RSV. Currently, RSV vaccines are not available, but candidate vaccines are being developed.
...
PMID:Respiratory syncytial virus infection in adults. 1745 71
The present study describes pathologic and virologic findings in 15 sheep and 6 goats that died of natural peste des petits ruminants virus infection in Turkey. Pathologic findings included erosive-ulcerative stomatitis, fibrino-necrotic tracheitis, bronchointerstitial
pneumonia
, multifocal coagulation necroses in the liver, and severe lymphocytolysis in lymphoid tissues. Syncytial cells were conspicuous, especially in the oral mucosa, pulmonary alveoli, liver, and lymphoid tissues. In addition to the typical tissue distribution, eosinophilic intracytoplasmic and/or intranuclear inclusions were observed in epithelial cells lining the renal pelvis and abomasal mucosa. Immunolabeling of the viral antigen was observed in the kidney, brain, rumen, abomasum, heart, and myocytes of the tongue besides its more typical locations. In this study, we report and describe in detail the first peste des petits ruminants endemic in Kirikkale Province, Central Anatolia of Turkey. In conclusion, these previously unreported pathologic findings in natural peste des petits ruminants virus infection establish a basis for resemblance to other morbillivirus infections, such as canine distemper and distemper of sea mammals. Reverse
transcriptase
-polymerase chain reaction analyses indicated that the 448-bp genome fragment was amplified in 18 cases (18/21, 85.7 %). Phylogenetic analysis showed that viruses belong to lineage 4 in the peste des petits ruminants virus common phylogenetic tree.
...
PMID:Natural peste des petits ruminants virus infection: novel pathologic findings resembling other morbillivirus infections. 1760 9
Mycoplasma hyopneumoniae causes swine
pneumonia
and contributes significantly to the porcine respiratory disease complex. The mechanisms of pathogenesis are difficult to address, since there is a lack of genetic tools, but microarrays are available and can be used to study transcriptional changes that occur during disease as a way to identify important virulence-related genes. Mycoplasmas were collected from bronchial alveolar lavage samples and compared to broth-grown cells using microarrays. Bronchial alveolar lavage was performed on pigs 28 days postinfection, and mycoplasmas were isolated by differential centrifugation. Mycoplasma RNA-enriched preparations were then obtained from total RNA by subtracting eucaryotic ribosomal and messenger RNAs. Labeled cDNAs were generated with mycoplasma open reading frame-specific primers. Nine biological replicates were analyzed. During lung infection, our analysis indicated that 79 M. hyopneumoniae genes were differentially expressed (P < 0.01), at a false-discovery rate of <2.7%. Of the down-regulated genes, 28 of 46 (61%) lacked an assigned function, in comparison to 21 of 33 (63%) of up-regulated genes. Four down-regulated genes and two up-regulated genes encoded putative lipoproteins. secA (mhp295) (P = 0.003) and two glycerol transport permease genes (potA [mhp380; P = 0.006] and ugpA [mhp381; P = 0.003]) were up-regulated in vivo. Elongation factor EF-G (fusA [mhp083]) (P = 0.002),
RNA polymerase
beta chain (rpoC [mhp635]) (P = 0.003), adenylate kinase (adk [mhp208]) (P = 0.001), prolyl aminoacyl tRNA synthetase (proS [mhp397]) (P = 0.009), and cysteinyl-tRNA synthetase (cysS [mhp661]) (P < 0.001) were down-regulated in vivo.
...
PMID:Transcriptome changes in Mycoplasma hyopneumoniae during infection. 1807 Aug 98
Human metapneumovirus (hMPV) is a cause of respiratory illness ranging from wheezing to bronchiolitis and
pneumonia
in children. A quantitative real-time reverse-
transcriptase
polymerase chain reaction (RT-PCR) assay was developed for the detection of all four main genetic lineages of hMPV and employed to validate an indirect immunofluorescence (IF) assay to detect hMPV positive specimens. The IF assay detected 24 positives from a screen of 625 randomly selected pediatric respiratory specimens collected (3.8% prevalence). From this cohort of 625 specimens, 229 were also tested by real-time RT-PCR assay. This included the 24 IF positive specimens and 205 randomly selected specimens from both study periods. In addition to confirming all the IF positives, the real-time assay detected an additional six hMPV positive specimens giving rise to a combined prevalence of 4.8%. Phylogenetic analysis showed that hMPV subtypes A2b and B2 to be the most prevalent genotypes circulating in our population and surprisingly no hMPV subgroups A1 or B1 were detected during this study period. Based on this phylogenetic analysis, we propose the existence of sub-clusters of hMPV genotype B2 present in our population which we term subtypes B2a and B2b. The mean log 10 copies/ml of quantitative RT-PCR determinations from these 30 hMPV positive respiratory specimens was 6.35 (range = 4.44-8.15). Statistical analysis of quantitative RT-PCR determinations of viral load from these 30 respiratory specimens suggests that hMPV genotype B specimens have a higher viral load than hMPV genotype A isolates (P < 0.03).
...
PMID:Molecular epidemiology of human metapneumovirus in Ireland. 1820 27
Legionella pneumophila causes severe
pneumonia
. Acetylation of histones is thought to be an important regulator of gene transcription, but its impact on L. pneumophila-induced expression of proinflammatory cytokines is unknown. L. pneumophila strain 130b induced the expression of the important chemoattractant IL-8 and genome-wide histone modifications in human lung epithelial A549 cells. We analyzed the IL-8-promoter and found that histone H4 was acetylated and H3 was phosphorylated at Ser(10) and acetylated at Lys(14), followed by transcription factor NF-kappaB. Recruitment of
RNA polymerase II
to the IL-8 promoter corresponded with increases in gene transcription. Histone modification and IL-8 release were dependent on p38 kinase and NF-kappaB pathways. Legionella-induced IL-8 expression was decreased by histone acetylase (HAT) inhibitor anacardic acid and enhanced by histone deacetylase (HDAC) inhibitor trichostatin A. After Legionella infection, HATs p300 and CREB-binding protein were time-dependently recruited to the IL-8 promoter, whereas HDAC1 and HDAC5 first decreased and later reappeared at the promoter. Legionella specifically induced expression of HDAC5 but not of other HDACs in lung epithelial cells, but knockdown of HDAC1 or 5 did not alter IL-8 release. Furthermore, Legionella-induced cytokine release, promoter-specific histone modifications, and
RNA polymerase II
recruitment were reduced in infection with flagellin-deletion mutants. Legionella-induced histone modification as well as HAT-/HDAC-dependent IL-8 release could also be shown in primary lung epithelial cells. In summary, histone acetylation seems to be important for the regulation of proinflammatory gene expression in L. pneumophila infected lung epithelial cells. These pathways may contribute to the host response in Legionnaires' disease.
...
PMID:Histone acetylation and flagellin are essential for Legionella pneumophila-induced cytokine expression. 1860 45
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