Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Necrotizing pneumonia caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates is increasingly common and frequently severe. The early inflammatory response in the lung after CA-MRSA infection remains largely undefined. Additionally, many workers have hypothesized that the Panton-Valentine leukocidin (PVL) is a key virulence determinant in CA-MRSA necrotizing pneumonia. We hypothesized that intratracheal inoculation of rats with a USA300 CA-MRSA isolate would result in early expression of genes involved in the immune response and that this would correlate with inflammation and tissue destruction characteristic of necrotizing pneumonia. In addition, we hypothesized that infection with a PVL deletion mutant would result in an attenuated early host response. Infection of rats with a sublethal inoculum of USA300 (strain LAC) resulted in rapid increased expression of most cytokine, chemokine, and inflammatory receptor gene transcripts studied, as assessed by quantitative real-time reverse transcriptase PCR (qRT-PCR). The increased gene transcription was followed by inflammation, increased bacterial survival in the lungs, and necrotizing pneumonia. Infection with strain LAC and infection with strain LAC Deltapvl (lukSF-PV deletion mutant) resulted in indistinguishable diseases, as assessed by mortality, in vivo bacterial recovery, and pulmonary pathology. Assessment of the transcription of inflammatory genes by qRT-PCR also revealed little difference after infection with LAC and after infection with LAC Deltapvl, either in animals that died or in animals that survived to 24 h after inoculation. We conclude that in a rat model of necrotizing pneumonia, there was an early, brisk inflammatory transcriptional response associated with neutrophil recruitment and tissue destruction. Deletion of lukSF-PV did not alter the early immune response to CA-MRSA in the lung.
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PMID:Transcription of inflammatory genes in the lung after infection with community-associated methicillin-resistant Staphylococcus aureus: a role for panton-valentine leukocidin? 1923 25

Many new polyisoprenylated benzophenones with a bicyclo[3.3.1]-nonane-2,4,9-trione core structure have been isolated from plants in the Clusiaceae family, and their potent biological properties have been the subject of several studies. This review summarizes the biological activities reported for these secondary metabolites including cytotoxic, antimicrobial, antioxidant, and anti-inflammatory activities. Our efforts during the past years have foremost been directed towards isolating new polyisoprenylated benzophenones, as well as understanding the possible target and mechanism of action through which these compounds arrest cancer cells and inhibit the progression of the cell-cycle. The transcription of genes is affected in cancer cells treated with polyisoprenylated benzophenones; the oncogene c-Myb is down-regulated and endoplasmatic stress genes XBP1, ATF4, and DDIT3/CHOP are turned on. Consequently, the expression of iNOS and cell cycle regulators such as cyclin D and E are reduced. Evidence presented by independent investigators suggests that polyisoprenylated benzophenones affect the mediators in the Akt/mTOR stress pathway, although the specific target remains to be discovered. In addition, benzophenones isolated from plants display high antioxidant capacity and protect cells from oxidative stress and the formation of ROS involved during the inflammatory process. Since antiviral activity was initially reported for guttiferone A, potent synthetic analogues have been developed as effective new non-nucleoside reverse transcriptase inhibitors (NNRTI) to treat drug resistant HIV-1. In addition, benzophenones exert antimicrobial effects particularly against MRSA. The structure-activity relationships of polyisoprenylated benzophenones from natural sources and those of synthetic analogues are included in this review. Absorption, metabolism, and elimination of benzophenones are also discussed.
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PMID:Polyisoprenylated benzophenones from Clusiaceae: potential drugs and lead compounds. 1990 62

Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA), a microtiter plate assay (MPA), polymerase chain reaction (PCR), and reverse transcriptase polymerase chain reaction (RT-PCR). Clones belonging to the same spa type were found to have similar properties in adheringto the polystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes). icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC) was confirmed by RT-PCR.
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PMID:Prevalence of adhesion and regulation of biofilm-related genes in different clones of Staphylococcus aureus. 2270 9

Staphylococcus aureus (S. aureus) is commonly associated with hospital-acquired infections and is known to form biofilms. Bacteria inside biofilms display an increased resistance to chemotherapeutics and host immune defences. Efficient antibiotics or combination therapy are urgently needed to treat patients with biofilm-associated MRSA infections. The objective of the current study was to evaluate the in vitro antimicrobial activities of totarol alone or in combination with berberine chloride (BBR) against S. aureus grown in planktonic and biofilm cultures. The synergistic antimicrobial effects between BBR and totarol were observed in all tested strains grown in biofilms using a chequerboard microdilution method, with the fractional inhibitory concentration index values ranging from 0.125 to 0.375. No antagonistic activity was observed in any of the strains tested in suspension or biofilm cultures. The synergistic activity against S. aureus biofilms was also corroborated by confocal laser scanning microscopy and adhesion assays. Moreover, the present study demonstrated that combination BBR and totarol treatment effectively decreased the formation of S. aureus biofilms by affecting extracellular genomic DNA release and polysaccharide intercellular adhesin expression. Subsequently, real-time reverse transcriptase PCR analysis revealed that the combination of BBR and totarol effectively inhibited the transcription of the biofilm-related genes sarA, cidA and icaA. These results suggest that the combination of totarol and BBR is momentous for the further development of a therapy protocol against S. aureus biofilms.
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PMID:The synergy of berberine chloride and totarol against Staphylococcus aureus grown in planktonic and biofilm cultures. 2627 83

We are concerned with the development of novel anti-infectives with dual antibacterial and antiretroviral activities for MRSA/HIV-1 co-infection. To achieve this goal, we exploited for the first time the mechanistic function similarity between the bacterial RNA polymerase (RNAP) "switch region" and the viral non-nucleoside reverse transcriptase inhibitor (NNRTI) binding site. Starting from our previously discovered RNAP inhibitors, we managed to develop potent RT inhibitors effective against several resistant HIV-1 strains with maintained or enhanced RNAP inhibitory properties following a structure-based design approach. A quantitative structure-activity relationship (QSAR) analysis revealed distinct molecular features necessary for RT inhibition. Furthermore, mode of action (MoA) studies revealed that these compounds inhibit RT noncompetitively, through a new mechanism via closing of the RT clamp. In addition, the novel RNAP/RT inhibitors are characterized by a potent antibacterial activity against S. aureus and in cellulo antiretroviral activity against NNRTI-resistant strains. In HeLa and HEK 293 cells, the compounds showed only marginal cytotoxicity.
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PMID:Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors. 2733 73