Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Impairment of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) function through a dominant negative PAX-8/PPAR-gamma fusion gene or other events resulting in wild-type PPAR-gamma downregulation has been implicated in malignant thyroid cell transformation. The aim of our study was to perform a systematic evaluation of PPAR-gamma mRNA and protein expression in normal thyroid tissue as opposed to benign thyroid pathologies of different functional status and thyroid malignancy, to gain further insights into a putative physiological role of PPAR-gamma in the thyroid and to define whether PPAR-gamma could serve as a marker of thyroid cell differentiation. Ten cold benign (CTN) and 10 toxic (TTN) thyroid nodules and corresponding normal thyroid tissues, 10 follicular thyroid cancers (FTC), 10 papillary thyroid cancers (PTC) and 8 Graves' disease (GD) thyroids were studied by real-time polymerase chain reaction (PCR), immunohistochemistry and reverse transcriptase (RT)-PCR (PAX-8/PPAR-gamma fusion gene). PPAR-gamma mRNA expression was demonstrated in all samples. When comparing benign nodular and normal thyroid tissue of the same patient no significant difference in PPAR-gamma mRNA expression was observed. PPAR-gamma mRNA levels were similar in CTN and FTC. In contrast, PPAR-gamma mRNA expression was downregulated in 9 of 10 PTC and all GD samples, whereby at least 4 fold downregulation (compared with normal and benign nodular thyroid tissues) was observed in the latter. Immunohistochemistry showed an increased, patchy PPAR-gamma nuclear staining in CTNs and TTNs and only faint staining in the corresponding normal thyroid tissues. A diffuse and weak PPAR-gamma staining pattern was observed in all GD samples. No PAX-8/PPAR-gamma rearrangements were detected in any of the 68 thyroid tissue samples. In conclusion PPAR-gamma mRNA and protein expression levels are not concordant in benign thyroid nodular disease. Furthermore there is no clear-cut association of PPAR-gamma mRNA expression with follicular thyroid tumorigenesis. Absence of a PAX-8/PPAR-gamma fusion gene in the series of 68 thyroid samples is in agreement with the suggestion of PAX-8/PPAR-gamma rearrangement being restricted to a subset of follicular thyroid cancers. The marked downregulation of PPAR-gamma in GD warrants further investigation and could be linked, for example, with changes in apoptosis.
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PMID:Evaluation of peroxisome proliferator-activated receptor-gamma expression in benign and malignant thyroid pathologies. 1618 7

Colonization of the human nasopharynx exposes Moraxella catarrhalis, a common cause of otitis media in children and exacerbations of chronic obstructive pulmonary disease in adults, to sudden downshifts in temperature, occurring when the host breathes cold air. We investigated whether in vitro cold shock influences the expressions of the outer membrane adhesins UspA1 and hemagglutinin, which are considered virulence factors, and of an M. catarrhalis homolog of recA, a housekeeping gene, which in Escherichia coli is induced by cold shock. Quantitative real-time reverse transcriptase PCR was used for measuring mRNA copy number. A screening experiment revealed that a cold shock at 26 degrees C maximally induced the copy number of uspA1. In comparison with 37 degrees C conditions, a 1-hour cold shock at 26 degrees C increased copy numbers of uspA1 and recA by 2.5-fold (11.2 +/- 1.8 versus 4.5 +/- 0.8 copies/CFU) and 2.7-fold (0.30 +/- 0.10 versus 0.11 +/- 0.06), respectively, but did not induce transcription of hag. Exposure to 26 degrees C increased surface expression of UspA1, as assessed by fluorescence-activated cell sorter analysis, and resulted in a significant increase in adherence of strain O35E to Chang human conjunctival cells (97.1% +/- 2.0% versus 48.3% +/- 9.2% at 37 degrees C; P = 0.01). Cold shock induction of uspA1 and recA was detected in strains belonging to either phylogenetic subpopulation of M. catarrhalis (16S rRNA types 1 and 2/3) and was most pronounced in type 2/3 strains (4- to 25-fold for uspA1), which do not express detectable amounts of UspA1 protein at 37 degrees C. These data indicate that cold shock at a physiologically relevant temperature of 26 degrees C induces the expression of at least one virulence factor (UspA1). To our knowledge, no similar data are available for other nasopharyngeal pathogens.
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PMID:Cold shock response of the UspA1 outer membrane adhesin of Moraxella catarrhalis. 1629 21

To understand the role of the Tigriopus japonicus Hsp20 gene, we isolated this gene from a whole body cDNA library and found two heat shock factor elements at the 5'-UTR. The transformed bacteria containing Tigriopus Hsp20 showed thermotolerance against heat shock (54 degrees C) with different ranges of time. The Tigriopus Hsp20 gene is comprised of 174 amino acid residues and shows similarity to Caenorhabditis elegans (27% identity), silkworm (24.1% identity), moth (24.1% identity), Mexican tetra (19.5% identity), zebrafish (19.5% identity), and spiny dogfish (17.2% identity) genes, but shows more similarity in the C-terminal region that contains an alpha-crystallin domain. Protein motifs such as an N-glycosylation site (67-70 NKSE) and a casein kinase II phosphorylation site were found in Tigriopus Hsp20. The genomic structure of the Tigriopus Hsp20 gene did not contain introns. To characterize the biochemical characteristics of the Tigriopus Hsp20 protein, we expressed Tigriopus Hsp20 in Escherichia coli and purified the soluble protein via 6x His-tag chromatography. To analyze the gene expression of Tigriopus Hsp20 against environmental stresses (e.g., water temperature and salinity), we performed a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). On exposure to different salinities, significant change in the expression of Tigriopus Hsp20 was not observed. However, upon heat shock (30 degrees C), Tigriopus Hsp20 expression was significantly increased, but in the case of cold shock (4 or 10 degrees C), expression was likely downregulated. These findings provide a better understanding of cellular protection mechanisms against environmental stress such as heat shock.
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PMID:The intertidal copepod Tigriopus japonicus small heat shock protein 20 gene (Hsp20) enhances thermotolerance of transformed Escherichia coli. 1640 54

Actinorhizal symbiosis is as important in biological nitrogen fixation as legume-rhizobium symbiosis in the global nitrogen cycle. To understand the function of hemoglobin (Hb) in actinorhizal symbiosis, we characterized a Hb of Alnus firma, AfHb1. A cDNA that encodes nonsymbiotic Hb (nonsym-Hb) was isolated from a cDNA library of A. firma nodules probed with LjHb1, a nonsym-Hb of Lotus japonicus. No homolog of symbiotic Hb (sym-Hb) could be identified by screening in the cDNA library or by polymerase chain reaction (PCR) using degenerate primers for other sym-Hb genes. The deduced amino acid sequence of AfHb1 showed 92% sequence similarity with a class 1 nonsym-Hb of Casuarina glauca. Quantitative reverse transcriptase-PCR analysis showed that AfHb1 was expressed strongly in the nodules and enhanced expression was detected under cold stress but not under hypoxia or osmotic stress. Moreover, AfHfb1 was strongly induced by the application of nitric oxide (NO) donors, and the application of a NO scavenger suppressed the effect of NO donors. Acetylene reduction was strongly inhibited by the addition of NO donors. AfHb1 may support the nitrogen fixation ability of members of the genus Frankia as a NO scavenger.
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PMID:A class 1 hemoglobin gene from Alnus firma functions in symbiotic and nonsymbiotic tissues to detoxify nitric oxide. 1661 Jul 47

Human rhinoviruses (HRV), members of the Picornaviridae family, are comprised of over 100 different virus serotypes. HRV represent the single most important etiological agents of the common cold [Arruda, E., Pitkaranta, A., Witek Jr., T.J., Doyle, C.A., Hayden, F.G., 1997. Frequency and natural history of rhinovirus infections in adults during autumn. J. Clin. Microbiol. 35, 2864-2868; Couch, R.B., 1990. Rhinoviruses. In: Fields, B.N., Knipe, D.M. (Eds.), Virology. Raven Press, New York, pp. 607-629; Turner, R.B., 2001. The treatment of rhinovirus infections: progress and potential. Antivir. Res. 49 (1), 1-14]. Although HRV-induced upper respiratory illness is often mild and self-limiting, the socioeconomic impact caused by missed school or work is enormous and the degree of inappropriate antibiotic use is significant. It has been estimated that upper respiratory disease accounts for at least 25 million absences from work and 23 million absences of school annually in the United States [Anzueto, A., Niederman, M.S., 2003. Diagnosis and treatment of rhinovirus respiratory infections. Chest 123 (5), 1664-1672; Rotbart, H.A., 2002. Treatment of picornavirus infections. Antivir. Res. 53, 83-98]. Increasing evidences also describe the link between HRV infection and more serious medical complications. HRV-induced colds are the important predisposing factors to acute otitis media, sinusitis, and are the major factors in the induction of exacerbations of asthma in adults and children. HRV infections are also associated with lower respiratory tract syndromes in individuals with cystic fibrosis, bronchitis, and other underlying respiratory disorders [Anzueto, A., Niederman, M.S., 2003. Diagnosis and treatment of rhinovirus respiratory infections. Chest 123 (5), 1664-1672; Gern, J.E., Busse, W.W., 1999. Association of rhinovirus infections with asthma. Clin. Microbiol. Rev. 12 (1), 9-18; Pitkaranta, A., Arruda, E., Malmberg, H., Hayden, F.G., 1997. Detection of rhinovirus in sinus brushings of patients with acute community-acquired sinusitis by reverse transcription-PCR. J. Clin. Microbiol. 35, 1791-1793; Pitkaranta, A., Virolainen, A., Jero, J., Arruda, E., Hayden, F.G., 1998. Detection of rhinovirus, respiratory syncytial virus, and coronavirus infections in acute otitis media by reverse transcriptase polymerase chain reaction. Pediatrics 102, 291-295; Rotbart, H.A., 2002. Treatment of picornavirus infections. Antivir. Res. 53, 83-98]. To date, no effective antiviral therapies have been approved for either the prevention or treatment of diseases caused by HRV infection. Thus, there still exists a significant unmet medical need to find agents that can shorten the duration of HRV-induced illness, lessen the severity of symptoms, minimize secondary bacterial infections and exacerbations of underlying disease and reduce virus transmission. Although effective over-the-counter products have been described that alleviate symptoms associated with the common cold [Anzueto, A., Niederman, M.S., 2003. Diagnosis and treatment of rhinovirus respiratory infections. Chest 123 (5), 1664-1672; Gwaltney, J.M., 2002a. Viral respiratory infection therapy: historical perspectives and current trials. Am. J. Med. 22 (112 Suppl. 6A), 33S-41S; Turner, R.B., 2001. The treatment of rhinovirus infections: progress and potential. Antivir. Res. 49 (1), 1-14; Sperber, S.J., Hayden, F.G., 1988. Chemotherapy of rhinovirus colds. Antimicrob. Agents Chemother. 32, 409-419], this review will primarily focus on the discovery and development of those agents that directly or indirectly impact virus replication specifically highlighting new advances and/or specific challenges with their development.
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PMID:Rhinovirus chemotherapy. 1667 37

The aim of the present study was to search for the differential gene expression and measure the serum level of a number of biochemical parameters in the cold zheng (CZ) and non-cold zheng (NCZ) in patients receiving hemodialysis. Hemodialysis (HD) patients were randomly selected from the CZ and NCZ groups. The between-group differences in gene expression were assessed using complementary DNA (cDNA) microarray. Differential gene expression was further validated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Our results demonstrated that the up-regulation of the inflammation-associated genes, ALOX5AP, S100A8 and S100A12, down-regulation of the genes related to immunity (DEFA4), metabolism (GNG11, PYGB, PRKAR2B), and growth/proliferation (HSF2, DDR2, TK1) were found in the CZ group. Furthermore, the CZ HD patients had significantly lower serum albumin levels compared with their NCZ counterparts (3.31 +/- 0.08 g/dL versus 4.18 +/- 0.12 g/dL). It appears reasonable to conclude that up-regulated inflammatory-gene expression (ALOX5AP, S100A8 and S100A12) may play an important role in CZ HD patients.
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PMID:Differential gene expression in hemodialysis patients with "cold" zheng. 1671 Aug 87

Stimuli-responsive bioconjugates consisting of avidin covalently linked to poly(N-isopropylacrylamide) were used for the recovery of poly(A) mRNA hybridized to biotinylated poly(dT)-tags from crude cell lysates (Jurkat cells) by affinity precipitation. The bioconjugates are soluble in cold water but precipitate readily once a critical solution temperature (33 degrees C in pure water) is surpassed. The process is fully reversible and shows the expected dependencies on the composition of the aqueous solution and the bioconjugate chemistry. The results of the affinity precipitation were compared to those achieved with an accepted standard purification of poly(A) mRNA using avidin-activated magnetic beads. Both yield and quality/purity of the affinity precipitated poly(A) mRNA were found to be similar or better (especially removal of rRNA) than for poly(A) mRNA prepared by the magnetic particle-based protocol, while both mRNA isolates performed equally well in standard reverse transcriptase amplification (RT-PCR) of a beta actin transcript fragment. Poly(A) mRNA purification schemes based on affinity precipitation require no dedicated equipment and should have advantages in terms of scalability, handling, and costs.
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PMID:Purification of RT-PCR competent poly(A) mRNA from crude cell lysate by affinity precipitation. 1713 10

Aedes aegypti (L.) is the primary vector of dengue viruses, a group of four serotypic single-stranded RNA viruses. Dengue virus RNA can be readily detected in fresh or dried infected mosquitoes by using reverse transcriptase-polymerase chain reaction (RT-PCR). The current study examined the persistence and limit of dengue virus RNA detection in infected Ae. aegypti killed and exposed to natural ambient tropical conditions of temperature and humidity. Under relatively harsh conditions, dengue RNA retained sufficient integrity to be detected in dried mosquitoes up to 13 wk after exposure to relatively high ambient temperatures (26.3-31.7 degrees C) and relative humidity (49.4-69.9%). These findings confirm that the necessity for testing either fresh or frozen mosquitoes is not a prerequisite when using RT-PCR as the viral detection method, and under particular epidemiological circumstances it allows for a more convenient means of conducting vector-virus surveillance activities where collection methods and logistics may preclude immediate testing or access to a cold chain.
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PMID:Persistence of dengue virus RNA in dried Aedes aegypti (Diptera: Culicidae) exposed to natural tropical conditions. 1729 36

The constitutive expression of the pea ABR17 (abscisic acid-responsive 17) cDNA, which is a member of the group 10 family of pathogenesis-related proteins (PR 10), in Arabidopsis thaliana is reported. The presence of ABR17 transcripts and the protein in the three transgenic lines is demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR) and two-dimensional electrophoresis followed by tandem mass spectrometry, respectively. Three independently derived transgenic lines containing ABR17 germinated better in the presence of salt, cold temperature or both. Furthermore, the transgenic plants also exhibited enhanced tolerance to freezing temperature, suggesting the potential utility of the ABR17 gene to engineer multiple stress tolerance. In order to obtain insights into the mechanism underlying ABR17-mediated stress tolerance, we have compared the proteome of a transgenic line with that of its wild-type counterpart. Several proteins were observed to be significantly altered in the transgenic line, including some with a role(s) in photosynthesis, stress tolerance and the regulation of gene expression. Our findings are discussed within the context of available genes to engineer multiple stress tolerance as well as the biological activities of the ABR17 protein.
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PMID:Constitutive expression of the pea ABA-responsive 17 (ABR17) cDNA confers multiple stress tolerance in Arabidopsis thaliana. 1730 28

Small interfering RNAs (siRNAs) associated with gene silencing are cellular defense mechanisms against invading viruses. The viruses fight back by suppressors or escape mechanisms. The retroviruses developed a unique escape mechanism by disguising as DNA proviruses. An evolutionary relationship between the siRNA machinery and the replication machinery of retroviruses is likely. The RNA cleavage enzymes PIWI and RNase H proteins are structurally related. This relationship can be extended from structure to function, since the retroviral reverse transcriptase (RT)/RNase H can also cause silencing of viral RNA by siRNA. Thus, both enzymes can cleave RNA-DNA hybrids and double-stranded RNA (dsRNA) with various efficiencies shown previously and here, demonstrating that their specificities are not absolute. Other similarities may exist, for example between PAZ and the RT and between RNA-binding proteins and the viral nucleocapsid protein. Dicer has some similarities with the viral integrase, since both specifically generate dinucleotide 3'-overhanging ends. We described previously the destruction of the human immunodeficiency virus (HIV) RNA by a DNA oligonucleotide ODN (oligodeoxynucleotide). Variants of the ODN indicated high length and sequence specificities, which is reminiscent of siRNA and designated here as "siDNA." Cleavage of the viral RNA in the presence of the ODN is caused by the retroviral RT/RNase H and cellular RNase H activities. Several siRNA-mediated antiviral defense mechanisms resemble the interferon system.
Cold Spring Harb Symp Quant Biol 2006
PMID:Relationship between retroviral replication and RNA interference machineries. 1738 18


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