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)

In a continuation of our earlier study on the involvement of HSP25 (now known as Hspb1) and HSP70 (now known as Hspa4) in the induction of an adaptive response, we examined the involvement of these proteins in the induction of the adaptive response using an animal model system. C57BL6 mice were irradiated with 5 cGy of gamma radiation three times in 1 week (for a total of 15 cGy), and a high challenge dose (6 Gy) was given on the day after the last low-dose irradiation. The survival time of the low-dose preirradiated mice was increased to 30%. The induction of apoptosis induced by 6 Gy was also reduced by this low-dose preirradiation regimen. To elucidate any link existing between the HSPs and the induction of the adaptive response, reverse transcriptase (RT)-polymerase chain reaction (PCR) analysis was performed using splenocytes. High-dose radiation up-regulated the expression of Hspb1 and especially Hspa4, while expression of other HSPs such as HSC70 (now know as Hspa8), Hsp90, and alphaB-crystalline (now known as Cryab) did not change. When splenocytes from Hspa4 transgenic mice were preirradiated with a low dose of radiation, a reduction in cell death after high-dose irradiation was observed. These results suggest that Hspa4 is a key molecule in the induction of the adaptive response.
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PMID:Hspa4 (HSP70) is involved in the radioadaptive response: results from mouse splenocytes. 1200 43

The evaluation of the effect of trace metals on health can be difficult, because of their presence in the environment in various chemical forms. Exposure to arsenic compounds is an example of this complexity, as it can be present in the environment in inorganic and organic forms. The effects of arsenic in vertebrates are complicated by several variables, such as speciation of the element, the exposure route, and the susceptibility of the particular animal species. The embryotoxicity and teratogenicity of three arsenic species - sodium arsenite (NaAsO(2)), disodium hydrogen arsenate (Na(2)HAsO(4)) and dimethylarsinic acid [(CH3)2AsOOH] - were evaluated by the modified frog embryo teratogenic assay on Xenopus (FETAX). We also show how the classical FETAX endpoints, based on morphological and morphometrical analysis, can conveniently be integrated with the study of molecular markers. Possible changes in the expression of the mRNA for the heat-shock protein HSP70, following exposure to NaAsO(2), were examined by using the reverse transcriptase polymerase chain reaction. HSP70 mRNA is strongly induced by arsenic.
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PMID:Arsenic toxicity and HSP70 expression in Xenopus laevis embryos. 1251 85

The purpose of this study was to investigate pulp cell responses during hypoxia and reoxygenation. Pulp tissues obtained from beagle dogs were cultured. In the control group, pulp cells were incubated in normoxic conditions (20% O2) for 1-4 d. In the hypoxia group, pulp cells were incubated under hypoxic conditions (2% O2) for 1-4 d. In the reoxygenation group, pulp cells were first incubated under hypoxic conditions for 24 h, and were then incubated in normoxic conditions (20% O2) for one to three additional days. Cell viability, MTT (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction assay, cellular proliferation, and alkaline phosphatase (ALPase) activity were determined. Expression of heat shock protein 70 (HSP70) and vascular endothelial growth factor (VEGF) was analysed by Western blotting. Hypoxia inducible factor-1alpha (HIF-1alpha) in pulp cells was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). The cell growth rate and ALPase activity were significantly higher in the hypoxia group than in the control group. After reoxygenation, cellular proliferation and ALPase activity decreased to the level of the control group while HSP70 expression increased. Hypoxia inducible factor-1alpha expression was detected in pulp cells, and VEGF expression (which is regulated by HIF-1alpha) increased under hypoxic conditions. These results suggest that dynamic responses to hypoxia and reoxygenation occur in pulp cells.
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PMID:Pulp cell responses during hypoxia and reoxygenation in vitro. 1288 99

Toxoplasma gondii (T. gondii)-derived heat shock protein 70 (T.g.HSP70) has been identified as a virulent molecule expressing only in T. gondii tachyzoites during lethal acute infection. Therefore, it is of importance to determine the expression of T.g.HSP70 mRNA in a quantitative manner for analysis of virulence of T. gondii in tissues. We have constructed a competitor T.g.HSP70 and have successfully established a quantitative competitive-reverse transcriptase-polymerase chain reaction (QC-RT-PCR) targeting T.g.HSP70 gene. By using the established QC-RT-PCR method, we have demonstrated that the copy number of T.g.HSP70 mRNA per T. gondii tachyzoite was highest in the lung among the organs examined in interferon-gamma knockout (GKO) mice.
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PMID:A quantitative assay method of Toxoplasma gondii HSP70 mRNA by quantitative competitive-reverse transcriptase-PCR. 1498 35

Real-time reverse transcriptase polymerase chain reaction (RT rtPCR) was used to quantify the pattern of inflammatory mediator mRNA expression in circulating leukocytes from adult patients diagnosed with severe sepsis. We analysed 29 blood samples from 26 severely septic patients with different septic sources and eight samples from eight healthy adult volunteers. RT rtPCR was used to quantify mRNA expression of 21 different inflammatory mediators in peripheral leukocytes. The median variability in gene expression in the sepsis patients was 10.5 times greater than the variability of the healthy comparison group. We found a significant change in the regulation for the following genes: C5aR (20-fold, P < 0.001), IL-8 (29-fold, P < 0.001), MMP9 (72-fold, P < 0.001), HSP70 (2.4-fold, P = 0.02), and RIP2 (1.8-fold, P < 0.04) were up-regulated. Conversely the median expression of IFNgamma, and IL-6 were zero (P < 0.001), and mtHSP (0.4-fold, P = 0.02) was significantly down-regulated. Using linear discriminant analysis, IFNgamma, IL-12, and TLR4 were correlated to a negative outcome. Different septic sources (peritonitis, burn, pneumonia and musculo-skeletal infections) resulted in significantly different mRNA patterns. The RT rtPCR is a useful tool to monitor the immune response in septic patients. We found a very high variability in inflammatory mediator expression among septic patients compared to healthy volunteers. This suggests that any future immune-modulatory therapy may need to be individualized to the patient's requirements as monitored by RT rtPCR. Different sources of sepsis may result in markedly different activation patterns.
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PMID:The use of real time rtPCR to quantify inflammatory mediator expression in leukocytes from patients with severe sepsis. 1564 82

It has been demonstrated that exposure to cocaine increases cell death in the fetal CNS. To examine the molecular mechanisms of this effect, we employed mouse oligo microarrays followed by real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) to compare expressions of apoptosis-related genes in the cerebral wall of 18-day-old (E18) fetuses from cocaine-treated (20 mg/kg cocaine, s.c., b.i.d., E8th-E18th) and drug-naive (saline, s.c.) mice. Out of approximately 400 relevant genes in the arrays, 53 showed alterations in expression in cocaine-exposed fetuses. Upregulation was observed in 35 proapoptotic and 8 antiapoptotic genes; 4 proapoptotic and 6 antiapoptotic genes were down-regulated. The affected genes encode a wide range of apoptosis-related proteins, including death receptors (NTF-R1, NTF-R2, DR3, DR5, LTbeta-R, GITR, P57 TR-1) and their adaptor and regulatory proteins (MASGE-D1, TRAF-2, SIVA, MET, FLIP, FAIM, IAP1, ATFA), members of transcription regulatory pathways (JNK, NF-kappaB, P53), members of BCL-2 family of proteins (BID, BAD, BAX, BIK, NIP21, NIP3, NIX, BCL-2), DNA damage sensor (PARP-1), caspases and their substrates and regulatory proteins (caspases 8, 4, 9, and 3, ACINUS, CIDE-A, CIDE-B, GAS2), mitochondrially released factors (cytochrome c, AIF, PRG3), specific endoplasmic reticulum- and oxidative stress-associated factors (BACH2, ABL1, ALG2, CHOP), members of cell survival AKT and HSP70 pathways (PIK3GA, PTEN, HSP70, BAG1, BAG2), and others. This suggests that cocaine affects survival of developing cerebral cells via multiple apoptosis-regulating mechanisms.
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PMID:Cocaine-induced changes in the expression of apoptosis-related genes in the fetal mouse cerebral wall. 1568 Nov 17

To develop genetic and physical maps for shrimp, accurate information on the actual number of chromosomes and a large number of genetic markers is needed. Previous reports have shown two different chromosome numbers for the Pacific whiteleg shrimp, Penaeus vannamei, the most important penaeid shrimp species cultured in the Western hemisphere. Preliminary results obtained by direct sequencing of clones from a Sau3A-digested genomic library of P. vannamei ovary identified a large number of (TAACC/GGTTA)-containing SSRs. The objectives of this study were to (1) examine the frequency of (TAACC)n repeats in 662 P. vannamei genomic clones that were directly sequenced, and perform homology searches of these clones, (2) confirm the number of chromosomes in testis of P. vannamei, and (3) localize the TAACC repeats in P. vannamei chromosome spreads using fluorescence in situ hybridization (FISH). Results for objective 1 showed that 395 out of the 662 clones sequenced contained single or multiple SSRs with three or more repeat motifs, 199 of which contained variable tandem repeats of the pentanucleotide (TAACC/GGTTA)n, with 3 to 14 copies per sequence. The frequency of (TAACC)n repeats in P. vannamei is 4.68 kb for SSRs with five or more repeat motifs. Sequence comparisons using the BLASTN nonredundant and expressed sequence tag (EST) databases indicated that most of the TAACC-containing clones were similar to either the core pentanucleotide repeat in PVPENTREP locus (GenBank accession no. X82619) or portions of 28S rRNA. Transposable elements (transposase for Tn1000 and reverse transcriptase family members), hypothetical or unnamed protein products, and genes of known function such as 18S and 28S rRNAs, heat shock protein 70, and thrombospondin were identified in non-TAACC-containing clones. For objective 2, the meiotic chromosome number of P. vannamei was confirmed as N = 44. For objective 3, four FISH probes (P1 to P4) containing different numbers of TAACC repeats produced positive signals on telomeres of P. vannamei chromosomes. A few chromosomes had positive signals interstitially. Probe signal strength and chromosome coverage differed in the general order of P1>P2>P3>P4, which correlated with the length of TAACC repeats within the probes: 83, 66, 35, and 30 bp, respectively, suggesting that the TAACC repeats, and not the flanking sequences, produced the TAACC signals at chromosome ends and TAACC is likely the telomere sequence for P. vannamei.
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PMID:Isolation and mapping of telomeric pentanucleotide (TAACC)n repeats of the Pacific whiteleg shrimp, Penaeus vannamei, using fluorescence in situ hybridization. 1672 13

The aim of the present study was to investigate the effects of environmentally important heavy metals and organochlorines on the transcriptional profiles of genes coding for heat shock cognate 70 (hsc70) and inducible heat shock protein 70 (hsp70) in a black sea bream fibroblast cell line. Using the nucleotide sequence information, from the cloned genes, specific reverse transcriptase-polymerase chain reaction (RT-PCR) methods were devised to test the effects of heavy metals (Cd2+, Cu2+ and Ni2+) and organochlorines (aroclor 1254, hexachlorobenzene and 2-4-dichloroaniline) on the cell stress response. Hsp70 was induced in fibroblasts upon heavy metal exposure concentrations as low as 0.01 microM whereas hsc70 expression was induced upon organochlorine exposure concentrations as low as 0.001 microM. Overall, our findings demonstrate that gene members of the HSP70 family are responsive to environmentally important chemicals.
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PMID:Impact of heavy metals and organochlorines on hsp70 and hsc70 gene expression in black sea bream fibroblasts. 1678 Sep 70

We used microarray technology to study differentially expressed genes in white spot syndrome virus (WSSV)-infected shrimp. A total of 3136 cDNA targets, including 1578 unique genes from a cephalothorax cDNA library and 1536 cDNA clones from reverse and forward suppression subtractive hybridization (SSH) libraries of Fenneropenaeus chinensis, plus 14 negative and 8 blank control clones, were spotted onto a 18 x 18 mm area of NH(2)-modified glass slides. Gene expression patterns in the cephalothorax of shrimp at 6 h after WSSV injection and moribund shrimp naturally infected by WSSV were analyzed. A total of 105 elements on the arrays showed a similar regulation pattern in artificially infected shrimp and naturally infected moribund shrimp; parts of the results were confirmed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The up-regulated expression of immune-related genes, including heat shock proteins (HSP70 and HSP90), trehalose-phosphate synthase (TPS), ubiquitin C, and so forth, were observed when shrimp were challenged with WSSV. Genes including myosin LC2, ATP synthase A chain, and arginine kinase were found to be down-regulated after WSSV infection. The expression of housekeeping genes such as actin, elongation factor, and tubulin is not stable, and so these genes are not suitable as internal standards for semiquantitative RT-PCR when shrimp are challenged by WSSV. As a substitute, we found that triosephosphate isomerase (TPI) was an ideal candidate of interstandards in this situation.
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PMID:Discovery of the genes in response to white spot syndrome virus (WSSV) infection in Fenneropenaeus chinensis through cDNA microarray. 1679 54

DL-alpha-Lipoic acid (LPA) was reported to be effective in reducing free radicals generated by oxidative stress. The protective of effect of LPA on methanol (MeOH) induced free radical changes and oxidative damages in discrete regions of rat brain have been reported in this study. Folate deficient rat (FDD) model was used. The five animal groups (saline control, FDD control, FDD+MeOH, FDD+LPA+MeOH, LPA control) were used. The FDD+MeOH and FDD+LPA+MeOH animals were injected intraperitoneally with methanol (3gm/kg). After 24h, the level of free radical scavengers such as, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione was estimated in six discrete regions of brain, retina and optic nerve. Level of protein thiol, protein carbonyl and lipid peroxidation was also estimated. Expression of heat shock protein 70 mRNA (hsp70) was studied in the cerebellum and hippocampus by reverse transcriptase PCR. All the samples showed elevation in the level of free radical scavenging enzymes and reduced level of glutathione in the FDD+MeOH group in relation to the other groups. hsp70 expression was more in FDD+MeOH group when compared to FDD+LPA+MeOH group. In conclusion, MeOH exposure leads to increased free radical generation and protein oxidative damages in the rat nervous tissue. Treatment with LPA prevents oxidative damage induced by MeOH exposure.
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PMID:Efficacy of DL-alpha-lipoic acid on methanol induced free radical changes, protein oxidative damages and hsp70 expression in folate deficient rat nervous tissue. 1739 94


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