Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Reverse transcriptase polymerase chain reaction (RT-PCR) was applied to assay mRNA expression of TRAIl(the TNF related apoptosis inducing ligand) receptors (DR5, DcR1, and DcR2) in 3 cases of normal ovarian tissues, 6 cases of ovarian benign tumors, and 16 cases of ovarian cancers. Peripheral blood lymphocytes were used as a positive control. Positive expression of the DR5 and DcR1 were found in peripheral blood lymphocytes and 3 cases of normal ovaries. Positive expressions of the DR5 and DcR1 were 83.3%(5/6) in benign ovarian tumors and 68.8%(11/16) in ovarian cancers respectively. Positive expression of the DcR2 was only found in normal ovaries and benign tumors. These findings suggest that expression of different receptors may play an important role in the apoptosis regulation of ovarian tumors, especially DcR2.
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PMID:[Expression of different receptors of the apoptosis inducing gene TRAIL in human ovarian tumors]. 1221 22

In vivo characterization of regulatory polymorphisms is a key requirement for next-generation human genetic analysis. Here we describe haploChIP, a method that uses chromatin immunoprecipitation (ChIP) and mass spectrometry to identify differential protein-DNA binding in vivo associated with allelic variants of a gene. We demonstrate this approach with the imprinted gene SNRPN. HaploChIP showed close correlation between the level of bound phosphorylated RNA polymerase II at the SNRPN locus and allele-specific expression. Application of the approach to the TNF/LTA locus identified functionally important haplotypes that correlate with allele-specific transcription of LTA. The haploChIP method may be useful in high-throughput screening for common DNA polymorphisms that affect gene regulation in vivo.
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PMID:In vivo characterization of regulatory polymorphisms by allele-specific quantification of RNA polymerase loading. 1266 61

The aim of this study is to identify the molecular mechanism of small-for-size graft injury through large-scale expression measurement of intragraft gene profile by carrier DNA (cDNA) microarray screening in liver transplantation. The studies compared 1,081 intragraft genes expression profiles using cDNA microarray of small-for-size grafts (<30% of recipient liver weight) with those of whole grafts (control group) 1, 3, and 24 hours after reperfusion in a rat liver transplantation model. Intragraft gene expression was detected by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). Hepatic ultrastructural features were shown by electron microscopy. In the small-for-size grafts, by cDNA microarray study, the vasoconstriction genes were found up-regulated together with adhesion molecules at 1 hour after reperfusion. Three and 24 hours after reperfusion, the vasopressin genes were found up-regulated together with adhesion molecules, inflammatory mediators and cell death signals, accompanied with down-regulation of the genes related to energy metabolism. By quantitative RT-PCR, intragraft messenger RNA (mRNA) expression of endothelin-1 (ET-1) and endothelin-1 receptor A (ETA) was up-regulated during the first 24 hours after reperfusion accompanied with down-regulation of heme oxygenase-1 (HO-1). The intragraft mRNA and plasma levels of inflammatory cytokines (interleukin [IL]-6, IL-15, tumor necrosis factor [TNF]-alpha) also were overexpressed during the first 24 hours after reperfusion. Sinusoidal congestion and disruption were found accompanied with mitochondrial swelling during the first 24 hours after reperfusion. The up-regulation of intragraft vasoconstriction genes accompanied by early overexpression of adhesion molecules and apoptotic signals, as well as down-regulation of HO-1 in small-for-size grafts may be related to sinusoidal injury leading to graft damage in liver transplantation.
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PMID:Intragraft gene expression profiles by cDNA microarray in small-for-size liver grafts. 1268 97

Inherited deficiency of the mitochondrial protein frataxin causes neural and cardiac cell degeneration, and Friedreich's ataxia. Five hypotheses for frataxin's mitochondrial function have been generated, largely from work in non-human cells: iron transporter, iron-sulfur cluster assembler, iron-storage protein, antioxidant and stimulator of oxidative phosphorylation. We analyzed gene expression in three human cell types using microarrays, and identified just 48 transcripts whose expression was significantly frataxin-dependent in at least two cell types. Significant decreases in seven transcripts occurred in the sulfur amino acid (SAA) biosynthetic pathway and the iron-sulfur cluster (ISC) biosynthetic pathway to which it is connected. By contrast, we did not observe a single frataxin-dependent transcript that fits with the other four current hypotheses. Quantitative reverse-transcriptase PCR analysis of ISC-S and rhodanese transcripts confirmed that the expression of these genes involved in ISC metabolism was lower in mutants. Amino acid analysis confirmed the defect in SAA metabolism: homocystine, cysteine, cystathionine and serine were significantly decreased in frataxin-deficient cell extracts and mitochondria. An ISC defect was further confirmed by observing decreases in succinate dehydrogenase and aconitase activities, whose activities require ISCs. The ISC-U scaffold protein was specifically decreased in frataxin-deficient cells, suggesting a role for frataxin in its expression or maintenance, and sodium sulfide partially rescued the oxidant-sensitivity of the FRDA cells. Also, multiple transcripts involved in the Fas/TNF/INF apoptosis pathway were up-regulated in frataxin-deficient cells, consistent with a multi-step mechanism of Friedreich's ataxia pathophysiology, and suggesting alternative possibilities for therapeutic intervention.
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PMID:Decreased expression of genes involved in sulfur amino acid metabolism in frataxin-deficient cells. 1283 93

Cl- channels have been implicated in essential cellular functions including volume regulation, progression of cell cycle, cell proliferation and contraction, but the physiological functions of the ClC-3 channel are controversial. We tested the hypothesis that the ClC-3 gene (ClCn-3) is upregulated in hypertensive pulmonary arteries of monocrotaline-treated rats, and upregulated ClC-3 channel aids viability of pulmonary artery smooth muscle cells (PASMCs). Experimental pulmonary hypertension was induced in rats by a single subcutaneous administration of monocrotaline (60 mg kg(-1)). Injected animals developed characteristic features of pulmonary hypertension including medial hypertrophy of pulmonary arteries and right ventricular hypertrophy. Reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry and Western immunoblot analysis indicated that histopathological alterations were associated with upregulation of the ClC-3 mRNA and protein expression in both smooth muscle cells of hypertensive pulmonary arteries and in cardiac myocytes. RT-PCR analysis of mRNA, extracted from canine cultured PASMCs, indicated that incubation with the inflammatory mediators endothelin-1 (ET-1), platelet-derived growth factor (PDGF), interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF alpha), but not transforming growth factor beta (TGFbeta), upregulated ClC-3 mRNA. Adenovirus-mediated delivery and overexpression of ClC-3 in canine PASMCs improved cell viability against increasing concentrations of hydrogen peroxide (H2O2, range 50-250 microM). In conclusion, upregulation of ClC-3 in rat hypertensive lung and heart is a novel observation. Our functional data suggest that upregulation of ClC-3 is an adaptive response of inflamed pulmonary artery, which enhances the viability of PASMCs against reactive oxygen species.
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PMID:ClC-3 chloride channel is upregulated by hypertrophy and inflammation in rat and canine pulmonary artery. 1572 95

Targeted inhibition of tumour necrosis factor-alpha (TNF-alpha) is an effective therapy in rheumatoid arthritis and Crohn's disease (CD). Infliximab, a monoclonal murine-human chimeric antibody to TNF-alpha, and etanercept, a fusion protein of two p75 chains of the TNF receptor II and the Fc portion of IgG1, are generally well tolerated. Rarely does clinically significant autoimmunity, including drug-induced lupus and vasculitis occur. Immunologic mechanisms underlying the development of autoimmunity in the presence of such powerful immunosuppressants are unknown. We describe a patient with CD, who developed cutaneous vasculitis on etanercept, which worsened significantly with switch to infliximab. Investigation of the associated systemic and local immune response demonstrated the absence of human antichimera antibodies, but mRNA for T-helper 1 cytokines, chemokines and defensins in the skin and elevated angiogenesis factors in the serum, as determined by reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Histopathology revealed a lymphocytic vasculitis composed of T cells. A permanent B-cell line (MD-B) producing extremely high amounts of chemokines and interleukin-6 was established from this patient's peripheral blood. Lesions progressed despite discontinuation of the drugs and (40 mg/day) prednisone but almost completely resolved with single dose of (0.1 mg/kg) intravenous dexamethasone, which may be therapy of choice for this reaction. A few lesions (<10) have recurred intermittently over 4 years of follow-up, suggesting possible persistence of this TNF-inhibitor-triggered autoimmune disease.
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PMID:Immunology of cutaneous vasculitis associated with both etanercept and infliximab. 1585 15

Tumor necrosis factor-alpha (TNF-alpha) is a potent mediator of inflammation, inducing expression of a gene network mediated by NF-kappaB. Previously we found that TNF-alpha-induced reactive oxygen species (ROS) production is required for NF-kappaB action because antioxidants inhibited TNF-alpha-inducible IL-8 expression without affecting its nuclear translocation. Here, we further investigated this ROS pathway controlling NF-kappaB/RelA dependent gene expression. We observed that TNF-alpha enhanced ROS production approximately 2-fold 20 min after stimulation and significantly increased oxidative DNA damage (8-oxoguanine lesions) over controls. Treatment with chemically unrelated antioxidants specifically inhibited expression of TNF-inducible NF-kappaB-dependent genes without producing detectable cytotoxicity or affecting GAPDH expression. We found that TNF-alpha-induced NF-kappaB/RelA Ser(276) phosphorylation, a modification critical for its transcriptional activity, was inhibited by abrogation of the ROS signaling pathway, whereas NF-kappaB/RelA Ser(536) phosphorylation was not. Interestingly, antioxidant treatment selectively inhibited TNF-alpha-induced catalytic activity of cAMP dependent protein kinase A (PKAc) but not mitogen-stress related kinase-1 (MSK1), kinases known to phosphorylate RelA at Ser(276). Using PKAc inhibitors and siRNA mediated PKAc knockdown, TNF-alpha-induced Ser(276) phosphorylation and IL-8 expression were both significantly reduced, indicating PKAc is required for RelA Ser(276) phosphorylation. Consistently, a site mutation of Rel A (Ser(276) to Ala) in RelA-deficient embryonic fibroblasts failed to activate IL-8 Luciferase activity in response to TNF-alpha. Furthermore, TNF-alpha-inducible NF-kappaB/RelA interaction with the co-activator CBP/p300, essential for enhanceosome formation, was attenuated by antioxidant treatment. Using chromatin immunoprecipitation assay (ChIP), we observed that recruitment of p300 and RNA polymerase II (Pol II) to the IL-8 promoter was also abrogated by antioxidant. These results indicate that the ROS-mediated TNF-alpha-induced IL-8 transcription is regulated by NF-kappaB/RelA phosphorylation at the critical Ser(276) residue by PKAc, resulting in stable enhanceosome formation on target genes. These studies provide insight into a novel antioxidant-sensitive pathway that can be targeted to inhibit NF-kappaB-mediated inflammation.
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PMID:TNF-alpha-induced NF-kappaB/RelA Ser(276) phosphorylation and enhanceosome formation is mediated by an ROS-dependent PKAc pathway. 1731 4

Histamine is an important mediator in immune responses, but it is unclear whether periodontal tissues express histamine receptors and are able to respond to histamine. We hypothesized that histamine, inflammatory cytokines, and bacterial components released in inflamed periodontal tissues may be synergistically involved in periodontitis. The present study showed that human gingival fibroblasts mainly express histamine receptor H1R, and responded to histamine to produce interleukin (IL)-8. Stimulation of gingival fibroblasts with tumor necrosis factor-alpha, IL-1alpha, and lipopolysaccharide markedly induced IL-8 production, and the IL-8 production was synergistically augmented in the presence of or pre-treatment with histamine. Selective inhibitors of mitogen-activated protein kinases (MAPKs), nuclear factor (NF)-kappaB, and phospholipase C (PLC) significantly inhibited the synergistic effect. These results indicate that histamine induces IL-8 production from gingival fibroblasts through H1R, and synergistically augments the inflammatory stimuli by amplification of the MAPK and NF-kappaB through H1R-linked PLC. Abbreviations used: HDC, histidine decarboxylase; LPS, lipopolysaccharide; IL, interleukin; TNF, tumor necrosis factor; HR, histamine receptor; PLC, phospholipase C; MAPK, mitogen-activated protein kinase; NF, nuclear factor; ERK, extracellular signal-related kinase; JNK, c-Jun N-terminal kinase; R, receptor; TLR, Toll-like receptor; alpha-MEM, alpha-minimum essential medium; FCS, fetal calf serum; RT-PCR, reverse-transcriptase polymerase chain-reaction; ELISA, enzyme-linked immunosorbent assay; SD, standard deviation; LDH, lactate dehydrogenase.
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PMID:Histamine amplifies immune response of gingival fibroblasts. 1795 1

Leukotrienes (LTs), metabolites of arachidonic acid through 5-lipoxygenase (5-LOX), have been known to play a role in leukocyte recruitment. However, the contribution of LTB4 to liver microcirculatory dysfunction during endotoxemia remains unknown. LTB4 receptor (BLT1) has been identified as a high-affinity receptor specific for LTB4. The present study was conducted to examine the roles of LTB4 and BLT1 in hepatic microcirculatory dysfunction elicited by LPS in mice. The number of leukocytes adhering to the endothelial cells of the hepatic microvessels and perfused sinusoids was determined 4 h after the administration of LPS (0.3 mg/kg, i.v.) to male C57Bl6 mice by in vivo microscopy. A 5-LOX synthase inhibitor, AA-861 (10 or 100 mg/kg, s.c.), was administered 30 min before LPS injection. BLT1 knockout mice were used to investigate whether LPS-induced hepatic microcirculatory dysfunction is mediated by BLT1 signaling. The expression of 5-LOX, intercellular adhesion molecule (ICAM) 1, and TNF-[alpha] in the liver was measured by real-time reverse-transcriptase-polymerase chain reaction. The administration of LPS caused significant accumulation of leukocyte adhesion to the hepatic microvessels and reduced sinusoidal perfusion when compared with saline-treated mice. The hepatic microcirculatory dysfunction elicited by LPS was minimized in mice pretreated with AA-861 or in BLT1 knockout mice. This was associated with the suppression of hepatic expression of 5-LOX, ICAM-1, and TNF-[alpha]. These findings suggest that the LTB4/BLT1 pathway mediates hepatic microcirculatory dysfunction by enhanced expression of ICAM-1 and TNF-[alpha] in a murine model of endotoxemia.
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PMID:Leukotriene B4/leukotriene B4 receptor pathway is involved in hepatic microcirculatory dysfunction elicited by endotoxin. 1800 32

Receptor activator of nuclear factor-kappaB ligand (RANKL) is a TNF-like factor that is both produced by osteoblasts, mesenchymal cells, and activated T cells and required for osteoclast maturation and survival. The gene is up-regulated by the two primary calcemic hormones, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and PTH. Previous studies have indicated that five enhancer regions located significantly upstream of the mouse Rankl transcriptional start site mediate up-regulation by 1,25(OH)2D3 and PTH. The most distal of these, termed mRLD5, is highly conserved in the human gene at -96 kb where it was also shown to be functionally active. Four additional mouse Rankl upstream enhancers are also highly conserved in the human gene at -20, -25, -75, and -87 kb. In the present studies, we characterized the activity of these regions, explored their capacity to mediate the actions of 1,25(OH)2D3, and identified the vitamin D response elements contained within the two most proximal segments. Interestingly, whereas the most distal of the five enhancers is the dominant mediator of 1,25(OH)2D3 activity in the mouse Rankl gene, that role in the human gene is manifested by the most proximal element at -20 kb. Importantly, activity at this region in response to 1,25(OH)2D3 was associated with a significant increase in histone acetylation as well as the enhanced recruitment of RNA polymerase II. Both likely reflect the primary role of this enhancer in human RANKL gene expression. Our studies confirm the complex nature of RANKL regulation and indicate that although the five enhancers are evolutionarily conserved across several species, their relative contributions to RANKL expression in response to 1,25(OH)2D3 may be different.
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PMID:An enhancer 20 kilobases upstream of the human receptor activator of nuclear factor-kappaB ligand gene mediates dominant activation by 1,25-dihydroxyvitamin D3. 1820 51


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