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)

We report the expression pattern of hemidesmosome-associated proteins laminin-5, composed of alpha 3 beta 3 gamma 2 chains, and HD1 in the developing mouse and human intestine, an organ in which variations in structure and function parallel morphogenesis and differentiation. Immunocytochemistry analysis revealed the coexpression of laminin-5 and HD1 at the basal pole of differentiating epithelial cells. Distinct noticeable variations occurring in the location of laminin alpha 3 chain in development of mouse gut were stressed by the reverse transcriptase-polymerase chain reaction data. A peculiar finding was also the location of laminin gamma 2 chain in the intestinal muscle coat. The cellular origin of laminin gamma 2 chain was examined by immunocytochemistry on interspecies hybrid intestines with specific antibodies recognizing mouse antigens. Complementary and sequential production of laminin gamma 2 chain was observed, by epithelial cells as establishment of the basement membrane occurs and by mesenchymal cells in the more differentiated organ. These results support the concept of mesenchymal involvement in deposition of basement membrane molecules, a crucial process for intestinal differentiation. Taken together these data provide the first evidence for the coexpression of hemidesmosome-associated proteins in the gut, a non-stratified tissue.
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PMID:Developmental expression of laminin-5 and HD1 in the intestine: epithelial to mesenchymal shift for the laminin gamma-2 chain subunit deposition. 901 43

CD30 is a member of the tumor necrosis factor (TNF) receptor family, originally described as a marker for Hodgkin and Reed-Sternberg cells in Hodgkin's disease, which has been found to be preferentially expressed by T cells producing Th2-type cytokines. The presence of CD30 expression was assessed by both immunohistochemistry and reverse transcriptase-polymerase chain reaction in the target organs of patients with Th1- or Th2-dominated disorders. CD30 expression was found in neither the gut of patients with Crohn's disease nor in the gastric antrum of Helicobacter pylori-infected patients, where there was high interferon-gamma (IFN-gamma) expression. In contrast, high CD30 expression in the apparent absence of IFN-gamma expression was observed in the skin of patients with systemic sclerosis or chronic graft versus host disease (GVHD), which can be considered Th2-dominated disorders. Moreover, high levels of soluble CD30 were found in the serum of both systemic sclerosis and GVHD patients but not in the serum of patients suffering from multiple sclerosis, a Th1-dominated disorder. Thus, CD30 expression appears to be preferentially associated with Th2-type responses not only in vitro but also in vivo.
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PMID:In vivo CD30 expression in human diseases with predominant activation of Th2-like T cells. 912 1

Antioxidant enzymes from S. mansoni, cytosolic Cu-Zn superoxide dismutase (CT-SOD), signal-peptide-containing SOD (SP-SOD), glutathione peroxidase (GPX), and glutathione transferase (GST) were compared for their relative levels of transcript expression throughout development in a semiquantitative reverse transcriptase-polymerase chain reaction assay. All of the antioxidant enzymes exhibited a similar pattern of developmental regulation. Adult worms have the highest level of specific mRNA compared with larval stages. GST shows the highest level of expression, being approximately 10-fold more abundant than CT-SOD and SP-SOD and 100-fold more abundant than GPX. This order of expression was nearly consistent for all the developmental stages studied. To localize the antioxidant enzymes, immunofluorescence staining was performed on 3-hr schistosomula and adult worms. GPX, SP-SOD, and CT-SOD were all found to be associated with the adult tegument and gut epithelium. SP-SOD was also associated with organelle and cell membranes of parenchymal cells and interestingly with the spines of adult worms. Schistosomula, on the other hand, showed little immunofluorescence. These studies further demonstrate the developmental regulation of antioxidant enzymes and localize them to the host-parasite interface, supporting the notion that they have a role in allowing adult worms to evade immune attack.
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PMID:Schistosoma mansoni: the developmental regulation and immunolocalization of antioxidant enzymes. 914 42

Trefoil polypeptides are expressed mainly in the amphibian skin and the gastrointestinal tract of mammals, usually coexpressed with mucin-glycoproteins. Recently, the trefoil polypeptides were shown to be expressed also in different areas of the human and murine brain. To investigate the expression and possible functions of ITF in rat pheochromocytoma (PC12) cells were employed. PC12 cells show a low basal expression of this polypeptide as determined by reverse transcriptase-polymerase chain reaction. After treatment with the synthetic glucocorticoid dexamethasone, the second messenger cyclic adenosine monophosphate and the neurotrophic factor nerve growth factor the expression of the trefoil polypeptide ITF was increased as shown by reverse transcriptase-polymerase chain reaction and by immunocytochemistry. Since these various stimuli can directly can directly alter the expression level of this peptide we conclude that the presented results may from the basis for further investigations of possible functions of this novel gut-brain polypeptide in neurons using PC12 cells.
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PMID:Expression of the trefoil polypeptide ITF in PC12 cells. 923 42

IgA nephropathy (IgAN) is characterized by the deposition of IgA in the glomerular mesangium and often leads to progressive renal dysfunction and kidney failure. We have previously shown that the mesangial IgA is likely to derive from the bone marrow plasma cells, and suggested that a primary abnormality within the mucosal immune system may underly the pathogenesis of IgAN. This study has analyzed the T cell receptor (TCR) variable (V) region expression by gamma delta T cells in the intestinal mucosa of patients with IgAN. The V gamma and V delta usage of TCR transcripts was determined using a semiquantitative reverse transcriptase-PCR protocol. Primers specific for the four human V gamma and six V delta subfamilies were used each with a constant (C) gamma or C delta specific primer, and the PCR-amplified TCR transcripts were detected by Southern blotting and oligonucleotide hybridization. gamma delta TCR V region expression was determined in gut biopsies and peripheral blood of 11 patients with IgAN, and the TCR V gamma and V delta repertoires were compared to those in gut and peripheral blood of 11 control individuals. gamma delta T cells in normal blood predominantly expressed V gamma 2 (V gamma 9 gene) and V delta 2 gene segments whereas those in normal gut mainly expressed V gamma 3 and V delta 3. In IgAN patients, V delta 2 was also the predominant V delta gene utilized by peripheral blood gamma delta T cells, however, we observed a predominance of V gamma 3 and reduced V gamma 2 usage by these cells. gamma delta T cells in the gut of IgAN patients mainly used V gamma 3 and V delta 1. While the gamma and delta TCR V region repertoires did not differ significantly between the peripheral blood of patients and controls, there were significant differences in V gamma and V delta repertoire expression between IgAN and control gut biopsies. V gamma 3 gene expression was significantly decreased in IgAN gut compared to control gut (P = 0.023). In addition, there was a significant decrease in V delta 3 gene expression in IgAN gut compared to control gut (P = 0.043). These findings indicate that a subpopulation of gamma delta T cells, which represent the majority of gamma delta T cells in normal gut mucosa, are significantly diminished in the gut of patients with IgAN. This suggests that a "hole" in the mucosal gamma delta T cell repertoire may play a fundamental role in contributing to the pathogenesis of IgAN.
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PMID:Expression of the mucosal gamma delta T cell receptor V region repertoire in patients with IgA nephropathy. 932 44

Introduction of fecal bacteria into germ-free (GF) Balb/c mice induces class II major histocompatibility complex (MHC) molecules on the small intestinal epithelium. In this study, we elucidated the regulatory mechanisms for the class II MHC molecule induction on the mouse small intestinal epithelium during microbial colonisation of the gut in ex-GF mice. Intraperitoneal injection of interferon-gamma (IFN-gamma) into GF Balb/c mice induced class II MHC expression on the small intestinal epithelial cells. Induction of these molecules was inhibited by peritoneal injection of a monoclonal antibody (mAb) against IFN-gamma on the conventionalisation of GF mice. RNA reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of the small intestinal epithelium indicated that the class II transactivator (CIITA), a regulatory factor for the class II MHC gene, and the I-E alpha chain, but not IFN-gamma receptor mRNA, increased during conventionalisation. The induction of class II MHC on the epithelial cells during the conventionalisation of GF C.B-17 scid mice was much lower than that in GF Balb/c mice. Immunocytochemical and RT-PCR analysis showed that both the number of IFN-gamma producing IEL and the level of the IFN-gamma mRNA in gamma delta TCR IEL were very low in the GF state, and gradually increased after microbial colonisation. After in vivo treatment with a mAb against gamma delta TCR, the number of gamma delta TCR-expressing IEL greatly decreased and the expression of class II MHC molecules on the small intestinal epithelium was repressed during the conventionalisation of GF mice. Taken together, these results suggested that gamma delta TCR-bearing IEL modulate class II MHC molecule expression on the small intestinal epithelium through the production of IFN-gamma during microbial colonisation in ex-GF mice.
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PMID:Gamma delta TCR-bearing intraepithelial lymphocytes regulate class II major histocompatibility complex molecule expression on the mouse small intestinal epithelium. 943 4

The gut of most insects is lined with a semi-permeable peritrophic membrane (or peritrophic matrix) composed of chitin, proteoglycans and proteins. Despite the probable importance of the peritrophic membrane in facilitating the digestive process and protecting insects from invasion by micro-organisms and parasites, there has been little characterization of the specific components and their interactions within this acellular structure. Here we report the characterization of an integral peritrophic membrane glycoprotein, peritrophin-48, from the larvae of the fly Lucilia cuprina, a primary agent of cutaneous myiasis in sheep. Peritrophin-48 was purified from peritrophic membrane obtained by larval culture and its location within the peritrophic membrane determined by immuno-fluorescence and immuno-gold localizations. The cDNA coding for peritrophin-48 was cloned and sequenced. The deduced amino acid sequence codes for a protein of 375 amino acids containing an amino-terminal signal sequence followed by five similar, but non-identical domains, each approximately 65-70 amino acids in length and characterised by a specific register of six cysteines. The deduced amino acid sequence shows significant similarity to two other peritrophic membrane proteins, peritrophin-95 and peritrophin-44, from the same species. A reverse transcriptase-PCR approach indicated that there are several highly related peritrophin-48 genes expressed in each individual. Reverse transcriptase-PCR also demonstrated the expression of peritrophin-48 in all three larval instars and adults but not pupae or eggs. Peritrophin-48 was expressed only by the cardia and by the larval midgut. A simple structural model of a basic unit of a type 2 peritrophic membrane is presented.
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PMID:cDNA and deduced amino acid sequences of a peritrophic membrane glycoprotein, 'peritrophin-48', from the larvae of Lucilia cuprina. 963 76

An experimental oral infection of neonatal (< 2 weeks old) lambs with a cervine isolate of Mycobacterium avium subspecies paratuberculosis (M.a. paratuberculosis), the causal agent of ruminant paratuberculosis (Johne's disease) was used to investigate bacteriological, histopathological and immunological changes during the early (up to 8 weeks) post-infection phase. In vitro culture for mycobacteria was positive in one faecal and three mesenteric lymph node (MLN) samples from the eight infected lambs. All mycobacterial isolates from MLN were identified as M.a. paratuberculosis by polymerase chain reaction (PCR). Small-to-medium sized focal granulomata were observed in jejunal (JPP) and ileal Peyer's patches (IPP) from four of the eight infected lambs. Compared with controls, JPP from all infected lambs had significantly (p < 0.05) higher proportions of CD8+ and CD2+ lymphocytes, and there were significantly (p < 0.05) fewer cells expressing B lymphocyte-associated markers in IPP and MLN. The T/B cell ratio was significantly (p < 0.05) increased in both JPP and MLN from infected lambs. The expression of a range of genes for cytokines was examined using specific reverse transcriptase PCR (RT-PCR) amplification of messenger RNA (mRNA) template isolated from MLN, JPP and IPP from both groups of animals. Densitometric analyses indicated that, in infected animals, MLN expressed significantly (p < 0.05) more mRNA for TNF-alpha: JPP had significantly increased (p < 0.05) mRNA for GM-CSF and significantly decreased (p < 0.05) mRNA for IL-4 and IFN-gamma. Infected lambs had significantly (p < 0.05) decreased titres of both circulating IgG and gut mycobacteria-associated IgG antibody. Infection was not associated with any consistent changes in lymphocyte reactivity to specific mycobacterial antigens, IFN-gamma release into supernatants from in vitro intestinal lymphocyte cultures or gut IgA antibody levels.
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PMID:Early immunopathological events in experimental ovine paratuberculosis. 965 60

We have isolated from mouse intestine a full-length cDNA clone that encodes an 86-amino acid precursor protein containing a 26-amino acid signal sequence. As deduced from its sequence, the mature 60-aa protein named MPGC60 belongs to the Kazal type of secreted trypsin inhibitors. The MPGC60 peptide has 58% homology with the PEC-60 peptide isolated from pig intestine. In the gut of adult mice, an increasing rostrocaudal gradient in MPGC60 mRNA levels was observed by Northern analysis. In situ hybridization analysis demonstrated strong Mpgc60 expression in Paneth cells and in a subset of goblet cells in the differentiated gut. During postnatal differentiation of the gut, a strong increase in Mpgc60 expression was detected in both small and large intestine. However, in small intestine activation of the Mpgc60 gene occurred earlier than in the large intestine. Apart from the intestinal tract, MPGC60 mRNA was also detectable in the mesenchyme surrounding the uterine epithelium and in endothelia of some blood vessels. However, in contrast to the situation observed in pig, no Mpgc60 expression was detectable by Northern, in situ and reverse transcriptase polymerase chain reaction (RT-PCR) analysis in cells of the immune system, that is, in monocytes, macrophages, peripheral blood and in spleen. Northern blot analysis on mRNA isolated from porcine and murine intestine showed a single transcript in mouse, but several transcripts in pig. Southern blot and fluorescent in situ hybridisation (FISH) analysis demonstrated the presence of a single gene situated in band A of chromosome 4. This region is syntenic with human chromosome regions 6q, 8q and 9p. The gene responsible for human hereditary mixed polyposis syndrome has been localized to human 6q. This raises the possibility that Mpgc60 is a candidate gene for this human disorder.
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PMID:Molecular cloning and characterization of murine Mpgc60, a gene predominantly expressed in the intestinal tract. 981 Jul 7

Gastrin (G-17) is a trophic hormone with a high affinity for the cholecystokinin-B receptor (CCK-BR); the mechanisms linking receptor binding and activation of downstream events to cell growth are not known, and these studies have been hampered by the lack of a cell model. We have established a pancreatic carcinoid cell line, BON, which produces a number of gut hormones; however, these cells lack native CCK-BR. The purpose of our study was to develop a model cell line containing the CCK-BR and to characterize the cellular mechanisms involved in gastrin regulation of human cell growth. BON cells were transfected with an expression plasmid containing the human CCK-BR, and stable clones were selected using G418. Functional CCK-BR was confirmed by reverse transcriptase-polymerase chain reaction, 125I-gastrin binding, and mobilization of intracellular calcium ([Ca2+]i) in response to G-17. Stable transfectants were treated with G-17 (+/-) the CCK-BR antagonist, L365,260 (L-60); growth was assessed using a Coulter counter. G-17 stimulated the growth of the stable clones, whereas the selective CCK-BR antagonist, L-60, abolished this G-17-mediated trophic effect. We have shown that G-17, acting through the CCK-BR, mobilizes [Ca2+]i as a second messenger and stimulates cell growth. Our unique BON cell line, stably transfected with the human CCK-BR, provides a novel paradigm to further delineate signaling mechanisms in gastrin regulation of human cell growth.
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PMID:A functional in vitro model to examine signaling mechanisms in gastrin-mediated human cell growth. 983 32


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