Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intradermal injection of MY-1, a nucleic acid fraction extracted from Mycobacterium bovis strain BCG, induced in situ infiltration of mononuclear cells, most of which were asialo GM1 (GA1)-positive as determined by immunofluorescence microscopy. The infiltration occurred with as little as 1 microgram of MY-1 and lasted for a week. Double immunofluorescence microscopy revealed that the infiltrating GA1-positive cells were all positive for Ly-5, and partially positive for Thy-1.2, but negative for Mac-1, Ia, mu-chain, Lyt-1, Lyt-2, L3T4, and Fc receptor II. They contained neither peroxidase nor nonspecific esterase. The infiltrating cells thus markedly resembled natural killer (NK) cells in their cytochemical characteristics and surface markers. DNase and RNase destroyed the GA1-positive cell-inducing activity of MY-1. These results indicate that the nucleic acid components of MY-1 are responsible for this effect.
 ...
PMID:In situ infiltration of natural killer-like cells induced by intradermal injection of the nucleic acid fraction from BCG. 248 May 10

To elucidate a possible involvement of nitric oxide in the development of a mesangial proliferative glomerulonephritis induced by anti-Thy-1 antibody administration, glomerular expression of three isoforms of NO synthase (NOS), inducible NOS (iNOS), brain NOS, and endothelial NOS, was examined at both mRNA and protein levels by ribonuclease protection assay and immunofluorescence microscopy. Light microscopy showed an accumulation of polymorphonuclear leukocytes at 1 hour, lysis of mesangial cells at 1 day, a mesangial proliferative lesion at 4 to 10 days, and minimal residual glomerular lesions by 28 days. Ribonuclease protection assay showed that the glomerular expression of iNOS mRNA peaked at 1 hour and decreased thereafter. No substantial expression of iNOS mRNA was observed in normal glomeruli or in the nephritic glomeruli obtained at different time points (1, 4, 10, or 28 days). By immunofluorescence microscopy with a specific monoclonal antibody, an intense reaction for iNOS was demonstrated in a few cells in the glomeruli at 1 hour. Most of the iNOS-positive cells were identified as polymorphonuclear leukocytes. iNOS-positive cells were found less frequently in the glomeruli on days 1 and 4. Endothelial NOS mRNA was constitutively expressed in normal glomeruli and increased biphasically with two peaks at 1 hour and at 4 days or later; however, the peak expression was much less than that of iNOS mRNA at 1 hour. Expression of brain NOS mRNA was not detectable in either normal or nephritic glomeruli. These results show that iNOS is predominantly expressed in polymorphonuclear leukocytes accumulating at 1 hour in the glomeruli of anti-Thy-1 glomerulonephritis and suggest an involvement of NO in the initiation of the disease.
 ...
PMID:Expression and localization of inducible nitric oxide synthase in anti-Thy-1 glomerulonephritis. 757 58

We previously reported an in vitro T-cell differentiation system in which the L4 lymphoid clone was cocultured with the St3 stromal line derived from the same murine thymic tumor, 15#4T.L4 cells in L4-St3 cocultures sequentially express Thy-1 and CD4 in a manner typical of normal thymocytes. In contrast, L4 cells grown in medium alone retain their Thy-1-CD4- phenotype. We also isolated L4 subclones from the coculture with increasingly differentiated phenotypes with respect to Thy-1 and CD4. We now report induction of an additional thymocyte differentiation marker, terminal deoxynucleotidyl transferase (TdT) in 15#4T cells (and to a lesser extent subcloned L4 cells) upon coculture with St3 stroma. Coculture of 15#4T cells with St3 stroma resulted in expression of TdT as measured by ribonuclease protection for TdT RNA and Western immunoblotting for TdT protein. Cocultured L4 cells were induced for TdT expression to a lesser degree and for a shorter period of time. The magnitude of TdT RNA induction was maximal for cell lines with the least mature differentiation phenotype (15#4T and L4: Thy-1-CD4-) and decreased proportionally for subclones with increasingly mature phenotype, e.g., L4E cells (Thy-1+CD4+). TdT protein was undetectable by Western immunoblotting and immunofluorescent staining of the L4E subclone on or off stroma. Recombination-activating gene-1 (RAG-1), which is expressed in immature thymocytes during T-cell receptor rearrangement, but suppressed in mature thymocytes, was also examined using the ribonuclease protection assay.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Stage-specific induction of terminal deoxynucleotidyl transferase in a T-lymphoid line upon coculture with a thymic stromal line. 772 91

Genetically engineered cells carrying genes for neurotrophic factors have potential application for treatment of neurodegenerative diseases and injuries to the nervous system. Brain-derived neurotrophic factor (BDNF) promotes the survival of specific neurons, including retinal ganglion cells (RGC). To determine whether genetically engineered astrocytes might be used for delivering bioactive BDNF, we infected primary type 1 rat astrocytes with a retrovirus harboring a human prepro-BDNF cDNA and assayed the medium conditioned by these astrocytes for effects on survival of rat RGCs in vitro. High levels of BDNF mRNA were expressed by infected astrocytes, but not by control astrocytes as determined by RNase protection assay using a BDNF specific probe. To test for secretion of bioactive BDNF from the transgenic astrocytes, embryonic day 17 rat retinas were dissociated and grown in medium conditioned (CM) for 24 h by astrocytes infected with a replication deficient retrovirus carrying BDNF, NGF, or alkaline phosphatase (AP) cDNA. After 3 days, the number of Thy-1 immunoreactive RGCs was counted. BDNF astrocyte CM significantly enhanced RGC survival by 15-fold compared to the AP control. NGF astrocyte CM had no significant effect. The rate of BDNF secretion was estimated at 83-166 pg/10(5) cells/h. This study demonstrates that astrocytes can be genetically engineered to synthesize and secrete bioactive BDNF. These techniques may be applicable to rescuing neurons from degenerative processes and also for enhancing their survival following transplantation.
 ...
PMID:Retinal ganglion cell survival is promoted by genetically modified astrocytes designed to secrete brain-derived neurotrophic factor (BDNF). 806 2

Glycoproteins generally exist as populations of glycosylated variants (glycoforms) of a single polypeptide. Although the same glycosylation machinery is available to all proteins that enter the secretory pathway in a given cell, most glycoproteins emerge with characteristic glycosylation patterns and heterogeneous populations of glycans at each glycosylation site. The factors that control the composition of the glycoform populations and the role that heterogeneity plays in the function of glycoproteins are important questions for glycobiology. A full understanding of the implications of glycosylation for the structure and function of a protein can only be reached when a glycoprotein is viewed as a single entity. Individual glycoproteins, by virtue of their unique structures, can selectively control their own glycosylation by modulating interactions with the glycosylating enzymes in the cell. Examples include protein-specific glycosylation within the immunoglobulins and immunoglobulin superfamily and site-specific processing in ribonuclease, Thy-1, IgG, tissue plasminogen activator, and influenza A hemagglutinin. General roles for the range of sugars on glycoproteins such as the leukocyte antigens include orientating the molecules on the cell surface. A major role for specific sugars is in recognition by lectins, including chaperones involved in protein folding. In addition, the recognition of identical motifs in different glycans allows a heterogeneous population of glycoforms to participate in specific biological interactions.
 ...
PMID:Glycosylation: heterogeneity and the 3D structure of proteins. 906 19

Fibronectins (FN) regulate cell migration, proliferation, and matrix formation during tissue injury. In humans, up to 20 different FN isoforms are generated by alternative splicing in three regions called EIIIA, EIIIB, and V, which have been implicated in the process undergoing wound healing and embryonic development. Specifically, EIIIA- and EIIIB-containing isoforms have been implicated in the regulation of cell proliferation and migration, whereas FN isoforms containing the full-length V region (named V120) are ligands to the VLA-4 integrin. To study the changes in the expression of FN isoforms in the anti-Thy-1 nephritis, an acute and self-resolutive model of mesangioproliferative nephritis, we analyzed the FN splicing patterns by means of ribonuclease protection assays. At Day 7 after anti-Thy-1 monoclonal injection, time of the maximal matrix expansion and glomerular hypercellularity, EIIIA+, EIIIB-, and V120 FN mRNA isoforms were increased. In accordance with the mRNA studies, FN proteins, including the EIIIA and V120 regions, increased in the mesangium of nephritic rats, as assayed by immunohistochemistry. Coinciding with the EIIIA and V120 isoforms up-regulation, there was an increase in mesangial cell proliferation and in the number of VLA-4+ infiltrating cells. At Day 14, in parallel with a remission of the above-mentioned changes, there was a decline in the mRNA and protein FN isoforms increased in the previous phase. The marked and reversible changes in the pattern of FN isoforms and their temporal association with other indicators of glomerular injury suggest that certain FN isotypes are important and coordinated components of the mechanisms attempting to reverse glomerular damage.
 ...
PMID:Changes in the pattern of fibronectin mRNA alternative splicing in acute experimental mesangioproliferative nephritis. 1006 6