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

---

Query: EC:3.1.27.5 (RNase)
17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xenopus embryos in solutions containing suramin show a dose-dependent decrease in the formation of dorsoanterior structures. Continuous treatment with 1 mM suramin produces embryos without mesodermal derivatives but with mesenchymal cells. Brief immersions of 20 min were used to determine the most sensitive stages and to establish dose-effect curves: a 20 min treatment with 3 mM suramin at stages 7-8.5 produces blastula-like embryos, never classified before, with atypical epidermis, cells full of yolk and mesenchyme in between. The lack of dorsal mesoderm was confirmed by an RNase protection assay with alpha-cardiac actin probe. Heparin also causes a reduction in dorsal structures, but its action is weaker and and there are also strong toxic effects such as superficial cell dissociation. The effect of heparin is dose-dependent and brief immersions show a very sensitive period around stage 6.5. The lowest DAI obtained is 1.5, an extremely microcephalic embryo with forked tail codes, a stocky notochord, and abnormally shaped, abundant neural tissue. Immunofluorescence shows that the distribution of fibronectin-containing fibrils is normal in heparin-treated embryos, whereas there are no such fibrils in suramin-treated embryos at control stage 12.
...
PMID:Suramin and heparin: aspecific inhibitors of mesoderm induction in the Xenopus laevis embryo. 818 50

The temporal changes in the expression of fibronectin and other extracellular matrix genes were studied in rat aortic rings incubated in vitro in a serum-free medium. Changes in all forms of fibronectin mRNA increased progressively during the 24-hour incubation period, although an increase in the alternatively spliced form of fibronectin designated EIIIA was most pronounced. Both collagen and elastin mRNA levels decreased markedly during the 24-hour interval, as did alpha-actin mRNA. The increase in the relative amount of the EIIIA isoform after a 24-hour incubation was also shown using ribonuclease protection assays. In situ hybridization showed the distribution of the induced fibronectin mRNA to be within all cell types, including endothelial cells, medial smooth muscle cells, and adventitial fibroblasts. Localization in the media was not uniform and was clearly identified mainly in clusters of cells distributed throughout the media. The early induction of fibronectin mRNA was inhibited by genistein, implicating tyrosine kinase activation as a causative factor in fibronectin expression. The in vitro changes reported may reflect a phenotypic change in vascular cell types that is both similar to and different from the changes reported in vivo under conditions in which vascular injury and repair occur.
...
PMID:Selective induction of an embryonic fibronectin isoform in the rat aorta in vitro. 837 Jan 23

Retinoic acid (RA) has been shown to rapidly modulate the collagen expression pattern of chondrocytes in vitro at doses of 1-10 microM. Embryonic chicken sternal chondrocytes stop synthesizing the cartilage-specific type II collagen within 2-4 days of RA treatment and turn on the synthesis of types I and III collagen and fibronectin. While suppression of type II collagen synthesis and onset of type III collagen and fibronectin synthesis have been shown to be regulated at the transcriptional level, conflicting data are available on a possible post-translational regulation of alpha 1(I) collagen gene expression. In this study we demonstrate by comparing a commonly used alpha 1(I) cDNA probe from the 3' end of the alpha 1(I) mRNA with a newly prepared alpha 1(I) cDNA probe from the 5' end (p1E1) that--in contrast to previous reports--chicken sternal chondrocytes do not contain untranslated alpha 1(I) mRNA which may become translatable after RA treatment. By in situ hybridization we show the absence of cytoplasmic alpha 1(I) mRNA from chondrocytes and its presence in the perichondrium of sternal cartilage. Perichondral cells might have contaminated sternal chondrocyte preparations, explaining low levels of alpha 1(I) mRNA seen by Northern hybridization and RNase protection assays of chicken sternal cartilage mRNA even with the p1E1 probe. We show by Northern hybridization and metabolic labeling with 3H-proline followed by SDS-gel electrophoresis that retinoic acid at 3 microM suppresses type II, IX, and X collagen gene expression within 2 days both at the mRNA and protein level and induces the onset of alpha 1(I), alpha 2(I), and alpha 1(III) expression within 3 days. No expression of CRABP, the cellular retinoic acid binding protein, was seen in RA-treated or control chondrocytes, indicating that CRABP protein is not involved in the RA-induced modulation of the chondrocytes.
...
PMID:Alterations of collagen mRNA expression during retinoic acid induced chondrocyte modulation: absence of untranslated alpha 1(I) mRNA in hyaline chondrocytes. 839 38

Different mRNAs for fibronectin arise from the variable processing of a single primary transcript. We used ribonuclease protection assay to investigate the changes occurring in fibronectin expression and the alternative splicing of mRNA precursor during aging in vitro of human diploid endothelial cells. Senescent endothelial cells release more protein and contain 4-5-fold more fibronectin mRNA than young cells. The pattern of alternative splicing of fibronectin mRNA, with the EDA and the CS1 segments largely included (35% and 77%, respectively) and the EDB segment undetectable, correlates well with previous studies at the protein level both in vitro and in vivo. No changes in the splicing pattern of fibronectin mRNA precursor were detected during endothelial cellular senescence. The increased expression of fibronectin in senescent cells may be a result of the activity of interleukin-1 alpha, which is overexpressed in senescent endothelial cells. It could be also important in vivo during aging and in atherosclerotic lesions.
...
PMID:Expression and alternative splicing of fibronectin mRNA in human diploid endothelial cells during aging in vitro. 850 66

Fibronectin, a large extracellular glycoprotein, mediates the interaction of cells with the extracellular matrix. Heterogeneity in the structure of fibronectin is largely due to the alternative splicing of three exons (IIIB, IIIA and V) during processing of the fibronectin primary transcript. Osteoarthritis, a degenerative disease of synovial joints, is characterized by a progressive loss of the articular cartilage eventually resulting in pain and loss of joint function. In contrast to the loss of most cartilage matrix proteins accompanying this process, osteoarthritic cartilage contains more fibronectin than disease-free cartilage. We examined the splicing patterns of fibronectin mRNA from adult human articular cartilage of normal and osteoarthritic joints by RNase protection (exon IIIA and exon IIIB) and reversed transcription-polymerase chain reaction (exon V) assays to determine whether or not the increased fibronectin content in osteoarthritic cartilage is also associated with differences in the splicing patterns of these three alternatively spliced exons. The results revealed no gross differences in splicing of these exons between the fibronectin mRNA isolated from adult human articular normal and osteoarthritic cartilage. Thus alterations in the structure of cartilage fibronectin do not appear to correlate with the increased level of fibronectin protein associated with osteoarthritis.
...
PMID:Splicing patterns of fibronectin mRNA from normal and osteoarthritic human articular cartilage. 858 48

The fibronectin monomer is comprised of three types of homologous repeating units, the types I, II, and III elements. Each type III repeat is encoded by two exons except for the two type III repeats involved in alternative splicing (IIIB and IIIA) and the type III-9 repeat which are all encoded by one exon. The fact that the type III-9 repeat is the only other type III repeat encoded by one exon has led to speculation that this exon may also be alternatively spliced. However, no evidence exists for alternative splicing of this exon in any tissues examined to date. The recent localization of a cell adhesion synergy site within the type III-9 repeat increases the likelihood of functional ramifications if the exon encoding this repeat is alternatively spliced in specific cells or tissues. We have shown previously that chick cartilage contains an unusual fibronectin mRNA splicing pattern and that the pattern changes during chondrogenesis from B+A+V+ to B+A-V+. In order to completely characterize the fibronectin mRNA in cartilage and other mesenchymal tissues for all possible alternative splicing events, we have determined whether or not the exon encoding the type III-9 repeat is alternatively spliced in these tissues. RNase protection and RT/PCR assays indicate that the fibronectin mRNA in all of these tissues, including cartilage, contains the type III-9 repeat as a constitutively included exon. Thus the exon encoding the type III-9 repeat will serve as a useful control exon for examining the regulation of tissue-specific alternative splicing during chondrogenesis.
...
PMID:The exon encoding the fibronectin type III-9 repeat is constitutively included in the mRNA from chick limb mesenchyme and cartilage. 860 3

The Milli-Q PF Plus water polishing system is equipped with high-purity ion and organic removal media and a capillary fiber ultrafiltration device. The system produces ultrapure water practically free of ribonuclease contamination. The necessity for diethyl pyrocarbonate (DEPC) treated solutions in RNA molecular biological procedures was tested by preparing RNA from a variety of tissues and tissue cultured cells using either DEPC-treated, autoclaved solutions or pure Milli-Q PF water dispensed directly from the system. Tissue sources included rabbit brain, heart, lung, liver, kidney, and bladder as well as cultured human corpus cavernosum smooth muscle cells (HCCSMC). RNA was prepared by solubilization in guanidinium isothiocyanate, phenol/chloroform extraction, and isopropanol precipitation followed by Northern blot analysis. Hybridization with fibronectin (approximately 7.6kb) and glyceraldehyde-3-phosphate dehydrogenase (1.2kb) revealed that water from a Milli-Q PF water system performed as well as DEPC-treated, autoclaved solutions. RNA stability at 37 degrees C was examined for various times using rabbit lung RNA in either DEPC-treated water or Milli-Q PF water. Intact RNA was detected after 6 hours in total RNA and by Northern blots hybridized with fibronectin. There was no significant difference in RNA degradation between DEPC-treated water or Milli-Q PF water. We conclude that Milli-Q PF water is an acceptable substitute to DEPC-treated water for the preparation of RNA and Northern blot analysis.
...
PMID:Comparison of Milli-Q PF plus water with DEPC-treated water in the preparation and analysis of RNA. 864 47

The Milli-Q PF Plus water-polishing system is equipped with high-purity ion and organic removal media and a capillary fiber ultrafiltration device. The system produces ultrapure water practically free of ribonuclease contamination. The necessity for diethyl pyrocarbonate (DEPC)-treated solutions in RNA molecular biological procedures was tested by preparing RNA from a variety of tissues and tissue-cultured cells using either DEPC-treated, autoclaved solutions or pure Milli-Q PF water dispensed directly from the system. Tissue sources included rabbit brain, heart, lung, liver kidney and bladder as well as cultured human corpus cavernosum smooth muscle cells. RNA was prepared by guanidinium isothiocyanate solubilization, phenol/chloroform extraction and isopropanol precipitation followed by Northern blot analysis. Hybridization with fibronectin (ca. 7.6 kb) and glyceraldehyde-3-phosphate dehydrogenase (1.2 kb) revealed that water from a Milli-Q PF water system performed as well as DEPC-treated, autoclaved solutions. RNA stability at 37 degrees C was examined for various times using rabbit lung RNA in either DEPC-treated water for Milli-Q PF water. Intact RNA was detected after 6 hours in total RNA and by Northern blots hybridized with fibronectin. There was no significant difference in RNA degradation between DEPC-treated water and Milli-Q PF water. We conclude that Milli-Q PF water is an acceptable substitute for DEPC-treated water for the preparation of RNA and Northern blot analysis.
...
PMID:Comparison of Milli-Q PF Plus water to DEPC-treated water in the preparation and analysis of RNA. 877 61

Fibronectin: (FNs) comprise a family of adhesive glycoproteins that are prominent components of mesangial extracellular matrix and accumulate during glomerular injury. By alternative splicing of an unique mRNA precursor, various FN isoforms can be originated. In rat, three regions of the molecule are involved: EIIIA, EIIIB and V. Because specific FN isoforms are expressed in embryogenesis and wound healing, conditions characterized by cell migration and adhesion, we examined the pattern of FN isoforms in the mild and severe phases of a progressive immune complex proliferative nephritis in rats. We constructed specific probes to analyze the splicing pattern of FN pre-mRNAs by ribonuclease protection assays. FN mRNAs containing EIIIA, EIIIB and V regions increased along, the progression of nephritis, though the increment of EIIIB-FN mRNA was modest. However, different regulation of all these isoforms was observed. The percentage of FN mRNA containing the EIIIA exon versus total FN increased with the severity of the disease, while the percentage of FN mRNA containing the EIIIB exon decreased. Relative V-FN mRNA expression versus total FN mRNA increased only in the severe phase. By means of specific antibodies we also studied the presence of EIIIA, EIIIB and V-FN proteins in the kidney. In the normal glomerutus, EIIIA-FN protein was barely detectable in the mesangium, increasing in the mild phase of nephritis. In the severe phase of nephritis, increased EIIIA-FN was localized in the mesangium, in Bowman's capsule and in crescents. By contrast, EIIIB-FN protein in the glomerulus was absent even in the severe phase. V120-FN protein, an isoform that mediates the attachment of leukocytes through the VLA-4 integrin, was present in the mesangium and glomerular capillary loops in control animals, and increased in the severe phase of nephritis, coinciding with a strong leukocyte infiltration. In conclusion, our results show that during immune glomerular injury there were marked changes in the pattern of FN isoforms expression. Since those isoforms, particularly V120 isoform, are important in cell adhesion and migration, their up-regulation may facilitate the recruitment of cells into the injured glomeruli. The blockade of the interaction between V120-FN and infiltrating leukocytes may represent a new approach to the treatment of nephritis.
...
PMID:Glomerular up-regulation of EIIIA and V120 fibronectin isoforms in proliferative immune complex nephritis. 887 66

RT-PCR was used to examine the expression of LAR (encoding the leukocyte-common antigen-related protein tyrosine phosphatase) in normal human colon mucosa, and colon polyps and tumors. Although the LAR protein was not detected in the colon in a previous immunohistochemical study, amplification of a region of LAR between the most membrane proximal (eighth) fibronectin type-III (FN-III) repeat and the transmembrane domain demonstrated LAR expression in all samples, but showed no difference in expression within matched samples from each patient examined. An additional minor fragment amplified in all reactions was consistently observed in colon and various cell line samples using this and two other LAR-specific sets of primers. Cloning and sequencing of the fragment identified it as deriving from a novel alternatively spliced form of LAR containing a retained intron of 85 bp. This intron encodes an additional 13 amino acids followed by an in-frame stop codon, thus its retention is predicted to give rise to a secreted LAR extracellular region isoform(s). LAR transcripts containing the intron were detected by RNase protection assay of colon samples and were present in most human tissues examined by Northern analysis. A protein in colon tumor extract was recognized by antiserum raised to the intron-encoded sequence. Soluble isoforms of the LAR extracellular immunoglobulin (Ig)-like/FN-III repeat-containing region could have a biological function distinct from those isoforms localized at the cell surface and/or coupled to intracellular phosphatase activity.
...
PMID:Novel alternative splicing predicts a secreted extracellular isoform of the human receptor-like protein tyrosine phosphatase LAR. 891 69


<< Previous 1 2 3 4 5 6 Next >>

---