Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA clone coding for a membrane proteoglycan core protein was isolated from a neonatal rat Schwann cell cDNA library by screening with an oligonucleotide based on a conserved sequence in cDNAs coding for previously described proteoglycan core proteins. Primer extension and polymerase chain reaction amplification were used to obtain additional 5' protein coding sequences. The deduced amino acid sequence predicted a 353 amino acid polypeptide with a single membrane spanning segment and a 34 amino acid hydrophilic COOH-terminal cytoplasmic domain. The putative extracellular domain contains three potential glycosaminoglycan attachment sites, as well as a domain rich in Thr and Pro residues. Analysis of the cDNA and deduced amino acid sequences revealed a high degree of identity with the transmembrane and cytoplasmic domains of previously described proteoglycans but a unique extracellular domain sequence. On Northern blots the cDNA hybridized to a single 5.6-kb mRNA that was present in Schwann cells, neonatal rat brain, rat heart, and rat smooth muscle cells. A 16-kD protein fragment encoded by the cDNA was expressed in bacteria and used to immunize rabbits. The resulting antibodies reacted on immunoblots with the core protein of a detergent extracted heparan sulfate proteoglycan. The core protein had an apparent mass of 120 kD. When the anti-core protein antibodies were used to stain tissue sections immunoreactivity was present in peripheral nerve, newborn rat brain, heart, aorta, and other neonatal tissues. A ribonuclease protection assay was used to quantitate levels of the core protein mRNA. High levels were found in neonatal rat brain, heart, and Schwann cells. The mRNA was barely detectable in neonatal or adult liver, or adult brain.
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PMID:Molecular cloning and characterization of N-syndecan, a novel transmembrane heparan sulfate proteoglycan. 155 52

Mice transgenic for growth hormone (GH) develop progressive glomerulosclerosis. The compositions of kidney extracellular matrix (ECM) and ECM mRNA were examined. The glomerulosclerotic areas in GH mice contained types I and IV collagen, laminin, and basement membrane heparan sulfate proteoglycan (HSPG), which increased with age. The type IV collagen, laminin B2, and HSPG mRNA levels in GH mice, measured by a solution hybridization RNase protection assay, were increased over normal littermates. These findings suggest that the accumulation of ECM components in the glomeruli of GH mice is regulated at the transcriptional level and that glomerulosclerosis is, in part, due to the excess production of ECM rather than simply a reduction in its turnover. The glomerular lesions in GH mice resemble diabetic nephropathy and may allow further dissection of the molecular basis of certain forms of glomerulosclerosis.
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PMID:Glomerulosclerosis in mice transgenic for growth hormone. Increased mesangial extracellular matrix is correlated with kidney mRNA levels. 202 27

Perlecan is a modular heparan sulfate proteoglycan that harbors five domains with homology to the low density lipoprotein receptor, epidermal growth factor, laminin and neural cell adhesion molecule. Using a monoclonal antibody directed against the laminin-like domain of perlecan, we have recently shown that perlecan is widely expressed in all lymphoreticular systems. To investigate further this observation we have studied the expression of perlecan in two human leukemic cell lines. Using reverse transcriptase-PCR, ribonuclease protection assay, and metabolic labeling we detected significant perlecan expression in the multipotential cell line K562, originally derived from a patient with chronic myelogenous leukemia. In contrast, the promyelocytic cell line HL-60 expressed perlecan at barely detectable levels. These results were intriguing because the K562 cells do not assemble or produce a classical basement membrane. Following induction with either sodium butyrate or the phorbol diester 12-0-tetradecanoylphorbol-13-acetate (TPA), K562 and HL-60 differentiate into early progenitor cells with erythroid or megakaryocytic properties, respectively. Following treatment of K562 and HL-60 cells with either of these agents, perlecan expression was markedly increased in K562 cells. In contrast, we could detect perlecan protein synthesis in HL-60 cells only at very low levels, even after induction with TPA or sodium butyrate. Collectively, these results indicate that perlecan is actively synthesized by bone marrow derived cells and suggest that this proteoglycan may play a role in hematopoietic cell differentiation.
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PMID:The proteoglycan perlecan is expressed in the erythroleukemia cell line K562 and is upregulated by sodium butyrate and phorbol ester. 754 67

The accumulation of excessive extracellular matrix (ECM) following tubular injury likely represents an imbalance between ECM production and degradation. We assessed the temporal relationship between the accumulation of ECM, cell adhesion molecules, matrix degrading proteinases, and their inhibitors in a rat model of anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN) by the RNase protection assay and immunohistochemistry. There was an increase in the steady state expression of fibronectin (FN) and alpha 2(IV) collagen mRNAs beginning on day 7 with the onset of neutrophil infiltration. An increase in alpha 1(III) collagen and alpha 1-integrin did not occur until days 9 and 10, respectively, at which time mononuclear leukocytes were the predominant infiltrating cell. Increased levels of FN, alpha 1(III), alpha 2(IV) and alpha 1-integrin mRNAs occurred through day 14. By immunohistochemistry, increased accumulation of collagen IV, heparan sulfate proteoglycan, and laminin were detected along the thicken TBM; collagens I and III were immunolocalized within the tubulo-interstitium, while FN was present in both the TBM and interstitium in rats with TIN on day 14. The increase in matrix accumulation was associated with little or no increase in proteinases. u-PA transcripts fell beginning on day 8, with recovery to control values by day 12. Transin mRNA was found at low levels only on days 8 and 9, and the protein could not be detected by Western blotting. In contrast, these changes were associated with an increase in proteinase inhibitors, so that TIMP and PAI-1 mRNAs increased beginning on day 7 and persisted through day 14.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Extracellular matrix accumulation in immune-mediated tubulointerstitial injury. 800 77

Proteinuria in diabetic nephropathy has been correlated with reduction in heparan sulfate proteoglycan (HSPG) content of the glomerular basement membrane. We have previously shown that the underlying mechanism probably involves reduction in the synthesis by glomerular epithelial cells. In this study we explored whether high glucose medium regulates basement membrane HSPG gene expression. Northern analysis demonstrated that rat glomerular epithelial cells in vitro constitutively express mRNA for basement membrane HSPG, similar to that observed in rat kidney glomerulus. RNase protection assay showed that incubation of glomerular epithelial cells with 30 mM glucose for 24 h and 7 days resulted in reduction in HSPG mRNA abundance. The decrease in mRNA abundance correlated with reduction in the synthesis of 35SO4-labeled basement membrane HSPG as measured by immunoprecipitation. Reduction in synthesis of HSPG could not be entirely accounted for by decrease in mRNA abundance, suggesting both transcriptional and posttranscriptional mechanisms may be involved in reduction of glomerular basement membrane HSPG synthesis by glomerular epithelial cells in diabetic nephropathy.
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PMID:Regulation of basement membrane heparan sulfate proteoglycan, perlecan, gene expression in glomerular epithelial cells by high glucose medium. 869 30

Perlecan, the basement membrane heparan sulfate proteoglycan (HSPG), has been fully cloned from mouse and human tissues. When a cRNA probe of murine perlecan cDNA was employed in RNase protection assay to test whether rat glomerular epithelial cells (GEC) constitutively express perlecan, several bands of hybridization were seen, suggesting that sequences between rat and murine perlecan may not be identical. Using primers based on published cDNA sequences of murine and human perlecan and poly A+ RNA of rat GEC, we synthesized a 497 bp product (RPD-I) by RT-PCR. The deduced aminoacid sequence showed an 85% and 88% homology with domain I of murine and human perlecan, respectively. The three putative sites containing the consensus sequence SGD for attachment of heparan sulfate chains were fully conserved in the rat perlecan as was a site (NFT) for attachment of N-linked oligosaccharide. RPD-I detected a > 9.5 kb transcript of perlecan in RNA of GEC, similar in size to that present in rat glomeruli. Employing a riboprobe synthesized from RPD-I in RNase protection assay we examined whether dbcAMP regulated perlecan expression in the GEC. At 1, 6, 24 and 48 h of incubation, 1 mM dbcAMP caused 43%, 32%, 47% and 40% reduction in mRNA abundance of perlecan, respectively. Immunoprecipitation showed a corresponding reduction of 61%, 70% and 65% in the synthesis of 35SO4 labeled basement membrane HSPG by the GEC following 12, 24 and 48 h of incubation with dbcAMP. Following incubation for 1 and 24 h prostaglandins, PGE1 and PGE2 (1 uM), known activators of glomerular adenylate cyclase, reduced perlecan mRNA abundance to a similar extent as dbcAMP on northern analysis. Our results show that glomerular basement membrane HSPG synthesized by the GEC belongs to the perlecan family. Decrease of GEC perlecan gene expression and synthesis by cAMP and prostaglandins may be of relevance to proteinuric states characterized by activation of these mediators.
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PMID:Cyclic AMP regulates basement membrane heparan sulfate proteoglycan, perlecan, metabolism in rat glomerular epithelial cells. 890 27

Thickening of the glomerular basement membrane (GBM) results from excessive accumulation of extracellular matrix (ECM) proteins following glomerular injury. We studied the temporal relationship between the expression of growth factors, ECM accumulation, ECM degrading proteinases, and their inhibitors in a rat model of anti-GBM antibody (Ab) glomerulonephritis (GN) by the RNase protection assay and immunohistochemistry. There were two- or fourfold increases in the expression of transforming growth factor-beta(1) (TGF-beta(1)) and platelet-derived growth factor (PDGF) A and B chain mRNAs 4 days after anti-GBM Ab administration. These changes were temporally associated with increased accumulation of alpha1(III) and alpha2(IV) collagens, fibronectin, and heparan sulfate proteoglycan along the GBM. The increase in matrix accumulation was associated with little or no increases in the proteinases, urokinase plasminogen activator (u-PA) and transin, respectively. There was a 1.6x increase in the u-PA/28s mRNA ratio on day 4 in rats with anti-GBM Ab GN, but this was not associated with an increase in u-PA biologic activity. By comparison, the mRNAs of the proteinase inhibitors, plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metalloproteinase (TIMP) were 5x greater than that of control rats on day 4. PAI-1 mRNA correlate with increased biologic activity. These data demonstrate a temporal association between TGF-beta(1) and PDGF expression and matrix accumulation within the GBM in anti-GBM Ab GN. In addition, it suggest that this matrix accumulation results from an imbalance between matrix synthesis and degradation.
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PMID:Glomerular extracellular matrix accumulation in experimental anti-GBM Ab glomerulonephritis. 1064 7

Heparan sulfate proteoglycans are found on the surface of most cells. Syndecan-4 is a widely expressed transmembrane heparan sulfate proteoglycan. Using quantitative RNase protection assays and immunoblotting, syndecan-4 expression was characterized in 3T3-F442A mouse adipoblasts. These cells exhibit dramatic changes in their biological and morphological characteristics during differentiation to adipocytes. During this process, the levels of syndecan-4 protein and mRNA expression changed dramatically. They peaked at the time when quiescent cells reentered the cell cycle before differentiation. Serum depletion-repletion also replicated the syndecan-4 mRNA induction when the cells were released back into proliferation, and a cycloheximide treatment abolished the peak of induction. In addition, inhibiting syndecan-4 induction with antisense oligonucleotides inhibited the proliferation of 3T3-F442A cells. In the terminally differentiated adipocytes characterized by the loss of proliferation capability, the serum inducibility of syndecan-4 is repressed, emphasizing the link between syndecan-4 induction in 3T3-F442A cells and cell proliferation.
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PMID:Characterization of syndecan-4 expression in 3T3-F442A mouse adipocytes: link between syndecan-4 induction and cell proliferation. 1168 61

As heparan sulfate proteoglycans (HSPGs) are known as co-receptors to interact with numerous growth factors and then modulate downstream biological activities, overexpression of HS/HSPG on cell surface acts as an increasingly reliable prognostic factor in tumor progression. Cell penetrating peptides (CPPs) are short-chain peptides developed as functionalized vectors for delivery approaches of impermeable agents. On cell surface negatively charged HS provides the initial attachment of basic CPPs by electrostatic interaction, leading to multiple cellular effects. Here a functional peptide (CPPecp) has been identified from critical HS binding region in hRNase3, a unique RNase family member with in vitro antitumor activity. In this study we analyze a set of HS-binding CPPs derived from natural proteins including CPPecp. In addition to cellular binding and internalization, CPPecp demonstrated multiple functions including strong binding activity to tumor cell surface with higher HS expression, significant inhibitory effects on cancer cell migration, and suppression of angiogenesis in vitro and in vivo. Moreover, different from conventional highly basic CPPs, CPPecp facilitated magnetic nanoparticle to selectively target tumor site in vivo. Therefore, CPPecp could engage its capacity to be developed as biomaterials for diagnostic imaging agent, therapeutic supplement, or functionalized vector for drug delivery.
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PMID:A Heparan Sulfate-Binding Cell Penetrating Peptide for Tumor Targeting and Migration Inhibition. 2606 87