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

Interstitial collagenase is secreted by the osteoblast in response to bone-resorbing agents. Previously, we cloned the rat interstitial collagenase cDNA from UMR 106-01 rat osteoblastic osteosarcoma cells. We demonstrated that induction of collagenase by PTH, a powerful resorbing agent, in UMR 106-01 cells is in part transcriptional. In the present study we isolate and characterize the rat interstitial collagenase gene. The gene consists of 10 exons and spans approximately 12 kbp. The major transcriptional start site, determined by primer extension analysis and confirmed by RNase protection assay, is 25 nucleotides upstream of the translational start site. The previously isolated cDNA was missing the 5'-untranslated sequence in addition to 17 nucleotides of the signal sequence of the preproenzyme; therefore, we also present these data. Chloramphenicol acetyl transferase (CAT) analyses were performed on the 5'-upstream region of the gene. These data indicate that PTH appears to mediate its effect through an AP-1 consensus-binding sequence (-51). Footprint analysis demonstrates protein binding to this site. Site-specific mutagenesis markedly decreased protein binding, which correlated directly with a decrease in CAT activation by PTH. Supershift data indicate that cAMP response element binding protein (CREB) is binding to this AP-1 consensus sequence. In addition we demonstrate that PTH induces phosphorylation of CREB.
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PMID:Parathyroid hormone induction of rat interstitial collagenase mRNA in osteosarcoma cells is mediated through an AP-1-binding site. 881 27

We compared two models of cardiac fibrosis in which collagen synthesis is controlled at different levels. Regulation is pretranslational in aldosterone-salt-induced hypertension in young rats and posttranslational in 24-month-old rats. However, little is known about the role of matrix metalloproteinases (MMP) in fibrosis development. Ventricular MMP activities were studied by zymography, and MMP-2 and MMP-1 mRNA levels were determined using slot-blot and ribonuclease protection assay, respectively. After 1 month of aldosterone-salt treatment, proMMP-2, MMP-2, and proMMP-1 collagenolytic activities and their gene expression were unchanged compared with sham-operated rats. After 2 months, total MMP-2 activity was increased by 40% with parallel stimulation of its gene expression. These changes were localized by in situ zymography within the media of coronary vessels. These results suggest that MMP play a prominent role in vascular remodeling during the first steps of hypertension. During aging, however, there were 40% and 45% decreases in MMP-2 and proMMP-1 activity, respectively, with a corresponding down-regulation of MMP-2 mRNA. These observations suggest that depression of the degradative pathway is partly responsible for age-associated fibrosis. Thus, MMP have differing involvements in the cardiac remodeling associated with hypertension or aging.
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PMID:Differential regulation of matrix metalloproteinases associated with aging and hypertension in the rat heart. 916 91

The accumulation of advanced glycosylation end products (AGEs) is believed to be a factor in the development of aging nephropathy. We have attempted to establish a link between the formation of AGEs and the onset of renal impairment with aging, indicated by albuminuria, using a fluorescence assay and immunohistochemical detection of AGEs in the renal extracellular matrix in rats. The fluorescence of collagenase-digested Type IV collagen from GBM increased with age, from 1.65 +/- 0.05 AU/mM OHPro (3 months) and 1.58 +/- 0.04 (10 months) to 2.16 +/- 0.06 (26 months) (p < 0.001) and 2.53 +/- 0.18 (30 months) (p < 0.001). In contrast, the extent of early glycation products significantly decreased from 5.35 +/- 0.25 nmol HCHO/nmol OHPro at 3 months to 3.14 +/- 0.19 at 10 months (p < 0.001), 3.42 +/- 0.38 at 26 months, and 0.74 +/- 0.08 at 30 months (p < 0.001). The urinary fluorescence of circulating AGE rose from 2.42 +/- 0.15 AU/mg protein (3 months), 1.69 +/- 0.07 (10 months), to 4.63 +/- 0.35 (26 months) (p < 0.01) and 4.73 +/- 0.72 (30 months), while the serum fluorescence increased from 0.39 +/- 0.02 AU/mg protein at 3 months and 0.43 +/- 0.02 at 10 months to 0.59 +/- 0.04 at 26 months (p < 0.001) and 0.54 +/- 0.03 at 30 months (p < 0.04). Polyclonal antibodies raised against AGE RNase showed faint areas of AGE immunoreactivity in mesangial areas in the nephrons of young rats. The immunolabeling of Bowman's capsule, the mesangial matrices, and the peripheral loops of glomerular and tubule basement membranes increased with rat age. The increase in circulating AGE peptides parallels the accumulation of AGEs in the nephron, and this parallels the pattern of extracellular matrix deposition, suggesting a close link between AGE accumulation and renal impairment in aging rats.
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PMID:Accumulation of advanced glycation endproducts in the rat nephron: link with circulating AGEs during aging. 926 67

Delayed reperfusion has a beneficial effect on prognosis, independent of infarct size. One potential mechanism to explain this observation may be an effect on infarct healing. In this study, the impact of delayed reperfusion on two aspects of the healing process was examined, the activity of matrix metalloproteinase (MMP) enzymes and the expression of fibronectin (FN) mRNA. The rat model of coronary artery ligation was used and rats were randomly assigned to delayed reperfusion (150 min following coronary ligation) or permanent ligation. Animals were subsequently killed 1, 2, 3 and 7 days following infarction. Infarct tissue was harvested for MMP activity (zymography), FN mRNA (RNase protection analysis) and protein (immunofluorescence microscopy and Western analysis), and collagen content (hydroxyproline concentration). Infarction produced marked activation of MMP-1, -2, and -9. Reperfusion significantly attenuated the activity of these enzymes (approximately 50% reduction in MMP-1, P=0.03 and ;60% reduction in MMP-2 at 7 days, P=0.001; approximately 55% reduction in MMP-9 at 24 h and 84% reduction at 48 h, P=0.01 and 0.002, respectively). Delayed reperfusion also produced a trend toward a greater increase in FN mRNA 24 h following infarction and immunofluorescent staining suggested the presence of more FN protein at this point. These data demonstrate that delayed reperfusion alters matrix metalloproteinase activity and fibronectin mRNA expression in the infarct zone. The impact of these changes on infarct healing and their association with the improved prognosis of a patent infarct vessel following infarction will require further study.
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PMID:Delayed reperfusion alters matrix metalloproteinase activity and fibronectin mRNA expression in the infarct zone of the ligated rat heart. 929 68

Matrix metalloproteinases (MMPs) are a family of proteinases that play a major role in the metabolic degradation of extracellular matrix proteins. In order to examine the expression pattern of different MMP or MMP-inhibitor genes two RNase protection assays (RPAs) were developed that allow the simultaneous and semiquantitative assessment of their respective mRNAs. Probes for the detection of MMPs stromelysin 1, 2 and 3, matrilysin, metalloelastase, gelatinase A and B, collagenase and membrane type MMP (MT1-MMP) were included in the first RPA probe set, while probes for tissue inhibitor of matrix metalloproteinase (TIMP) 1, 2, 3 and alpha 2-macroglobulin (alpha 2-M) were included in the second probe set (inhibitor of matrix metalloproteinase-IMP set). Titration experiments revealed that this method allows the detection of MMP and inhibitor mRNAs present in at least 0.03 microgram of spleen poly(A)+ RNA. Both RPA sets were further evaluated by analyzing the expression of MMP and IMP genes in brain, kidney, spleen and liver in a murine model for endotoxemia after intraperitoneal LPS injection. Control animals showed an organ-specific constitutive expression of one or more MMPs and a high expression of TIMPs. Following LPS injection, an organ-specific upregulation or induction of MMP and TIMP RNA species was found. This change was most pronounced in the spleen, while liver, kidney and brain showed minor or no changes in MMP expression. An IMP upregulation was detected in all organs. These RPA probe sets provide a valuable tool for the simultaneous assessment of MMP and IMP gene expression under physiological and pathological conditions.
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PMID:RNAse protection assays for the simultaneous and semiquantitative analysis of multiple murine matrix metalloproteinase (MMP) and MMP inhibitor mRNAs. 932 62

Angiotensin II is an established regulator of vascular tone and smooth muscle cell (SMC) growth. However, there are little data about its effect on collagen synthesis by SMCs and none regarding the mechanism of such an effect. We studied the effect of angiotensin II on collagen production by human arterial SMCs, using uptake of [(3)H]proline into collagenase-digestible proteins, and by ribonuclease protection assay for mRNA encoding the proalpha1 chain of type I collagen, the major collagen in arteries. This revealed a dose-dependent increase in relative collagen synthesis rate and a dose-dependent increase in proalpha1(I) collagen mRNA abundance, with the half-maximal effect at 1.7 nmol/L. Angiotensin II-stimulated collagen expression was associated with a 6-fold increase in transforming growth factor-beta (TGF-beta) production and was inhibited by a neutralizing antibody to TGF-beta. Both collagen production and TGF-beta release were inhibited by the AT(1)-specific antagonist, losartan, but not by the AT(2) receptor antagonist, PD123319. To determined if tyrosine phosphorylation was functionally linked to collagen synthesis, we studied the effect of 2 mechanistically distinct inhibitors of tyrosine kinase, genistein, and tyrphostin A25. These inhibitors abrogated angiotensin II-mediated procollagen mRNA expression and angiotensin II-mediated TGF-beta production, whereas the inactive homolog tyrphostin A1 had no effect. We conclude that angiotensin II stimulates collagen production in human arterial SMCs via the AT(1) receptor and an autocrine loop of TGF-beta, induction of which requires tyrosine phosphorylation.
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PMID:Angiotensin II stimulates collagen synthesis in human vascular smooth muscle cells. Involvement of the AT(1) receptor, transforming growth factor-beta, and tyrosine phosphorylation. 1044 62

There is compelling in vitro and in vivo evidence to implicate mast cells in the development of fibrosis. However, an important question remains as to the mechanisms by which mast cells mediate fibrosis. Recent evidence from our laboratory (Gruber et al., 1997, J. Immunol. , 158:2310-2317) has revealed that tryptase, the unique and abundant serine protease of human mast cells, is capable of activating fibroblasts by stimulating chemotaxis, proliferation, and procollagen mRNA synthesis. Regulation of matrix metalloproteinase (MMP) expression is another key step in connective tissue remodeling. Therefore, the effect of tryptase on fibroblast MMP expression was investigated. Proteolytically active tryptase did not alter the cellular mRNA levels for fibroblast MMP-1, MMP-2, MMP-3, and MMP-9 as detected by RNase protection assays. Moreover, tryptase did not alter the basal levels of MMP-1, MMP-2, MMP-3, MMP-9, or the tissue inhibitor of MMP-1 (TIMP-1) in fibroblast conditioned media as detected by specific enzyme-linked immunosorbent assay (ELISA). These results indicate that tryptase does not increase MMP expression in normal dermal fibroblasts. Moreover, these data strengthen the potential role of this unique serine protease as a potent fibrogenic factor.
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PMID:Mast cell tryptase does not alter matrix metalloproteinase expression in human dermal fibroblasts: further evidence that proteolytically-active tryptase is a potent fibrogenic factor. 1049 10

Human fibroblast activation protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein selectively expressed by fibroblastic cells in areas of active tissue remodeling, such as the embryonic mesenchyme, areas of wound healing, the gravid uterus, and the reactive stroma of epithelial cancers. Homologues of FAP have been identified in the mouse and Xenopus laevis. FAP is a dual-specificity enzyme that acts as a dipeptidyl peptidase and collagenase in vitro. To explore the role of FAP in vivo, Fap(-/-) mice were generated by homologous recombination. RNase protection analysis and reverse transcription-PCR confirmed the absence of full-length Fap transcripts in mouse embryonic tissues. No FAP protein was detected in Fap(-/-) animals by immunohistochemistry, and no FAP-specific dipeptidyl peptidase activity was found. We report that Fap(-/-) mice are fertile, show no overt developmental defects, and have no general change in cancer susceptibility.
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PMID:Targeted disruption of mouse fibroblast activation protein. 1062 66

Components of the extracellular matrix take part in tissue rebuilding as well as activating surface-bound growth factors. In the present study, expression and selected activities of urokinase-type plasminogen activator (uPA), matrix metalloproteinases (MMPs), their inhibitors (plasminogen activator inhibitor 1 (PAI-1) and tissue inhibitors of metalloproteinases (TIMPs)) were examined in bovine oviducts by RT--PCR, ribonuclease protection assay and activity assays. A high content of mRNA encoding for uPA was detected before ovulation with a three-fold decrease after ovulation. In contrast, PAI-1 expression appeared to be stable during the oestrous cycle. Oviductal flushings produced caseinolytic zones in zymograms containing plasminogen at approximately 50 kDa and 28 kDa. An activity assay for uPA showed highest net activity during the early to mid-luteal phase. Increased TIMP-1 and MMP-2 mRNA concentrations were found around the time of ovulation compared with the luteal phase. In contrast, MMP-1 mRNA transcripts were enriched during the early to mid-luteal phase. Gelatin zymograms detected a 70--72 kDa protease activity showing an oestrous cycle-dependent activity with highest activity before ovulation. Reverse zymography detecting TIMPs revealed proteins between 21 kDa and 24 kDa. Only for the smallest (21 kDa) protein were amounts increased around the time of ovulation compared with the luteal phase. The observation that several extracellular matrix components were regulated distinctly in bovine oviducts indicates that local interactions between these components, growth factors, gametes and the embryo are possible and may influence fertilization and early embryonic development.
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PMID:Differential expression of extracellular matrix components in the bovine oviduct during the oestrous cycle. 1142 36

Circulating B cells enter the CNS as part of normal immune surveillance and in pathologic states, including the common and disabling illness multiple sclerosis. However, little is known about the molecular mechanisms that mediate human B cell interaction with the specialized brain endothelial cells comprising the blood-brain barrier (BBB). We studied the molecular mechanisms that regulate the migration of normal human B cells purified ex vivo, across human adult brain-derived endothelial cells (HBECs). We found that B cells migrated across HBECs more efficiently than T cells from the same individuals. B cell migration was significantly inhibited by blocking Abs to the adhesion molecules ICAM-1 and VLA-4, but not VCAM-1, similar to the results previously reported for T cells. Blockade of the chemokines monocyte chemoattractant protein-1 and IL-8, but not RANTES or IFN-gamma-inducible protein-10, significantly inhibited B cell migration, and these results were correlated with the chemokine receptor expression of B cells measured by flow cytometry and by RNase protection assay. Tissue inhibitor of metalloproteinase-1, a natural inhibitor of matrix metalloproteinases, significantly decreased B cell migration across the HBECs. A comprehensive RT-PCR comparative analysis of all known matrix metalloproteinases and tissue inhibitors of metalloproteinases in human B and T cells revealed distinct profiles of expression of these molecules in the different cell subsets. Our results provide insights into the molecular mechanisms that underlie human B cell migration across the BBB. Furthermore, they identify potential common, and unique, therapeutic targets for limiting CNS B cell infiltration and predict how therapies currently developed to target T cell migration, such as anti-VLA-4 Abs, may impact on B cell trafficking.
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PMID:Determinants of human B cell migration across brain endothelial cells. 1270 26


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