Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To define the potential role of interleukin-6 (IL-6) and its soluble receptor alpha in cartilage metabolism, we analyzed their effects on tissue inhibitor of metalloproteases (TIMP) synthesis by synoviocytes and chondrocytes. TIMP-1 production by isolated human articular synovial fibroblasts and chondrocytes, stimulated by IL-6 and/or its soluble receptor, was first assayed by specific enzyme-linked immunosorbent assay; the slight stimulatory effect of IL-6 on TIMP-1 production by both types of cells was markedly amplified by the addition of soluble receptor, the maximal secretion being observed only at 96 h. TIMP-1 mRNA expression, determined by ribonuclease protection assay, was induced by IL-6 together with its soluble receptor, but TIMP-2 and -3 mRNAs were not affected by these factors. A specific neutralizing antibody abolished the effects of the soluble receptor. Finally, supernatant from synoviocytes stimulated by IL-6 plus its soluble receptor blocked almost completely the collagenolytic activity of supernatant from IL-1-induced synoviocytes. These observations indicate that IL-6 and its soluble receptor have a protective role in the metabolism of cartilage. Given the high levels of soluble receptor in synovial fluid and the marked induction of IL-6 by IL-1 or TNF-alpha, it is likely that IL-6 and its soluble receptor are critical in controlling the catabolic effects of pro-inflammatory cytokines.
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PMID:Interleukin (IL)-6 and its soluble receptor induce TIMP-1 expression in synoviocytes and chondrocytes, and block IL-1-induced collagenolytic activity. 959

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

Virions of southern bean mosaic virus (SBMV) show two distinct sensitivity patterns upon heating. Infectivity loss and capsid denaturation occur concurrently if virions are exposed at 50-55 degrees in 0.1 M sodium phosphate buffer, pH 7.5, or 0.1 M glycine-phosphate buffer, pH 9.0. Contrastingly, virions are inactivated without any detectable capsid damage at 65-70 degrees in 0.1 M sodium phosphate buffer, pH 6.0, 0.1 M Tris-HCI buffer, pH 7.5, or 0.1 M glycine-NaOH buffer, pH 9.0. Heat treatment causes no genomic degradation in these two situations; the divergent sensitivity of virions is due, apparently, to a differential thermal tolerance of the capsid protein to the buffer components and/or pH. SBMV-RNA isolated from virions inactivated at 65 degrees in 0.1 M Tris-HCl buffer, pH 7.5, possesses low infectivity (1-2%). Observations based upon sucrose gradient sedimentation, temperature: absorbance relationship, and sensitivity to ribonuclease T(1) suggest that such RNA is structurally more compact and stable relative to that of the RNA from the nonheated virions. Neither the capsid protein nor the genome protein plays a direct role in the temperature-induced structural stabilization of SBMV-RNA in situ. If treated with 8 M urea, 50% formamide or exposed at 55 degrees , the infectivity of RNA from the heat-inactivated SBMV is restored and is comparable to that of the RNA isolated from the nonheated virions. The observed mode of SBMV thermal inactivation, i.e., stabilization of RNA structure in situ, is unique among the viruses. Furthermore, these results suggest that the ability to initiate infection depends upon the secondary structure of the SBMV genome.
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PMID:Temperature-induced structural stabilization of the encapsidated RNA of southern bean mosaic virus and its biologic significance. 1863 30