Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of the calcium antagonist verapamil on the synthesis of fetal rat bone collagen and noncollagen protein were investigated in tissue culture. Protein synthesis was quantitated by measuring the incorporation of [3H]proline into collagenase-digestible (CDP) and noncollagen protein (NCP) using bacterial collagenase; [3H]proline was added for the last 2 h of culture. Verapamil (10(-5)--10(-4) M) decreased the incorporation of label into CDP and NCP after 24 h of culture; CDP formation was inhibited to a greater extent than NCP. The inhibitory response was observed in the presence and absence of unlabeled medium proline and was not associated with changes in trichloroacetic acid-extractable radioactivity. Increasing medium calcium from 1.0 to 5.0 mM did not affect the response to 10(-4) M verapamil, whereas 3.0 mM calcium abolished the response to 10(-5) M verapamil. The inhibitory effect was reversed by 48 h of control treatment subsequent to 24-h treatment with the antagonist. Verapamil did not decrease the incorporation of [3H]thymidine into DNA or [3H]uridine into RNA, nor was there any effect of the antagonist on the DNA content of cultured bones. The prostaglandin synthetase inhibitor indomethacin did not affect the response to verapamil. We conclude that a critical concentration of intracellular calcium is necessary for normal synthesis of skeletal protein in tissue culture, and that collagen may be more sensitive to changes in intracellular calcium than NCP. In addition, other ions (e.g. sodium and potassium) may also be involved in the control of skeletal protein synthesis.
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PMID:Effects of the calcium antagonist verapamil on in vitro synthesis of skeletal collagen and noncollagen protein. 48 4

The effects of parathyroid hormone (PTH) on bone collagen synthesis were assessed in organ cultures of fetal rat calvaria by measuring the incorporation of [3H]proline into collagenase-digestible (CDP) and non-collagen protein (NCP) using purified bacterial collagenase. 1) PTH decreased the incorporation of labeled proline into CDP at concentrations similar to those which stimulate bone resorption in vitro. 2) This effect was observed in bones treated for 6 h, but not for 3 h; it was maximal at 24 h and was maintained for 96 h. Bones treated with PTH for 48 h and transferred to control media for 48 h showed recovery of CDP labeling to control values. 3) the effect was specific for bone collagen. There was little alteration in the incorporation of proline into NCP, and incorporation into collagen was not inhibited. 4) The effect could be ascribed to decreased collagen synthesis and not to changes in amino acid uptake, precursor pool size, or degradation of newly synthesized CDP. In 3 hour experiments, PTH did increase the labeling of CDP and NCP, but only at tracer concentration of proline in the medium, compatible with an early stimulation of amino acid uptake. 5) Similar inhibition was observed with purified bovine (1-84) PTH and synthetic bovine PTH (1-34) as well as with crude homologous PTH obtained from rat parathyroid gland culture fluid. Human (hCT) and salmon (sCT) calcitonin did not inhibit the effect of PTH on the labeling of CDP nor did they stimulate CDP labeling directly at concentrations which inhibited bone resorption. Dibutyryl cyclic-3',5'-adenosine monophosphate (D3cAMP) inhibited labeling of CDP at concentrations of .03 to .3 mM, thus mimicking the action of PTH. However, in this system DBcAMP inhibited 45Ca release, thus mimicking CT. We conclude that the direct effect of PTH on bone collagen synthesis is a slow reversible inhibition, not opposed by CT. This effect may be mediated by cAMP formation in bone cells.
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PMID:Hormonal control of bone collagen synthesis in vitro: effects of parathyroid hormone and calcitonin. 94 52

Rat collagen type I was digested with bacterial collagenase. The peptides obtained were submitted to gel filtration on Sephadex G-25. Two fractions differing in molecular weight (CDP I-3000 D and CDP II-1200 D) were obtained. These fractions administered to rats were found to have an inhibiting effect on the central nervous system (CNS) in Lat's test and the mobility of the animals recorded on a motimeter was found to be reduced. This effect was dependent on the peptide dose and occurred after intravenous (iv) as well as intraventricular (icv) injection.
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PMID:The effect of collagen degradation products (CDP) on the central nervous system (CNS). 133 76

Avian skin fibroblasts were isolated, cultured and incubated with [3H]proline for 24 h. The cells exported radiolabeled collagenase-digestible (CDP) and non-collagenase-digestible (NCDP) proteins into the medium. Human, bovine and avian growth hormone (GH) as well as insulin-like growth factor I (IGF-I) attenuated the appearance of [3H]CDP in the medium without affecting [3H]NCDP. The appearance of [3H]CDP was not affected by prolactin. The effects of GH and IGF-I were enhanced by increasing concentrations of fetal calf serum (FCS). A synergism was observed between GH and IGF-I in their effect on CDP. Each peptide, at an ineffective concentration, increased the sensitivity of the cells to the other peptide. Collagenase activity in the medium was enhanced by IGF-I, but not modified by GH, FCS, or by their interaction with IGF-I. GH and IGF-I inhibition of type I procollagen gene expression was demonstrated with the aid of probes containing sequences corresponding to the mRNAs for avian alpha I and alpha II chains. The results suggest that GH and IGF-I cooperate in regulating collagen synthesis, but collagen degradation is affected by IGF-I and not by GH.
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PMID:Growth hormone and insulin-like growth factor I regulate collagen gene expression and extracellular collagen in cultures of avian skin fibroblasts. 165 42

We examined the interaction of parathyroid hormone (PTH) and recombinant human insulin-like growth factor I (IGF-I) on collagen synthesis in 21-day fetal rat calvariae as assessed by measuring the incorporation of [3H]proline into collagenase-digestible protein. After 96 hours of culture, 10 nM PTH antagonized the stimulation of collagen synthesis and partially blocked the increase in dry weight produced by 10 nM IGF-I. The effect of PTH to block IGF-I stimulated collagen synthesis was observed in the central bone of calvariae and was mimicked by forskolin and phorbol 12-myristate 13-acetate, but not by 1,25-dihydroxyvitamin D3, transforming growth factor-alpha or dexamethasone. Our data are consistent with the concept that the direct effect of PTH is to inhibit basal CDP labeling and fully oppose IGF-I stimulated CDP labeling. The finding that this effect of PTH is mimicked by forskolin and PMA suggests that this block in IGF-I stimulation of CDP labeling involves both cAMP and protein kinase C mediated pathways.
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PMID:Parathyroid hormone blocks the stimulatory effect of insulin-like growth factor-I on collagen synthesis in cultured 21-day fetal rat calvariae. 196 62

High levels of interleukin-6 (IL-6) have been detected in synovial fluid from patients with inflammatory arthropathies associated with local bone resorption, suggesting a role for IL-6 as a local regulator of bone resorption and remodeling. In the present study we examined the effects of IL-6 on [3H]thymidine ([3H]TdR) incorporation, collagen synthesis, and alkaline phosphatase activity in UMR-106-01 rat osteoblastic osteosarcoma cells. IL-6 stimulated a dose-dependent increase in [3H]TdR incorporation that was maximal at 1000 U/ml (-147% of basal, p less than 0.005) in osteoblastlike cells that were in a logarithmic phase of growth. The increase in [3H]TdR incorporation was maximal between 12 and 24 h and was neutralized by pretreatment with the polyclonal rabbit antibody to IL-6. IL-6 also increased cell number and the secretion of prostaglandin E2 in UMR-106-01 cells in logarithmic growth phase. The stimulation of [3H]TdR incorporation and release of PGE2 into the culture medium by IL-6 was inhibited by indomethacin. A 24 h exposure of the osteoblastlike cells to 1000 U/ml of IL-6 reduced [3H]proline incorporation into collagenase-digestible (CDP) protein to 73% of control values (p less than 0.01). Noncollagen protein (NCP) synthesis was inhibited to 80% of control values (p less than 0.01) by 1000 U/ml of IL-6. The inhibitory effect was relatively greater on CDP than on NCP and consequently resulted in a decrease in the percentage of collagen synthesis. Alkaline phosphatase activity was not altered in these cells after a 24 h exposure to 1-1000 U/ml of IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of interleukin-6 on cellular function in UMR-106-01 osteoblastlike cells. 202 35

To assess the effects of heparin on bone formation we measured [3H]proline incorporation into collagenase-digestible (CDP) and noncollagen protein (NCP), [3H]thymidine (TdR) incorporation into DNA, and DNA content in 21-day-old fetal rat calvaria cultured in BGJ medium with bovine serum albumin for 24-96 hours. Heparin at 5-125 micrograms/ml decreased TdR incorporation by 26-51% at 24 and 96 hours. At 96 hours, heparin 5, 25, and 125 micrograms/ml decreased [3H]proline incorporation into CDP by 41, 48, and 32%, respectively, with no significant change in NCP. To evaluate the possible role of PGE2 in these inhibitory responses, media PGE2 concentration was measured and the effects of heparin on CDP labeling and DNA synthesis were tested in the presence of indomethacin, piroxicam, and flurbiprofen to inhibit endogenous prostaglandin E2 (PGE2) production and in the presence of a high concentration (10(-7) M) of exogenous PGE2. Heparin did not alter PGE2 production at 24 hours but at 48 hours there was a significant reduction. At 96 hours, indomethacin (10(-6) M) inhibited [3H]-proline incorporation into CDP by 38% but had no effect on the labeling of NCP. Heparin had no further significant inhibitory effect in the presence of indomethacin. Piroxicam and flurbiprofen did not alter DNA content and had a smaller inhibitory effect than indomethacin on the labeling of CDP. Moreover, addition of heparin produced a further inhibition of CDP and DNA content and finally, heparin decreased CDP labeling by 71% in the presence of PGE2.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of heparin on bone formation in cultured fetal rat calvaria. 210 77

Although most studies show that prostaglandin E2 (PGE2) is the most potent and effective of the prostanoids in bone, recent data in cell culture suggest that PGF2 alpha may have unique effects, particularly on cell replication. The present study was undertaken to compare the effects of PGF2 alpha and PGE2 in cultured neonatal mouse parietal bones by simultaneous measurement of bone resorption as release of previously incorporated 45Ca, bone formation as incorporation of [3H]proline into collagenase-digestible (CDP) and noncollagen protein, and DNA synthesis as incorporation of [3H]thymidine. PGF2 alpha was less effective than PGE2 as a stimulator of bone resorption, and its effects were partially inhibited by indomethacin and markedly inhibited by glucocorticoids. In contrast, the resorptive response to PGE2 was unaffected by indomethacin and only partially inhibited by cortisol. PGF2 alpha had little effect on bone formation, in contrast to the biphasic effect of PGE2, which inhibited labeling of CDP in the absence of cortisol and stimulated CDP labeling in the presence of cortisol. PGF2 alpha increased thymidine incorporation into DNA, but the effect was smaller than that of PGE2 and was inhibited by indomethacin. These observations suggested that PGF2 alpha might act in part by stimulating PGE2 production. By RIA, PGE2 concentrations were increased in the medium of bones treated with PGF2 alpha, and this increase was blocked by indomethacin. By HPLC, bones prelabeled with [3H]arachidonic acid showed an increase in labeled PGE2 release, and RIA showed an increase in PGE2 after PGF2 alpha treatment. These results indicate that PGF2 alpha is a relatively weak agonist in bone compared to PGE2 and that some of the effects of PGF2 alpha on bone resorption, formation, and cell replication may be mediated by an increase in endogenous PGE2 production.
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PMID:Effects of prostaglandin F2 alpha on bone formation and resorption in cultured neonatal mouse calvariae: role of prostaglandin E2 production. 229 53

Transforming growth factor alpha (TGF-alpha) and interleukin-1 (IL-1) have been shown to affect bone metabolism in vitro by prostaglandin-dependent and PG-independent mechanisms. We assessed the effects of the combination of these two agents on [3H]thymidine (TdR) incorporation into DNA, DNA content, [3H]proline incorporation into collagenase-digestible (CDP), noncollagen protein (NCP), and PGE2 production in 21 day fetal rat calvaria cultured for 24-96 h. We also determined whether TGF-alpha plus IL-1 altered procollagen mRNA levels at 96 h. TGF-alpha, 1-30 ng/ml, produced a 41-59% increase in TdR incorporation into DNA, but the effect was partially blocked by human recombinant IL-1. At 96 h TGF-alpha alone or in combination with IL-1 significantly increased the DNA content of calvaria. At 96 h, TGF-alpha inhibited CDP labeling and the addition of IL-1 further enhanced this inhibitory effect. The enhanced inhibitory effect of TGF-alpha plus IL-1 on collagen synthesis was associated with a synergistic increase in prostaglandin accumulation in the medium. Addition of indomethacin blocked PGE2 accumulation and partially reversed the inhibitory effect of TGF-alpha alone or in combination with IL-1 on collagen synthesis. TGF-alpha decreased procollagen mRNA levels by 55%, but the combination of TGF-alpha plus IL-1 decreased procollagen mRNA levels by 82%. Our results show that TGF-alpha and IL-1, which are both produced by certain tumors as well as activated macrophages, appear to act synergistically to increase prostaglandin synthesis and inhibit collagen synthesis in vitro. Thus these agents may have a regulatory role on bone formation in vivo.
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PMID:Effects of transforming growth factor alpha and interleukin-1 on DNA synthesis, collagen synthesis, procollagen mRNA levels, and prostaglandin E2 production in cultured fetal rat calvaria. 281 17

The effects of triamcinolone hexacetonide (TH) on the synthesis of collagen and noncollagen proteins were tested in mandibular condylar cartilage of newborn mice. Four-day-old ICR mice received a single i.p. injection of TH at doses ranging from 0.4 to 4.0 mg/kg body weight. Hydrocortisone, deoxycorticosterone, dexamethasone, and progesterone were administered at a dose of 4.0 mg/kg. Test animals and nontreated and vehicle-treated controls were sacrificed after 24, 48, and 72 hours and were processed for electron microscopy. Additional animals were injected with 5 microCi of 3H-proline 2 hours before sacrifice. The specimens were extracted with 5% TCA containing 1 mM proline followed by 5% TCA, acetone, and ether, homogenized and digested with purified bacterial collagenase, and the amounts of radioactivity in collagenase digestible (CDP) and noncollagen proteins (NCP) were determined. The present results revealed that triamcinolone led to a significant dose-dependent decrease in the protein content of the tissue that lasted for 3 days (12-14% at the dose of 4 mg/kg). The incorporation of 3H-proline into CDP was reduced by 39, 57, and 42% at 24, 48, and 72 hours, respectively whereas the incorporation into NCP was reduced by 20, 35, and 23%, respectively. When compared with other steroids, dexamethasone revealed a similar inhibitory effect, whereas hydrocortisone and deoxycorticosterone had no significant effect. Progesterone, on the other hand, showed a transient (24 hours) stimulatory effect on the synthesis of collagen synthesis (21%, P less than 0.05). Electron microscopy showed an atypical arrangement of collagen fibers and accumulation of large aggregates of collagen that filled the entire matrical space between cartilage cells.
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PMID:Triamcinolone impairs the synthesis of collagen and noncollagen proteins in condylar cartilage of newborn mice. 312 68


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