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Karin Scharffetter-kochanek - One of the best experts on this subject based on the ideXlab platform.
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Myocardial fibrosis in transforming growth factor‐β1 (TGF‐β1) transgenic mice is associated with inhibition of Interstitial Collagenase
European journal of clinical investigation, 2002Co-Authors: Ute Seeland, R. Hinrichs, Karin Scharffetter-kochanek, C. Haeuseler, S. Rosenkranz, T. Pfitzner, Michael BöhmAbstract:BACKGROUND TGF-beta(1) mediates effects on fibroblast proliferation and collagen synthesis in the myocardium. The extracellular matrix remodeling depends on the fibrillar collagen degrading matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). The in vivo effects of TGF-beta(1) on the MMP/TIMP system in TGF-beta(1) overexpressing transgenic mice were studied. METHODS Male Alb/TGF-beta(1)(cys(223,225)ser) transgenic mice (TG) and nontransgenic controls (C; 8 weeks) were examined. Protein expression of collagen type I, -III, Interstitial Collagenase (Int Coll), MMP-2, -9, TIMP-1, -2, -4 and TGF-beta(1) as well as enzyme activity (MMP-2, -9) were measured (Western blots, zymographic assays). mRNA expression of the Interstitial Collagenase and MMP-9 was studied with the Light-Cycler based real-time PCR. RESULTS Overexpression of TGF-beta(1) resulted in a 10-fold increase in plasma and a seven-fold increase in myocardial TGF-beta(1) concentrations. Relative heart weights increased (mg g(-1): 7.8 +/- 0.4 vs. 4.8 +/- 0.6, n = 6; P < 0.01) in TG compared to C. Collagen type I and III increased in TG (1.9-fold and 1.7-fold) compared to controls. Interstitial Collagenase protein activity (- 91%) and mRNA expression (-75%) in TG were reduced (P < 0.05-P < 0.001). Gelatinase (MMP-2, MMP-9) expression and activity were not significantly alterated. MMP-inhibitors were increased 2.5-fold (TIMP-1, -4) and 6-fold (TIMP-2) in TG. CONCLUSIONS TGF-beta(1) produces myocardial fibrosis in vivo. This effect is not only produced by a stimulation of matrix protein formation: a complex regulation of MMP and TIMP interaction, namely decrease of expression and activity of Interstitial Collagenase and an enhanced inhibition by increased levels of TIMPs, are involved. These mechanisms are optional targets for therapeutic interventions in myocardial diseases.
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Ultraviolet‐B induction of Interstitial Collagenase and stromelyin‐1 occurs in human dermal fibroblasts via an autocrine interleukin‐6‐dependent loop
FEBS letters, 1999Co-Authors: Peter Brenneisen, Meinhard Wlaschek, Jutta Wenk, R. Blaudschun, R. Hinrichs, Joachim Dissemond, Thomas Krieg, Karin Scharffetter-kochanekAbstract:Ultraviolet-B irradiation of human dermal fibroblasts has earlier been shown to induce matrix-degrading metalloproteinases, thus driving connective tissue degradation in photoaging and photocarcinogenesis. Herein, we report that Ultraviolet-B irradiation led to a dramatic increase in specific mRNA and protein levels of Interstitial Collagenase, stromelysin and interleukin-6. By contrast, the major tissue inhibitor of matrix-degrading metalloproteinases, TIMP-1, was unaffected. Monospecific neutralizing antibodies directed against human interleukin-6 significantly reduced the Interstitial Collagenase and stromelysin-1 protein levels. Taken together, our data provide the first evidence that Ultraviolet-B induction of Interstitial Collagenase and stromelysin-1 occurs via the synthesis and release of interleukin-6. Hence, this newly identified autocrine mechanism may contribute to dermal photodamage.
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Singlet oxygen is an early intermediate in cytokine-dependent ultraviolet-A induction of Interstitial Collagenase in human dermal fibroblasts in vitro
FEBS letters, 1997Co-Authors: Meinhard Wlaschek, Peter Brenneisen, Jutta Wenk, Karlis Briviba, Agatha Schwarz, Helmut Sies, Karin Scharffetter-kochanekAbstract:Ultraviolet (UV) A irradiation of human dermal fibroblasts elicits an increase in specific mRNA amounts and bioactivities of the cytokines IL-1α, IL-1β, and IL-6. These effects are enhanced in deuterium oxide-based medium and are diminished in the presence of non-toxic concentrations of sodium azide. Furthermore, generating singlet oxygen outside the cells by irradiation of rose bengal-coated resin particles with visible light (λ>450 nm) results in the induction of Interstitial Collagenase, IL-1 and IL-6, similar to the response observed with UVA irradiation. These observations suggest that singlet oxygen is an early intermediate in the signaling pathway of IL-1 and IL-6 mediating UVA induction of Interstitial Collagenase (E.C. 3.4.24.7). Furthermore, singlet oxygen appears to initiate this complex UV response at the cell membrane.
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Singlet Oxygen May Mediate the Ultraviolet A-Induced Synthesis of Interstitial Collagenase
The Journal of investigative dermatology, 1995Co-Authors: Meinhard Wlaschek, Karlis Briviba, Helmut Sies, George P. Stricklin, Karin Scharffetter-kochanekAbstract:Singlet oxygen has been postulated to be generated by Ultraviolet (UV) A irradiation of mammalian cells. We studied the role of singlet oxygen in the down-stream signaling of the complex UV response leading to the induction of matrix-metalloproteinase-1 (Interstitial Collagenase/MMP-1). Exposure of cultured human fibroblasts to singlet oxygen, generated in a dark reaction by thermodissociation of the endoperoxide of the disodium salt of 3,3'-(1,4-naphthylidene) dipropionate (NDPO2) induced Collagenase mRNA steady state levels in a dose dependent manner. The increase in Collagenase expression after singlet-oxygen exposure generated with 3 mM NDPO2 was equivalent to that observed with UVA at a dose rate of 200-300 kJ/m2 and developed in a similar time course, In contrast, mRNA levels of TIMP-1, the specific tissue inhibitor of metalloproteinases, remained unchanged. Indirect evidence for the role of singlet oxygen in the UVA induction of Collagenase comes from studies using singlet oxygen enhancer or quencher. Accordingly, incubation in deuterium oxide, an enhancer of singlet-oxygen lifetime, led to an additional increase in steady-state levels of Collagenase mRNA after exposure to NDPO2 or to UVA irradiation, In contrast, sodium azide, a potent quencher of singlet oxygen, almost totally abrogated the induction of Collagenase after exposure of fibroblasts to NDPO2 or to UVA irradiation. Similar results were obtained in studies of the proteins by radioimmunoprecipitation of MMP-1 and TIMP-1 using specific antibodies, Collectively, our data provide circumstantial evidence that singlet oxygen mediates the UVA induction of Collagenase in vitro, whereas It does not exert any effect on TIMP-1 synthesis. The unbalanced synthesis of Interstitial Collagenase may contribute to the connective tissue damage in viva related to photoaging and other photocutaneous disorders.
Meinhard Wlaschek - One of the best experts on this subject based on the ideXlab platform.
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Ultraviolet‐B induction of Interstitial Collagenase and stromelyin‐1 occurs in human dermal fibroblasts via an autocrine interleukin‐6‐dependent loop
FEBS letters, 1999Co-Authors: Peter Brenneisen, Meinhard Wlaschek, Jutta Wenk, R. Blaudschun, R. Hinrichs, Joachim Dissemond, Thomas Krieg, Karin Scharffetter-kochanekAbstract:Ultraviolet-B irradiation of human dermal fibroblasts has earlier been shown to induce matrix-degrading metalloproteinases, thus driving connective tissue degradation in photoaging and photocarcinogenesis. Herein, we report that Ultraviolet-B irradiation led to a dramatic increase in specific mRNA and protein levels of Interstitial Collagenase, stromelysin and interleukin-6. By contrast, the major tissue inhibitor of matrix-degrading metalloproteinases, TIMP-1, was unaffected. Monospecific neutralizing antibodies directed against human interleukin-6 significantly reduced the Interstitial Collagenase and stromelysin-1 protein levels. Taken together, our data provide the first evidence that Ultraviolet-B induction of Interstitial Collagenase and stromelysin-1 occurs via the synthesis and release of interleukin-6. Hence, this newly identified autocrine mechanism may contribute to dermal photodamage.
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ultraviolet b induction of Interstitial Collagenase and stromelyin 1 occurs in human dermal fibroblasts via an autocrine interleukin 6 dependent loop
FEBS Letters, 1999Co-Authors: Peter Brenneisen, Meinhard Wlaschek, Jutta Wenk, R. Blaudschun, R. Hinrichs, Joachim Dissemond, Thomas Krieg, Karin ScharffetterkochanekAbstract:Ultraviolet-B irradiation of human dermal fibroblasts has earlier been shown to induce matrix-degrading metalloproteinases, thus driving connective tissue degradation in photoaging and photocarcinogenesis. Herein, we report that Ultraviolet-B irradiation led to a dramatic increase in specific mRNA and protein levels of Interstitial Collagenase, stromelysin and interleukin-6. By contrast, the major tissue inhibitor of matrix-degrading metalloproteinases, TIMP-1, was unaffected. Monospecific neutralizing antibodies directed against human interleukin-6 significantly reduced the Interstitial Collagenase and stromelysin-1 protein levels. Taken together, our data provide the first evidence that Ultraviolet-B induction of Interstitial Collagenase and stromelysin-1 occurs via the synthesis and release of interleukin-6. Hence, this newly identified autocrine mechanism may contribute to dermal photodamage.
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Singlet oxygen is an early intermediate in cytokine-dependent ultraviolet-A induction of Interstitial Collagenase in human dermal fibroblasts in vitro
FEBS letters, 1997Co-Authors: Meinhard Wlaschek, Peter Brenneisen, Jutta Wenk, Karlis Briviba, Agatha Schwarz, Helmut Sies, Karin Scharffetter-kochanekAbstract:Ultraviolet (UV) A irradiation of human dermal fibroblasts elicits an increase in specific mRNA amounts and bioactivities of the cytokines IL-1α, IL-1β, and IL-6. These effects are enhanced in deuterium oxide-based medium and are diminished in the presence of non-toxic concentrations of sodium azide. Furthermore, generating singlet oxygen outside the cells by irradiation of rose bengal-coated resin particles with visible light (λ>450 nm) results in the induction of Interstitial Collagenase, IL-1 and IL-6, similar to the response observed with UVA irradiation. These observations suggest that singlet oxygen is an early intermediate in the signaling pathway of IL-1 and IL-6 mediating UVA induction of Interstitial Collagenase (E.C. 3.4.24.7). Furthermore, singlet oxygen appears to initiate this complex UV response at the cell membrane.
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Singlet Oxygen May Mediate the Ultraviolet A-Induced Synthesis of Interstitial Collagenase
The Journal of investigative dermatology, 1995Co-Authors: Meinhard Wlaschek, Karlis Briviba, Helmut Sies, George P. Stricklin, Karin Scharffetter-kochanekAbstract:Singlet oxygen has been postulated to be generated by Ultraviolet (UV) A irradiation of mammalian cells. We studied the role of singlet oxygen in the down-stream signaling of the complex UV response leading to the induction of matrix-metalloproteinase-1 (Interstitial Collagenase/MMP-1). Exposure of cultured human fibroblasts to singlet oxygen, generated in a dark reaction by thermodissociation of the endoperoxide of the disodium salt of 3,3'-(1,4-naphthylidene) dipropionate (NDPO2) induced Collagenase mRNA steady state levels in a dose dependent manner. The increase in Collagenase expression after singlet-oxygen exposure generated with 3 mM NDPO2 was equivalent to that observed with UVA at a dose rate of 200-300 kJ/m2 and developed in a similar time course, In contrast, mRNA levels of TIMP-1, the specific tissue inhibitor of metalloproteinases, remained unchanged. Indirect evidence for the role of singlet oxygen in the UVA induction of Collagenase comes from studies using singlet oxygen enhancer or quencher. Accordingly, incubation in deuterium oxide, an enhancer of singlet-oxygen lifetime, led to an additional increase in steady-state levels of Collagenase mRNA after exposure to NDPO2 or to UVA irradiation, In contrast, sodium azide, a potent quencher of singlet oxygen, almost totally abrogated the induction of Collagenase after exposure of fibroblasts to NDPO2 or to UVA irradiation. Similar results were obtained in studies of the proteins by radioimmunoprecipitation of MMP-1 and TIMP-1 using specific antibodies, Collectively, our data provide circumstantial evidence that singlet oxygen mediates the UVA induction of Collagenase in vitro, whereas It does not exert any effect on TIMP-1 synthesis. The unbalanced synthesis of Interstitial Collagenase may contribute to the connective tissue damage in viva related to photoaging and other photocutaneous disorders.
Ernesto Canalis - One of the best experts on this subject based on the ideXlab platform.
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Transcriptional and posttranscriptional regulation of Interstitial Collagenase by platelet-derived growth factor BB in bone cell cultures.
Endocrinology, 1996Co-Authors: Samuel Varghese, J J Jeffrey, Anne M. Delany, L Liang, Bari Gabbitas, Ernesto CanalisAbstract:Platelet-derived growth factor (PDGF), a bone cell mitogen, stimulates bone collagen degradation and does not enhance bone matrix apposition rates. The mechanism of the effect on collagen degradation is unknown, and it could involve changes in Interstitial Collagenase synthesis. We tested the effects of PDGF on Interstitial Collagenase expression in cultures of osteoblast-enriched cells from fetal rat calvariae (Ob cells). After 4-8 h of treatment, PDGF BB at 0.3 nM increased steady state Collagenase messenger RNA (mRNA), whereas PDGF AA had no effect. The effect of PDGF BB on Collagenase transcripts was dose dependent. PDGF BB increased the levels of immunoreactive Collagenase after 6 h, whereas the levels were decreased after 16 h. Stimulation of Collagenase mRNA by PDGF BB was dependent on de novo protein synthesis and activation of protein kinase C. PDGF BB prolonged the half-life of Collagenase mRNA in transcriptionally arrested cells. PDGF BB initially increased and subsequently decreased the rate o...
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Cortisol Increases Interstitial Collagenase Expression in Osteoblasts by Post-transcriptional Mechanisms
The Journal of biological chemistry, 1995Co-Authors: Anne M. Delany, Sheila Rydziel, John J. Jeffrey, Ernesto CanalisAbstract:Glucocorticoids regulate both bone formation and bone resorption. In osteoblasts, they inhibit type I collagen synthesis; however, there is limited information about their effects on Interstitial Collagenase, the enzyme that degrades type I collagen. We used primary cultures of osteoblast-enriched cells from fetal rat calvariae (Ob cells) to study the effects of cortisol on Collagenase expression. Northern blot analysis showed that cortisol increased Collagenase transcript levels in a dose- and time-dependent manner, which was paralleled by an increase in immunoreactive metalloproteinase in the culture medium. Cortisol increased the half-life of Collagenase mRNA from 6 to 12 h in transcription-arrested Ob cells. In contrast, cortisol modestly decreased Collagenase gene transcription after 24 h of treatment. The up-regulation of Collagenase by cortisol is osteoblast-specific, since the glucocorticoid decreased phorbol 12-myristate 13-acetate-induced Collagenase mRNA expression in rat fibroblasts, a result that agrees with other studies of Collagenase gene regulation in fibroblastic cells. In conclusion, cortisol increases Interstitial Collagenase transcript levels by post-transcriptional mechanisms in osteoblastic cells. Our data demonstrate that glucocorticoids regulate Collagenase gene expression in a novel tissue-specific manner, further highlighting the differences in gene regulation between osteoblastic and fibroblastic cells.
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Basic fibroblast growth factor stimulates expression of Interstitial Collagenase and inhibitors of metalloproteinases in rat bone cells
Endocrinology, 1995Co-Authors: Samuel Varghese, Melinda L. Ramsby, J J Jeffrey, Ernesto CanalisAbstract:Basic fibroblast growth factor (bFGF) is a bone cell mitogen that affects osteoblastic function by suppressing type I collagen synthesis. The investigators in this study examined whether bFGF also regulates Interstitial Collagenase and tissue inhibitors of metalloproteinases (TIMPs) in osteoblast-enriched cells isolated from 22-day fetal rat calvariae. After exposure to 600 pM bFGF, Interstitial Collagenase messenger RNA (mRNA) levels, as determined by Northern hybridization analysis, increased after 2 h and were maximally stimulated to approximately 13-fold at 6 h. Exposure of osteoblast-enriched cells to 0.06-6 nM bFGF increased Collagenase mRNA in a dose-dependent manner, and bFGF also increased immunoreactive Collagenase measured in the culture medium by Western blot analysis. The protein synthesis inhibitor cycloheximide, as well as two inhibitors of protein kinase C, staurosporine and sangivamycin, prevented the bFGF induction of Collagenase transcripts, whereas indomethacin, an inhibitor of prostag...
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Basic fibroblast growth factor stimulates expression of Interstitial Collagenase and inhibitors of metalloproteinases in rat bone cells
Endocrinology, 1995Co-Authors: Samuel Varghese, Melinda L. Ramsby, J J Jeffrey, Ernesto CanalisAbstract:Basic fibroblast growth factor (bFGF) is a bone cell mitogen that affects osteoblastic function by suppressing type I collagen synthesis. The investigators in this study examined whether bFGF also regulates Interstitial Collagenase and tissue inhibitors of metalloproteinases (TIMPs) in osteoblast-enriched cells isolated from 22-day fetal rat calvariae. After exposure to 600 pM bFGF, Interstitial Collagenase messenger RNA (mRNA) levels, as determined by Northern hybridization analysis, increased after 2 h and were maximally stimulated to approximately 13-fold at 6 h. Exposure of osteoblast-enriched cells to 0.06-6 nM bFGF increased Collagenase mRNA in a dose-dependent manner, and bFGF also increased immunoreactive Collagenase measured in the culture medium by Western blot analysis. The protein synthesis inhibitor cycloheximide, as well as two inhibitors of protein kinase C, staurosporine and sangivamycin, prevented the bFGF induction of Collagenase transcripts, whereas indomethacin, an inhibitor of prostag...
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Insulin-like growth factors inhibit Interstitial Collagenase synthesis in bone cell cultures
Endocrinology, 1995Co-Authors: Ernesto Canalis, Sheila Rydziel, Samuel Varghese, Anne M. Delany, J J JeffreyAbstract:Insulin-like growth factor-I (IGF-I) and IGF-II are among the most prevalent growth factors secreted by bone cells and are presumed to act as autocrine regulators of bone formation. We recently demonstrated that IGFs inhibit bone collagen degradation, and we postulated that they may either inhibit the expression of Interstitial Collagenase or stimulate the synthesis of tissue inhibitors of metalloproteinase-1 (TIMP-1), -2, or -3. We tested the effects of IGF-I and -II on Collagenase and TIMP-1, -2, and -3 expression in cultures of osteoblast-enriched cells from 22-day-old fetal rat calvariae (Ob cells). Steady state messenger RNA (mRNA) levels were determined by Northern blot analysis, and Collagenase concentrations were determined in the culture medium by a specific immunoassay. After 2-6 h of treatment, IGF-I and -II decreased Collagenase transcripts by up to 80%. IGF-I was a more potent inhibitor than IGF-II, because it was active at doses as low as 10 nM, whereas a dose of 100 nM was required to obser...
Larry M. Wahl - One of the best experts on this subject based on the ideXlab platform.
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interleukin 4 inhibition of prostaglandin e2 synthesis blocks Interstitial Collagenase and 92 kda type iv Collagenase gelatinase production by human monocytes
Journal of Biological Chemistry, 1992Co-Authors: Marta L Corcoran, William G Stetlerstevenson, P D Brown, Larry M. WahlAbstract:Abstract Activation of human monocytes results in the production of Interstitial Collagenase through a prostaglandin E2 (PGE2)-cAMP-dependent pathway. Inasmuch as interleukin 4 (IL-4) has been shown to inhibit PGE2 synthesis by monocytes, we examined the effect of IL-4 on the production of human monocyte Interstitial Collagenase. Additionally, we also assessed the effect of IL-4 on the production of 92-kDa type IV Collagenase/gelatinase and tissue inhibitor of metalloproteinase-1 (TIMP-1) by monocytes. The inhibition of PGE2 synthesis by IL-4 resulted in decreased Interstitial Collagenase protein and activity that could be restored by exogenous PGE2 or dibutyryl cyclic AMP (Bt2cAMP). IL-4 also suppressed ConA-stimulated 92-kDa type IV Collagenase/gelatinase protein and zymogram enzyme activity that could be reversed by exogenous PGE2 or Bt2cAMP. Moreover, indomethacin suppressed the ConA-induced production of 92-kDa type IV Collagenase/gelatinase. These data demonstrate that, like monocyte Interstitial Collagenase, the conA-inducible monocyte 92-kDa type IV Collagenase/gelatinase is regulated through a PGE2-mediated cAMP-dependent pathway. In contrast to ConA stimulation, unstimulated monocytes released low levels of 92-kDa type IV Collagenase/gelatinase that were not affected by IL-4, PGE2, or Bt2cAMP, indicating that basal production of this enzyme is PGE2-cAMP independent. IL-4 inhibition of both Collagenases was not a result of increased TIMP expression since Western analysis of 28.5-kDa TIMP-1 revealed that IL-4 did not alter the increased TIMP-1 protein in response to ConA. These data indicate that IL-4 may function in natural host regulation of connective tissue damage by monocytes.
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Interleukin 4 inhibition of prostaglandin E2 synthesis blocks Interstitial Collagenase and 92-kDa type IV Collagenase/gelatinase production by human monocytes.
The Journal of biological chemistry, 1992Co-Authors: Marta L Corcoran, William G. Stetler-stevenson, Peter D Brown, Larry M. WahlAbstract:Activation of human monocytes results in the production of Interstitial Collagenase through a prostaglandin E2 (PGE2)-cAMP-dependent pathway. Inasmuch as interleukin 4 (IL-4) has been shown to inhibit PGE2 synthesis by monocytes, we examined the effect of IL-4 on the production of human monocyte Interstitial Collagenase. Additionally, we also assessed the effect of IL-4 on the production of 92-kDa type IV Collagenase/gelatinase and tissue inhibitor of metalloproteinase-1 (TIMP-1) by monocytes. The inhibition of PGE2 synthesis by IL-4 resulted in decreased Interstitial Collagenase protein and activity that could be restored by exogenous PGE2 or dibutyryl cyclic AMP (Bt2cAMP). IL-4 also suppressed ConA-stimulated 92-kDa type IV Collagenase/gelatinase protein and zymogram enzyme activity that could be reversed by exogenous PGE2 or Bt2cAMP. Moreover, indomethacin suppressed the ConA-induced production of 92-kDa type IV Collagenase/gelatinase. These data demonstrate that, like monocyte Interstitial Collagenase, the conA-inducible monocyte 92-kDa type IV Collagenase/gelatinase is regulated through a PGE2-mediated cAMP-dependent pathway. In contrast to ConA stimulation, unstimulated monocytes released low levels of 92-kDa type IV Collagenase/gelatinase that were not affected by IL-4, PGE2, or Bt2cAMP, indicating that basal production of this enzyme is PGE2-cAMP independent. IL-4 inhibition of both Collagenases was not a result of increased TIMP expression since Western analysis of 28.5-kDa TIMP-1 revealed that IL-4 did not alter the increased TIMP-1 protein in response to ConA. These data indicate that IL-4 may function in natural host regulation of connective tissue damage by monocytes.
J J Jeffrey - One of the best experts on this subject based on the ideXlab platform.
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Regulation of the rat Interstitial Collagenase promoter by IL‐1β, c‐Jun, and ras‐dependent signaling in growth plate chondrocytes
Journal of Cellular Biochemistry, 1997Co-Authors: R.m. Grumbles, J J Jeffrey, David S HowellAbstract:In an attempt to better define molecular influences on rat Interstitial Collagenase gene expression in cartilage, the promoter function was characterized using transient transfection assay, electrophoresis mobility shift assay, and genetic analysis in isolated growth plate chondrocytes. Data from 5'-flanking deletion and selected mutations suggest that multiple cis elements in both the proximal and distal regions of the promoter were important in the regulation of promoter activity. A proximal tumor response element (TRE) was shown to be necessary for basal and interleukin (IL)-1 beta-inducible reporter gene activity. Cells stimulated by IL-1 beta (1 ng/ml; 18 h) had elevated TRE binding activity, and one of the factors involved was identified as the nuclear protein, c-Jun. Indeed, c-Jun directed antisense oligonucleotides reduced rat Interstitial Collagenase mRNA. A sense oligonucleotide was ineffective. Regulation of promoter activity was susceptible to Ras-dependent signaling as expression of dominant negative mutant of Ras kinase (pZIP-RasN17) reduced reporter gene activity. In a comparison of proximal promoter reporter plasmid activity between proliferative and hypertrophic cells, inhibition of Ras-dependent signaling was less effective in the later cell type. This study suggests that the activation of nuclear binding proteins that bind TRE may be a common event with IL-1 beta regulation. Moreover, these data suggest that the regulation of rat Interstitial Collagenase gene expression is a combinatorial process and multiple cis-acting regulatory sites may interact to exert different effects dependent on the stage of chondrocyte differentiation.
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regulation of the rat Interstitial Collagenase promoter by il 1β c jun and ras dependent signaling in growth plate chondrocytes
Journal of Cellular Biochemistry, 1997Co-Authors: R.m. Grumbles, J J Jeffrey, L Shao, David S HowellAbstract:In an attempt to better define molecular influences on rat Interstitial Collagenase gene expression in cartilage, the promoter function was characterized using transient transfection assay, electrophoresis mobility shift assay, and genetic analysis in isolated growth plate chondrocytes. Data from 5'-flanking deletion and selected mutations suggest that multiple cis elements in both the proximal and distal regions of the promoter were important in the regulation of promoter activity. A proximal tumor response element (TRE) was shown to be necessary for basal and interleukin (IL)-1 beta-inducible reporter gene activity. Cells stimulated by IL-1 beta (1 ng/ml; 18 h) had elevated TRE binding activity, and one of the factors involved was identified as the nuclear protein, c-Jun. Indeed, c-Jun directed antisense oligonucleotides reduced rat Interstitial Collagenase mRNA. A sense oligonucleotide was ineffective. Regulation of promoter activity was susceptible to Ras-dependent signaling as expression of dominant negative mutant of Ras kinase (pZIP-RasN17) reduced reporter gene activity. In a comparison of proximal promoter reporter plasmid activity between proliferative and hypertrophic cells, inhibition of Ras-dependent signaling was less effective in the later cell type. This study suggests that the activation of nuclear binding proteins that bind TRE may be a common event with IL-1 beta regulation. Moreover, these data suggest that the regulation of rat Interstitial Collagenase gene expression is a combinatorial process and multiple cis-acting regulatory sites may interact to exert different effects dependent on the stage of chondrocyte differentiation.
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regulation of rat Interstitial Collagenase gene expression in growth cartilage and chondrocytes by vitamin d3 interleukin 1β and okadaic acid
Journal of Cellular Biochemistry, 1996Co-Authors: R.m. Grumbles, J J Jeffrey, L Shao, David S HowellAbstract:The Interstitial Collagenase produced by the rat growth plate chondrocytes is the homologue of the human Collagenase-3, or matrix metalloproteinase-13. This enzyme is responsible for the loss of collagen during hypertrophy of chondrocytes and for the degradation of transverse septa in long bone growth. Rachitic rats (42 days, male Sprague-Dawley) had an 8-fold higher level of Collagenase mRNA in the hypertrophic versus proliferative zone of growth plate cartilage. Intramuscular injection of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3; 1.0 micrograms/kg body weight) in rachitic rats increased Collagenase mRNA another 1.5-fold in the hypertrophic zone. The regulation of Collagenase gene by 1,25-(OH)2D3 and interleukin (IL)-1 beta in cultured proliferative chondrocytes was studied by means of steady-state mRNA and half-life determination of mRNA using the transcriptional inhibitor actinomycin D, and nuclear run-on transcription analyses. Treatment of cells with 1,25-(OH)2D3 (10(-6) M) and IL-1 beta (2 ng/ml) increased Collagenase mRNA 8- and 13-fold, respectively. Additionally, the Collagenase mRNA half-life was increased by 1,25-(OH)2D3 and IL-1 beta. In the presence of a protein kinase C inhibitor, staurosporine, 1,25-(OH)2 D3 induction of Collagenase mRNA was blocked. Here the addition of phorbol 12-myrisate 13-acetate (PMA) to activate protein kinase C increased Collagenase mRNA 10-fold. However, in the presence of staurosporine (50 nM), PMA induction was blocked, whereas IL-1 beta was not. IL-1 beta is known to activate several phosphorylation pathways. Okadaic acid (500 nM), a protein phosphatase inhibitor, increased the relative Collagenase mRNA abundance 10-fold. The rate of the rat Collagenase gene transcription in nuclei was increased with 1,25-(OH)2D3, IL-1 beta and okadaic acid. In separate experiments, the Collagenase promoter was ligated to a reporter plasmid and the plasmid was transfected into chondrocytes. The results showed that 1,25-(OH)2D3, IL-1 beta, and PMA increased reporter activity 2.5-, 2.8-, and 3.27-fold, respectively. Thus, there are multiple nuclear and cytoplasmic mechanisms by which cartilage modulators regulate rat Interstitial Collagenase gene expression.
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Transcriptional and posttranscriptional regulation of Interstitial Collagenase by platelet-derived growth factor BB in bone cell cultures.
Endocrinology, 1996Co-Authors: Samuel Varghese, J J Jeffrey, Anne M. Delany, L Liang, Bari Gabbitas, Ernesto CanalisAbstract:Platelet-derived growth factor (PDGF), a bone cell mitogen, stimulates bone collagen degradation and does not enhance bone matrix apposition rates. The mechanism of the effect on collagen degradation is unknown, and it could involve changes in Interstitial Collagenase synthesis. We tested the effects of PDGF on Interstitial Collagenase expression in cultures of osteoblast-enriched cells from fetal rat calvariae (Ob cells). After 4-8 h of treatment, PDGF BB at 0.3 nM increased steady state Collagenase messenger RNA (mRNA), whereas PDGF AA had no effect. The effect of PDGF BB on Collagenase transcripts was dose dependent. PDGF BB increased the levels of immunoreactive Collagenase after 6 h, whereas the levels were decreased after 16 h. Stimulation of Collagenase mRNA by PDGF BB was dependent on de novo protein synthesis and activation of protein kinase C. PDGF BB prolonged the half-life of Collagenase mRNA in transcriptionally arrested cells. PDGF BB initially increased and subsequently decreased the rate o...
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Basic fibroblast growth factor stimulates expression of Interstitial Collagenase and inhibitors of metalloproteinases in rat bone cells
Endocrinology, 1995Co-Authors: Samuel Varghese, Melinda L. Ramsby, J J Jeffrey, Ernesto CanalisAbstract:Basic fibroblast growth factor (bFGF) is a bone cell mitogen that affects osteoblastic function by suppressing type I collagen synthesis. The investigators in this study examined whether bFGF also regulates Interstitial Collagenase and tissue inhibitors of metalloproteinases (TIMPs) in osteoblast-enriched cells isolated from 22-day fetal rat calvariae. After exposure to 600 pM bFGF, Interstitial Collagenase messenger RNA (mRNA) levels, as determined by Northern hybridization analysis, increased after 2 h and were maximally stimulated to approximately 13-fold at 6 h. Exposure of osteoblast-enriched cells to 0.06-6 nM bFGF increased Collagenase mRNA in a dose-dependent manner, and bFGF also increased immunoreactive Collagenase measured in the culture medium by Western blot analysis. The protein synthesis inhibitor cycloheximide, as well as two inhibitors of protein kinase C, staurosporine and sangivamycin, prevented the bFGF induction of Collagenase transcripts, whereas indomethacin, an inhibitor of prostag...
