scholarly journals Requirement of Cyclin D1 in Mesangial Cell Mitogenesis

2000 ◽  
Vol 11 (8) ◽  
pp. 1398-1408
Author(s):  
STEFAN LANG ◽  
ANDREA HARTNER ◽  
R. BERND STERZEL ◽  
HARALD O. SCHÖCKLMANN
Keyword(s):  
Growth Factor ◽  
Protein Expression ◽  
Cyclin D1 ◽  
Transforming Growth Factor ◽  
D1 Protein ◽  
Transforming Growth Factor Β1 ◽  
Protein Levels ◽  
Cyclin D1 Protein

Abstract. Hyperplasia of mesangial cells (MC) is a frequent finding in glomerulonephritis. The control and function of cyclin D1, a regulator of cell cycle progression, in MC proliferation in vivo and in vitro were investigated. In a rat model of mesangioproliferative glomerulonephritis, increases in the number of cyclin D1-positive MC nuclei were prominent on day 5 of the disease, preceding the peak of MC hyperplasia. In growth-arrested rat MC in culture, mitogenic stimulation with serum or platelet-derived growth factor (PDGF) led to rapid increases in cyclin D1 protein expression. Transforming growth factor-β1 inhibited PDGF induction of cyclin D1 protein at 12 h. In an examination of the subcellular distribution of cyclin D1, it was observed that stimulation of MC with PDGF for 6 h caused translocation of cyclin D1 from the cytoplasm into the nucleus. Coincubation with PDGF and transforming growth factor-β1 completely inhibited this effect, without altering the cellular cyclin D1 protein abundance at that time point. To test whether reduction of cyclin D1 protein levels was sufficient to inhibit mitogenesis, MC were transfected with antisense oligonucleotides (ODN) complementary to rat cyclin D1 mRNA. Antisense ODN against cyclin D1 reduced the serum- or PDGF-induced protein expression of cyclin D1 to 27 or 10% of control levels, respectively. These inhibitory effects were correlated with diminished cyclin-dependent kinase 4 activity. Antisense ODN against cyclin D1 also decreased the PDGF-induced increase in p21Waf-1 protein levels. The MC proliferation caused by serum or PDGF was markedly inhibited by antisense ODN against cyclin D1, as measured by [3H]thymidine uptake and cell counts. It is concluded that increased cyclin D1 protein expression of MC is required for MC proliferation. Targeting cyclin D1 expression may represent an effective means to inhibit MC proliferation in vitro and in vivo.

scholarly journals Increased serum and bone matrix levels of transforming growth factor β1 in patients with GH deficiency in response to GH treatment

2011 ◽  
Vol 165 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Thor Ueland ◽  
Tove Lekva ◽  
Kari Otterdal ◽  
Tuva B Dahl ◽  
Nicoleta Cristina Olarescu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cortical Bone ◽  
Transforming Growth Factor ◽  
Bone Cells ◽  
Gh Deficiency ◽  
Bone Matrix ◽  
Transforming Growth Factor Β1 ◽  
Gh Treatment

ObjectivePatients with adult onset GH deficiency (aoGHD) have secondary osteoporosis, which is reversed by long-term GH substitution. Transforming growth factor β1 (TGFβ1 or TGFB1) is abundant in bone tissue and could mediate some effects of GH/IGFs on bone. We investigated its regulation by GH/IGF1in vivoandin vitro.Design and methodsThe effects of GH substitution (9–12 months, placebo controlled) on circulating and cortical bone matrix contents of TGFβ1 were investigated in patients with aoGHD. The effects of GH/IGF1 on TGFβ1 secretion in osteoblasts (hFOB), adipocytes, and THP-1 macrophages as well as the effects on release from platelets were investigatedin vitro.ResultsIn vivoGH substitution increased TGFβ1 protein levels in cortical bone and serum.In vitro, GH/IGF1 stimulation induced a significant increase in TGFβ1 secretion in hFOB. In contrast, no major effect of GH/IGF1 on TGFβ1 was found in adipocytes and THP-1 macrophages. Finally, a minor modifying effect on SFLLRN-stimulated platelet release of TGFβ1 was observed in the presence of IGF1.ConclusionGH substitution increases TGFβ1in vivoandin vitro, and this effect could contribute to improved bone metabolism during such therapy, potentially reflecting direct effect of GH/IGF1 on bone cells.

Comparison of Release Profiles of Various Growth Factors from Biodegradable Carriers

1998 ◽  
Vol 530 ◽  
Author(s):  
Y. Tabata ◽  
M. Yamamoto ◽  
Y. Ikada
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
The Body ◽  
Bone Morphogenetic Protein 2 ◽  
Biodegradable Hydrogel ◽  
Tgf Β1

AbstractA biodegradable hydrogel was prepared by glutaraldehyde crosslinking of acidic gelatin with an isoelectric point (IEP) of 5.0 as a carrier to release basic growth factors on the basis of polyion complexation. Basic fibroblast growth factor (bFGF), transforming growth factor β1 (TGF-β1), and bone morphogenetic protein-2 (BMP-2) were sorbed from their aqueous solution into the dried gelatin hydrogels to prepare respective growth factor-incorporating hydrogels. Under an in vitro non-degradation condition, approximately 20 % of incorporated bFGF and TGF-β1 was released from the hydrogels within initial 40 min, followed by no further release, whereas a large initial release of BMP-2 was observed. After subcutaneous implantation of the gelatin hydrogels incorporating 125I-labeled growth factor in the mouse back, the remaining radioactivity was measured to estimate the in vivo release profile of growth factors. Incorporation into gelatin hydrogels enabled bFGF and TGF-β1 to retain in the body for about 15 days and the retention period well correlated with that of the gelatin hydrogel. Taken together, it is likely that the growth factors ionically complexed with acidic gelatin were released in vivo as a result of hydrogel biodegradation. On the contrary, basic BMP-2 did not ionically interact with acidic gelatin, resulting in no sustained released by the present biodegradable carrier system.

scholarly journals Platelet-induced cell signaling during liver regeneration

2021 ◽  
Vol 108 (Supplement_4) ◽  
Author(s):  
A Balaphas ◽  
J Meyer ◽  
R Perozzo ◽  
M Zeisser Labouebe ◽  
S Berndt ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Transforming Growth Factor ◽  
Fold Increase ◽  
Transforming Growth Factor Β1 ◽  
Remnant Liver ◽  
Liver Sinusoidal Endothelial Cells

Abstract Objective To investigate the mechanisms driving the interaction of platelets with liver sinusoidal endothelial cells (LSEC) during liver regeneration. Methods Platelets were tracked in vivo in mice by intravital confocal microscopy after partial hepatectomy. In vitro, we isolated highly pure mouse LSEC and analyzed their interactions with platelets, hepatic stellate cells (HSC), Kupffer cells and hepatocytes. Results Recruited platelets adhered to LSEC in vivo within the remnant liver segments following partial hepatectomy and were necessary for the interleukin 6 (IL-6) burst that occurred afterwards. In vitro, platelets were activated after incubation with LSEC and released transforming growth factor β1 (TGF-β1), which stimulated LSEC to secrete IL-6 (fold increase of 9.8±0.73 relative to baseline). Antibody-mediated neutralization of TGF-B1 or its downstream SMAD signalling pathway prevented the effects of activated platelets on LSEC. We also demonstrated that IL-6 released by LSEC stimulates HSC to produce hepatocyte growth factor (HGF) a main mitogen for hepatocytes. Conclusion Our results suggest that after hepatectomy, platelets initiate liver regeneration by interacting with LSEC and stimulate IL-6 release, which in turn stimulates HSC to produce HGF.

The Effect of Relaxin Treatment on Skeletal Muscle Injuries

2005 ◽  
Vol 33 (12) ◽  
pp. 1816-1824 ◽  
Author(s):  
Shinichi Negishi ◽  
Yong Li ◽  
Arvydas Usas ◽  
Freddie H. Fu ◽  
Johnny Huard
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Functional Recovery ◽  
Muscle Regeneration ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
C2c12 Cells ◽  
Muscle Injuries

Background Injured skeletal muscle can repair itself via spontaneous regeneration; however, the overproduction of extracellular matrix and excessive collagen deposition lead to fibrosis. Neutralization of the effect of transforming growth factor-β1, a key fibrotic cytokine, on myogenic cell differentiation after muscle injury can prevent fibrosis, enhance muscle regeneration, and thereby improve the functional recovery of injured muscle. Hypothesis The hormone relaxin, a member of the family of insulin-like growth factors, can act as an antifibrosis agent and improve the healing of injured muscle. Study Design Controlled laboratory study. Methods In vitro: Myoblasts (C2C12 cells) and myofibroblasts (transforming growth factor-β1-transfected myoblasts) were incubated with relaxin, and cell growth and differentiation were examined. Myogenic and fibrotic protein expression was determined by Western blot analysis. In vivo: Relaxin was injected intramuscularly at different time points after laceration injury. Skeletal muscle healing was evaluated via histologic, immunohistochemical, and physiologic tests. Results Relaxin treatment resulted in a dose-dependent decrease in myofibroblast proliferation, down-regulated expression of the fibrotic protein α-smooth muscle actin, and promoted the proliferation and differentiation of myoblasts in vitro. Relaxin therapy enhanced muscle regeneration, reduced fibrosis, and improved injured muscle strength in vivo. Conclusion Administration of relaxin can significantly improve skeletal muscle healing. Clinical Relevance These findings may facilitate the development of techniques to eliminate fibrosis, enhance muscle regeneration, and improve functional recovery after muscle injuries.

scholarly journals Arrest of G1-S Progression by the p53-Inducible Gene PC3 Is Rb Dependent and Relies on the Inhibition of Cyclin D1 Transcription

2000 ◽  
Vol 20 (5) ◽  
pp. 1797-1815 ◽  
Author(s):  
Daniele Guardavaccaro ◽  
Giuseppina Corrente ◽  
Francesca Covone ◽  
Laura Micheli ◽  
Igea D'Agnano ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
D1 Protein ◽  
Down Regulation ◽  
Inhibition Of Proliferation ◽  
Protein Levels ◽  
Growth Inhibitory ◽  
Cyclin D1 Protein ◽  
Cdk4 Activity ◽  
Inducible Gene

ABSTRACT The p53-inducible gene PC3 (TIS21, BTG2) is endowed with antiproliferative activity. Here we report that expression ofPC3 in cycling cells induced accumulation of hypophosphorylated, growth-inhibitory forms of pRb and led to G1 arrest. This latter was not observed in cells with genetic disruption of the Rb gene, indicating that thePC3-mediated G1 arrest was Rb dependent. Furthermore, (i) the arrest of G1-S transition exerted by PC3 was completely rescued by coexpression of cyclin D1 but not by that of cyclin A or E; (ii) expression of PC3 caused a significant down-regulation of cyclin D1 protein levels, also in Rb-defective cells, accompanied by inhibition of CDK4 activity in vivo; and (iii) the removal from the PC3 molecule of residues 50 to 68, a conserved domain of the PC3/BTG/Tob gene family, which we term GR, led to a loss of the inhibition of proliferation as well as of the down-regulation of cyclin D1 levels. These data point to cyclin D1 down-regulation as the main factor responsible for the growth inhibition by PC3. Such an effect was associated with a decrease of cyclin D1 transcript and of cyclin D1 promoter activity, whereas no effect of PC3 was observed on cyclin D1 protein stability. Taken together, these findings indicate that PC3 impairs G1-S transition by inhibiting pRb function in consequence of a reduction of cyclin D1 levels and that PC3 acts, either directly or indirectly, as a transcriptional regulator of cyclin D1.

scholarly journals Interleukin-13 augments transforming growth factor-β1-induced tissue inhibitor of metalloproteinase-1 expression in primary human airway fibroblasts

2005 ◽  
Vol 288 (2) ◽  
pp. C435-C442 ◽  
Author(s):  
XiuXia Zhou ◽  
John B. Trudeau ◽  
Kathryn J. Schoonover ◽  
Jessica I. Lundin ◽  
Steve M. Barnes ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protein Expression ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Tissue Inhibitor ◽  
Mrna Stabilization ◽  
Protein Levels ◽  
Human Airway ◽  
Tgf Β1

Tissue inhibitor of metalloproteinase (TIMP)-1 is a potent inhibitor of activated matrix metalloproteinases (MMPs) such as gelatinases and collagenases. TIMP-1 is induced by transforming growth factor-β1 (TGF-β1), but details regarding signaling pathways remain unclear. T-helper-2 cytokines also have profibrotic properties and can interact with TGF-β. In the present study, we examined the effects of interleukin (IL)-13 (2,500 pM) on TGF-β1 (200 pM)-induced expression of TIMP-1 mRNA and protein in primary human airway fibroblasts obtained from 57 human subjects. IL-13 alone had no effect on TIMP-1 mRNA or protein expression. However, IL-13 synergistically augmented TGF-β1-induced TIMP-1 mRNA and protein expression ( P < 0.001 vs. TGF-β1 alone). The upregulation of TIMP-1 by the combination of TGF-β1 and IL-13 involved increased transcription, with little effect on mRNA stabilization. Initial exploration of the pathways leading to the synergy determined that activation of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway by IL-13 may have a negative effect on TIMP-1 production. The specific PI3K inhibitor LY-294002 in the presence of TGF-β1, IL-13, or the combination of the two caused significant increases in TIMP-1 mRNA expression, while LY-294002 increased TIMP-1 protein levels in the presence of IL-13 alone. These results suggest that IL-13 augments TGF-β1-induced profibrotic responses at both the mRNA and protein levels. Although IL-13 induced activation of PI3K-Akt, the activation did not contribute to the synergy observed with TGF-β1 plus IL-13 in TIMP-1 expression and in fact may dampen it. The mechanisms behind the synergy remain to be determined.

scholarly journals The Fibronectin Domain ED-A Is Crucial for Myofibroblastic Phenotype Induction by Transforming Growth Factor-β1

1998 ◽  
Vol 142 (3) ◽  
pp. 873-881 ◽  
Author(s):  
Guido Serini ◽  
Marie-Luce Bochaton-Piallat ◽  
Patricia Ropraz ◽  
Antoine Geinoz ◽  
Laura Borsi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
De Novo ◽  
Transforming Growth Factor Β1 ◽  
Type I ◽  
Plasminogen Activator Inhibitor 1 ◽  
Matrix Assembly ◽  
Actin Expression

Transforming growth factor-β1 (TGFβ1), a major promoter of myofibroblast differentiation, induces α-smooth muscle (sn) actin, modulates the expression of adhesive receptors, and enhances the synthesis of extracellular matrix (ECM) molecules including ED-A fibronectin (FN), an isoform de novo expressed during wound healing and fibrotic changes. We report here that ED-A FN deposition precedes α-SM actin expression by fibroblasts during granulation tissue evolution in vivo and after TGFβ1 stimulation in vitro. Moreover, there is a correlation between in vitro expression of α-SM actin and ED-A FN in different fibroblastic populations. Seeding fibroblasts on ED-A FN does not elicit per se α-SM actin expression; however, incubation of fibroblasts with the anti-ED-A monoclonal antibody IST-9 specifically blocks the TGFβ1-triggered enhancement of α-SM actin and collagen type I, but not that of plasminogen activator inhibitor-1 mRNA. Interestingly, the same inhibiting action is exerted by the soluble recombinant domain ED-A, but neither of these inhibitory agents alter FN matrix assembly. Our findings indicate that ED-A–containing polymerized FN is necessary for the induction of the myofibroblastic phenotype by TGFβ1 and identify a hitherto unknown mechanism of cytokine-determined gene stimulation based on the generation of an ECM-derived permissive outside in signaling, under the control of the cytokine itself.

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