Effect of steroids on cartilage metabolism "in vitro"

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S35-S40 ◽  
Author(s):  
Marc V.L. DU CAJU ◽  
Raoul P. ROOMAN
Keyword(s):  
Growth Factor ◽  
Thymidine Incorporation ◽  
Normal Serum ◽  
Synthetic Analogue ◽  
Factor Activity ◽  
Poor Growth ◽  
Cartilage Metabolism ◽  
Glucocorticoid Administration

ABSTRACT Conditions characterized by high levels of glucocorticoids are associated with poor growth. Serum somatomedin or insulin-like growth factor activity measured by cartilage bioassay systems is low, but is generally not accompanied by a fall in somatomedin concentration. Hydrocortisone and a synthetic analogue, dexamethasone, impaired the serum stimulated "in vitro" 35S sulphate and 3H-thymidine incorporation in porcine rib cartilage at physiological concentrations. Hydrocortisone added at a concentration of 0,1 μg/ml decreased the potency of normal serum to 50 % of controls. Dexamethasone was at least 10 times more potent. Removal of "in vitro" or "in vivo" administered hydrocortisone with dextran-coated charcoal restored the sulphate and thymidine activity to normal. We conclude that physiological amounts of glucocorticoids inhibit the "in vitro" porcine cartilage metabolism. Glucocorticoid administration "in vivo" does not abolish the activity of the cartilage stimulating effect of serum but affects cartilage metabolism directly or by the induction of locally produced inhibitors of cartilage metabolism.

Parathyroid hormone potentiates the effect of insulin-like growth factor-I on bone formation

1989 ◽  
Vol 121 (3) ◽  
pp. 435-442 ◽  
Author(s):  
E. Martin Spencer ◽  
Erwin C. C. Si ◽  
Chung C. Liu ◽  
Guy A. Howard
Keyword(s):  
Parathyroid Hormone ◽  
Growth Factor ◽  
Bone Formation ◽  
Trabecular Bone ◽  
Thymidine Incorporation ◽  
Bone Apposition ◽  
Factor I ◽  
Igf I

Abstract. Insulin-like growth factor-I and parathyroid hormone are both known regulators of bone formation. In this study, human recombinant IGF-I and bovine PTH (1–34) and their combination were studied for their effects in vitro on the proliferation of embryonic chick osteoblast-like cells (osteoblasts) and in vivo on bone formation in normal rats. Osteoblasts from 17-day-old chick embryos were cultured in serum-free BGJb medium containing 0.1% bovine albumin. After 2 days, IGF-I and/or PTH were added. Twenty-four hours later [3H]thymidine incorporation into trichloroacetic acid precipitable material was quantified as an index of cell proliferation. This has previously been shown to reflect actual cell division. IGF-I at doses ranging from 0.85 to 13.6 nmol/l caused a dose-dependent increase in [3H]thymidine incorporation into osteoblasts. PTH alone (10 to 1000 pmol/l) had no significant effect. However, when combined with IGF-I, PTH potentiated the mitogenic effect of IGF-I and achieved statistical significance at 30 and 100 pmol/l (p <0.05). This potentiation was also studied in vivo. The right hindlimbs of rats weighing 150 g were infused intra-arterially by an osmotic minipump with graded doses of IGF-I (0.1 to 0.4 nmol/day) and/or PTH (0.27 nmol/day) for 7 days. The rate of trabecular bone apposition (formation) was measured by double tetracycline labelling and compared with the contralateral uninfused limb which acted as the control. Histomorphometric data revaled that neither IGF-I nor PTH alone had a significant effect on trabecular bone apposition rate compared with control limbs. The co-infusion of IGF-I (0.4 nmol/day) and PTH (0.27 nmol/day) resulted in a marked increase in trabecular bone apposition rate. The results of 2 studies were significant at p < 0.01. These data suggest that PTH potentiates the effect of IGF-I on bone formation both in vivo and in vitro.

scholarly journals Dynamic changes of podocytes caused by fibroblast growth factor 2 in culture

2021 ◽  
Author(s):  
Eishin Yaoita ◽  
Masaaki Nameta ◽  
Yutaka Yoshida ◽  
Hidehiko Fujinaka
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Quiescent State ◽  
Fibroblast Growth ◽  
Gene Expressions ◽  
Dynamic Changes ◽  
Ki 67

AbstractFibroblast growth factor 2 (FGF2) augments podocyte injury, which induces glomerulosclerosis, although the mechanisms remain obscure. In this study, we investigated the effects of FGF2 on cultured podocytes with interdigitating cell processes in rats. After 48 h incubation with FGF2 dynamic changes in the shape of primary processes and cell bodies of podocytes resulted in the loss of interdigitation, which was clearly shown by time-lapse photography. FGF2 reduced the gene expressions of constituents of the slit diaphragm, inflections of intercellular junctions positive for nephrin, and the width of the intercellular space. Immunostaining for the proliferation marker Ki-67 was rarely seen and weakly stained in the control without FGF2, whereas intensely stained cells were frequently found in the presence of FGF2. Binucleation and cell division were also observed, although no significant increase in cell number was shown. An in vitro scratch assay revealed that FGF2 enhanced migration of podocytes. These findings show that FGF2 makes podocytes to transition from the quiescent state into the cell cycle and change their morphology due to enhanced motility, and that the culture system in this study is useful for analyzing the pathological changes of podocytes in vivo.

scholarly journals Hyperglycaemia up-regulates placental growth factor (PlGF) expression and secretion in endothelial cells via suppression of PI3 kinase-Akt signalling and activation of FOXO1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samir Sissaoui ◽  
Stuart Egginton ◽  
Ling Ting ◽  
Asif Ahmed ◽  
Peter W. Hewett
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Endothelial Dysfunction ◽  
Akt Activation ◽  
Forkhead Box ◽  
Pi3k Activity ◽  
Binding Sequence

AbstractPlacenta growth factor (PlGF) is a pro-inflammatory angiogenic mediator that promotes many pathologies including diabetic complications and atherosclerosis. Widespread endothelial dysfunction precedes the onset of these conditions. As very little is known of the mechanism(s) controlling PlGF expression in pathology we investigated the role of hyperglycaemia in the regulation of PlGF production in endothelial cells. Hyperglycaemia stimulated PlGF secretion in cultured primary endothelial cells, which was suppressed by IGF-1-mediated PI3K/Akt activation. Inhibition of PI3K activity resulted in significant PlGF mRNA up-regulation and protein secretion. Similarly, loss or inhibition of Akt activity significantly increased basal PlGF expression and prevented any further PlGF secretion in hyperglycaemia. Conversely, constitutive Akt activation blocked PlGF secretion irrespective of upstream PI3K activity demonstrating that Akt is a central regulator of PlGF expression. Knock-down of the Forkhead box O-1 (FOXO1) transcription factor, which is negatively regulated by Akt, suppressed both basal and hyperglycaemia-induced PlGF secretion, whilst FOXO1 gain-of-function up-regulated PlGF in vitro and in vivo. FOXO1 association to a FOXO binding sequence identified in the PlGF promoter also increased in hyperglycaemia. This study identifies the PI3K/Akt/FOXO1 signalling axis as a key regulator of PlGF expression and unifying pathway by which PlGF may contribute to common disorders characterised by endothelial dysfunction, providing a target for therapy.

Combined Effects of Bone Marrow-Derived Mesenchymal Stem Cells and PLGA-PEG-PLGA Scaffolds on Repair of Articular Cartilage Defect

2013 ◽  
Vol 815 ◽  
pp. 345-349 ◽  
Author(s):  
Ching Wen Hsu ◽  
Ping Liu ◽  
Song Song Zhu ◽  
Feng Deng ◽  
Bi Zhang
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Articular Cartilage ◽  
Growth Factor ◽  
Cartilage Defect ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
Cartilage Defects

Here we reported a combined technique for articular cartilage repair, consisting of bone arrow mesenchymal stem cells (BMMSCs) and poly (dl-lactide-co-glycolide-b-ethylene glycol-b-dl-lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymers carried with tissue growth factor (TGF-belat1). In the present study, BMMSCs seeded on PLGA-PEG-PLGA with were incubated in vitro, carried or not TGF-belta1, Then the effects of the composite on repair of cartilage defect were evaluated in rabbit knee joints in vivo. Full-thickness cartilage defects (diameter: 5 mm; depth: 3 mm) in the patellar groove were either left empty (n=18), implanted with BMMSCs/PLGA (n=18), TGF-belta1 modified BMMSCs/PLGA-PEG-PLGA. The defect area was examined grossly, histologically at 6, 24 weeks postoperatively. After implantation, the BMMSCs /PLGA-PEG-PLGA with TGF-belta1 group showed successful hyaline-like cartilage regeneration similar to normal cartilage, which was superior to the other groups using gross examination, qualitative and quantitative histology. These findings suggested that a combination of BMMSCs/PLGA-PEG-PLGA carried with tissue growth factor (TGF-belat1) may be an alternative treatment for large osteochondral defects in high loading sites.

scholarly journals Oligosaccharide G19 inhibits U-87 MG human glioma cells growth in vitro and in vivo by targeting epidermal growth factor (EGF) and activating p53/p21 signaling

Glycobiology ◽  
2014 ◽  
Vol 24 (8) ◽  
pp. 748-765 ◽  
Author(s):  
Hailing Liu ◽  
Ling Zhou ◽  
Songshan Shi ◽  
Ying Wang ◽  
Xinyan Ni ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Glioma Cells ◽  
Human Glioma ◽  
Human Glioma Cells ◽  
Epidermal Growth
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