Effects of Transforming Growth Factor-β and Mechanical Strain on Osteoblast Cell Counts: An in Vitro Model for Distraction Osteogenesis

2000 ◽  
Vol 105 (1) ◽  
pp. 130-136 ◽  
Author(s):  
Arun K. Gosain ◽  
Lian-Sheng Song ◽  
Timothy Santoro ◽  
Dorothee Weihrauch ◽  
Brook O. Bosi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Distraction Osteogenesis ◽  
In Vitro Model ◽  
Transforming Growth Factor ◽  
Mechanical Strain ◽  
Transforming Growth Factor Β ◽  
Osteoblast Cell ◽  
Cell Counts ◽  
Vitro Model

scholarly journals Toll-like receptor 4 activation attenuates profibrotic response in control lung fibroblasts but not in fibroblasts from patients with IPF

2017 ◽  
Vol 312 (1) ◽  
pp. L42-L55 ◽  
Author(s):  
Simone Ebener ◽  
Sandra Barnowski ◽  
Carlos Wotzkow ◽  
Thomas M. Marti ◽  
Elena Lopez-Rodriguez ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Tissue Growth ◽  
Lung Fibroblasts ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Vitro Model ◽  
Fibroblast Foci

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a median survival of 3 yr. IPF deteriorates upon viral or bacterial lung infection although pulmonary infection (pneumonia) in healthy lungs rarely induces fibrosis. Bacterial lipopolysaccharide (LPS) activates Toll-like receptor 4 (TLR4), initiating proinflammatory pathways. As TLR4 has already been linked to hepatic fibrosis and scleroderma, we now investigated the role of TLR4 in IPF fibroblasts. Lung tissue sections from patients with IPF were analyzed for TLR4 expression. Isolated normal human lung fibroblasts (NL-FB) and IPF fibroblasts (IPF-FB) were exposed to LPS and transforming growth factor-β (TGF-β) before expression analysis of receptors, profibrotic mediators, and cytokines. TLR4 is expressed in fibroblast foci of IPF lungs as well as in primary NL-FB and IPF-FB. As a model for a gram-negative pneumonia in the nonfibrotic lung, NL-FB and IPF-FB were coexposed to LPS and TGF-β. Whereas NL-FB produced significantly less connective tissue growth factor upon costimulation compared with TGF-β stimulation alone, IPF-FB showed significantly increased profibrotic markers compared with control fibroblasts after costimulation. Although levels of antifibrotic prostaglandin E2 were elevated after costimulation, they were not responsible for this effect. However, significant downregulation of TGF-β receptor type 1 in control fibroblasts seems to contribute to the reduced profibrotic response in our in vitro model. Normal and IPF fibroblasts thus differ in their profibrotic response upon LPS-induced TLR4 stimulation.

scholarly journals Metformin activity in an in vitro model of posterior capsule opacification

2018 ◽  
Vol 17 (4) ◽  
pp. 105-112
Author(s):  
Jade Marie Lasiste ◽  
Pablo Zoroquiain ◽  
Denise Miyamoto ◽  
Miguel Burnier
Keyword(s):  
Growth Factor ◽  
Western Blot ◽  
In Vitro Model ◽  
Transforming Growth Factor ◽  
Posterior Capsule Opacification ◽  
Posterior Capsule ◽  
Vitro Model ◽  
And Migration ◽  
E Cadherin

Purpose: To determine the activity of metformin in an in vitro model of posterior capsule opacification (PCO).Design: Experimental laboratory research. Methods: The HLE-B3 lens epithelial cell line was treated with PCO induction media (PCOM) supplemented with transforming growth factor-beta (TGF-β) and fibroblast growth factor (FGF). Different metformin concentrations (0-100 mM) were used. The following cellular parameters were assessed: (1) survival, using a viability assay; (2) morphology, via microscopy and image analysis; (3) migration, using the wound assay; (4) and expression of epithelial (Pax6, E-cadherin) and mesenchymal (α-smooth muscle actin or α-SMA, fibronectin) markers via Western blot. Expression of the uptake receptor SLC22A1 was evaluated in HLE-B3 and in human donor eyes with Western blot and immunohistochemistry, respectively. Statistical analysis of variance (ANOVA) with Tukey post-hoc test was done for analysis of cytotoxicity, morphology and migration data. Results: Metformin was lethal to half (LC50) of the cells at 30 mM, and a decrease in viability (P<0.05) was noted at 5 mM. LECs in PCOM treated with 1 mM metformin showed increased Pax6 and E-cadherin and decreased α-SMA and fibronectin expression. LECs in PCOM treated with metformin also maintained epithelial morphology. Migration was inhibited with 0.5 mM metformin (P<0.05). Both HLE-B3 and the lens epithelium in donor eyes were found to express SLC22A1.Conclusion: Metformin decreased survival and migration in LECs, maintaining epithelial phenotype and reducing mesenchymal marker expression. Metformin therefore has potential as an adjunct in PCO prevention.Financial Disclosures: This work was partially funded by Mitacs Canada.

Transforming growth factor-alpha enhances alveolar epithelial cell repair in a new in vitro model

1994 ◽  
Vol 267 (6) ◽  
pp. L728-L738 ◽  
Author(s):  
F. Kheradmand ◽  
H. G. Folkesson ◽  
L. Shum ◽  
R. Derynk ◽  
R. Pytela ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cell ◽  
Wound Repair ◽  
Wound Closure ◽  
Transforming Growth Factor ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial ◽  
Factor Alpha ◽  
Vitro Model

Alveolar epithelial type II cells are essential for regenerating an intact alveolar barrier after destruction of type I cells in vivo. The first objective of these experimental studies was to develop an in vitro model to quantify alveolar epithelial cell wound repair. The second objective was to investigate mechanisms of alveolar epithelial cell wound healing by studying the effects of serum and transforming growth factor-alpha (TGF-alpha) on wound closure. Primary cultures of rat alveolar type II cells were prepared by standard methods and grown to form confluent monolayers in 48 h. Then a wound was made by denuding an area (mean initial area of 2.1 +/- 0.6 mm2) of the monolayer. Re-epithelialization of the denuded area over time in the presence or absence of serum was measured using quantitative measurements from time-lapse video microscopy. The half time of wound healing was significantly enhanced in the presence of serum compared with serum-free conditions (2.4 +/- 0.2 vs. 17.4 +/- 0.8 h, P < 0.001). We then tested the hypothesis that TGF-alpha is an important growth factor for stimulating wound repair of alveolar epithelial cells. Exogenous addition of TGF-alpha in serum-free medium resulted in a significantly more rapid wound closure, and, furthermore, the addition of a monoclonal antibody to TGF-alpha in the presence of serum significantly decreased fourfold the rate of wound closure. Measurement of internuclear cell distance confirmed that both cell motility and cell spreading were responsible for closure of the wound. These data demonstrate that 1) the mechanisms of alveolar cell repair can be studied in vitro and that 2) TGF-alpha is a potent growth factor that enhances in vitro alveolar epithelial cell wound closure.

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