Interrupted Treatment With Growth Factors in Combination With Hydrodynamic Forces Enhances ECM Deposition in Tissue-Engineered Cartilage

2011 ◽  
Author(s):  
Yueh-Hsun Yang ◽  
Gilda A. Barabino
Keyword(s):  
Shear Stress ◽  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Hydrodynamic Forces ◽  
Tissue Growth ◽  
In Vitro Cultivation ◽  
Mechanical Stimuli ◽  
Engineered Cartilage

Achievement of viable engineered tissues through in-vitro cultivation in bioreactor systems requires a thorough understanding of the complex interplay between mechanical forces and biochemical cues. Briefly, bioreactors have been employed to impart mechanical stimuli to support tissue growth and development. Continuous fluid-induced shear stress, for example, has been shown to influence morphology and properties of engineered cartilage.1 Fluid flow enhances mass transfer mechanisms and simultaneously provides mechanical stimuli across or through the construct to emulate shear forces that occur in the knee or other joints. Critical biochemical factors, such as growth factors, are secreted by cells2,3 and involved in cell-to-cell signaling. Guided by these molecules, cells can communicate with each other and work synergistically to accomplish a specific task. It has also been demonstrated that the pathways of certain growth factors, such as transforming growth factor-β (TGF-β) family and insulin-like growth factor-1 (IGF-1), are responsive to shear stress, resulting in enhanced cell and tissue activities, and their expression is also up-regulated by fluid-induced shear stress.4,5 This evidence suggests their involvement in mechanotransduction mechanisms. However, a combination of mechanical and biochemical stimuli results in a complex culture environment which is not yet fully characterized. The present study was designed to obtain an understanding of the combined effects of hydrodynamic forces and growth factors on cartilage regeneration by employing a custom-designed wavy-walled bioreactor1 (WWB) and by selecting IGF-1 and TGF-β1 as two model molecules. We hypothesized that bioprocessing conditions which optimize mechanical, biochemical and compositional properties of tissue-engineered cartilage can be achieved under hydrodynamic stimuli in combination with an appropriate use of IGF-1 or TGF-β.

The Response of Tissue Engineered Cartilage to the Temporal Application of Transforming and Insulin-Like Growth Factors

2007 ◽  
Author(s):  
Christopher J. O’Conor ◽  
Kenneth W. Ng ◽  
Lindsay E. Kugler ◽  
Gerard A. Ateshian ◽  
Clark T. Hung
Keyword(s):  
Tissue Engineering ◽  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
Mechanical Stimuli ◽  
Tissue Development ◽  
Engineering Research ◽  
Engineered Cartilage

Agarose has been used as an experimental scaffold for cartilage tissue engineering research due to its biocompatibility with chondrocytes, support of cartilage tissue development, and ability to transmit mechanical stimuli [1–3]. Tissue engineering studies have demonstrated that the temporal application of transforming growth factor (TGF) β3 for only 2 weeks elicits rapid tissue development that results in mechanical properties approaching native values [4]. However, it is not known whether this response to a 2-week exposure to growth factors is unique to TGF-β3. Therefore, the present study characterizes the response of tissue engineered cartilage to the temporal application of the anabolic growth factors TGF-β1, TGF-β3, and insulin-like growth factor I (IGF-I).

Cytokines and Growth Factors Involved in Peritoneal Fibrosis of Peritoneal Dialysis Patients

2005 ◽  
Vol 28 (2) ◽  
pp. 129-134 ◽  
Author(s):  
K.-H. Oh ◽  
P.J. Margetts
Keyword(s):  
Peritoneal Dialysis ◽  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Fibroblast Growth Factors ◽  
Tissue Growth ◽  
Platelet Derived Growth Factor ◽  
Fibroblast Growth ◽  
Dialysis Patients ◽  
Peritoneal Fibrosis

Peritoneal fibrosis is initiated by exposure of peritoneal tissues to numerous harmful agents encountered during peritoneal dialysis. These agents interact with cells within the peritoneum to induce growth factors and cytokines that are important in the initiation, progression and maintenance of fibrosis. Some of the mediators implicated in the pathogenesis of peritoneal fibrosis include transforming growth factor (TGF) ß, connective tissue growth factor (CTGF), fibroblast growth factors (FGF), and platelet derived growth factor (PDGF).

Modulation of growth factor incorporation into ECM of human osteoblast-like cells in vitro by 17 beta-estradiol

1994 ◽  
Vol 267 (6) ◽  
pp. E990-E1001 ◽  
Author(s):  
M. Slater ◽  
J. Patava ◽  
K. Kingham ◽  
R. S. Mason
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Bone Growth ◽  
Transforming Growth Factor ◽  
Bone Matrix ◽  
Tgf Beta ◽  
Subsequent Formation ◽  
Igf I

Human fetal osteoblast-like cells formed a regular multilayered structure in vitro with an extensive collagen-based extracellular matrix. With colloidal gold immunocytochemistry, labels for alkaline phosphatase and osteocalcin were distributed in a relatively diffuse pattern, in contrast to the bone growth factors, insulin-like growth factors I and II (IGF-I and IGF-II), transforming growth factor-beta 1 (TGF-beta 1), and basic fibroblast growth factor, which were colocalized in the collagenous matrix of the multilayer. The inclusion of 17 beta-estradiol (10(-11) to 10(-9) M) in the culture medium increased multilayer depths, increased labeling for IGF-I, IGF-II, and TGF-beta 1, and resulted in earlier detection of TGF-beta 1 label. In contrast, the increase in multilayer depth resulting from treatment with human platelets, an exogenous source of growth factors, was not accompanied by an increase in matrix IGF-I, IGF-II, or TGF-beta 1 label, suggesting a particular effect of estradiol to facilitate this process. Because growth factors in bone matrix may act as coupling agents when released during resorption, reduced growth factor incorporation in the presence of reduced sex steroid concentrations may lead to uncoupling of resorption and subsequent formation.

TGF-β and CTGF have overlapping and distinct fibrogenic effects on human renal cells

2002 ◽  
Vol 283 (4) ◽  
pp. F707-F716 ◽  
Author(s):  
Elizabeth Gore-Hyer ◽  
Daniel Shegogue ◽  
Malgorzata Markiewicz ◽  
Shianlen Lo ◽  
Debra Hazen-Martin ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Growth Factor ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Tissue Growth ◽  
Mrna Levels ◽  
Potent Inducer ◽  
Collagen Promoter

Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are ubiquitously expressed in various forms of tissue fibrosis, including fibrotic diseases of the kidney. To clarify the common and divergent roles of these growth factors in the cells responsible for pathological extracellular matrix (ECM) deposition in renal fibrosis, the effects of TGF-β and CTGF on ECM expression in primary human mesangial (HMCs) and human proximal tubule epithelial cells (HTECs) were studied. Both TGF-β and CTGF significantly induced collagen protein expression with similar potency in HMCs. Additionally, α2(I)-collagen promoter activity and mRNA levels were similarly induced by TGF-β and CTGF in HMCs. However, only TGF-β stimulated collagenous protein synthesis in HTECs. HTEC expression of tenascin-C (TN-C) was increased by TGF-β and CTGF, although TGF-β was the more potent inducer. Thus both growth factors elicit similar profibrogenic effects on ECM production in HMCs, while promoting divergent effects in HTECs. CTGF induction of TN-C, a marker of epithelial-mesenchymal transdifferentiation (EMT), with no significant induction of collagenous protein synthesis in HTECs, may suggest a more predominant role for CTGF in EMT rather than induction of excessive collagen deposition by HTECs during renal fibrosis.

Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis

2017 ◽  
Vol 204 (3-4) ◽  
pp. 191-198 ◽  
Author(s):  
Gemma A. Figtree ◽  
Kristen J. Bubb ◽  
Owen Tang ◽  
Eddy Kizana ◽  
Carmine Gentile
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Three Dimensional ◽  
In Vitro Models ◽  
Tissue Growth ◽  
Cardiovascular Research

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.

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 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 Age-dependent shifts in renal response to injury relate to altered BMP6/CTGF expression and signaling

2016 ◽  
Vol 311 (5) ◽  
pp. F926-F934 ◽  
Author(s):  
Lucas L. Falke ◽  
Hiroshi Kinashi ◽  
Amelie Dendooven ◽  
Roel Broekhuizen ◽  
Reinout Stoop ◽  
...  
Keyword(s):  
Growth Factor ◽  
Tissue Damage ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Renal Tissue ◽  
Tissue Growth ◽  
Bmp Signaling ◽  
Obstructive Nephropathy ◽  
Young Mice

Age is associated with an increased prevalence of chronic kidney disease (CKD), which, through progressive tissue damage and fibrosis, ultimately leads to loss of kidney function. Although much effort is put into studying CKD development experimentally, age has rarely been taken into account. Therefore, we investigated the effect of age on the development of renal tissue damage and fibrosis in a mouse model of obstructive nephropathy (i.e., unilateral ureter obstruction; UUO). We observed that after 14 days, obstructed kidneys of old mice had more tubulointerstitial atrophic damage but less fibrosis than those of young mice. This was associated with reduced connective tissue growth factor (CTGF), and higher bone morphogenetic protein 6 (BMP6) expression and pSMAD1/5/8 signaling, while transforming growth factor-β expression and transcriptional activity were no different in obstructed kidneys of old and young mice. In vitro, CTGF bound to and inhibited BMP6 activity. In summary, our data suggest that in obstructive nephropathy atrophy increases and fibrosis decreases with age and that this relates to increased BMP signaling, most likely due to higher BMP6 and lower CTGF expression.

scholarly journals It Takes Two to Tango: Endothelial TGFβ/BMP Signaling Crosstalk with Mechanobiology

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1965 ◽  
Author(s):  
Christian Hiepen ◽  
Paul-Lennard Mendez ◽  
Petra Knaus
Keyword(s):  
Shear Stress ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Research Field ◽  
Bmp Signaling ◽  
Growth Factor Signaling ◽  
Mechanical Stimuli ◽  
Signaling Crosstalk

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta (TGFβ) superfamily of cytokines. While some ligand members are potent inducers of angiogenesis, others promote vascular homeostasis. However, the precise understanding of the molecular mechanisms underlying these functions is still a growing research field. In bone, the tissue in which BMPs were first discovered, crosstalk of TGFβ/BMP signaling with mechanobiology is well understood. Likewise, the endothelium represents a tissue that is constantly exposed to multiple mechanical triggers, such as wall shear stress, elicited by blood flow or strain, and tension from the surrounding cells and to the extracellular matrix. To integrate mechanical stimuli, the cytoskeleton plays a pivotal role in the transduction of these forces in endothelial cells. Importantly, mechanical forces integrate on several levels of the TGFβ/BMP pathway, such as receptors and SMADs, but also global cell-architecture and nuclear chromatin re-organization. Here, we summarize the current literature on crosstalk mechanisms between biochemical cues elicited by TGFβ/BMP growth factors and mechanical cues, as shear stress or matrix stiffness that collectively orchestrate endothelial function. We focus on the different subcellular compartments in which the forces are sensed and integrated into the TGFβ/BMP growth factor signaling.

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