Regulation of human lung fibroblast phenotype and function by vitronectin and vitronectin integrins

2001 ◽  
Vol 114 (19) ◽  
pp. 3507-3516 ◽  
Author(s):  
Amelia K. Scaffidi ◽  
Yuben P. Moodley ◽  
Markus Weichselbaum ◽  
Philip J. Thompson ◽  
Darryl A. Knight
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Monoclonal Antibodies ◽  
Human Lung ◽  
Stress Fibers ◽  
Collagen Gels ◽  
Human Lung Fibroblast ◽  
Myofibroblast Phenotype ◽  
And Function ◽  
Blocking Antibodies

Myofibroblasts, characterised by high expression of α-smooth muscle actin (α-SMA), are important and transient cells in normal wound healing but are found in increased number in various pathological conditions of the lung including asthma and pulmonary fibrosis. The mechanisms that regulate the myofibroblast phenotype are unknown but are likely to involve signals from the extracellular matrix transmitted via specific integrins. Vitronectin is a glycoprotein released during inflammation and has been shown to regulate the phenotype of vascular smooth muscle cells via αv and β1 integrins. In the current study we have examined whether vitronectin influences the phenotype and function of normal human lung fibroblasts (HFL-1). Incubation of HFL-1 cells with vitronectin induced a concentration-dependent reduction in α-SMA expression. By contrast, function-blocking monoclonal antibodies to the vitronectin integrins αv, β1, αvβ3 and αvβ5 induced the expression of α-SMA and its organization into stress fibers. Expression of α-SMA induced by all function-blocking monoclonal antibodies was abrogated by inhibition of protein kinase C and phosphatidylinositol-3 kinase, but the effects of inhibition of other signalling pathways was integrin dependent. Exposure to other extracellular matrix proteins such as fibronectin, collagen or their integrins did not influence expression of α-SMA. The expression and organization of α-SMA induced by exposure to function-blocking antibodies was translated into an augmented capacity of HFL-1 cells to contract fibroblast populated collagen gels. By contrast, contraction of collagen gels following incubation with vitronectin was not significantly different to control. This study has shown that vitronectin influences the phenotype and behaviour of HFL-1 cells by downregulating the expression of α-SMA and reducing their contractile ability. By contrast, occupancy of specific integrins by function-blocking antibodies upregulated the expression of α-SMA and induced the formation of functional stress fibers capable of contracting collagen gels. These results suggest that vitronectin modulates the fibroblast-myofibroblast phenotype, implying an important role in the remodelling process during lung development or response to injury.

Extracellular matrix and airway smooth muscle interactions: a target for modulating airway wall remodelling and hyperresponsiveness?This article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research.

2007 ◽  
Vol 85 (7) ◽  
pp. 666-671 ◽  
Author(s):  
Thai Tran ◽  
Andrew J. Halayko
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Molecular Mechanisms ◽  
Matrix Proteins ◽  
Airway Smooth Muscle Cells ◽  
Airway Wall ◽  
Future Directions ◽  
Airway Function ◽  
And Function

The airway smooth muscle from asthmatic airways produces increased amounts and an altered composition of extracellular matrix proteins. The extracellular matrix can in turn influence the phenotype and function of airway smooth muscle cells, affecting the biochemical, geometric, and mechanical properties of the airway wall. This review provides a brief overview of the current understanding of the biology associated with airway smooth muscle interactions with the extracellular matrix. We present future directions needed for the study of cellular and molecular mechanisms that determine the outcomes of extracellular matrix – airway smooth muscle interactions, and discuss their possible importance as determinants of airway function in asthma.

scholarly journals Cytoskeleton and Adhesion in Myogenesis

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Manoel Luís Costa
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Muscle Function ◽  
Force Production ◽  
Structure And Function ◽  
Cytoskeletal Proteins ◽  
Skeletal Muscle Differentiation ◽  
And Function ◽  
Structural Adaptations

The function of muscle is to contract, which means to exert force on a substrate. The adaptations required for skeletal muscle differentiation, from a prototypic cell, involve specialization of housekeeping cytoskeletal contracting and supporting systems into crystalline arrays of proteins. Here I discuss the changes that all three cytoskeletal systems (microfilaments, intermediate filaments, and microtubules) undergo through myogenesis. I also discuss their interaction, through the membrane, to extracellular matrix and to other cells, where force will be exerted during contraction. The three cytoskeletal systems are necessary for the muscle cell and must exert complementary roles in the cell. Muscle is a responsive system, where structure and function are integrated: the structural adaptations it undergoes depend on force production. In this way, the muscle cytoskeleton is a portrait of its physiology. I review the cytoskeletal proteins and structures involved in muscle function and focus particularly on their role in myogenesis, the process by which this incredible muscle machine is made. Although the focus is on skeletal muscle, some of the discussion is applicable to cardiac and smooth muscle.

Sodium nitroprusside augments human lung fibroblast collagen gel contraction independently of NO-cGMP pathway

2000 ◽  
Vol 278 (5) ◽  
pp. L1032-L1038 ◽  
Author(s):  
X. D. Liu ◽  
C. M. Skold ◽  
T. Umino ◽  
J. R. Spurzem ◽  
D. J. Romberger ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Human Lung ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Lung Fibroblast ◽  
Type I ◽  
Collagen Gels ◽  
Human Lung Fibroblast ◽  
Collagen Gel Contraction ◽  
Cgmp Pathway

Nitric oxide (NO) relaxes vascular smooth muscle in part through an accumulation of cGMP in the target cells. We hypothesized that a similar effect may also exist on collagen gel contraction mediated by human fetal lung (HFL1) fibroblasts, a model of wound contraction. To evaluate this, HFL1 cells were cultured in three-dimensional type I collagen gels and floated in serum-free DMEM with and without various NO donors. Gel size was measured with an image analyzer. Sodium nitroprusside (SNP, 100 μM) significantly augmented collagen gel contraction by HFL1 cells (78.5 ± 0.8 vs. 58.3 ± 2.1, P < 0.01), whereas S-nitroso- N-acetylpenicillamine, 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride, NONOate, and N G-monomethyl-l-arginine did not affect the contraction. Sodium ferricyanide, sodium nitrate, or sodium nitrite was not active. The augmentory effect of SNP could not be blocked by 1 H-[1,2,4]-oxadiazolo-[4,3- a]-quinoxalin-1-one, whereas it was partially reversed by 8-(4-chlorophenylthio) (CPT)-cGMP. To further explore the mechanisms by which SNP acted, fibronectin and PGE2 production were measured by immunoassay after 2 days of gel contraction. SNP inhibited PGE2 production and increased fibronectin production by HFL1 cells in a concentration-dependent manner. CPT-cGMP had opposite effects on fibronectin and PGE2 production. Addition of exogenous PGE2 blocked SNP-augmented contraction and fibronectin production by HFL1 cells. Therefore, SNP was able to augment human lung fibroblast-mediated collagen gel contraction, an effect that appears to be independent of NO production and not mediated through cGMP. Decreased PGE2 production and augmented fibronectin production may have a role in this effect. These data suggest that human lung fibroblasts in three-dimensional type I collagen gels respond distinctly to SNP by mechanisms unrelated to the NO-cGMP pathway.

scholarly journals Endothelial TGF-β signaling instructs smooth muscle development in the cardiac outflow tract

2020 ◽  
Author(s):  
Giulia L.M. Boezio ◽  
Anabela Bensimon-Brito ◽  
Janett Piesker ◽  
Stefan Guenther ◽  
Christian S.M. Helker ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Muscle Development ◽  
Outflow Tract ◽  
Aortic Aneurysms ◽  
Type I ◽  
Β Receptor ◽  
And Function ◽  
Cardiac Outflow

SummaryThe development of the cardiac outflow tract (OFT), which connects the heart to the great arteries, relies on a complex crosstalk between endothelial (ECs) and smooth muscle (SMCs) cells. Defects in OFT development can lead to severe malformations, including aortic aneurysms, which have often been associated with impaired TGF-β signaling. To further investigate the role of TGF-β signaling in OFT formation, we generated zebrafish lacking the type I TGF-β receptor Alk5 and found a strikingly specific dilation of the OFT. alk5 mutants also exhibit increased EC numbers, extracellular matrix (ECM) and SMC disorganization. Surprisingly, endothelial-specific alk5 overexpression in alk5 mutants rescues both endothelial and SMC defects. Furthermore, modulation of the ECM gene fibulin-5, a TGF-β target, partially restores OFT morphology and function. These findings reveal a new requirement for endothelial TGF-β signaling in OFT morphogenesis and suggest an important role for the endothelium in the etiology of aortic malformations.

scholarly journals Oxidation and chemical modification of lung β-galactoside-specific lectin

1986 ◽  
Vol 238 (3) ◽  
pp. 683-689 ◽  
Author(s):  
P L Whitney ◽  
J T Powell ◽  
G L Sanford
Keyword(s):  
Tissue Culture ◽  
Chemical Modification ◽  
Culture Medium ◽  
Human Lung ◽  
Atmospheric Oxygen ◽  
Lung Fibroblast ◽  
Rat Lung ◽  
Human Lung Fibroblast ◽  
Disulphide Bonds ◽  
And Function

Galaptins are small, soluble, lectins with a specificity for beta-galactose residues. Many galaptins are inactivated by atmospheric oxygen and are protected by disulphide-reducing reagents. We find that each subunit of rat lung galaptin contains one residue of tryptophan and six of cysteine. Oxygen inactivates rat lung galaptin by oxidation of the cysteine residues. During oxidation, the normal dimeric structure is maintained and all disulphide bonds are formed within individual subunits. Exogenous thiols protect against inactivation, but oxidized thiols accelerate inactivation. Human lung fibroblast galaptin is almost completely inactivated within 1 h in tissue culture medium at 37 degrees C. Alkylation of native rat lung galaptin with iodoacetate or ethyleneimine causes substantial loss of activity. The dimeric galaptin structure is maintained. In contrast, alkylation with iodoacetamide yields carboxamidomethyl-galaptin, which is fully active and stable to atmospheric oxygen in the absence of disulphide-reducing reagents. This derivative is very useful for studies of galaptin properties and function.

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