Lung tissue mechanics and extracellular matrix composition in a murine model of silicosis

2001 ◽  
Vol 90 (4) ◽  
pp. 1400-1406 ◽  
Author(s):  
Débora S. Faffe ◽  
Gabriela H. Silva ◽  
Pedro M. P. Kurtz ◽  
Elnara M. Negri ◽  
Vera L. Capelozzi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Lung Tissue ◽  
Elastic System ◽  
Elastic Fiber ◽  
Dynamic Mechanical Properties ◽  
Tissue Mechanics ◽  
Matrix Composition ◽  
Elastic Fibers ◽  
Oxytalan Fibers

The dynamic mechanical properties of lung tissue and its contents of collagen and elastic fibers were studied in strips prepared from mice instilled intratracheally with saline (C) or silica [15 (S15) and 30 days (S30) after instillation]. Resistance, elastance, and hysteresivity were studied during oscillations at different frequencies on S15 and S30. Elastance increased from C to silica groups but was similar between S15 and S30. Resistance was augmented from C to S15 and S30 and was greater in S30 than in S15 at higher frequencies. Hysteresivity was higher in S30 than in C and S15. Silica groups presented a greater amount of collagen than did C. Elastic fiber content increased progressively along time. This increment was related to the higher amount of oxytalan fibers at 15 and 30 days, whereas elaunin and fully developed elastic fibers were augmented only at 30 days. Silicosis led not only to pulmonary fibrosis but also to fibroelastosis, thus assigning a major role to the elastic system in the silicotic lung.

scholarly journals Effects of chronic l-NAME treatment lung tissue mechanics, eosinophilic and extracellular matrix responses induced by chronic pulmonary inflammation

2008 ◽  
Vol 294 (6) ◽  
pp. L1197-L1205 ◽  
Author(s):  
Patrícia Angeli ◽  
Carla M. Prado ◽  
Débora G. Xisto ◽  
Pedro L. Silva ◽  
Caroline P. Pássaro ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Lung Tissue ◽  
Pulmonary Inflammation ◽  
Elastic Fiber ◽  
Tissue Mechanics ◽  
Elastic Fibers ◽  
Distal Lung ◽  
Alveolar Septa

The importance of lung tissue in asthma pathophysiology has been recently recognized. Although nitric oxide mediates smooth muscle tonus control in airways, its effects on lung tissue responsiveness have not been investigated previously. We hypothesized that chronic nitric oxide synthase (NOS) inhibition by Nω-nitro-l-arginine methyl ester (l-NAME) may modulate lung tissue mechanics and eosinophil and extracellular matrix remodeling in guinea pigs with chronic pulmonary inflammation. Animals were submitted to seven saline or ovalbumin exposures with increasing doses (1∼5 mg/ml for 4 wk) and treated or not with l-NAME in drinking water. After the seventh inhalation (72 h), animals were anesthetized and exsanguinated, and oscillatory mechanics of lung tissue strips were performed in baseline condition and after ovalbumin challenge (0.1%). Using morphometry, we assessed the density of eosinophils, neuronal NOS (nNOS)- and inducible NOS (iNOS)-positive distal lung cells, smooth muscle cells, as well as collagen and elastic fibers in lung tissue. Ovalbumin-exposed animals had an increase in baseline and maximal tissue resistance and elastance, eosinophil density, nNOS- and iNOS-positive cells, the amount of collagen and elastic fibers, and isoprostane-8-PGF2α expression in the alveolar septa compared with controls ( P < 0.05). l-NAME treatment in ovalbumin-exposed animals attenuated lung tissue mechanical responses ( P < 0.01), nNOS- and iNOS-positive cells, elastic fiber content ( P < 0.001), and isoprostane-8-PGF2α in the alveolar septa ( P < 0.001). However, this treatment did not affect the total number of eosinophils and collagen deposition. These data suggest that NO contributes to distal lung parenchyma constriction and to elastic fiber deposition in this model. One possibility may be related to the effects of NO activating the oxidative stress pathway.

Elastic fiber system evaluated in the digestive organ of rats

Microscopy ◽  
2019 ◽  
Author(s):  
Kouji Inoue ◽  
Noriyuki Kuroda ◽  
Tetsuji Sato
Keyword(s):  
Digestive Tract ◽  
Hard Palate ◽  
Elastic System ◽  
Elastic Fiber ◽  
Elastic Fibers ◽  
Tissue Elasticity ◽  
Fiber System ◽  
Electron Microscopic ◽  
Tissue Resistance ◽  
Oxytalan Fibers

Abstract According to our previous reports, the intraperiodontal elastic fiber system comprises oxytalan fibers, whereas all types of elastic system fibers are present in the gingiva. Much remains to be elucidated regarding the topographic development of the elastic fiber system that constitutes the walls of the digestive organs. This study aimed to examine the topographic development of the elastic fiber system in the periodontal tissue, oral cavity and digestive tract of rats at light- and electron microscopic levels. At embryonic day 20, in situ hybridization revealed the mRNA expression of tropoelastin in the putative gingival lamina propria but not in the dental follicle. At the postnatal stage, the masticatory mucous membrane of the gingiva and hard palate comprised three different types of elastic system fibers (oxytalan, elaunin and elastic fibers). Conversely, the elastic fiber system comprised elaunin and elastic fibers in other oral mucosae and the lining mucosae of digestive tract organs (the esophagus, stomach and small intestine). The findings of our study suggest that the elastic fiber system is mainly related to tissue resistance in the periodontal ligament and tissue elasticity in the oral mucosae without masticatory mucosae and the overlying mucosa of digestive tracts and both functions in the gingiva and hard palate, respectively. The appearance of elaunin fibers in the periodontium of rats aged 14 weeks suggests the expression of tropoelastin induced by mechanical stressors such as mastication. The intraperiodontal difference in the distribution of elaunin fibers suggests heterogeneity among fibroblasts constituting the periodontium.

scholarly journals Lung Parenchymal Mechanics in Health and Disease

2009 ◽  
Vol 89 (3) ◽  
pp. 759-775 ◽  
Author(s):  
Débora S. Faffe ◽  
Walter A. Zin
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Lung Tissue ◽  
Lung Parenchyma ◽  
Elastic Fibers ◽  
Tissue Composition ◽  
Health And Disease ◽  
Complex Structural ◽  
Main Determinants ◽  
The Relationship

The mechanical properties of lung tissue are important determinants of lung physiological functions. The connective tissue is composed mainly of cells and extracellular matrix, where collagen and elastic fibers are the main determinants of lung tissue mechanical properties. These fibers have essentially different elastic properties, form a continuous network along the lungs, and are responsible for passive expiration. In the last decade, many studies analyzed the relationship between tissue composition, microstructure, and macrophysiology, showing that the lung physiological behavior reflects both the mechanical properties of tissue individual components and its complex structural organization. Different lung pathologies such as acute respiratory distress syndrome, fibrosis, inflammation, and emphysema can affect the extracellular matrix. This review focuses on the mechanical properties of lung tissue and how the stress-bearing elements of lung parenchyma can influence its behavior.

Different strains of mice present distinct lung tissue mechanics and extracellular matrix composition in a model of chronic allergic asthma

2009 ◽  
Vol 165 (2-3) ◽  
pp. 202-207 ◽  
Author(s):  
Mariana A. Antunes ◽  
Soraia C. Abreu ◽  
Nilsa R. Damaceno-Rodrigues ◽  
Edwin R. Parra ◽  
Vera L. Capelozzi ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Allergic Asthma ◽  
Lung Tissue ◽  
Tissue Mechanics ◽  
Matrix Composition ◽  
Different Strains

scholarly journals Nanoindentation of histological specimens: Mapping the elastic properties of soft tissues

2009 ◽  
Vol 24 (3) ◽  
pp. 638-646 ◽  
Author(s):  
R. Akhtar ◽  
N. Schwarzer ◽  
M.J. Sherratt ◽  
R.E.B. Watson ◽  
H.K. Graham ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Elastic Modulus ◽  
Soft Tissues ◽  
Elastic Fiber ◽  
Vena Cava ◽  
Elastic Fibers ◽  
Fiber Density ◽  
Tissue Microstructure ◽  
Micromechanical Properties

Although alterations in the gross mechanical properties of dynamic and compliant tissues have a major impact on human health and morbidity, there are no well-established techniques to characterize the micromechanical properties of tissues such as blood vessels and lungs. We have used nanoindentation to spatially map the micromechanical properties of 5-μm-thick sections of ferret aorta and vena cava and to relate these mechanical properties to the histological distribution of fluorescent elastic fibers. To decouple the effect of the glass substrate on our analysis of the nanoindentation data, we have used the extended Oliver and Pharr method. The elastic modulus of the aorta decreased progressively from 35 MPa in the adventitial (outermost) layer to 8 MPa at the intimal (innermost) layer. In contrast, the vena cava was relatively stiff, with an elastic modulus >30 MPa in both the extracellular matrix-rich adventitial and intimal regions of the vessel. The central, highly cellularized, medial layer of the vena cava, however, had an invariant elastic modulus of ∼20 MPa. In extracellular matrix-rich regions of the tissue, the elastic modulus, as determined by nanoindentation, was inversely correlated with elastic fiber density. Thus, we show it is possible to distinguish and spatially resolve differences in the micromechanical properties of large arteries and veins, which are related to the tissue microstructure.

Mouse strain dependence of lung tissue mechanics: Role of specific extracellular matrix composition

2006 ◽  
Vol 152 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Debora S. Faffe ◽  
Elizabeth S. D’Alessandro ◽  
Debora G. Xisto ◽  
Mariana A. Antunes ◽  
Pablo V. Romero ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lung Tissue ◽  
Mouse Strain ◽  
Tissue Mechanics ◽  
Matrix Composition ◽  
Strain Dependence

Comparison of rat and mouse pulmonary tissue mechanical properties and histology

2002 ◽  
Vol 92 (1) ◽  
pp. 230-234 ◽  
Author(s):  
Débora S. Faffe ◽  
Patricia R. M. Rocco ◽  
Elnara M. Negri ◽  
Walter A. Zin
Keyword(s):  
Mechanical Properties ◽  
Blood Vessel ◽  
Elastic Fiber ◽  
Dynamic Mechanical Properties ◽  
Elastic Fibers ◽  
Rat Lung ◽  
Positive Dependence ◽  
Pulmonary Tissue ◽  
Sinusoidal Oscillations ◽  
The Mean

The present study compares the dynamic mechanical properties and the contents of collagen and elastic fibers (oxytalan + elaunin + fully developed elastic fibers) of mice and rat lung strips. Resistance, elastance (E), and hysteresivity (η) were obtained during sinusoidal oscillations. The relative amounts of blood vessel, bronchial, and alveolar walls, as well as the mean alveolar diameter were determined. In both species, resistance had a negative and E a positive dependence on frequency, whereas η remained unchanged. Mice showed higher E and lower η than rats. Although collagen and elastic fiber contents were similar in both groups, mice had more oxytalan and less elaunin and fully developed elastic fibers than rats. Rats showed less alveolar and more blood vessel walls and higher mean alveolar diameter than mice. In conclusion, mice and rats present distinct tissue mechanical properties, which are accompanied by specific extracellular fiber composition.

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs

2008 ◽  
Vol 104 (6) ◽  
pp. 1778-1785 ◽  
Author(s):  
Adriane S. Nakashima ◽  
Carla M. Prado ◽  
Tatiana Lanças ◽  
Viviane C. Ruiz ◽  
David I. Kasahara ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lung Tissue ◽  
Guinea Pigs ◽  
Oral Tolerance ◽  
Elastic Fiber ◽  
Allergic Inflammation ◽  
Tissue Mechanics ◽  
Fiber Content ◽  
Extracellular Matrix Remodeling ◽  
Matrix Remodeling

Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1–5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.

Elastin exhibits a distinctive temporal and spatial pattern of distribution in the developing chick limb in association with the establishment of the cartilaginous skeleton

1994 ◽  
Vol 107 (9) ◽  
pp. 2623-2634 ◽  
Author(s):  
J.M. Hurle ◽  
G. Corson ◽  
K. Daniels ◽  
R.S. Reiter ◽  
L.Y. Sakai ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Spatial Pattern ◽  
Elastic Fiber ◽  
Spatial Location ◽  
Limb Bud ◽  
Confocal Laser ◽  
Elastic Fibers ◽  
Type I ◽  
Temporal And Spatial

In this work we have analyzed the presence of elastic components in the extracellular matrices of the developing chick leg bud. The distributions of elastin and fibrillin were studied immunohistochemically in whole-mount preparations using confocal laser microscopy. The association of these constituents of the elastic matrix with other components of the extracellular matrix was also studied, using several additional antibodies. Our results reveal the transient presence of an elastin-rich scaffold of extracellular matrix fibrillar material in association with the establishment of the cartilaginous skeleton of the leg bud. The scaffold consisted of elastin-positive fibers extending from the ectodermal surface of the limb to the central cartilage-forming regions and between adjacent cartilages. Fibrillin immunolabeling was negative in this fibrillar scaffold while other components of the extracellular matrix including: tenascin, laminin and collagens type I, type III and type VI; appeared codistributed with elastin in some regions of the scaffold. Progressive changes in the spatial pattern of distribution of the elastin-positive scaffold were detected in explant cultures in which one expects a modification in the mechanical stresses of the tissues related to growth. A scaffold of elastin comparable to that found in vivo was also observed in high-density micromass cultures of isolated limb mesodermal cells. In this case the elastic fibers are observed filling the spaces located between the cartilaginous nodules. The fibers become reoriented and attach to the ectodermal basal surface when an ectodermal fragment is located at the top of the growing micromass. Our results suggest that the formation of the cartilaginous skeleton of the limb involves the segregation of the undifferentiated limb mesenchyme into chondrogenic and elastogenic cell lineages. Further, a role for the elastic fiber scaffold in coordinating the size and the spatial location of the cartilaginous skeletal elements within the limb bud is also suggested from our observations.

scholarly journals Influence of obesity on remodeling of lung tissue and organization of extracellular matrix after blunt thorax trauma

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Pengfei Xu ◽  
Fabian Gärtner ◽  
Adrian Gihring ◽  
Congxing Liu ◽  
Timo Burster ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lung Tissue ◽  
Protein Level ◽  
Morphological Changes ◽  
Matrix Composition ◽  
Collagen Deposition ◽  
Obese Mice ◽  
Time Points ◽  
Extracellular Matrix Components ◽  
Thorax Trauma

Abstract Background Previously, it has been shown that obesity is a risk factor for recovery, regeneration, and tissue repair after blunt trauma and can affect the rate of muscle recovery and collagen deposition after trauma. To date, lung tissue regeneration and extracellular matrix regulation in obese mice after injury has not been investigated in detail yet. Methods This study uses an established blunt thorax trauma model to analyze morphological changes and alterations on gene and protein level in lean or obese (diet-induced obesity for 16 ± 1 week) male C57BL/6 J mice at various time-points after trauma induction (1 h, 6 h, 24 h, 72 h and 192 h). Results Morphological analysis after injury showed lung parenchyma damage at early time-points in both lean and obese mice. At later time-points a better regenerative capacity of lean mice was observed, since obese animals still exhibited alveoli collapse, wall thickness as well as remaining filled alveoli structures. Although lean mice showed significantly increased collagen and fibronectin gene levels, analysis of collagen deposition showed no difference based on colorimetric quantification of collagen and visual assessment of Sirius red staining. When investigating the organization of the ECM on gene level, a decreased response of obese mice after trauma regarding extracellular matrix composition and organization was detectable. Differences in the lung tissue between the diets regarding early responding MMPs (MMP8/9) and late responding MMPs (MMP2) could be observed on gene and protein level. Obese mice show differences in regulation of extracellular matrix components compared to normal weight mice, which results in a decreased total MMP activity in obese animals during the whole regeneration phase. Starting at 6 h post traumatic injury, lean mice show a 50% increase in total MMP activity compared to control animals, while MMP activity in obese mice drops to 50%. Conclusions In conclusion, abnormal regulation of the levels of extracellular matrix genes in the lung may contribute to an aberrant regeneration after trauma induction with a delay of repair and pathological changes of the lung tissue in obese mice.

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