Percolation of collagen stress in a random network model of the alveolar wall

Casey, D.; Jawde, Samer Bou; Herrmann, Jacob; Mori, Vitor; Mahoney, James; Suki, Bélâ; Bates, Jason H. T.

doi:10.1038/s41598-021-95911-w

Cited by 11 publications

(5 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was therefore unexpected that elastase would cause such a dramatic reduction in tensile properties, given that the collagen itself was largely unaffected (Figure 4c and Supplemental Figure S3b). One possible explanation is that elastic fibers enable load transfer between collagen fibers, as has been proposed in other tissues [57].…”

Section: Discussionmentioning

confidence: 83%

Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine

Loffet

Durel

Kam

et al. 2023

Preprint

View full text Add to dashboard Cite

During embryonic development, tissues must possess precise material properties to ensure that cell-generated forces give rise to the stereotyped morphologies of developing organs. However, the question of how material properties are established and regulated during development remains understudied. Here, we aim to address these broader questions through the study of intestinal looping, a process by which the initially straight intestinal tube buckles into loops, permitting ordered packing within the body cavity. Looping results from elongation of the tube against the constraint of an attached tissue, the dorsal mesentery, which is elastically stretched by the elongating tube to nearly triple its length. This elastic energy storage allows the mesentery to provide stable compressive forces that ultimately buckle the tube into loops. Beginning with a transcriptomic analysis of the mesentery, we identified widespread upregulation of extracellular matrix related genes during looping, including genes related to elastic fiber deposition. Combining molecular and mechanical analyses, we conclude that elastin confers tensile stiffness to the mesentery, enabling its mechanical role in organizing the developing small intestine. These results shed light on the role of elastin as a driver of morphogenesis that extends beyond its more established role in resisting cyclic deformation in adult tissues.

show abstract

Section: Discussionmentioning

confidence: 83%

Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine

Loffet

Durel

Kam

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…It has previously been used to quantify collagen content as the summation of the pixels from histopathology of a fibrotic lung (Anathy et al 2018 ). While fibrosis is commonly thought of as an excess of collagen deposition, it is now recognized that aberrant crosslinking and reorganization of existing collagen are factors that contribute to disease progression (Jones et al 2018 ; Casey et al 2021 ). Hence, quantifying changes in tissue structure via a fractal dimension may provide an alternative metric of phenotypic changes in fibrosis to complement the conventional metric of total collagen.…”

Section: Discussionmentioning

confidence: 99%

Local fractal dimension of collagen detects increased spatial complexity in fibrosis

Casey,

Lahue,

Mori

et al. 2023

Histochem Cell Biol

Self Cite

View full text Add to dashboard Cite

Increase of collagen content and reorganization characterizes fibrosis but quantifying the latter remains challenging. Spatially complex structures are often analyzed via the fractal dimension; however, established methods for calculating this quantity either provide a single dimension for an entire object or a spatially distributed dimension that only considers binary images. These neglect valuable information related to collagen density in images of fibrotic tissue. We sought to develop a fractal analysis that can be applied to 3-dimensional (3D) images of fibrotic tissue. A fractal dimension map for each image was calculated by determining a single fractal dimension for a small area surrounding each image pixel, using fiber thickness as the third dimension. We found that this local fractal dimension increased with age and with progression of fibrosis regardless of collagen content. Our new method of distributed 3D fractal analysis can thus distinguish between changes in collagen content and organization induced by fibrosis.

show abstract

“…On the other hand, the assumption of spherical symmetry allows for an analytic solution to our model and thus the computation of the stresses on the fiber systems. Our model does not account for mechanical interactions between the elastin and collagen fiber system 50 . Despite these limitations, however, our model provides novel insight into how the total lung P–V curve arises from gravity acting on the distributed mechanical properties of individual alveoli as determined by fiber stresses within the septal walls in the human lung.…”

Section: Discussionmentioning

confidence: 99%

Modeling the influence of gravity and the mechanical properties of elastin and collagen fibers on alveolar and lung pressure–volume curves

Shi

Herrmann

Jawde

et al. 2022

Sci Rep

View full text Add to dashboard Cite

The relationship between pressure (P) and volume (V) in the human lung has been extensively studied. However, the combined effects of gravity and the mechanical properties of elastin and collagen on alveolar and lung P–V curves during breathing are not well understood. Here, we extended a previously established thick-walled spherical model of a single alveolus with wavy collagen fibers during positive pressure inflation. First, we updated the model for negative pressure-driven inflation that allowed incorporation of a gravity-induced pleural pressure gradient to predict how the static alveolar P–V relations vary spatially throughout an upright human lung. Second, by introducing dynamic surface tension and collagen viscoelasticity, we computed the hysteresis loop of the lung P–V curve. The model was tested by comparing its predicted regional ventilation to literature data, which offered insight into the effects of microgravity on ventilation. The model has also produced novel testable predictions for future experiments about the variation of mechanical stresses in the septal walls and the contribution of collagen and elastin fibers to the P–V curve and throughout the lung. The model may help us better understand how mechanical stresses arising from breathing and pleural pressure variations affect regional cellular mechanotransduction in the lung.

show abstract

Percolation of collagen stress in a random network model of the alveolar wall

Cited by 11 publications

References 35 publications

Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine

Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine

Local fractal dimension of collagen detects increased spatial complexity in fibrosis

Modeling the influence of gravity and the mechanical properties of elastin and collagen fibers on alveolar and lung pressure–volume curves

Contact Info

Product

Resources

About