scholarly journals Beyond muscles: Role of intramuscular connective tissue elasticity and passive stiffness in the octopus arm muscle function

2021 ◽  
Author(s):  
Alessio Di Clemente ◽  
Federica Maiole ◽  
Irene Bornia ◽  
Letizia Zullo
Keyword(s):  
Connective Tissue ◽  
Elastic Fiber ◽  
Length Change ◽  
Confocal Imaging ◽  
Elastic Fibers ◽  
Tissue Elasticity ◽  
Resistance To Deformation ◽  
Arm Motion ◽  
And Control

The octopus arm is a ‘one of a kind’ muscular hydrostat, as demonstrated by its high maneuverability and complexity of motions. It is composed of a complex array of muscles and intramuscular connective tissue, allowing force and shape production. In this study, we investigated the organization of the intramuscular elastic fibers in two main muscles composing the arm bulk: the longitudinal (L) and the transverse (T) muscles. We assessed their contribution to the muscles’ passive elasticity and stiffness and inferred their possible roles in limb deformation. First, we performed confocal imaging of whole arm samples and provided evidence of a muscle-specific organization of elastic fibers (more chaotic and less coiled in T than in L). We next show that in an arm at rest, L muscles are maintained under 20% compression and T muscles under 30% stretching. Hence, tensional stresses are inherently present in the arm and affect the strain of elastic fibers. Because connective tissue in muscles is used to transmit stress and store elastic energy, we investigated the contribution of elastic fibers to passive forces using step-stretch and sinusoidal length-change protocols. We observed a higher viscoelasticity of L and a higher stiffness of T muscles, in line with their elastic fiber configurations. This suggests that L might be involved in energy storage and damping, while T in posture maintenance and resistance to deformation. The elastic fiber configuration thus supports the specific role of muscles during movement and may contribute to the mechanics, energetic and control of arm motion.

Toward a kinetic theory of connective tissue micromechanics

1993 ◽  
Vol 74 (2) ◽  
pp. 665-681 ◽  
Author(s):  
S. M. Mijailovich ◽  
D. Stamenovic ◽  
J. J. Fredberg
Keyword(s):  
Connective Tissue ◽  
Three Dimensional ◽  
Elastic Fibers ◽  
Tissue Elasticity ◽  
Field Equations ◽  
Fiber Network ◽  
Rate Dependent ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
And Diffusion

The aim of this study is to develop unifying concepts at the microstructural level to account for macroscopic connective tissue dynamics. We establish the hypothesis that rate-dependent and rate-independent dissipative stresses arise in the interaction among fibers in the connective tissue matrix. A quantitative theoretical analysis is specified in terms of geometry and material properties of connective tissue fibers and surrounding constituents. The analysis leads to the notion of slip and diffusion boundary layers, which become unifying concepts in understanding mechanisms that underlie connective tissue elasticity and energy dissipation during various types of loading. The complex three-dimensional fiber network is simplified to the interaction of two ideally elastic fibers that dissipate energy on slipping interface surfaces. The effects of such interactions are assumed to be expressed in the aggregate matrix. Special solutions of the field equations are obtained analytically, whereas the general solution of the model field equations is obtained numerically. The solutions lead to predictions of tissue behavior that are qualitatively, if not quantitatively, consistent with reports of a variety of dynamic moduli, their dependencies on the rate and amplitude of load application, and some features associated with preconditioning.

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 Elastin biology and tissue engineering with adult cells

2013 ◽  
Vol 4 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Cassandra B. Saitow ◽  
Steven G. Wise ◽  
Anthony S. Weiss ◽  
John J. Castellot ◽  
David L. Kaplan
Keyword(s):  
Tissue Engineering ◽  
Normal Development ◽  
Elastic Fiber ◽  
Elastic Fibers ◽  
Accessory Proteins ◽  
Engineering Research ◽  
Elastin Gene ◽  
Tissue Engineering Research ◽  
Adult Cells

AbstractThe inability of adult cells to produce well-organized, robust elastic fibers has long been a barrier to the successful engineering of certain tissues. In this review, we focus primarily on elastin with respect to tissue-engineered vascular substitutes. To understand elastin regulation during normal development, we describe the role of various elastic fiber accessory proteins. Biochemical pathways regulating expression of the elastin gene are addressed, with particular focus on tissue-engineering research using adult-derived cells.

Histological Evaluation of the Skin After Fat Grafting: A Blinded, Randomized, Controlled Clinical Study

2020 ◽  
Vol 40 (6) ◽  
pp. NP388-NP393
Author(s):  
Juan P B R Maricevich ◽  
Marcel F M B Lima ◽  
Ana Carolina Maricevich ◽  
Marco A B R Maricevich ◽  
Larissa F J Silva ◽  
...  
Keyword(s):  
Inflammatory Infiltrate ◽  
Elastic Fiber ◽  
Fat Grafting ◽  
Histological Evaluation ◽  
Fat Graft ◽  
Elastic Fibers ◽  
Control Group ◽  
Vascular Density ◽  
Randomized Controlled ◽  
And Control

Abstract Background Autologous fat graft is often employed to treat body contour defects. There is currently increased interest in the regenerative properties of fat grafting. Objectives The authors evaluated the histological changes of fat grafting in a blinded randomized controlled trial of staged fat grafting-abdominoplasty. Methods Ten women between 24 and 55 years of age with a body mass index <30 kg/m2 and previous cesarean scar were submitted to fat grafting followed by staged abdominoplasty. The C-section scar served as a landmark for standardization of fat grafting site and control. One side of the abdomen was fat grafted and the other was left intact (control). At the time of abdominoplasty, 4 months later, a full-thickness skin sample from each hemi abdomen (fat-grafted area and control) was collected and sent to histological analysis. Results All of the fat-grafted samples showed extracellular lipids and signs of fat graft viability, whereas no such changes occurred in the control group. There were no statistically significant differences in fat-grafted vs control samples regarding skin inflammatory infiltrate (P = 0.582), dermis thickness (P = 0.973), vascular density (P = 0.326), and amount of elastic fibers (P = 1). Conclusions The histological evaluation of women’s abdominoplasty surgical site skin after 4 months of fat grafting showed signs of fat graft in 100% of the grafted sides but no change in skin inflammatory infiltrate, dermis thickness, vascularity density, or elastic fiber quantity.

scholarly journals Functionally Distinct Tendons From Elastin Haploinsufficient Mice Exhibit Mild Stiffening and Tendon-Specific Structural Alteration

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Jeremy D. Eekhoff ◽  
Fei Fang ◽  
Lindsey G. Kahan ◽  
Gabriela Espinosa ◽  
Austin J. Cocciolone ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Fiber ◽  
Mechanical Effect ◽  
Elastic Fibers ◽  
Minor Role ◽  
Tendon Mechanics ◽  
Different Types ◽  
A Minor ◽  
Collagen Alignment

Elastic fibers are present in low quantities in tendon, where they are located both within fascicles near tenocytes and more broadly in the interfascicular matrix (IFM). While elastic fibers have long been known to be significant in the mechanics of elastin-rich tissue (i.e., vasculature, skin, lungs), recent studies have suggested a mechanical role for elastic fibers in tendons that is dependent on specific tendon function. However, the exact contribution of elastin to properties of different types of tendons (e.g., positional, energy-storing) remains unknown. Therefore, this study purposed to evaluate the role of elastin in the mechanical properties and collagen alignment of functionally distinct supraspinatus tendons (SSTs) and Achilles tendons (ATs) from elastin haploinsufficient (HET) and wild type (WT) mice. Despite the significant decrease in elastin in HET tendons, a slight increase in linear stiffness of both tendons was the only significant mechanical effect of elastin haploinsufficiency. Additionally, there were significant changes in collagen nanostructure and subtle alteration to collagen alignment in the AT but not the SST. Hence, elastin may play only a minor role in tendon mechanical properties. Alternatively, larger changes to tendon mechanics may have been mitigated by developmental compensation of HET tendons and/or the role of elastic fibers may be less prominent in smaller mouse tendons compared to the larger bovine and human tendons evaluated in previous studies. Further research will be necessary to fully elucidate the influence of various elastic fiber components on structure–function relationships in functionally distinct tendons.

scholarly journals Elastin, arterial mechanics, and cardiovascular disease

2018 ◽  
Vol 315 (2) ◽  
pp. H189-H205 ◽  
Author(s):  
Austin J. Cocciolone ◽  
Jie Z. Hawes ◽  
Marius C. Staiculescu ◽  
Elizabeth O. Johnson ◽  
Monzur Murshed ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Aortic Stenosis ◽  
Autosomal Dominant ◽  
Elastic Fiber ◽  
Cutis Laxa ◽  
Supravalvular Aortic Stenosis ◽  
Elastic Fibers ◽  
Arterial Mechanics ◽  
Fiber Assembly

Large, elastic arteries are composed of cells and a specialized extracellular matrix that provides reversible elasticity and strength. Elastin is the matrix protein responsible for this reversible elasticity that reduces the workload on the heart and dampens pulsatile flow in distal arteries. Here, we summarize the elastin protein biochemistry, self-association behavior, cross-linking process, and multistep elastic fiber assembly that provide large arteries with their unique mechanical properties. We present measures of passive arterial mechanics that depend on elastic fiber amounts and integrity such as the Windkessel effect, structural and material stiffness, and energy storage. We discuss supravalvular aortic stenosis and autosomal dominant cutis laxa-1, which are genetic disorders caused by mutations in the elastin gene. We present mouse models of supravalvular aortic stenosis, autosomal dominant cutis laxa-1, and graded elastin amounts that have been invaluable for understanding the role of elastin in arterial mechanics and cardiovascular disease. We summarize acquired diseases associated with elastic fiber defects, including hypertension and arterial stiffness, diabetes, obesity, atherosclerosis, calcification, and aneurysms and dissections. We mention animal models that have helped delineate the role of elastic fiber defects in these acquired diseases. We briefly summarize challenges and recent advances in generating functional elastic fibers in tissue-engineered arteries. We conclude with suggestions for future research and opportunities for therapeutic intervention in genetic and acquired elastinopathies.

Strategies For Immunodissection Of The Connective Tissue Matrix And Basement Membranes

1999 ◽  
Vol 5 (S2) ◽  
pp. 1222-1223
Author(s):  
Douglas R. Keene ◽  
Sara F. Tufa
Keyword(s):  
Connective Tissue ◽  
Elastic Fiber ◽  
Dry Weight ◽  
Basement Membranes ◽  
The Matrix ◽  
Connective Tissue Matrix ◽  
Main Component ◽  
Tissue Matrix ◽  
And Task

Connective tissue matrices are quite diversified and include that composing skin, tendon, bone, cartilage, cornea and many others. The main component of the connective tissue matrix is collagen, composing approximately 70% of the dry weight of the human body. More members of the collagen family are discovered each year, with over twenty types described to date. Many of these collagens are tissue specific. In addition to the collagens, the connective tissue matrix is also the residence of epithelial and endothelial basement membranes and many other molecules including a variety of proteoglycans and elastic fiber components. The cells within the matrix are highly differentiated and task specific.Using immunocytochemical technique applied at the level of the electron microscope, we have focused our resources to understand the structure and functional role of these matrix molecules.

scholarly journals Role of LTBP4 in alveolarization, angiogenesis, and fibrosis in lungs

2017 ◽  
Vol 313 (4) ◽  
pp. L687-L698 ◽  
Author(s):  
Insa Bultmann-Mellin ◽  
Katharina Dinger ◽  
Carolin Debuschewitz ◽  
Katharina M. A. Loewe ◽  
Yvonne Melcher ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Transforming Growth Factor ◽  
Elastic Fiber ◽  
Transforming Growth Factor Β ◽  
Matrix Proteins ◽  
Extracellular Matrix Protein ◽  
Elastic Fibers ◽  
Fiber Network

Deficiency of the extracellular matrix protein latent transforming growth factor-β (TGF-β)-binding protein-4 (LTBP4) results in lack of intact elastic fibers, which leads to disturbed pulmonary development and lack of normal alveolarization in humans and mice. Formation of alveoli and alveolar septation in pulmonary development requires the concerted interaction of extracellular matrix proteins, growth factors such as TGF-β, fibroblasts, and myofibroblasts to promote elastogenesis as well as vascular formation in the alveolar septae. To investigate the role of LTBP4 in this context, lungs of LTBP4-deficient ( Ltbp4−/−) mice were analyzed in close detail. We elucidate the role of LTBP4 in pulmonary alveolarization and show that three different, interacting mechanisms might contribute to alveolar septation defects in Ltbp4−/− lungs: 1) absence of an intact elastic fiber network, 2) reduced angiogenesis, and 3) upregulation of TGF-β activity resulting in profibrotic processes in the lung.

scholarly journals Characterization of spontaneous air space enlargement in mice lacking microfibrillar-associated protein 4

2015 ◽  
Vol 308 (11) ◽  
pp. L1114-L1124 ◽  
Author(s):  
Anne Trommelholt Holm ◽  
Helle Wulf-Johansson ◽  
Svend Hvidsten ◽  
Patricia Troest Jorgensen ◽  
Anders Schlosser ◽  
...  
Keyword(s):  
Elastic Fiber ◽  
Lung Parenchyma ◽  
Elastic Fibers ◽  
Breath Hold ◽  
Transmission Electron ◽  
Air Space ◽  
Alveolar Surface

Microfibrillar-associated protein 4 (MFAP4) is localized to elastic fibers in blood vessels and the interalveolar septa of the lungs and is further present in bronchoalveolar lavage. Mfap4 has been previously suggested to be involved in elastogenesis in the lung. We tested this prediction and aimed to characterize the pulmonary function changes and emphysematous changes that occur in Mfap4-deficient ( Mfap4 −/−) mice. Significant changes included increases in total lung capacity and compliance, which were evident in Mfap4 −/− mice at 6 and 8 mo but not at 3 mo of age. Using in vivo breath-hold gated microcomputed tomography (micro-CT) in 8-mo-old Mfap4 −/− mice, we found that the mean density of the lung parenchyma was decreased, and the low-attenuation area (LAA) was significantly increased by 14% compared with Mfap4 +/+ mice. Transmission electron microscopy (TEM) did not reveal differences in the organization of elastic fibers, and there was no difference in elastin content, but a borderline significant increase in elastin mRNA expression in 3-mo-old mice. Stereological analysis showed that alveolar surface density in relation to the lung parenchyma and total alveolar surface area inside of the lung were both significantly decreased in Mfap4−/− mice by 25 and 15%, respectively. The data did not support an essential role of MFAP4 in pulmonary elastic fiber organization or content but indicated increased turnover in young Mfap4 −/− mice. However, Mfap4 −/− mice developed a spontaneous loss of lung function, which was evident at 6 mo of age, and moderate air space enlargement, with emphysema-like changes.

Sign in / Sign up

Export Citation Format

Share Document