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Functions of elastic fibers

Functions of elastic fibers

Histology: connective tissue (development and structures

Elastic fibres are yellowish branching fibres made mainly of the protein elastin that are often found in plates or perforated membranes, such as the walls of large arteries. They may not exhibit orderly fibrous subunits under microscopic analysis, unlike collagenous fibres, and often tend to be composed of minute fibrils around a solid heart. Elastic fibers, unlike collagenous fibres, are not broken down by hot water and are immune to most enzymes. The fibres are highly elastic, as their name implies, and provide elasticity to tissues such as the skin, lungs, and certain large blood vessels, such as the aorta.

Connective tissue: extracellular matrix

a collection of books (AEMB, volume 385)

Components of connective tissue | fibers | cells | ground

a summary

Elastin

Elastic fibers in the extracellular matrix play a big role in the elasticity of many tissues in the vertebrate body. They make up a small but significant portion of the dry weight in certain tissues, such as the skin (2–4%), but they can make up more than half of the dry weight in others, such as broad arteries and some specialized ligaments. Elastic fibers can be seen in the electron microscope to be made up of two sections. 3–1 Up to 90% of the mature fiber is made up of an amorphous fraction with no discernible normal or repeating structure. The microfibrillar component is made up of 10–12 nm fibrils that are mostly found around the amorphous component’s periphery, but are also found within it to some degree (Fig. 1). The two elements are chemically distinct in addition to being distinguishable morphologically. The elastic fiber’s amorphous component is made up of a single protein called elastin, which is responsible for the elastic properties. Although the microfibrils’ exact composition is unknown, it is likely that they are made up of multiple glycoproteins. Keywords: 4 Fiber with Elasticity Immunoelectron fusion Elastin Gene Fetal Bladder Microscopy Cell BioI

Elastic fibers & elastic connective tissue

The extracellular matrix (ECM), which is made up of collagen, glycoproteins, glycosaminoglycans, and proteoglycans, has elastin as its most stable protein (Aumailley and Gayraud, 1998). It’s found in large quantities in organs like arteries and lungs that rely on their elastic properties to function. Elastin is produced around the time of birth, when these organs begin to work, and then ceases in the postnatal period. The majority of protein stays in the body for the rest of one’s life (Shapiro et al., 1991). In pathological conditions, it can be degraded and resynthesised in different organs. In the later stages of wound healing, elastic fibers appear in the scar (Raghunath et al., 1996; Sproul and Argraves, 2013). Elastin accumulates in fibrotic livers regardless of the cause (Liban and Ungar, 1959), and its slow turnover can contribute significantly to the disease’s irreversibility.
Elastic fibers are made up of an insoluble elastin core, microfibrils on the fiber’s surface, and a number of attached proteins that aid in the fiber’s assembly (Kielty et al., 2002). Elastic fibers are not a part of the ECM that is inert. Tropoelastin, elastin polymer, and elastin degradation products are all biologically active and can affect inflammatory and connective tissue cells in the organ (Almine et al., 2012). Furthermore, microfibrils bind TGF-superfamily cytokines, which may affect the progression of liver fibrosis, regeneration, and cancer (Bissell et al., 2001; Dooley and ten Dijke, 2012).

Connective tissue – structure & function – histology

The extracellular matrix’s cellular maintenance necessitates an efficient control that integrates enzymatic degradation with collagen fibril and fiber repair. The long-term maintenance of elastic fibers under stress, as well as the diffusion of general degradative and regenerative particles associated with digestion and repair processes, are investigated in this paper. Using the assumption that cells regularly probe fiber stiffness to change the output and release of degradative and regenerative particles, computational findings show that homeostatic fiber stiffness can be achieved. This mechanism, however, is incapable of maintaining a homogeneous fiber. To account for axial homogeneity, we implement a robust control mechanism that is locally controlled by how mechanical forces applied to the fiber ends modulate particle binding affinity. The axial distribution of collagen fibril diameters obtained from scanning electron microscopic images of normal rat thoracic aorta agrees with the diameter variations along the fiber predicted by this model. Only when the applied force on the fiber is in the range where the variance of local stiffness along the fiber reaches a minimum value do the model predictions match the experiments. As a result, our model predicts that the biophysical properties of the fibers play a critical role in the fibers’ long-term regulatory maintenance.