Elastin Smooth muscle cells

VAPG Elastin Non-integrin receptor Vascular smooth muscle cells... 

Elastogenesis occurs primarily during late fetal and early neonatal periods. Elastin is synthesized and secreted from several cell types including smooth muscle cells, fibroblasts, endothelial cells, chondroblasts, and mesothelial cells (Uitto et al, 1991) with tissue-specific induction of elastin expression during development (Swee et al, 1995). After elastin has been deposited, its synthesis ceases and very little turnover of elastin is seen during adult life, unless the elastic fibers are subject to injury. In this case,... 

Carreras, I., Rich, C. B., Panchenko, M. P., and Foster, J. A. (2002). Basic fibroblast growth factor decreases elastin gene transcription in aortic smooth muscle cells. / Cell. Biochem. 85, 592—600. 

Ooyama, T., Fukuda, K., Oda, H., Nakamura, H., and Hikita, Y. (1987). Substratum-bound elastin peptide inhibits aortic smooth muscle cell migration in vitro. Arteriosclerosis 7, 593-598. 

Gobin AS, West JL (2003) Val-ala-pro-gly, an elastin-derived non-integrin ligand smooth muscle cell adhesion and specificity. J Biomed Mat Res A 67A(l) 255-259... 

Figure 7. Portion of an intimal smooth muscle cell and the adjacent intercellular matrix from a primate artery (Macaca nemestrina) stained with ruthenium red. The ruthenium red stains numerous polygonal granules associated with each other through 30-60 A diameter filamentous projections which, based on studies with chondroitinases, must represent dermatan sulfate-containing proteoglycans (X 40,000). As shown in the insert, the 30-60 A filaments interconnect granules, collagen fibers, elastin, and the surfaces of cells (X 140,000). Reproduced from Proteoglycans in Primate Arteries. I. Ultrastructural Localization and Distribution in the Intima, by Thomas N. Wight and Russell Ross, J. Cell Biol. (1975) 67,...

In the progressing lesion, a number of additional processes come into play, the most important of which are cellular necrosis with the release of foam-cell lipids to the interstitium, and the mitogen-stimulated proliferation of myointimal cells (smooth muscle cells), with the subsequent synthesis of collagens, elastin and proteoglycans. 

Elastic fibers are usually found in tissues rich in smooth muscle or tissues containing fibroblasts possessing some of characteristics of smooth muscle cells (4). There is a recent report, however, that suggests elastin-like proteins may be secreted from chondrocytes (25). When elastin is secreted, it is accompanied by other proteins that appear to be important to its alignment into fibrils. One of these proteins is referred to as microfibrillar protein (cf. Table I, ref. 2). When elastin is secreted, it combines with the microfibrillar protein to form a complex which is initially rich in the microfibrillar protein. 

The exact form in which non-crosslinked elastin is secreted from smooth muscle cells is yet to be clearly defined. Foster et al. (36) have suggested that a non-cross linked elastin (pro-elastin) is secreted from smooth muscle cells in a form that is approximately 120,000 to 140,000 daltons. They have suggested that proelastin is cleaved to smaller molecular weight forms of non-crosslinked elastin. It should be noted, however, that this view is not entirely supported by data from other laboratories. There are two reports on the use of isolated mRNA from chick aorta suggesting only a 70,000 dalton non-cross linked elastin is the major product of translation (37,38). There is also a recent report suggesting that aortic mRMA translates a 200,000 dalton putative elastin product (39). We have recently isolated a non-crosslinked elastin from the aortas of copper deficient chicks that appears to be 100,000 daltons (27). Its amino acid composition is similar to that for tropoelastin (Table III). A major problem in resolving these points is that the trypsin-like proteinase associated with elastin is not easily denatured or separated from the non-crosslinked forms of elastin. The proteinase is also not readily inhibited by commonly used inhibitors for trypsin-like proteinases (26). 

The normal artery is composed of three distinct layers (Fig. 34.21). That which is closest to the lumen of the vessel, the intima, is lined by a monolayer of endothelial cells that are bathed by the circulating blood. Just beneath these specialized cells lies the subintimal extracellular matrix, in which some vascular smooth muscle cells are embedded (the subintimal space). The middle layer, known as the tunica media, is separated from the intima by the internal elastic lamina. The tunica media contains lamellae of smooth muscle cells surrounded by an elastin- and collagen-rich matrix. The external elastic lamina forms the border between the tunica media and the outermost layer, the adventitia. This layer contains nerve fibers and mast cells. It is the origin of the vasa vasorum, which supply blood to the outer two thirds of the tunica media. 

Elastin is the major protein found in elastic fibers, which are located in the ECM of connective tissue of smooth muscle cells, endothelial and microvascular cells, chondrocytes, and fibroblasts. Elastic fibers allow tissues to expand and contract this is of particular importance to blood vessels, which must deform and reform repeatedly in response to the changes in intravascular pressure that occur with the contraction of the left ventricle of the heart. It is also important for the lungs, which stretch each time a breath is inhaled and return to their original shape with each exhalation. In addition to elastin, the elastic fibers contain microfibrils, which are composed of a number of acidic glycoproteins, the major ones being fibrillin-1 and fibrillin-2. 

Cheng, S. X Chen, Z. R and Chen, G. Q. Xhe expression of cross-linked elastin by rabbit blood vessel smooth muscle cells cultured in polyhydroxyalkanoate scaffolds. Biomater. 2008, 29(31), 4187- 194. 

The media represents the major portion of the vessel wall and provides most of the mechanical strength necessary to sustain structural integrity. The media is organized into alternating layers of interconnected smooth muscle cells and elastic lamellae. There is evidence of coUagen throughout the media. These small collagen fibers are found within the bands of smooth muscle and may participate in the transfer of forces between the smooth muscle cells and the elastic lamellae. The elastic lamellae are composed principally of the fiberous protein elastin. The number of elastic lamellae depends upon the wall thickness and the anatomical location [12]. In the case of the canine carotid, the elastic lamellae account for a major component of the static structural response of the blood vessel [13]. This response is modulated... 

Several surface-bound receptors on cells, including EBP, have been studied to evaluate cell-matrix interactions, especially with elastin-derived matrices. Several studies have described the role of EBP elastin-binding interactions and downstream effects including cell proliferation, chemotaxis, and changes in cell morphology for several cell types including smooth muscle cells, endothelial cells, fibroblasts, and MSCs [101-104]. 

S. Mochizuki, B. Brassart, A. Hinek, Signaling pathways transduced through the elastin receptor facilitate proliferation of arterial smooth muscle cells, J. Biol. Chem. 277 (2002) 44854-44863. 

The prediction in 1979 that hydroxylation of proline (Pro, P) would impair fiber formation was borne out 6 years later in cell culture. Using aortic smooth muscle cells in culture with substantial amount of the cofactor ascorbate, Barone et al. found an overhydroxylation of the Pro residues in elastin. Furthermore, over-hydroxylated the elastin remained in solution at 37° C at a higher than normal concentration with limited formation of insoluble elastin. Tlius, as had been predicted from what is now called the consilient mechanism for hydrophobic association, making the elastin more polar by hydroxylation impairs fiber formation. 

Elastin is synthesized by fibroblasts and smooth muscle cells. Elasticity in the tissue is given by elastin (Ardelt 1964). Tissues dependent on a great degree of elasticity are, e.g., blood vessels, lung, elastic ligaments, bladder, and skin. 

Elastin VGVAPG Elastin-binding protein Maintaining elasticity in vascular smooth muscle cells [7]... 

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