ReviewVascular collagens: spotlight on the role of type VIII collagen in atherogenesis
Introduction
Collagen is the major component of the extracellular matrix of the vessel wall and has a critical impact in atherogenesis. Collagen is crucial for the maintenance of vessel wall integrity and elasticity. Tensile strength and elastic resilience of the vessel wall, or tissues in general, depend on the composition of the collagen fibers and their size or diameter [1]. Collagen is involved in the processes of cell differentiation, adhesion, migration, proliferation and apoptosis [2], [3], [4]. In atherogenesis accumulation of collagen which might finally lead to vessel wall occlusion is also essential for the maintenance of plaque stability [5], [6], [7], [8], [9]. It has been reported that the bulk of vascular collagen is produced by smooth muscle cells. However, collagens can also be produced by endothelial cells, adventitial fibroblasts and macrophages [10], [11], [12].
At least 19 different collagens encoded by 33 genes have been described [13], [14]. To form a collagen molecule three procollagen chains assemble to a triple-helical structure which is typical for all collagen molecules. Collagen biosynthesis includes a variety of transcriptional and posttranslational, intracellular and extracellular events. Intracellular processes include regulation of transcription and mRNA stability, formation of the α procollagen chains, hydroxylation, glycosylation, assembly of the procollagen chains, and secretion. Extracellular processes include processing of the procollagen molecules, assembly of the collagen fibrils and cross-linking [13], [15].
Section snippets
Vascular collagens
Among the 19 collagens described 13 collagens are found in the vessel wall or are expressed by cells of the vessel wall in vitro (for summary Table 1, Table 2). However, none of these collagens is restricted to the vessel wall. According to the macromolecular structure which is constituted by the various collagen molecules, the vascular collagens are subdivided into three morphologically distinct groups: fibrilar collagens, non-fibrilar collagens (fibril associated collagens; microfibrilar
Fibrilar collagens
Among the vessel wall collagens, fibrilar collagen dominates. In the atherosclerotic plaque it comprises up to 60% of total protein [16]. The collagen fibers being responsible for tensile strength and elastic resilience are mainly composed of type I and type III collagen [17], [18], [19]. To a minor degree collagen fibrils also contain type V collagen [20], [21], [22]. In contrast to the large, parallelly running, densely packed collagen fibrils of tendon or bone, vascular collagen fibrils are
Non-fibrilar collagens
In comparison with fibrilar collagens, the members of the other collagen groups (for summary see Table 1) are less abundant in the vessel wall. Nevertheless, their lower abundance must not necessarily be related with lower functional impact.
Fibril associated collagens, so-called FACIT collagens [47], like type XIV and type XVI collagen, consist of a shorter and a longer triple-helical domain connected by a short non-helical region. The longer one of the two triple-helices binds specifically to
Network forming type VIII collagen
During the last years network forming type VIII collagen became an increasing focus of interest, particularly in the context of atherogenesis.
Expression of type VIII collagen by cells of the vessel wall in vitro and occurrence in normal and atherosclerotic arteries
In the vessel wall, type VIII collagen is widely distributed. Its expression by endothelial cells, smooth muscle cells and monocytes/macrophages (cellular functions are summarized in Table 3), points to a fundamental role in vessel physiology.
Concluding remarks
While the particular function of type VIII collagen in the vasculature is elusive yet, the data summarized in this review suggest a role of type VIII collagen in the maintenance of vessel wall integrity and structure. The interactions of type VIII collagen with other components of the vascular extracellular matrix is summarized in Fig. 1. Analogous to its role in the Descemet's membrane of the cornea, type VIII collagen might constitute a 3-D meshwork stabilizing the vascular wall. It might
References (134)
- et al.
Collagens and atherosclerosis
Exp. Gerontol.
(1999) Atherosclerosis is an inflammatory disease
Am. Heart J.
(1999)- et al.
Biosynthetic and structural properties of endothelial cell type VIII collagen
J. Biol. Chem.
(1983) Collagen biosynthesis: a mini-review cluster
Matrix Biol.
(1998)- et al.
Copolymerization of pNcollagen III and collagen I. pNcollagen III decreases the rate of incorporation of collagen I into fibrils, the amount of collagen I incorporated, and the diameter of the fibrils formed
J. Biol. Chem.
(1991) - et al.
The collagen fibril: the almost crystalline structure
J. Struct. Biol.
(1998) - et al.
Immunoelectron microscopical evidence that type V collagen is a fibrillar collagen: importance for an aggregating capability of the preparation for reconstituting banding fibrils
Matrix
(1989) - et al.
The contribution of collagenous proteins to tissue-specific matrix assemblies
Curr. Opin. Cell. Biol.
(1990) - et al.
Localization of collagen types I, III, IV and V, fibronectin and laminin in human arteries by the indirect immunofluorescence method
Pathol. Res. Pract.
(1986) Cellular and molecular studies of atherogenesis
Atherosclerosis
(1997)
The collagen receptor integrins have distinct ligand recognition and signaling functions
Matrix Biol.
Platelet adhesion to collagen types I through VIII under conditions of stasis and flow is mediated by GPIa/IIa (alpha 2 beta 1-integrin)
Blood
Collagens serve as an extracellular store of bioactive interleukin 2
J Biol Chem
Collagen type XVI expression is modulated by basic fibroblast growth factor and transforming growth factor-beta
FEBS Lett.
Microfibrils from the arterial subendothelium
Int. Rev. Cytol.
The platelet reactivity of collagen type VI
Coll. Relat. Res.
Structure and composition of type IV collagen of bovine aorta
Biochim. Biophys. Acta
Basement membrane (type IV) collagen
Matrix Biol.
Primary structure of the alpha 1 chain of human type XV collagen and exon-intron organization in the 3′ region of the corresponding gene
J. Biol. Chem.
Complete primary structure of two variant forms of human type XVIII collagen and tissue-specific differences in the expression of the corresponding transcripts
Matrix Biol.
The short and long forms of type XVIII collagen show clear tissue specificities in their expression and location in basement membrane zones in humans
Am. J. Pathol.
The triple-helical region of human type XIX collagen consists of multiple collagenous subdomains and exhibits limited sequence homology to alpha 1(XVI)
J. Biol. Chem.
Platelet activation by basement membrane collagens
Thromb. Res.
Specific inhibition of vascular cell adhesion molecule-1 expression by type IV collagen in endothelial cells
Biochem. Biophys. Res. Commun.
Type XIII collagen is identified as a plasma membrane protein
J. Biol. Chem.
The cloning and sequencing of alpha 1(VIII) collagen cDNAs demonstrate that type VIII collagen is a short chain collagen and contains triple-helical and carboxyl-terminal non-triple-helical domains similar to those of type X collagen
J. Biol. Chem.
The alpha 2(VIII) collagen gene. A novel member of the short chain collagen family located on the human chromosome 1
J. Biol. Chem.
The alpha 1 (VIII) collagen gene is homologous to the alpha 1 (X) collagen gene and contains a large exon encoding the entire triple helical and carboxyl-terminal non-triple helical domains of the alpha 1 (VIII) polypeptide
J. Biol. Chem.
Type VIII collagen
The primary structure of a triple-helical domain of collagen type VIII from bovine Descemet's membrane
FEBS Lett.
Cleavage of type VIII collagen by human neutrophil elastase
Biochim. Biophys. Acta
The alpha1(VIII) and alpha2(VIII) collagen chains form two distinct homotrimeric proteins in vivo
Matrix Biol.
The alpha1(VIII) and alpha2(VIII) chains of type VIII collagen can form stable homotrimeric molecules
J. Biol. Chem.
Type VIII collagen
Int. J. Biochem. Cell. Biol.
Endothelial cells secrete a novel collagen type in vitro independently of prolyl hydroxylation
Coll. Relat. Res.
Collagen structure and functional implications
The phenotypes of smooth muscle expressed in human atheroma
Ann. New York Acad. Sci.
Cell biology of atherosclerosis
Annu. Rev. Physiol.
The pathogenesis of atherosclerosis: a perspective for the 1990s
Nature
Collagen synthesis in atherosclerosis: too much and not enough
Cardiovasc. Res.
The unstable atheroma
Arterioscler. Thromb. Vasc. Biol.
Changing concepts of atherogenesis
J. Intern. Med.
Origin of extracellular matrix synthesis during coronary repair
Circulation
Human macrophages synthesize type VIII collagen in vitro and in the atherosclerotic plaque
FASEB J.
Collagen family of proteins
FASEB J.
Collagens: molecular biology, diseases, and potentials for therapy
Annu. Rev. Biochem.
Collagens in atherosclerotic vessel wall lesions
Curr. Top. Pathol.
Covalent crosslinking between molecules of type I and type III collagen. The involvement of the N-terminal, nonhelical regions of the alpha 1 (I) and alpha 1 (III) chains in the formation of intermolecular crosslinks
Eur. J. Biochem.
In vitro formation of hybrid fibrils of type V collagen and type I collagen. Limited growth of type I collagen into thick fibrils by type V collagen
Connect. Tissue Res.
The fibril structure of type V collagen triple-helical domain
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