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- Schonherr, E, et al.
(author)
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Decorin deficiency leads to impaired angiogenesis in injured mouse cornea
- 2004
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In: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 41:6, s. 499-508
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Journal article (peer-reviewed)abstract
- Small leucine-rich proteoglycans play important roles in the organization of the extracellular matrix as well as for the regulation of cell behavior; two biological processes that are essential for angiogenesis. We investigated consequences of the targeted ablation of decorin (DCN), biglycan (BGN) and fibromodulin (FMOD) genes on inflammation-induced angiogenesis in the cornea. In wildtype mice, DCN was localized exclusively to the corneal stroma, while FMOD and BGN were more prominently expressed in epithelial cells. Endothelial cells from limbus blood vessels expressed BGN and FMOD, but no DCN. However, after induction of angiogenesis by chemical cauterization, DCN was expressed in the newly formed capillaries, together with BGN and FMOD. Notably, in DCN-deficient mice, the growth of vessels was significantly diminished, whereas it did not significantly change in FMOD- or BGN-deficient animals. Moreover, blood vessels of DCN-deficient mice exhibited a similar expression level of BGN as control mice, while FMOD was increased on day 3 after injury. These results indicate that DCN, in addition to its effects on fibrillogenesis, plays a regulatory role in angiogenesis and that FMOD in endothelial cells may be able to partially substitute for DCN.
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| 2. |
- Kassner, A, et al.
(author)
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Molecular structure and interaction of recombinant human type XVI collagen
- 2004
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In: Journal of Molecular Biology. - : Elsevier BV. - 1089-8638 .- 0022-2836. ; 339:4, s. 835-853
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Journal article (peer-reviewed)abstract
- Collagen XVI is a minor component of at least two different extracellular fibrillar networks of specialized regions of skin and cartilage. In skin, collagen XVI is integrated into particular fibrillin-rich microfibrils lacking an amorphous elastin core. In cartilage, collagen XVI is a component of small heterotypic D-banded fibrils, mainly occurring in the territorial matrix of chondrocytes. Here, we present the first direct evidence for the molecular structure and functional properties of these fibril-associated collagens with interrupted triple helices (FACIT). We have expressed recombinantly the full-length alpha1 chain of human collagen XVI in HEK 293 EBNA cells in large quantities using an episomal expression system. Secreted full-length recombinant collagen XVI forms stable disulfide-bonded homotrimers and is rapidly proteolytically processed to distinct fragments at specific protease sequence motifs, one resembling an aggrecanase recognition site. Limited trypsin digestion assays and thermal transition curves imply sequential thermal denaturation of individual triple helical domains of this recombinant collagen, similar to authentic collagen XVI. Molecular images of collagen XVI reveal rod-like molecules which harbor multiple sharp kinks attributing a highly flexible structure presumably introduced by non-collagenous (NC) regions. Terminally located cloverleaf-shaped nodules correspond to the large NC NC11 domain of trimeric collagen XVI. The total length of individual trimeric recombinant collagen XVI molecules constitutes about 240 nm as calculated by atomic force and negative staining electron microscopy. Recombinant collagen XVI interacts with fibrillin-1 and with fibronectin indicating multiple molecular interactions in which this ubiquitously expressed and versatile FACIT-collagen can participate. In vitro generated collagen XVI provides an indispensable tool for future determination of its function during supramolecular assembly of matrix aggregates and its role in maintenance, organization and interaction of fibrillar structures. (C) 2004 Elsevier Ltd. All rights reserved.
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