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Functions of lumican and fibromodulin: Lessons from knockout mice.
- Source :
- Glycoconjugate Journal; May2002, Vol. 19 Issue 4/5, p287-293, 7p
- Publication Year :
- 2002
-
Abstract
- Lumican and fibromodulin are collagen-binding leucine-rich proteoglycans widely distributed in interstitial connective tissues. The phenotypes of lumican-null ( Lum<superscript>−/−</superscript>), Fibromodulin-null ( Fmod<superscript>−/−</superscript>) and compound double-null ( Lum<superscript>−/−</superscript> Fmod<superscript>−/−</superscript>) mice identify a broad range of tissues where these two proteoglycans have overlapping and unique roles in modulating the extracellular matrix and cellular behavior. The lumican-deficient mice have reduced corneal transparency and skin fragility. The Lum<superscript>−/−</superscript> Fmod<superscript>−/−</superscript> mice are smaller than their wildtype littermates, display gait abnormality, joint laxity and age-dependent osteoarthritis. Misaligned knee patella, severe knee dysmorphogenesis and extreme tendon weakness are the likely cause for joint-laxity. Fibromodulin deficiency alone leads to significant reduction in tendon stiffness in the Lum<superscript>+/+</superscript> Fmod<superscript>−/−</superscript> mice, with further loss in stiffness in a lumican gene dose-dependent way. At the level of ultrastructure, the Lum<superscript>−/−</superscript> cornea, skin and tendon show irregular collagen fibril contours and increased fibril diameter. The Fmod<superscript>−/−</superscript> tendon contains irregular contoured collagen fibrils, with increased frequency of small diameter fibrils. The tendons of Lum<superscript>−/−</superscript> Fmod<superscript>−/−</superscript> have an abnormally high frequency of small and large diameter fibrils indicating a de-regulation of collagen fibril formation and maturation. In tissues like the tendon, where both proteoglycans are present, fibromodulin may be required early in collagen fibrillogenesis to stabilize small-diameter fibril-intermediates and lumican may be needed at a later stage, primarily to limit lateral growth of fibrils Published in 2003. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02820080
- Volume :
- 19
- Issue :
- 4/5
- Database :
- Complementary Index
- Journal :
- Glycoconjugate Journal
- Publication Type :
- Academic Journal
- Accession number :
- 50194411
- Full Text :
- https://doi.org/10.1023/A:1025348417078