integument
• skin contains increased proteoglycans and contains about 2-fold more decorin and biglycan
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• collage fibril diameter is 7% thinner in skin
• however, reticular dermis shows regularly contoured collage fibrils with typical collagen banding pattern and collagen quantity per wet tissue is unchanged and no apparent abnormalities are seen in the structure of the dermis or hypodermis at 2 months of age and no differences in the density of blood vessels or macrophages are seen
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• skin toughness, or energy required to achieve failure, is almost 75% greater than in wild-type mice at 4 months of age
• however, other mechanical parameters, including failure stress and strain, are not different but tend toward greater strength
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homeostasis/metabolism
• however, no differences in hyaluronic acid levels
• 4-month-old skin has more than double the chondroitin/dermatan sulfate content but lower heparan sulfate content with decreased sulfation
• compositional analysis of chondroitin/dermatan sulfate shows a decrease in non-sulfated disaccharide structures UA-GalNAc compensated by an increase in the 4-O-sulfated disaccharide structures UA-GalNAc-4S
• the 2- and 4-disulfated structures UA-2S-GalNAc-4S are slightly reduced
• iduronic acid-containing structures are increased in skin and contain mostly 4-sulfated iduronic-N-acetyl galactosamine
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behavior/neurological
N |
• mice exhibit normal behavior up to 15 months of age
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