Sulfate composition of dermatan sulfate from scar tissue

FGF-10 and specific structural elements of dermatan sulfate size and sulfation promote maximal keratinocyte migration and cellular proliferation

Fibroblast growth factor-10 (FGF-10) is essential for epithelial development, while other members of this family, such as FGF-7, are not. FGF-10 is abundantly released into wounds following injury, and likely an essential growth factor required for this process. To evaluate how activation of this growth factor is controlled, multiple glycosaminoglycans were combined with FGF-10 assayed by measurement of the proliferation of cell lines expressing FGF receptor-2-IIIb, or keratinocyte migration in an in vitro wound repair assay. Dermatan sulfate (DS) exhibited greater potency than heparan sulfate or other chondroitin sulfates found in wounds. Structural variants of DS between 10 and 20 disaccharides containing iduronic acid showed maximal capacity to enable FGF-10 receptor stimulation. Furthermore, FGF-10 and DS markedly enhanced migration of keratinocytes in an in vitro wound scratch assay, while FGF-7 or other glycosaminoglycans did not. These data strongly suggest that FGF-10 activity is uniquely important in wound repair and that specific DS structural properties are necessary to promote FGF-10 function. These observations identify a novel interplay between DS and FGF-10 in mediating wound repair.

Altered dermatan sulfate structure and reduced heparin cofactor II-stimulating activity of biglycan and decorin from human atherosclerotic plaque

Biglycan and decorin are small dermatan sulfate-containing proteoglycans in the extracellular matrix of the artery wall. The dermatan sulfate chains are known to stimulate thrombin inhibition by heparin cofactor II (HCII), a plasma proteinase inhibitor that has been detected within the artery wall. The purpose of this study was to analyze the HCII-stimulatory activity of biglycan and decorin isolated from normal human aorta and atherosclerotic lesions type II through VI and to correlate activity with dermatan sulfate chain composition and structure. Biglycan and decorin from plaque exhibited a 24-75% and 38-79% loss of activity, respectively, in thrombin-HCII inhibition assays relative to proteoglycan from normal aorta. A significant negative linear relationship was observed between lesion severity and HCII stimulatory activity (r = 0.79, biglycan; r = 0.63, decorin; p < 0.05). Biglycan, but not decorin, from atherosclerotic plaque contained significantly reduced amounts of iduronic acid and disulfated disaccharides DeltaDi-2,4S and DeltaDi-4,6S relative to proteoglycan from normal artery. Affinity coelectrophoresis analysis of a subset of samples demonstrated that increased interaction of proteoglycan with HCII in agarose gels paralleled increased activity in thrombin-HCII inhibition assays. In conclusion, both biglycan and decorin from atherosclerotic plaque possessed reduced activity with HCII, but only biglycan demonstrated a correlation between activity and specific glycosaminoglycan structural features. Loss of the ability of biglycan and decorin in atherosclerotic lesions to regulate thrombin activity through HCII may be critical in the progression of the disease.

Temporal changes in disaccharide composition of dermatan sulfate in the skin after epicutaneous application of hapten

Glycosaminoglycans change their amount, structure and distribution with age, differentiation and pathologic conditions. In order to investigate temporal changes in dermatan sulfate in the skin during inflammation and subsequent healing, 2,4-dinitrofluorobenzene (DNFB) was applied once to the dorsal skin of female BALB/cA mice, and the disaccharide composition of dermatan sulfate was examined. Application of DNFB induced a transient increase in the thickness of the dermis, which reached a maximum on day 15 and decreased to the control level on day 35. The total amount of unsaturated disaccharides from dermatan sulfate per cm2 in the DNFB-treated skin showed a temporal pattern similar to that of the thickness of the dermis. Mol% of 4,5-unsaturated 2-sulfo-hexuronic acid-4-sulfated N-acetylgalactosamine (deltaDi-diSB), the second most abundant unsaturated disaccharide from dermatan sulfate, decreased rapidly on day 3 in the DNFB-treated skin, remained less than the control on days 7 and 15, and returned to the control level on day 35. These results suggest that a single application of DNFB induces temporal changes not only in the amount but also in the structure of dermatan sulfate.

High-field NMR as a technique for the determination of polysaccharide structures

NMR spectroscopy has played a developing role in the study of polysaccharide structures for over 30 years. Many new bacterial polysaccharide repeat unit structures have recently been published as a result of the application of modern NMR techniques. NMR can also be used to elucidate the structures of both regular and heterogeneous polysaccharides from fungal and plant sources, as well as complex glycosaminoglycans of animal origin. In addition to covalent structure, conformation and dynamics of polysaccharides are susceptible to NMR analysis, both in solution and in the solid state. Improvements in NMR technology with potential applications to polysaccharide studies hold promise for the future.