Identification of sulfated mucopolysaccharides including heparin in the lesional skin of a patient with mastocytosis

Abstract

Comparison of the [35S]mucopolysaccharides extracted after in vitro incubation of skin biopsy specimens from nonlesional and lesional sites of a patient with mastocytosis showed that lesional sites incorporated sulfate into heparin. After in vitro incorporation of the [35S]sulfate, the tissues were extracted sequentially by a 3-step procedure which utilized high salt concentrations, enzymatic digestion and base hydrolysis to liberate essentially all the counts. The extracted [35S]mucopolysaccharides were separated from free [35S]sulfate, histamine, protein, and hyaluronic acid by ion-exchange chromatography utilizing Dowex 1. The [35S]mucopolysaccharide extracts of the nonlesional skin were completely degraded by treatment with chondroitinase ABC, as they are predominantly dermatan sulfate with small amounts of chondroitin sulfates. The absolute quantity of sulfated mucopolysaccharides after Dowex 1 chromatography in micrograms or uronic acid per mg wet weight of starting tissue was higher in the lesional than the nonlesional specimen while the specific incorporation of [35S]sulfate per microgram of uronic acid was the same. Approximately one-half of the [35S]mucopolysaccharides obtained in the 3 sequential extracts of lesional tissue was resistant to degradation by chondroitinase ABC as determined by gel filtration before and after enzyme treatment, indicating the presence of sulfated mucopolysaccharides in addition to chondroitin and dermatan sulfates. Heparinase treatment of the chondroitinase ABC-resistant [35S]mucopolysaccharides followed by gel filtration revealed an equal distribution of label between heparin and heparinase-resistant material presumed to be heparin sulfate. Heparin was also directly demonstrated in extracts of lesional mastocytosis skin by chemical and functional criteria.