Complex Saccharide Metabolism in Cystic Fibrosis Fibroblasts

Abstract

Extract: There are several reports of secretory and other abnormalities present in cultured fibroblasts from patients with cystic fibrosis (CF). We have, therefore, investigated aspects of complex saccharide synthesis and secretion by such cells compared with fibroblasts derived from heterozygous (HZ) parents and from normal (N) children. The main glycosaminoglycans produced by skin fibroblasts during in vitro culture were hyaluronic acid, heparan sulfates, and dermatan sulfate-like materials. Using double-label experiments with D-[³H]- or [¹⁴C]glucosamine and analyzing the products by ion exchange chromatography, it was shown for five CF, two HZ, and four N lines that these polysaccharides were secreted into the medium in approximately similar proportions to each other. Moreover, experiments in which three CF, nine HZ, and three N lines were grown in log phase for up to 5 days in the presence of [³⁶S]sulfate and [³H]glucosamine indicate that, during such a period, CF fibroblasts do not secrete complex carbohydrates at rates significantly different from N or HZ cells. Neither do such cells show an abnormal intracellular accumulation of complex carbohydrates. The latter observation was further confirmed by preparing whole cell autoradiographs during growth of six CF, two HZ, and three N lines in the presence of D-[³H]glucosamine and, subsequently, after addition of unlabeled medium.

Speculation: Fibroblasts derived from children with cystic fibrosis are not abnormal with regard to their complex carbohydrate metabolism.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD