Sulfation of Chondroitin/Dermatan Sulfate by Cystic Fibrosis Pancreatic Duct Cells Is Not Different from Control Cells

• Published in: Biochemical and molecular medicine 1997-10, Vol.62 (1), p.85-94
• Main Authors: Hill, Warren G., Harper, Gregory S., Rozaklis, Tina, Hopwood, John J.
• Format: Article
• Language: English
• Subjects: Cell Line; CFTR; Chondroitin Sulfates - metabolism; cystic fibrosis; Cystic Fibrosis - metabolism; Cystic Fibrosis Transmembrane Conductance Regulator - physiology; Dermatan Sulfate - metabolism; glycosaminoglycans; Humans; pancreatic cells; Pancreatic Ducts - metabolism; sulfation
• ISSN: 1077-3150; 1095-5577
• DOI: 10.1006/bmme.1997.2625

Cystic fibrosis is associated with mutations of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated plasma membrane chloride channel. Cystic fibrosis patients have been reported to possess elevated sulfation of glycoconjugates, which may contribute to the pathogenesis of the disease. Sulfation of glycosaminoglycans by a cystic fibrosis pancreatic adenocarcinoma cell line homozygous for ΔF508(CFPAC-1), a control pancreatic cell line (PANC-1), two CFPAC-1 cell lines transfected with the gene for CFTR (PLJ-CFTR-4.7, TR20), and a mock-transfected CFPAC-1 control (PLJ-6) was investigated. Cells were radiolabeled with [35S]sulfate and [3H]glucosamine, and glycosaminoglycans secreted into the medium after 24 and 72 h were isolated. Chondroitinase ABC digestion of chondroitin/dermatan sulfate allowed the recovery of disaccharides which were analyzed for their degree of sulfation by strong anion-exchange HPLC. No differences in the extent of sulfation by any of the cell lines were noted. However, glycoaminoglycans synthesized by cystic fibrosis cells consistently exhibited twofold higher [35S]-sulfate:[3H]glucosamine ratios than the controls. We conclude that CFTR plays no role in the sulfation of chondroitin/dermatan sulfate by pancreatic cells and that isotope incorporation ratios alone are insufficient evidence of changes in sulfation levels.