Effect of CFTR modifiers on arylsulfatase B activity in cystic fibrosis and normal human bronchial epithelial cells

Pulm Pharmacol Ther. 2016 Feb:36:22-30. doi: 10.1016/j.pupt.2015.11.005. Epub 2015 Nov 30.

Abstract

Background: The enzyme Arylsulfatase B (ARSB; N-acetylgalactosamine 4-sulfatase), is required for degradation of sulfated glycosaminoglycans (GAGs) which accumulate in cystic fibrosis. ARSB is reduced in cystic fibrosis cells and increases when defective CFTR is repaired by insertion of the normal gene. This study was undertaken to determine if modification of CFTR by small molecule correctors or potentiators could also increase ARSB and reduce the accumulation of chondroitin 4-sulfate (C4S).

Methods: CF bronchial epithelial cells homozygous for the F508 deletion (ACD#14071) and normal human bronchial epithelial cells (BEC) were grown and differentiated following an established protocol. Cells were treated with either VRT-532, a CFTR potentiator, or VRT-534, a CFTR corrector, or vehicle control. The impact on ARSB activity, protein and mRNA expression, C4S and total sulfated glycosaminoglycan content, Interleukin-8 and Interleukin-6 secretion, and neutrophil chemotaxis was determined by specific assays.

Results: The CFTR potentiator, but not the corrector, increased ARSB activity and expression to the level in the normal bronchial epithelial cells (BEC). Concomitantly, total sulfated glycosaminoglycans and C4S declined, secreted IL-8 increased, secreted IL-6 declined, and neutrophil chemotaxis to the spent media obtained from the potentiator-treated CF cells increased.

Conclusion: The CFTR potentiator increased ARSB activity and expression and associated effects. This suggests that a critical interaction between CFTR and ARSB is related to CFTR function in regulation of a ligand-gated anion channel at the cell membrane, rather than to CFTR processing and intracellular trafficking.

Keywords: Arylsulfatase B; CFTR; Chondroitin 4-sulfate; Corrector; Cystic fibrosis; Glycosaminoglycans; Interleukin-6; Interleukin-8; Neutrophil migration; Potentiator.

MeSH terms

  • Bronchi / drug effects*
  • Cell Line
  • Chemotaxis, Leukocyte / drug effects
  • Chondroitin Sulfates / metabolism
  • Cresols / pharmacology
  • Cystic Fibrosis / enzymology*
  • Cystic Fibrosis Transmembrane Conductance Regulator / drug effects*
  • Epithelial Cells / drug effects*
  • Glycosaminoglycans / metabolism
  • Humans
  • Interleukin-6 / biosynthesis
  • Interleukin-8 / biosynthesis
  • N-Acetylgalactosamine-4-Sulfatase / metabolism*
  • Pyrazoles / pharmacology
  • Respiratory Mucosa / cytology
  • Respiratory Mucosa / drug effects*

Substances

  • CXCL8 protein, human
  • Cresols
  • Glycosaminoglycans
  • IL6 protein, human
  • Interleukin-6
  • Interleukin-8
  • Pyrazoles
  • VRT 532
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Chondroitin Sulfates
  • N-Acetylgalactosamine-4-Sulfatase