Drug induced exocytosis of glycogen in Pompe disease

Christopher T. Turner, Maria Fuller, John J. Hopwood, Peter J. Meikle, Doug A. Brooks

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Pompe disease is caused by a deficiency in the lysosomal enzyme α-glucosidase, and this leads to glycogen accumulation in the autolysosomes of patient cells. Glycogen storage material is exocytosed at a basal rate in cultured Pompe cells, with one study showing up to 80% is released under specific culture conditions. Critically, exocytosis induction may reduce glycogen storage in Pompe patients, providing the basis for a therapeutic strategy whereby stored glycogen is redirected to an extracellular location and subsequently degraded by circulating amylases. The focus of the current study was to identify compounds capable of inducing rapid glycogen exocytosis in cultured Pompe cells. Here, calcimycin, lysophosphatidylcholine and α-L-iduronidase each significantly increased glycogen exocytosis compared to vehicle-treated controls. The most effective compound, calcimycin, induced exocytosis through a Ca2+-dependent mechanism, although was unable to release a pool of vesicular glycogen larger than the calcimycin-induced exocytic pore. There was reduced glycogen release from Pompe compared to unaffected cells, primarily due to increased granule size in Pompe cells. Drug induced exocytosis therefore shows promise as a therapeutic approach for Pompe patients but strategies are required to enhance the release of large molecular weight glycogen granules.

Original languageEnglish
Pages (from-to)721-727
Number of pages7
JournalBiochemical and Biophysical Research Communications
Volume479
Issue number4
DOIs
Publication statusPublished - 28 Oct 2016

Keywords

  • Exocytosis
  • Glycogen
  • Lysosomal storage disorder
  • Pompe disease

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Turner, C. T., Fuller, M., Hopwood, J. J., Meikle, P. J., & Brooks, D. A. (2016). Drug induced exocytosis of glycogen in Pompe disease. Biochemical and Biophysical Research Communications, 479(4), 721-727. https://doi.org/10.1016/j.bbrc.2016.09.145