In vivo treatment with granulocyte colony-stimulating factor does not delay apoptosis in human neutrophils by increasing the expression of the vacuolar proton ATPase

Julie Zimbelman, Gail Thurman, Patrick J. Leavey, Misoo C. Ellison, Daniel R. Ambruso

Research output: Contribution to journalArticle


Background: Neutrophils die by apoptosis, and in vivo administration of granulocyte colony-stimulating factor (G-CSF) delays this apoptotic cell death. G-CSF administered in vitro correlates delayed apoptosis with upregulation of the vacuolar proton ATPase (v-ATPase). Because this enzyme requires assembly of membrane and cytosolic domains to function, we hypothesized that in vivo G-CSF would increase synthesis and assembly of v-ATPase components to delay apoptosis. Methods: Volunteers received G-CSF for 5 days, and each had a paired control. Neutrophils were isolated from subjects before the first and after the fifth injection. Proteins from cytosol or plasma membrane or from whole cell lysates were resolved by SDS-polyacrylamide gel electrophoresis and immunoblotted with antibody to the 33kDa v-ATPase E subunit. Densitometry quantified immunoreactivity. Results: No significant increase on the E subunit occurred between treated and control groups. Conclusion: In vivo G-CSF does not increase the amount of v-ATPase in neutrophils. Although G-CSF in vivo delays apoptosis, the mechanism(s) by which this occurs is not known.

Original languageEnglish (US)
Pages (from-to)33-37
Number of pages5
JournalJournal of Investigative Medicine
Issue number1
StatePublished - Jan 1 2002



  • Apoptosis
  • Cytokines
  • Granulocyte colony-stimulating factor
  • Neutrophils
  • Vacuolar ATPase

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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