Cholesterol effects on vesicle pools in chromaffin cells revealed by carbon-fiber microelectrode amperometry

Secil Koseoglu, Sara A. Love, Christy L. Haynes

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Cell-cell communication is often achieved via granular exocytosis, as in neurons during synaptic transmission or neuroendocrine cells during blood hormone control. Owing to its critical role in membrane properties and SNARE function, cholesterol is expected to play an important role in the highly conserved process of exocytosis. In this work, membrane cholesterol concentration is systematically varied in primary culture mouse chromaffin cells, and the change in secretion behavior of distinct vesicle pools as well as pool recovery following stimulation is measured using carbon-fiber microelectrode amperometry. Amperometric traces obtained from activation of the younger readily releasable and slowly releasable pool (RRP/SRP) vesicles at depleted cholesterol levels showed fewer sustained fusion pore features (6.1±1.1% of spikes compared with 11.2±1.0% for control), revealing that cholesterol content influences fusion pore formation and stability during exocytosis. Moreover, subsequent stimulation of RRP/SRP vesicles showed that cellular cholesterol level influences both the quantal recovery and kinetics of the later release events. Finally, diverging effects of cholesterol on RRP and the older reserve pool vesicle release suggest two different mechanisms for the release of these two vesicular pools.

Original languageEnglish (US)
Pages (from-to)2963-2971
Number of pages9
JournalAnalytical and Bioanalytical Chemistry
Volume400
Issue number9
DOIs
StatePublished - Jul 2011

Bibliographical note

Funding Information:
Acknowledgment We thank Shencheng Ge for assistance with cholesterol analysis and amperometry experiments. This work was supported by the National Institute of Health New Innovator Award to C.L.H. and by the National Science Foundation (No. CHE-0645041).

Keywords

  • Carbon-fiber microelectrode
  • Cholesterol
  • Chromaffin cell
  • Exocytosis
  • Vesicle pools

Fingerprint Dive into the research topics of 'Cholesterol effects on vesicle pools in chromaffin cells revealed by carbon-fiber microelectrode amperometry'. Together they form a unique fingerprint.

Cite this