File(s) not publicly available
Mitochondria exert a negative feedback on the propagation of intracellular Ca2+ waves in rat cortical astrocytes
journal contribution
posted on 2023-06-08, 15:14 authored by Eric Boitier, Ruth Rea, Michael R DuchenWe have used digital fluorescence imaging techniques to explore the interplay between mitochondrial Ca2+ uptake and physiological Ca2+ signaling in rat cortical astrocytes. A rise in cytosolic Ca2+ ([Ca2+]cyt), resulting from mobilization of ER Ca2+ stores was followed by a rise in mitochondrial Ca2+ ([Ca2+]m, monitored using rhod-2). Whereas [Ca2+]cyt recovered within ~1 min, the time to recovery for [Ca2+]m was ~30 min. Dissipating the mitochondrial membrane potential (??m, using the mitochondrial uncoupler carbonyl cyanide p-trifluoromethoxy-phenyl-hydrazone [FCCP] with oligomycin) prevented mitochondrial Ca2+ uptake and slowed the rate of decay of [Ca2+]cyt transients, suggesting that mitochondrial Ca2+ uptake plays a significant role in the clearance of physiological [Ca2+]cyt loads in astrocytes. Ca2+ signals in these cells initiated either by receptor-mediated ER Ca2+ release or mechanical stimulation often consisted of propagating waves (measured using fluo-3). In response to either stimulus, the wave traveled at a mean speed of 22.9 ± 11.2 µm/s (n = 262). This was followed by a wave of mitochondrial depolarization (measured using tetramethylrhodamine ethyl ester [TMRE]), consistent with Ca2+ uptake into mitochondria as the Ca2+ wave traveled across the cell. Collapse of ??m to prevent mitochondrial Ca2+ uptake significantly increased the rate of propagation of the Ca2+ waves by 50%. Taken together, these data suggest that cytosolic Ca2+ buffering by mitochondria provides a potent mechanism to regulate the localized spread of astrocytic Ca2+ signals.
History
Publication status
- Published
Journal
Journal of Cell BiologyISSN
0021-9525Publisher
Rockefeller University PressExternal DOI
Issue
4Volume
145Page range
795-808Department affiliated with
- Neuroscience Publications
Notes
Department of Physiology, UCL, London, UKFull text available
- No
Peer reviewed?
- Yes
Legacy Posted Date
2013-06-14Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC