• Home
  1. Home
  2. Ionic imbalance, in addition to molecular crowding, abates cytoskeletal dynamics and vesicle motility during hypertonic stress
Scientific article
English

Ionic imbalance, in addition to molecular crowding, abates cytoskeletal dynamics and vesicle motility during hypertonic stress

Contributors

Nunes-Hasler, Paula; Monnay, Isabelle; Meda, Paolo; Feraille, Eric; Brown, Dennis; Hasler, Udo

Published in

Proceedings of the National Academy of Sciences of the United States of America, vol. 112, no. 24, p. E3104-3113

Publication date

2015

Abstract

Cell volume homeostasis is vital for the maintenance of optimal protein density and cellular function. Numerous mammalian cell types are routinely exposed to acute hypertonic challenge and shrink. Molecular crowding modifies biochemical reaction rates and decreases macromolecule diffusion. Cell volume is restored rapidly by ion influx but at the expense of elevated intracellular sodium and chloride levels that persist long after challenge. Although recent studies have highlighted the role of molecular crowding on the effects of hypertonicity, the effects of ionic imbalance on cellular trafficking dynamics in living cells are largely unexplored. By tracking distinct fluorescently labeled endosome/vesicle populations by live-cell imaging, we show that vesicle motility is reduced dramatically in a variety of cell types at the onset of hypertonic challenge. Live-cell imaging of actin and tubulin revealed similar arrested microfilament motility upon challenge. Vesicle motility recovered long after cell volume, a process that required functional regulatory volume increase and was accelerated by a return of extracellular osmolality to isosmotic levels. This delay suggests that, although volume-induced molecular crowding contributes to trafficking defects, it alone cannot explain the observed effects. Using fluorescent indicators and FRET-based probes, we found that intracellular ATP abundance and mitochondrial potential were reduced by hypertonicity and recovered after longer periods of time. Similar to the effects of osmotic challenge, isovolumetric elevation of intracellular chloride concentration by ionophores transiently decreased ATP production by mitochondria and abated microfilament and vesicle motility. These data illustrate how perturbed ionic balance, in addition to molecular crowding, affects membrane trafficking.

UNIGE affiliation entities

UNIGE research groups

Citation (ISO format)

NUNES-HASLER, Paula et al. Ionic imbalance, in addition to molecular crowding, abates cytoskeletal dynamics and vesicle motility during hypertonic stress. In: Proceedings of the National Academy of Sciences of the United States of America, 2015, vol. 112, n° 24, p. E3104–3113. doi: 10.1073/pnas.1421290112

Main files (1)

Article (Published version)

Identifiers

Journal ISSN

0027-8424
643views
5downloads

Technical informations

Creation

20/07/2015 17:33:00

First validation

20/07/2015 17:33:00

Update

14/03/2023 23:39:12

Status update

14/03/2023 23:39:12

Last indexation

31/10/2024 01:22:43
All rights reserved by Archive ouverte UNIGE and the University of Geneva
OpenAIRE Indexed & Validated