Role of cytoskeleton network in anisosmotic volume changes of intact and permeabilized A549 cells

Alexandra Platonova, Olga Ponomarchuk, Francis Boudreault, Leonid V. Kapilevich, Georgy V. Maksimov, Ryszard Grygorczyk, Sergei N. Orlov

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Recently we found that cytoplasm of permeabilized mammalian cells behaves as a hydrogel displaying intrinsic osmosensitivity. This study examined the role of microfilaments and microtubules in the regulation of hydrogel osmosensitivity, volume-sensitive ion transporters, and their contribution to volume modulation of intact cells. We found that intact and digitonin-permeabilized A549 cells displayed similar rate of shrinkage triggered by hyperosmotic medium. It was significantly slowed-down in both cell preparations after disruption of actin microfilaments by cytochalasin B, suggesting that rapid water release by intact cytoplasmic hydrogel contributes to hyperosmotic shrinkage. In hyposmotic swelling experiments, disruption of microtubules by vinblastine attenuated the maximal amplitude of swelling in intact cells and completely abolished it in permeabilized cells. The swelling of intact cells also triggered ~ 10-fold elevation of furosemide-resistant 86Rb+ (K+) permeability and the regulatory volume decrease (RVD), both of which were abolished by Ba2 +. Interestingly, RVD and K+ permeability remained unaffected in cytocholasin/vinblastine treated cells demonstrating that cytoskeleton disruption has no direct impact on Ba2 +-sensitive K+-channels involved in RVD. Our results show, for the first time, that the cytoskeleton network contributes directly to passive cell volume adjustments in anisosmotic media via the modulation of the water retained by the cytoplasmic hydrogel.

Original languageEnglish
Pages (from-to)2337-2343
Number of pages7
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1848
Issue number10
DOIs
Publication statusPublished - 23 Jul 2015
Externally publishedYes

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Keywords

  • Hydrogel
  • K<sup>+</sup> channels
  • Microfilaments
  • Microtubules
  • Regulatory volume decrease

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Biophysics
  • Medicine(all)

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