Unprecedented cell-selection using ultra-quick freezing combined with aquaporin expression

PLoS One. 2014 Feb 18;9(2):e87644. doi: 10.1371/journal.pone.0087644. eCollection 2014.

Abstract

Freezing is usually used for preservation and storage of biological samples; however, this process may have some adverse effects such as cell membrane damage. Aquaporin (AQP), a water channel protein, has been suggested to play some roles for cryopreservation although its molecular mechanism remains unclear. Here we show that membrane damage caused by ultra-quick freezing is rescued by the expression of AQP4. We next examine if the expression of AQP combined with ultra-quick freezing can be used to select cells efficiently under freezing conditions where most cells are died. CHO cells stably expressing AQP4 were exclusively selected from mixed cell cultures. Having identified the increased expression of AQP4 during ES cell differentiation into neuro-ectoderm using bioinformatics, we confirmed the improved survival of differentiated ES cells with AQP4 expression. Finally we show that CHO cells transiently transfected with Endothelin receptor A and Aqp4 were also selected and concentrated by multiple cycles of freezing/thawing, which was confirmed with calcium imaging in response to endothelin. Furthermore, we found that the expression of AQP enables a reduction in the amount of cryoprotectants for freezing, thereby decreasing osmotic stress and cellular toxicity. Taken together, we propose that this simple but efficient and safe method may be applicable to the selection of mammalian cells for applications in regenerative medicine as well as cell-based functional assays or drug screening protocols.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aquaporin 1 / metabolism
  • Aquaporin 4 / metabolism*
  • CHO Cells
  • Cell Membrane / metabolism
  • Cell Membrane Permeability / genetics
  • Cell Survival
  • Cells, Cultured
  • Cricetinae
  • Cricetulus
  • Cryopreservation / methods*
  • Dogs
  • Embryonic Stem Cells / cytology
  • Freezing
  • Humans
  • Madin Darby Canine Kidney Cells
  • Mice
  • Mice, Transgenic
  • Neural Plate / metabolism
  • Osmosis
  • Plasmids / metabolism
  • Receptor, Endothelin A / metabolism

Substances

  • AQP1 protein, human
  • Aqp4 protein, mouse
  • Aquaporin 4
  • Receptor, Endothelin A
  • Aquaporin 1

Grants and funding

This work was supported by Grant-in-Aid for Young Scientists (B) of MEXT of Japan (22791938 and 24792152), Strategic International Research Cooperative Program, Japan Science and Technology Agency (JST), Keio Gijuku Academic Development Funds and Keio University Special Grant-in-Aid for Innovative Collaborative Research Projects. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.