Stabilization of living cells during dehydration could facilitate the storage and transport of nucleated cells. HeLa cells, known for their resilience and insensitivity to environmental stresses, provide a useful platform for the investigation of resistance to dehydration-induced damage. HeLa cells from two sources [the American Type Culture Collection (ATCC) and the European Collection of Cell Cultures (ECCC)] were compared with regard to their survival following vacuum-drying and the dependence of viability on drying temperature. Interestingly, a substantial difference in dehydration resistance appeared between the two cell lines dried after they were loaded with trehalose. At all temperatures tested, the ATCC cell line showed higher viability than the ECCC cell line. For both lines, viabilities decreased at elevated drying temperatures, but even when the cells were dried at 45°C, the ATCC line survived well compared to the ECCC line (27% vs. 0%, respectively, when dried to 0.3 g H 2O/g dry weight). The difference in survival was not due to variability in trehalose-loading. However, immunoblot analysis indicated that the ATCC line showed higher concentrations of all types of heat shock proteins (HSPs) tested, indicating one important difference between the two cell lines. In an effort to determine the functional consequence of higher levels of endogenous HSPs in the ATCC line, the physical state of the cell membranes and degree of oxidation were compared in the two lines. Steady-state anisotropy measurements indicated that the membranes of the ATCC cell line have a higher degree of order as compared to the ECCC cells, which correlates well with the known effect of small HSPs in decreasing fluidity of model membranes. In addition, the ATCC line showed better protection against oxidative damage. These findings provide additional evidence that HSPs may help to protect mammalian cells during drying and rehydration.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)