Insights on cryoprotectant toxicity from gene expression profiling of endothelial cells exposed to ethylene glycol

Cryopreservation consists of preserving living cells or tissues at <-100˚C and has many applications in, for instance, stem cell and organ banking. Cryoprotectant agents, like ethylene glycol, are required for successful cryopreservation but have toxic side effects due to largely unknown mechanisms. In this work, we studied the toxicity of ethylene glycol in Human Umbilical Vein Endothelial Cells (HUVECs). Exposing cells to 60% ethylene glycol for two hours at 4˚C resulted in a slight decrease in cell growth, suggesting a modest toxicity of ethylene glycol and that HUVECs do not exhibit particular sensitivity to it. Gene expression analysis with whole genome micro-arrays revealed signatures indicative of a generalized stress response at 24 hours after stress and recovery at 72 hours, involving signaling pathways, glycoproteins, and genes involved in extracellular and transmembrane functions. These results reveal a new paradigm and signatures for future experiments in elucidating the toxicity effects of ethylene glycol in vascular endothelial cells. 18 samples; 2 timepoints (24h and 72h), 6 controls per timepoint - 3 non treaded samples and 3 cold controls; other 3 were treated with increasing concentrations of EG.