Improved post thaw function and genetic changes for mesenchymal stromal cells cryopreserved using multicomponent osmolyte solutions

We report genome-wide expression changes that occur in H9-iMSCs frozen with different freezing methods that include DMSO and non-DMSO experimental solutions such as SGC (sucrose-glycerol-creatinine, SMC (sucrose-mannitol-creatinine), and SGI (sucrose-mannitol-isoleucine). mRNA-Seq analysis shows that DMSO samples cluster with fresh samples in the same clade, while all samples using the experimental solutions cluster together. In addition, we also see that cells frozen using experimental solutions have upregulation of a number of key molecular function pathways including extracellular matrix structural genes, receptor binding, and growth factor expression. Overall design: H9 MSCs were cultured in alpha-MEM base (Life Technologies), 10% FBS (qualified), and 1% non-essential amino acids (Life Technologies). Culture flasks were coated with 0.01% porcine gelatin (Fisher) for a minimum of 2 hours before H9 MSC seeding. H9 MSCs were seeded in gelatin-coated flasks at a density of approximately 2500 cells/cm2. Cells were split when they reached 70% confluence and were used for experiments only from passages 8 to 12. Control cells in media were similarly combined stepwise with DMSO at a 1:1 final volume ratio. Each of these vials was incubated at room temperature for 0, 1, or 2 hours. Experimental solutions were frozen using a 3°C/min cooling rate while DMSO solutions were frozen using a 1°C/min cooling rate. Samples were submerged in a 37ºC bath to just under cap level, and agitated until only a small ice crystal was present. The cells were combined with acridine orange/propidium iodide (AO/PI) and enumerated using a hemocytometer. Samples were diluted, centrifuged and supernatant was aspirated, followed by preparation for RNA isolation. Purified RNA was then submitted for RNA-sequencing.

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Pollock K, Samsonraj RM, Dudakovic A, Thaler R, Stumbras A, McKenna DH, Dosa PI, van Wijnen AJ, Hubel A