Effects of Recombinant AavLEA1 Protein on Human Umbilical Cord Matrix Mesenchymal Stem Cells Survival During Cryopreservation.

Recently, many studies have found that late embryogenesis abundant (LEA) proteins could protect cells from drought, high salinity, and other stress conditions. Because LEA proteins maintain the integrity and stability of cell membranes, LEA proteins increase the cell's tolerance to dehydration stress, and reduce the osmotic and freezing damage during freezing. Whether LEA proteins could reduce cryopreservation damage and improve cell viability remains to be confirmed. In this study, we purified the recombinant AavLEA1 proteins, examined their thermal solubility and the effect of AavLEA1 proteins on the osmotic stress of cells, and studied the effects of the AavLEA1 protein on cryopreservation of human umbilical cord matrix mesenchymal stem cells (hUCM-MSCs). We utilized three concentrations of AavLEA1 protein (0.1, 0.5, and 2 mg/mL) to cryopreserve hUCM-MSCs and analyzed cell viability and apoptosis of MSCs after slow-cooling cryopreservation. We also examined the cryopreservation effect of AavLEA1 protein on hUCM-MSCs survival with 0%, 2%, 5%, and 10% (v/v) dimethyl sulfoxide (DMSO). We found that the survival rate of hUCM-MSCs supplemented with AavLEA1 protein was significantly higher than that of MSCs cryopreserved with low concentration of DMSO solution, and the apoptosis and necrosis rates were correspondingly reduced. In conclusion, recombinant AavLEA1 protein can improve the efficiency of MSC cryopreservation, increase the hUCM-MSCs viability, and partly replace DMSO during cryopreservation.