Improved Hypothermic Preservation of Human Renal Cells Through Suppression of Both Apoptosis and Necrosis

A new platform of hypothermic solutions, the HypoThermosol® (HTS) series, has been developed for the improved hypothermic storage of cells, tissues, and organs. Cells and tissues cold-stored in HTS-FRS demonstrate improved viability when returned to normothermic temperatures in comparison with the parent solution, HTS-BASE, or University of Wisconsin (UW) solution (UW-ViaSpan®). While our group and others have implicated apoptosis as a major player in cell death initiated by extended hypothermic storage, it has been unclear if the improved performance of HTS-FRS as a hypothermic storage solution is due to its ability to inhibit apoptosis. Data reported herein show that human renal cells hypothermically stored in renal cell culture medium, HTS-FRS, HTS-BASE, or UW solution demonstrated improved survival in HTS-FRS. Following 5 days of hypothermic preservation and 1 day of recovery at 37°C, cells preserved in HTS-FRS exhibit 75% metabolic activity, whereas cells stored in HTS-BASE, UW, or culture media demonstrate 32%, 17%, and 6% recovery, respectively. In addition, cells stored in HTS-BASE supplemented with caspase inhibitor exhibit increased cell numbers in comparison to cells stored in HTS-BASE (72% vs. 30% after 7 days of cold storage and 2 days of recovery). Experiments with annexin and propidium iodide as well as assessment of caspase activities suggest that the improved performance of HTS-FRS as a preservation solution may be due to its ability to inhibit both apoptosis and necrosis.