Effect of normothermic machine perfusion conditions on mesenchymal stromal cells

J.M. Sierra Parraga, K. Rozenberg, M. Eijken, H.G.D. Leuvenink, J. Hunter, A.M. Merino, C. Moers, B.K. Møller, R.J. Ploeg, C.C. Baan, B. Jespersen, M.J. Hoogduijn

Wednesday 13 march 2019

14:20 - 14:22h at Koningin Máximazaal

Categories: Basaal, Parallelsessie

Parallel session: Parallelsessie III - Basaal I

Background: Ex-situnormothermic machine perfusion (NMP) may allow better assessment of kidney quality and targeted damage to organs prior to transplantation. Mesenchymal stromal cells (MSC) have bone shown to stimulate kidney repair. Therefore, the combination of NMP and MSC therapy offers potential. NMP conditions concern the infusion of thawed cryopreserved MSC, the fact that they are delivered in suspension and the biochemical composition of the perfusion fluid itself. In this study the effect of NMP on survival, metabolism and function of human (h) MSC and porcine (p) MSC was studiedin vitro.The effect of NMP on MSCs immediately after culture was compared to frozen-thawed batches or MSCs, the latter being preferred for most clinical applications for practical reasons.

Methods: In this study, the effect of NMP conditions on survival, metabolism and function of human (h) MSC and porcine (p) MSC was studiedin vitroby flow cytometry.The capacity of MSC to adhere to endothelial cells was tested in a bespoke NMP solution and the effect of NMP conditions on MSCs immediately after culture was compared to frozen-thawed batches or MSCs, the latter being preferred for most clinical applications for practical reasons.

Results: pMSC were found to be very sensitive when compared to hMSC, 40 and 70% respectively. When MSCs were able to survive, survival of the cells was not affected. The perfusion fluid did not affect survival of fresh MSC in suspension compared to the control culture medium. However, the freeze-thawing process is impaired the survival of hMSC; 95% survival of fresh hMSC compared to 70% survival of thawed hMSC. Furthermore, thawed MSC shows increased levels of reactive oxygen species, which indicates elevated levels of oxidative stress, and reduced mitochondrial activity, which implies reduced metabolism. The adherence of human and MSC to endothelial cells (EC) was reduced after the thawing process, an effect that was boosted in the perfusion fluid.

Conclusions: To summarize, we observed that conditions required for machine perfusion are influencing the behavior of MSC. The freeze-thawing process reduces immediate survival and metabolism and increases oxidative stress, whilst their ability to adhere to endothelial cells was diminished. In addition, we found that our hMSC and pMSC behaved differently, which has to be considered before translating results from animal experiments to clinical studies.