Harvesting organs from Donation after Circulatory Death (DCD) is a way to expand kidney pool for transplantation but grafts have worse long-term outcome. Hypoxia shifts cells to anerobic metabolism and inhibits glucose oxidative phosphorilation. Glycolysis remains the only mechanism of ATP production and the conversion of pyruvate into lactate overloads cells with lactate and protons. Proton excess dysrupts phospholipid membrane integrity, shortage of ATP deprives ion transporters of fuel causing ion accumulation and cell swelling. We hypothesize that pretransplant conditioning of kidney with Mesenchymal Stromal Cells (MSC) prepares renal environment to prevent injury.
Aim: To evaluate the effects of MSC pretransplant reconditioning on gene renal expression.
We used Fisher rats as kidney donors, Lewis rats as MSC donors. After 20 min of warm ischemia bilateral nephrectomy was performed, kidneys were perfused for 4 h at 4°C with Belzer UW solution (BS) (A) or BS supplemented with 3 millions MSC (B). Gene renal expression of 6 kidneys for each group was studied by microarray analysis at the end of perfusion. To confirm array results we evaluated by RT PCR pivotal genes of upregulated sets: SLC16A1, principal lactate transporter, IDH2 encoding citric acid cycle enzyme, ATP6V0D2 encoding subunit of vacuolar H+ ATPases, NDUFS8 encoding subunit of mitochondrial NADH essential for respiratory electron transport, PDH encoding enzyme that catalyzes the conversion of pyruvate to acetyl-CoA.
Array analysis showed in kidneys of B compared with A the upregulation of 19/485 gene sets involved in SRP-dependent cotranslational protein targeting to membrane, citric acid cycle, respiratory electron transport, ATP synthesis, ribosome synthesis. NDFUS8, SLC16A1, IDH2, ATP6V0D2, PDH mRNA levels in graft were significantly lower in A than in B.
These results demonstrate that MSC preconditioning of graft may afford early protection from ischemia/reperfusion injury upregulating genes involved in energy saving.
