Mesenchymal stromal cells do not protect against renal ischaemia reperfusion injury in either an in vitro human model or an in vivo murine model

Abstract

Aim: Mesenchymal Stromal Cells (MSC) have been shown in a number of studies to be beneficial in protecting kidneys from renal ischaemia reperfusion injury (IRI). The goal of this work was to confirm efficacy of MSC and examine the relationship between MSC and the immune response to IRI. Methods: An in vitro model of IRI was developed using an immortalised cell line of human Proximal Tubular Epithelial Cells (HK2 cells) and exposing them to hydrogen peroxide to simulate oxidative stress. Bone marrow and placental derived human MSC were applied to the model with and without the presence of Dendritic Cells (DC) and CD4 cells. PTEC viability and damage was assessed at 24 hours by flow cytometry and lactate dehydrogenase (LDH) concentration respectively. A murine model of bilateral renal IRI was optimised with 8 week old C57/Bl6 mice and MSC administered at the time of reperfusion. GFP+ MSC were administered either intravenously (IV), intra-peritoneally (IP), by sub-capsular injection (SC) or intra-arterially (IA). Renal structure and function was assessed at 48 hours. In Vitro Results: Neither bone marrow derived MSC nor placental derived MSC increased the proportion of live HK2 cells (53.8 ± 3.9% and 41.4 ± 9.2% respectively, vs 41.8 ± 10.8% with no MSC). There was no difference in cytotoxicity as measured by LDH (91.8 ± 13.2% and 88 ± 6.5% respectively vs control 100%). CD4 cells and DC did not increase the proportion of live cells in the presence of MSC (56.3 ± 6.5% for CD4 cells and 52 ± 9.4% for DC vs 47.6 ± 5.3% with HK2/MSC alone) or alter cytotoxicity. This model was tested with direct and indirect cell culture, MSC conditioned media, and MSC pre-stimulated with interferon gamma and TNF alpha without any change in the results. In Vivo Results: MSC were able to be found in the kidney at 48 hours by GFP DNA PCR and immunohistochemistry when administered IV, SC, IP and IA. However, there was no statistical difference found between mice administered vehicle and mice administered MSC in serum creatinine, serum urea or histological score at 48 hours, regardless of the mode of administration of MSC. Conclusion: These studies found that MSC did not protect against renal IRI.L6211036622018-03-14 <br />