3D spheroid culture enhances survival and therapeutic capacities of MSCs injected into ischemic kidney.

Three-dimensional (3D) cell culture has been reported to increase the therapeutic potentials of mesenchymal stem cells (MSCs). In this study, we aimed to investigate the therapeutic effects of 3D spheroids of human adipose-derived MSCs for acute kidney injury (AKI). In vitro studies indicated that 3D spheroids of MSCs produced higher levels of extracellular matrix proteins (including collagen I, fibronectin and laminin), and exhibited stronger anti-apoptotic and anti-oxidative capacities than two-dimensional (2D) cultured cells. Furthermore, 3D culture increased the paracrine secretion of cytokines by MSCs, including angiogenic factors (VEGF and basic fibroblast growth factor), anti-apoptotic factors (epidermal growth factor and hepatocyte growth factor), the anti-oxidative factor insulin-like growth factor and the anti-inflammatory protein tumour necrosis factor-alpha stimulated gene/protein 6. Consistent with in vitro experiments, 3D spheroids of MSCs showed enhanced survival and paracrine effects in vivo. More importantly, when injected into the kidney of model rats with ischemia-reperfusion (I/R)-induced AKI, 3D spheroids were more beneficial in protecting the I/R kidney against apoptosis, reducing tissue damage, promoting vascularization and ameliorating renal function compared with 2D cultured cells. Therefore, the 3D culture strategy improved the therapeutic effects of MSCs, and might be promising for AKI treatment.