Aims: The optimal time for mesenchymal stem cell (MSCs) transplantation remains an unresolved issue. We compared the effects of MSCs on a rat remnant kidney model.
Methods: Male Sprague-Dawley rats were randomly divided and treated with a corresponding reagent at 4, 8, 12 and 16 weeks, respectively. A remnant kidney model was established and MSCs were injected into rats. The migration of MSCs was then assessed by using cell-tracking experiments. Renal function and histological analyses were performed 4 weeks after MSC transplantation. Immunohistochemistry, Western blotting and real-time polymerase chain reaction were used to detect the TGF-β1 and α-SMA levels.
Results: Four weeks after MSC injection, MSCs were found to migrate to the injured kidney. Significant histological damage improvement was observed after the treatment of MSCs at 4 and 8 weeks. The functional benefits of MSC treatment were observed in the 5/6 nephrectomy (Nx) + MSC group and the benefits were significantly higher at 4 and 8 weeks than at other time points (p < 0.05). Meanwhile, serum creatinine and urea levels as well as glomerular sclerosis and tubulointerstitial injury indexes were decreased at 4 and 8 weeks. Compared with the 5/6 Nx + PBS group, TGF-β1 and α-SMA levels were decreased in the 5/6 Nx + MSC group.
Conclusion: These data can be used to optimize the MSC transplantation time point as a therapeutic modality.