[The effects of mesenchymal stem cells on the aging kidneys in rats].

Objective: To study the effect of mesenchymal stem cells on the aging rat kidney and to explore the underlying mechanism.

Methods: Rat models of senile kidney were built with hypodermic injection of D-galactose daily. Injections of MSCs of 3 x 10(6) were given to each rat through vena caudalis and CFSE was used as a tracing label to detect the distribution of MSCs in vivo. After 24 h, rats were dissected and their kidneys were frozen for section. MSCs were observed with Fluophot and quantitative analysis of the various parameters of kidney was performed under a light microscope with BI2000 image analysis system. The contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in serum and kidney were measured wtih hydroxylamine and chromatometry. The expression of VEGF and P16 mRNA in kidney tissue was detected with real-time PCR and Western blotting.

Results: MSCs was found homing in the rat kidney, and the glomerular size, sclerosis-rate and the average cell count of glomerulus in the treated group were different from those of the model group (P < 0.05). In the treated group, the activity of SOD was significantly higher and the content of MDA was lower in serum and kidney than that in the model control group (P < 0.05). The expression of VEGF mRNA and protein in the kidneys of MSCs group increased significantly as compared with the model group (P < 0.05). The expression of P16 mRNA and protein in the kidney of MSCs group decreased significantly compared with the model group (P < 0.05).

Conclusion: MSCs can increase the expression of VEGF while decrease the expression of P16, so as to play a key role in the anti-aging on rat kidney.