Objective      To determine the effect of  transplantaiton of human bone morphogenetic protein-7 (BMP-7) expressed bone marrow mesenchymal stem cells (BM-MSCs) on the expression of endogenous and exogenous hBMP-7 in the kidney after ischemia-reperfusion injury

(IRI)

and evaluate the protective effects of hBMP-7-expressed BM-MSCs transplantation.       Methods       A total of 45 rabbits were divided randomly into three groups (n=15): control group

BM-MSCs transplantation group and hBMP-7-expressed BM-MSCs transplantation group. After the establishment of kidney IRI in the left kidney

the animals received an infusion via renal artery of 1 ml normal saline

BM-MSCs or hBMP-7-expressed BM-MSCs （2×10

7

）. Blood samples and kidney was taken at the time points of 3

7 and 14 d after the injury. Serum levels of creatinine and urea were detected to evaluate renal function. The damage of renal tubules was evaluated by HE staining. The expression of BMP-7 and hBMP-7 were detected with ELISA and RT-PCR methods.      Results       Serum levels of creatinine and urea were significantly lower in the group injected with hBMP-7-expressed BM-MSCs than in the other 2 groups (P0.05)

so did the damage in renal tubules at the 3 time points (P0.05). The protein level of hBMP-7 was 81.8±25.5

107.8±33.4 and 49.6±17.8 pg/mg respectively in the group at the 3 time points

while that of mRNA was 0.82±0.12

0.69±0.13 and 0.42±0.10 respectively

both of them were detected for 2 weeks. The protein level of BMP-7 in the group was 95.9±21.3

137.0±14.9

and 192.1±18.0 in the group and that of mRNA was 1.08±0.33

1.36±0.17 and 1.64±0.21 at the 3 time points

both of which were higher than those in the other group （P0.05）.      Conclusion       Not only can hBMP-7-expressed BM-MSCs take exogenous hBMP-7 to IRI kidney

but also improve the expression of endogenous BMP-7

thereby

attenuate the renal damage and promote the renal functional repair.