hBMP-7修饰的骨髓间充质干细胞对肾脏BMP-7的影响

目的观察人骨形态发生蛋白-7(hBMP-7)基因修饰的骨髓间充质干细胞(BM-MSCs)移植对缺血再灌注损伤(ischemia-reperfusion injury,IRI)肾脏内源和外源BMP-7表达的影响,探讨其对IRI肾脏的保护作用。方法 45只兔采用随机数字表的方法分为对照组(Ⅰ组)、单纯BM-MSCs移植组(Ⅱ组)和基因修饰的BM-MSCs移植组(Ⅲ组)(n=15)。构建hBMP-7重组腺病毒并转染兔BM-MSCs,建立肾脏IRI模型后,移植组于肾血流恢复后经肾动脉推注单纯和基因修饰的自体BM-MSCs,对照组同法推注等量生理盐水。3组分别于术后3、7、14 d采用随机数字表的方法取5只兔经耳缘静脉采血,检测血清肌酐(Crea)和尿素(Urea),观察肾功能情况;同时取肾组织进行HE染色行肾小管损伤评分,ELISA和RT-PCR法分别检测肾脏hBMP-7和BMP-7的蛋白浓度和mRNA表达。结果肾脏IRI后3、7、14 d,Ⅲ组Crea和Urea明显低于Ⅰ组和Ⅱ组(P<0.05);Ⅲ组肾小管损伤评分均低于Ⅰ组和Ⅱ组(P<0.05);Ⅲ组检测到第3、7、14天hBMP-7蛋白[(81.8±25.5)、(107.8±33.4)、(49.6±17.8)pg/mg]和mRNA(0.82±0.12、0.69±0.13、0.42±0.10)的表达并维持至少2周;Ⅲ组第3、7、14天BMP-7 mRNA(1.08±0.33、1.36±0.17、1.64±0.21)和BMP-7蛋白(95.9±21.3、137.0±14.9、192.1±18.0)的表达均高于Ⅰ组和Ⅱ组(P<0.05)。结论 hBMP-7基因修饰的BM-MSCs移植既能携带外源性hBMP-7在缺血再灌注损伤肾脏中表达,又能提高内源性BMP-7的表达,减轻肾脏损伤,促进肾脏修复,改善肾脏功能。

hBMP-7-modified bone marrow mesenchymal stem cells attenuate kidney ischemiareperfusion injury in rabbits

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(2×107).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(P<0.05),so did the damage in renal tubules at the 3 time points(P<0.05).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(P<0.05).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.