骨髓间充质干细胞体内分化为肾小管上皮细胞的实验研究

Study on differentiation of bone marrow mesenchymal stem cells into renal tubular epithelial cells in vivo

目的探讨骨髓间充质干细胞(mesenchymal stem cells,MSCs)能否在体内分化为肾小管上皮细胞。方法取SD雄性大鼠胫、股骨骨髓,密度梯度离心法分离MSCs,采用4,6-联脒-2-苯基吲哚(4,6-diamidino-2-phenylindole,DAPI)进行标记。32只雌性SD大鼠复制缺血再灌注肾损伤模型后随机分为移植组和对照组,移植组于缺血45min后经下腔静脉注入用DAPI标记的MSCs,对照组注入等量的生理盐水。分别于术后1d、2d、3d、4d处死大鼠,留取肾组织,荧光显微镜观察移植的MSCs在肾组织中的分布,采用能与肾小管内腔壁特异结合的蓖麻血凝素(Ricinus communis agglurinin,RCA)对迁移入肾脏的MSCs分化状况进行鉴定。结果移植组术后第三天肾组织内可见DAPI标记细胞,第四天DAPI标记细胞明显增多(P<0.05),且多数DAPI标记细胞能结合RCA。对照组没有发现DAPI标记细胞。结论移植的外源性MSCs能够迁移、定居于肾组织中并分化为肾小管上皮细胞。

Objective To study bone marrow mesenchymal stem cells （MSCs） whether to differentiate into renal tubular epithelial cells in vivo in rat. Methods MSCs were collected from tibia and femur of male SD rat, then isolated by percoll density gradient centrifugation and labeled with 4,6-diamidino-2-phenylindole（DAPI）. 32 female SD rats were subjected to clamping renal pedicles for 45 minutes and divided randomly into the transplanted group and the control group. DAPI-labeled MSCs or saline were transPlanted into the rats by inferior vena cava. Animals were sacrificed at 1, 2, 3, 4 days after operation, respectively. Fluorescence microscope was performed to identify transplanted MSCs in renal tissue. To confirm if the MSCs may differentiate into renal tubular ceils, ricinus communis agglurinin（RCA） which binds specifically to the luminal surface of tubules was used. Results The DApI-positive cells which expressed RCA-positive simultaneously could be found in the renal tissue in transplanted group at the 3rd day, and significantly increased at the 4th day （P〈0.05）. Conclusions MSCs can differentiate into renal tubular epithelial cells in vivo.