人脐带源间充质干细胞向急性肾损伤肾脏的归巢及保护作用

Homing of human umbilical cord-derived mesenchymal stem cells to the injured kidney and their protective effects

背景:多项研究表明间充质干细胞具有治疗急性肾损伤潜能,脐带源间充质干细胞具有干细胞的共性而且优点很多,如容易分离培养、体外扩增快、免疫原性低、不存在伦理问题等,因此越来越受到国内外研究者的重视。目的:观察人脐带源间充质干细胞对急性肾损伤大鼠肾组织的修复作用。方法:将30只大鼠随机分为3组,正常对照组、模型对照组、人脐带源间充质干细胞移植组。正常对照组大鼠仅做暴露肾脏处理,模型对照组、人脐带源间充质干细胞移植组大鼠夹闭双侧肾蒂45 min,细胞移植组手术完成后尾静脉注射经DAPI标记的脐带源间充质干细胞1 mL,模型对照组注射等量的生理盐水。7 d后处死大鼠,全自动生化仪法检测血肌酐、尿素氮水平;取左肾于光镜下观察肾组织病理改变;取右肾于免疫荧光显微镜下观察肾组织上DAPI阳性细胞数。结果与结论:细胞移植组与模型对照组比较血清肌酐、尿素氮水平明显降低(P<0.05),提示人脐带源间充质干细胞对肾功能有一定改善作用;细胞移植组与模型对照组比较病理情况明显好转,肾小管坏死评分指数明显降低;细胞移植7 d后肾组织冰冻切片上仍可见散在分布的蓝色荧光细胞。结果表明人脐带源间充质干细胞可向损伤的肾小管上皮迁移,对肾组织起到保护和促进修复作用。

BACKGROUND： An increasing number of studies have shown that mesenchymal stem cells have the potential to treat acute kidney injury. Umbilical cord-derived mesenchymal stem cells have general characteristics of stem cells and many advantages, such as easy to isolate and culture, in vitro fast amplification, low immunogenicity and no ethical problems, which have garnered increasing attentions.OBJECTIVE： To study the repairing effects of human umbilical cord-derived mesenchymal stem cells on acute kidney injury in rats. METHODS： Thirty rats were randomized into three groups： a normal control group, a model group and a cell transplantation group. Rats in the model and cell transplantation were subjected to clamping the renal pedicles for 45 minutes, and then injected 1 m L of DAPI-labeled umbilical cord-derived mesenchymal stem cells or 1 m L of saline via the tail vein. In the normal control group, the kidney was only exposed with no treatment. At 7 days after treatment, the rats were killed to take left kidney tissues for pathological observation under light microscope and right kidney for observation of DAPI-positive cell counting. Automatic biochemical analyzer was used to detect serum creatinine and urea ammonia levels. RESULTS AND CONCLUSION： Compared with the model group, the levels of serum creatinine and urea ammonia were significantly lower in the cell transplantation group（P〈0.05）, suggesting that human umbilical cord-derived mesenchymal stem cells can improve the kidney function to a certain extent. Pathological findingsshowed that the pathological damage was improved more remarkably in the cell transplantation group than the model group, and the tubular necrosis index decreased significantly in the cell transplantation group. At 7 days after cell transplantation, blue fluorescent cells were scattered on renal tissue frozen sections. These results indicate that human umbilical cord-derived mesenchymal stem cells can migrate to the injured tubular epithelial tissues, and promote the repair of the injured kidney.