骨髓间充质干细胞移植对嘌呤霉素氨基核苷肾病大鼠足细胞修复作用的研究

Bone mesenchymal stem cell transplantation repairs glomerular podocytes in rats with puromycin aminonucleoside-induced nephrosis

目的探讨骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)移植对嘌呤霉素氨基核苷(puromycin aminonucleoside,PAN)肾病大鼠足细胞修复作用及其对裂孔隔膜分子Nephrin表达的影响,为BMSCs移植治疗肾病综合征提供实验依据。方法 45只雄性Sprague-Dawley大鼠随机分为3组,每组15只。模型组:一次性腹腔注射PAN(0.15mg/g)造模;BMSCs组:PAN造模+BMSCs移植(细胞移植前经Brdu标记示踪);对照组:不予以造模。实验第10天杀鼠,留取标本行血、尿、肾组织超微结构检测,免疫组化检测肾脏Brdu标记阳性细胞的表达,半定量RT-PCR及Western blot方法检测Nephrin表达变化。结果模型组大鼠出现大量蛋白尿、血白蛋白降低、胆固醇升高,伴有广泛足突的融合。与模型组比较,BMSCs组尿蛋白、血胆固醇降低,血白蛋白回升及足突融合现象改善,差异有统计学意义(P<0.05);免疫组化显示,BMSCs组肾组织中可见阳性细胞,模型组及对照组未见阳性细胞;半定量RT-PCR及Western blot显示,模型组Nephrin相对表达量较对照组明显下降,BMSCS组与模型组比较有所增加,差异有统计学意义(P<0.05)。结论 BMSCs移植对PAN肾病大鼠足突融合有一定的改善,Nephrin表达的变化可能在其中发挥了作用。

Objective To investigate the effect of bone mesenchymal stem cell（BMSC）transplantation on repair of glomerular podocytes and on the Nephrin expression in rats with puromycin aminonucleoside（PAN）-induced nephrosis.Methods Forty-five Sprague-Dawley rats were randomly divided into three groups（n=15 each）：a nephrosis model group that received a single intraperitoneal injection of PAN（0.15 mg/g）;a BMSC transplantation group that received a single intraperitoneal injection of PAN（0.15 mg/g）followed by BMSC transfusion;a control group that received a single intraperitoneal injection of normal saline.Ten days after injection,the rats were sacrificed.The 24 hrs urinary protein content and serum albumin and cholesterol levels were measured 24 hrs before sacrifice.Changes of glomerular podocytes were observed under an electron microscope.Brdu labeled positive cells in kidneys were measured by immunohistochemical technology.RT-PCR and Western blot were used to assess the expression of mRNA and protein of Nephrin.Results In the nephrosis model group,urinary protein and blood cholesterol contents increased,plasma albumin content decreased compared with those in the control group.Extensive fusion of podocyte foot processes was observed in the nephrosis model group.The BMSC transplantation group had decreased urinary protein and blood cholesterol contents and increased plasma albumin content compared with the nephrosis model group.Fusion of podocyte foot processes was also improved.Brdu labeled positive cells were seen in kidneys in the BMSC transplantation group,but not in the nephrosis model and the control groups.Nephrin mRNA and protein expression decreased significantly in the nephrosis model group compared with that in the control group.The BMSC transplantation group had increased Nephrin mRNA and protein expression compared with the nephrosis model group.Conclusions BMSCs can repair glomerular podocytes in PAN-induced nephrosis rats,and the changes of Nephrin expression may be involved in the process.