地塞米松对嘌呤霉素损伤足细胞nephrin mRNA表达的影响及意义

目的 观察嘌呤霉素(PAN)和地塞米松(DEX)干预后足细胞形态及nephrin mRNA表达变化,探讨DEX保护PAN诱导体外培养足细胞损伤的作用机制.方法 将体外培养的小鼠肾小球足细胞分为三组,分别为对照组、PAN组和DEX组.对照组加入等体积RPMI-1640培养液培养；PAN组加入PAN(终浓度50 mg/L)；DEX组同时加入PAN(终浓度50 mg/L)和DEX(终浓度1 mmol/L).培养8h、24 h和48 h后,相差显微镜下观察足细胞形态变化；用图像处理软件分析各组细胞胞体面积的差异.采用实时荧光定量聚合酶链式反应检测培养24h、48 h时足细胞nephrin mRNA表达.结果 对照组足细胞形态正常,细胞胞体较大,可见树枝样突起及细胞间形成相互连接；PAN诱导足细胞损伤8h、24 h和48 h时,足细胞面积均较对照组明显缩小,分别为对照组的75％、46％和27％(P＜0.01),足细胞足突及细胞间连接消失.DEX组在干预8h、24 h和48 h时,足细胞胞体面积均明显大于PAN组(P＜0.01),部分足细胞可见足突及细胞间连接.PAN组足细胞培养24 h和48 h时,nephrin mRNA表达较对照组明显下降(P＜ 0.01)；DEX组干预后24h及48 h,足细胞nephrin mRNA表达均较PAN组显著升高(P＜ 0.01).结论 DEX对PAN诱导足细胞损伤具有保护作用,其作用机制可能与上调足细胞分子nephrin mRNA表达有关.

Effect of dexamethasone on expression of nephrin mRNA in impaired podocytes induced by puromycin aminonucleoside

Objective To observe the changes in podocyte morphology and expression of nephrin mRNA after intervention with pummyein aminonueleoside （ PAN ） and then dexamethasone （ DEX ）, and to explore the mechanism of action of of DEX in protection of impaired podocytes caused by PAN. Methods The cultured mouse podocytes were divided into 3 groups： control group （ application of RPMI-1640 with the same volume ）, PAN group （ PAN of 50mg/L ）, and DEX group （ PAN of 50 mg/L plus DEX of 1 μmol/L ）. Podoeyte morphology was observed with phase- contrast microscopy and analyzed with the image software 8 h, 24 h, and 48h after treatment expression of nephrin mRNA was detected by semi-quantitative RT-PCR 24 h and 48h after treatment. Results In the control group normal podocytes with a larger size, ＇branch-shaped＇, and intercellular junction were observed. As compared with the control group, treatment with PAN induced significant shrinkage of podocytes, and the cell size decreased to 75%, 46 % %, and 27% at 8 h, 24 h, and 48 h, respectively （ P〈 0.01 ）, with disappearance of podocyte foot process and intercellular junction. As compared with PAN group, DEX improved the shrinkage of podcytes, and the cell size increased obviously 8 h, 24 h, and 48h after treatment （ P〈 0.01 ）, RT- PCR revealed the expression of nephrin mRNA decreased more significantly in PAN group than in control group at 24 h and 48 h （P〈 0.01 ）. As compared with PAN group, the expression of nephrin mRNA in DEX group was significantly increased at 24 h and 48 h （ P 〈 0.01 ）. Conclusions Dexamethasone has a protective effect on impaired podocytes caused by pummyein aminonueleoside, whose mechanism of action was associated with the upregulation of nephrin mRNA expression in the cells.