肾病综合征患者肾组织podocin的表达

目的 观察不同病理类型､ 不同激素反应性肾病综合征(NS)患者肾小球足细胞中podocin的表达和分布特征｡方法 肾组织作冰冻切片免疫荧光双染色, 以激光共聚焦显微镜采集图像｡与定位标志Ⅳ型胶原α3链比较｡ 受检NS患者21例, 其中局灶节段性肾小球硬化(FSGS)12例(难治性7例, 非难治性5例)､ 微小病变(MCD)5例､ 膜性肾病(MN)4例;正常肾组织对照3例｡采用LSM 510图像处理系统进行处理｡荧光强度以吸光度表示｡ 结果 (1)podocin在正常肾组织沿肾小球基底膜呈连续､ 线形分布｡部分FSGS患者podocin的分布呈点状､ 短线条状, 少数患者未见podocin沉积｡(2)FSGS患者肾小球中podocin表达量(80.5±33.5)与对照正常肾组织(138.4±38.1)比较,显著减少(P=0.0211), 其中难治性FSGS(67.2±30.5)与正常肾组织的差异有统计学意义(P=0.0131); 非难治性FSGS患者(99.0±31.0)与正常肾组织的差异无统计学意义(P=0.1585)｡(3)MCD(112.1±47.6)､ MN(92.5±34.8)患者podocin的表达量亦降低,与正常肾组织比较,无统计学意义(P=0.4497, P=0.1570)｡(4)不同病理类型各组NS患者肾小球中podocin表达量的差异均无统计学意义(P > 0.05)｡结论 FSGS的NS患者肾小球中podocin的表达减少, 难治性FSGS患者尤为明显, 部分FSGS患者podocin分布发生改变｡podocin的检测可能在FSGS激素疗效评价方面有一定价值｡

Glomerular expression of podocin in patients with nephrotic syndrome

Objective To determine the distribution and expression of podocin in glomerular podocytes among nephrotic syndrome(NS) patients with different pathology and response to steroid. Methods Twenty-one NS patients were examined. Among them, twelve patients presented focal segmental glomerulosclerosis (FSGS), including seven steroid-resistant or steroid-dependent patients, and five steroid-sensitive patients,five patients were diagnosed as minimal change disease (MCD) and four patients as membranous nephropathy(MN). Three normal renal specimens were set as control group. Immunofluorescence staining, confocal laser scanning microscopy and LSM-510 graphic system were used to detect the expression and distribution of podocin in podocytes. Type IV collagen alpha 3 chain was also stained as location comparison. Results (1)In control group, the distribution of podocin showed a linear pattern along glomerular basement membrane. MCD and MN revealed a similar pattern. Part of FSGS, however, showed dotted or short linear patterns. (2)The podocin expression in NS patients with FSGS was significantly lower than that in normal kidney(80.5±33.5 vs 138.4±38.1, P < 0.05). In steroid-resistant and steroid-dependent patients, the expression of podocin decreased significantly; however in steroid-sensitive patients, the decrease of podocin was not statistically significant. (3)There were no significant differences of podocin expression among MCD(112.1±47.6), MN(92.5±34.8) and control groups(P=0.4497,P=0.1570 respectively). (4)No significant differences of podocin expression were observed in different pathology with NS(P > 0.05). Conclusion The expression of podocin decreases significantly in NS patients with FSGS, especially in steroid-resistant and steroid-dependent FSGS patients. Part of FSGS patients shows abnormal distribution patterns. The expression of podocin may play a role in the sensitivity of steroid.