Wen Yueqiang, Zhou Peilan, Liu Lingling, Wang Zebin, Zhang Yajie, Liang Jianbo
a Department of Nephrology , The Second Affiliated Hospital, Guangzhou Medical University , Guangzhou , P.R. China and.
b Department of General Medicine , The Third Affiliated Hospital, Sun Yat-sen University , Guangzhou , P.R. China.
J Recept Signal Transduct Res. 2016;36(2):173-80. doi: 10.3109/10799893.2015.1069847. Epub 2015 Sep 23.
Calcineurin binding protein 1 (Cabin1) is a natural inhibitor of calcineurin (CN). Moreover, Cabin1 retards tumor cell apoptosis by regulating p53. This study was designed to observe the expression of Cabin1 during podocyte injury, as well as its relationship with p53. Sprague-Dawley rats were used for the establishment of 5/6 nephrectomized rat model. Sham-operated rats underwent ventral laparotomy without nephrectomy. Then, rats were sacrificed at 8 and 12 weeks after nephrectomy. WT-1, a podocyte nuclear protein, was used for indicating the localization of Cabin1 in glomeruli. As tacrolimus protects podocyte via inhibiting AngiotensinII (AngII) induced CN activation. Cultured podocytes were injured by AngII or restored by tacrolimus. The protein expression and localization was detected by western blot or immunofluorescence staining. Cabin1 was knocked down by siRNA in cultured podocytes. In 5/6 nephrectomized rats, the colocalization of Cabin1 and WT-1 became more obviously in podocyte nuclei. Cabin1 protein was markedly increased in rats at 8 and 12 weeks after nephrectomy, as well as in AngII injured podocytes at 48 h (0.99 ± 0.12 in AngII group versus 0.80 ± 0.16 in control group). Cabin1 and p53 colocalized in cultured podocyte nuclei, p53 expression was significantly decreased (0.21 ± 0.05 in siRNA group versus 0.31 ± 0.05 in negative control group) after Cabin1 was being knocked down. In conclusion, Cabin1 expression significantly increases during podocyte injury. Knockdown of Cabin1 induces p53 expression decrease in cultured podocyte. Cabin1 may provide a new target to investigate podocyte injury.
钙调神经磷酸酶结合蛋白1（Cabin1）是钙调神经磷酸酶（CN）的天然抑制剂。此外，Cabin1通过调节p53来延缓肿瘤细胞凋亡。本研究旨在观察足细胞损伤时Cabin1的表达情况及其与p53的关系。采用Sprague-Dawley大鼠建立5/6肾切除大鼠模型。假手术大鼠仅行腹部正中切口，不切除肾脏。然后，在肾切除术后8周和12周处死大鼠。足细胞核蛋白WT-1用于指示Cabin1在肾小球中的定位。由于他克莫司通过抑制血管紧张素II（AngII）诱导的CN激活来保护足细胞。培养的足细胞用AngII损伤或用他克莫司恢复。通过蛋白质免疫印迹法或免疫荧光染色检测蛋白质表达和定位。在培养的足细胞中用小干扰RNA（siRNA）敲低Cabin1。在5/6肾切除大鼠中，Cabin1与WT-1在足细胞核中的共定位变得更加明显。肾切除术后8周和12周大鼠以及48小时时AngII损伤的足细胞中Cabin1蛋白明显增加（AngII组为0.99±0.12，对照组为0.80±0.16）。Cabin1和p53在培养的足细胞核中共定位，敲低Cabin1后p53表达明显降低（siRNA组为每0.21±0.05，阴性对照组为0.31±0.05）。总之，足细胞损伤时Cabin1表达明显增加。敲低Cabin1可导致培养的足细胞中p53表达降低。Cabin1可能为研究足细胞损伤提供新的靶点。
