Cyclosporine A protects podocytes via stabilization of cofilin-1 expression in the unphosphorylated state
Cyclosporine A protects podocytes via stabilization of cofilin-1 expression in the unphosphorylated state
复制标题
环孢素 a 通过稳定非磷酸化状态下的 cofilin-1 表达来保护足细胞
DOI：
10.1177/1535370214530365
复制
发表时间：
2014-08-01
影响因子：
3.2
通讯作者：
Ding, Jie
中科院分区：
文献类型：
--
作者：
Li, Xiaoyan;Zhang, Xiaoyan;Ding, Jie
足细胞足突（FP）在肾病综合征中失调。足细胞FPs的消失通常是在肌动蛋白细胞骨架受到扰动后出现的。最近的数据表明，钙调神经磷酸酶（CaN）抑制剂环孢素A （cyclosporine A, CsA）的作用独立于其对t细胞的作用，并且CsA已被确定为通过稳定足细胞中的突触肽来稳定肌动蛋白细胞骨架，从而直接减少蛋白尿。另有研究表明，CsA可在小管上皮细胞内直接调控cofilin-1。然而，是否synaptopodin是CsA的唯一靶点，或者CsA的抗蛋白尿作用是否通过调节足细胞中的cofilin-1发挥，目前还没有研究。本研究检测了嘌呤霉素氨基核苷（PAN）诱导的CsA肾病大鼠和有/无CsA暴露于PAN的培养足细胞中nephrin、synaptopodin、cofilin-1和磷酸化cofilin-1 （phop -cofilin-1）的表达和分布变化。通过敲低Cofilin-1、synaptopodin mRNA或与siRNA结合，探讨Cofilin-1是否对CsA的保护作用起关键作用，以及CsA对Cofilin-1的作用是否独立于其对synaptopodin的作用。我们发现CsA在体内和体外均能减少尿蛋白，修复泛素肾病的FP消失，恢复nephrin、synaptopodin、cofilin-1、phoo -cofilin-1的表达。CsA对PAN损伤的肌动蛋白骨架也有修复作用。与阴性对照相比，cofilin-1被敲除后，CsA的保护作用减弱。Synaptopodin敲除对cofilin-1无影响。cofilin-1和synaptopodin同时被敲除时，CsA的保护作用明显低于仅敲除cofilin-1时。综上所述，CsA的抗蛋白尿作用是通过上调cofilin-1的表达来稳定足细胞肌动蛋白细胞骨架，而不依赖于其对synaptopodin的作用。
Podocyte foot process (FP) is dysregulated in nephrotic syndrome. The effacement of podocyte FPs typically arises following perturbations in the actin cytoskeleton. Recent data suggest that the effects of calcineurin (CaN) inhibitor cyclosporine A (CsA) are independent of its effects on T-cells, and CsA has been identified as stabilizing the actin cytoskeleton through stabilizing synaptopodin in podocytes, and thereby directly reducing proteinuria. Other studies showed that CsA could regulate cofilin-1 directly within tubular epithelial cells. However, whether synaptopodin is the only target of CsA or whether the antiproteinuric role of CsA is played by regulating cofilin-1 in podocytes has not been studied. In the present study, changes in the expression and distribution of nephrin, synaptopodin, cofilin-1 and phosphorylated cofilin-1 (pho-cofilin-1) were detected in both puromycin aminonucleoside (PAN) induced nephrotic rats treated with CsA and cultured podocytes exposed to PAN with/without CsA. Cofilin-1, synaptopodin mRNA was knocked down or combined by siRNA to investigate whether cofilin-1 was critical for the protective effect of CsA and whether the effect of CsA on cofilin-1 was independent of its effect on synaptopodin. We found that CsA reduced proteinuria and repaired FP effacement of PAN-induced nephropathy, restored expression of nephrin, synaptopodin, cofilin-1, pho-cofilin-1 both in vivo and in vitro. CsA also repaired actin cytoskeleton impaired by PAN in vitro. The protective effect of CsA was diminished when cofilin-1 was knocked down compared to negative control. Synaptopodin knocked down had no effect on cofilin-1. The protective effect of CsA decreased significantly when cofilin-1 and synaptopodin were simultaneously knocked down compared to only cofilin-1 knock down. In conclusion, the antiproteinuric effect of CsA is derived from the stabilization of the podocyte actin cytoskeleton by upregulating expression of cofilin-1, which was independent of its effect on synaptopodin.