Primary cilia disappear in rat podocytes during glomerular development
Primary cilia disappear in rat podocytes during glomerular development
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DOI：
10.1007/s00441-010-0983-7
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发表时间：
2010-07-01
影响因子：
3.6
通讯作者：
Sakai, Tatsuo
中科院分区：
文献类型：
--
作者：
Ichimura, Koichiro;Kurihara, Hidetake;Sakai, Tatsuo
大多数肾小管上皮细胞表达原纤毛，原纤毛相关蛋白的突变是众所周知的，导致几种囊性肾病。然而，到目前为止，还不清楚哺乳动物足细胞是否表达初级纤毛在体内。在这项研究中，我们确定初级纤毛是否存在于大鼠未成熟和成熟肾小球足细胞的透射电子显微镜的连续切片。在未成熟的胎鼠肾小球中，足细胞在S形体（88 +/-5%，n = 3）、毛细血管袢（95 +/-4%，n = A 4）和成熟肾小球（76 A +/-13%，n = 5）阶段表达高百分比的初级纤毛。肾小球成熟期纤毛足细胞比例明显低于前两个阶段。在成年大鼠的成熟肾小球中，完全没有发现纤毛足细胞（0A +/-0%，n = 11）。这些结果表明，初级纤毛在大鼠足细胞肾小球发育过程中逐渐消失。由于肾小球滤过率在发育过程中增加，足细胞上的初级纤毛受到更强的弯曲力。因此，初级纤毛的消失可能会阻止过多的钙离子通过纤毛相关的多囊蛋白复合物和成熟足细胞中的细胞内信号级联的干扰进入。
Most tubular epithelial cell types express primary cilia, and mutations of primary-cilium-associated proteins are well known to cause several kinds of cystic renal disease. However, until now, it has been unclear whether mammalian podocytes express primary cilia in vivo. In this study, we determined whether primary cilia are present in the podocytes of rat immature and mature glomeruli by means of transmission electron microscopy of serial ultrathin sections. In immature glomeruli of fetal rats, podocytes express the primary cilia with high percentages at the S-shaped body (88 +/- 5%, n = 3), capillary loop (95 +/- 4%, n = A 4), and maturing glomerulus (76 A +/- 13%, n = 5) stages. The percentage of ciliated podocytes was significantly lower at the maturing glomerulus stage than at the former two stages. In mature glomeruli of adult rats, ciliated podocytes were not found at all (0 A +/- 0%, n = 11). These findings indicate that the primary cilia gradually disappear in rat podocytes during glomerular development. Since glomerular filtration rate increases during development, the primary cilia on the podocytes are subjected to a stronger bending force. Thus, the disappearance of the primary cilia presumably prevents the entry of excessive calcium-ions via the cilium-associated polycystin complexes and the disturbance of intracellular signaling cascades in mature podocytes.