Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
Cell Tissue Res. 2013 Jun;352(3):707-25. doi: 10.1007/s00441-013-1615-9. Epub 2013 May 4.
The present investigation was designed to clarify the role of the subcommissural organ (SCO) in the pathogenesis of hydrocephalus occurring in the HTx rat. The brains of non-affected and hydrocephalic HTx rats from embryonic day 15 (E15) to postnatal day 10 (PN10) were processed for electron microscopy, lectin binding and immunocytochemistry by using a series of antibodies. Cerebrospinal fluid (CSF) samples of non-affected and hydrocephalic HTx rats were collected at PN1, PN7 and PN30 and analysed by one- and two-dimensional electrophoresis, immunoblotting and nanoLC-ESI-MS/MS. A distinct malformation of the SCO is present as early as E15. Since stenosis of the Sylvius aqueduct (SA) occurs at E18 and dilation of the lateral ventricles starts at E19, the malformation of the SCO clearly precedes the onset of hydrocephalus. In the affected rats, the cephalic and caudal thirds of the SCO showed high secretory activity with all methods used, whereas the middle third showed no signs of secretion. At E18, the middle non-secretory third of the SCO progressively fused with the ventral wall of SA, resulting in marked aqueduct stenosis and severe hydrocephalus. The abnormal development of the SCO resulted in the permanent absence of Reissner's fibre (RF) and led to changes in the protein composition of the CSF. Since the SCO is the source of a large mass of sialilated glycoproteins that form the RF and of those that remain CSF-soluble, we hypothesize that the absence of this large mass of negatively charged molecules from the SA domain results in SA stenosis and impairs the bulk flow of CSF through the aqueduct.
本研究旨在阐明室下器官（SCO）在 HTx 大鼠脑积水发病机制中的作用。从胚胎第 15 天（E15）到出生后第 10 天（PN10），对未受影响和脑积水 HTx 大鼠的大脑进行电子显微镜、凝集素结合和免疫细胞化学处理，使用一系列抗体。在 PN1、PN7 和 PN30 收集未受影响和脑积水 HTx 大鼠的脑脊液（CSF）样本，并通过一维和二维电泳、免疫印迹和纳升液相色谱-电喷雾-串联质谱（nanoLC-ESI-MS/MS）进行分析。早在 E15 就存在 SCO 的明显畸形。由于 Sylvius 导水管（SA）狭窄发生在 E18，侧脑室扩张始于 E19，因此 SCO 的畸形明显早于脑积水的发生。在受影响的大鼠中，SCO 的头部和尾部三分之一表现出高分泌活性，所有方法均显示出高分泌活性，而中间三分之一没有分泌迹象。在 E18，SCO 的中间非分泌三分之一逐渐与 SA 的腹侧壁融合，导致明显的导水管狭窄和严重的脑积水。SCO 的异常发育导致 Reissner's 纤维（RF）永久缺失，并导致 CSF 蛋白组成发生变化。由于 SCO 是大量唾液酸化糖蛋白的来源，这些糖蛋白形成 RF 并保持 CSF 可溶性，因此我们假设大量带负电荷的分子从 SA 区域缺失会导致 SA 狭窄并损害 CSF 通过导水管的批量流动。
