BackgroundGenetic disruption of slc4a10, which encodes the sodium-dependent chloride/bicarbonate exchanger Ncbe, leads to a major decrease in Na+-dependent HCO3− import into choroid plexus epithelial cells in mice and to a marked reduction in brain intraventricular fluid volume. This suggests that Ncbe functionally is a key element in vectorial Na+ transport and thereby for cerebrospinal fluid secretion in the choroid plexus. However, slc4a10 disruption results in severe changes in expression of Na+,K+-ATPase complexes and other major transport proteins, indicating that profound cellular changes accompany the genetic manipulation.MethodsA tandem mass tag labeling strategy was chosen for quantitative mass spectrometry. Alterations in the broader patterns of protein expression in the choroid plexus in response to genetic disruption of Ncbe was validated by semi-quantitative immunoblotting, immunohistochemistry and morphometry.ResultsThe abundance of 601 proteins were found significantly altered in the choroid plexus from Ncbe ko mice relative to Ncbe wt. In addition to a variety of transport proteins, particularly large changes in the abundance of proteins involved in cellular energy metabolism were detected in the Ncbe ko mice. In general, the abundance of rate limiting glycolytic enzymes and several mitochondrial enzymes were reduced following slc4a10 disruption. Surprisingly, this was accompanied by increased ATP levels in choroid plexus cells, indicating that the reduction in capacity for energy metabolism was adaptive to high ATP rather than causal for a decreased capacity for ion and water transport. Ncbe-deficient cells also had a reduced cell area and decreased K+ content.ConclusionOur findings suggest that the lack of effective Na+-entry into the epithelial cells of the choroid plexus leads to a profound change in the cellular phenotype, shifting from a high-rate secretory function towards a more dormant state; similar to what is observed during ageing or Alzheimer’s disease.

中文翻译：

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slc4a10 的遗传破坏改变了脉络丛上皮细胞代谢和矢量离子转运的能力

背景 slc4a10（编码钠依赖性氯化物/碳酸氢盐交换器 Ncbe）的遗传破坏导致 Na+ 依赖性 HCO3- 输入到小鼠脉络丛上皮细胞的显着减少，并导致脑室内液量显着减少。这表明 Ncbe 在功能上是载体 Na+ 转运的关键因素，因此是脉络丛中脑脊液分泌的关键因素。然而，slc4a10 的破坏导致 Na+、K+-ATPase 复合物和其他主要转运蛋白的表达发生严重变化，表明基因操作伴随着深刻的细胞变化。方法 选择串联质量标签标记策略进行定量质谱分析。通过半定量免疫印迹、免疫组织化学和形态计量学验证了脉络丛中更广泛的蛋白质表达模式的改变，以响应 Ncbe 的遗传破坏。结果发现 Ncbe ko 小鼠脉络丛中 601 种蛋白质的丰度发生显着变化。 Ncbe重量。除了各种转运蛋白外，在 Ncbe ko 小鼠中还检测到参与细胞能量代谢的蛋白质丰度发生了特别大的变化。一般来说，slc4a10 破坏后限速糖酵解酶和几种线粒体酶的丰度减少。令人惊讶的是，这伴随着脉络丛细胞中 ATP 水平的增加，表明能量代谢能力的降低是适应高 ATP 的，而不是离子和水运输能力降低的原因。Ncbe 缺陷细胞的细胞面积也减少，K+ 含量降低。结论我们的研究结果表明，缺乏有效的 Na+ 进入脉络丛上皮细胞导致细胞表型发生深刻变化，从高速率转变为分泌功能趋向于休眠状态；类似于在衰老或阿尔茨海默病期间观察到的情况。从高速分泌功能转向更休眠的状态；类似于在衰老或阿尔茨海默病期间观察到的情况。从高速分泌功能转向更休眠的状态；类似于在衰老或阿尔茨海默病期间观察到的情况。