The tale of two (distal nephron) cell types.
The tale of two (distal nephron) cell types.
复制标题
两种（远端肾单位）细胞类型的故事。
DOI：
10.1152/ajprenal.00044.2018
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Butterworth,MichaelB
中科院分区：
文献类型：
--
作者：
Butterworth,MichaelB
肾脏肾单位代表了一个小小管中上皮细胞分化和特化48的精美例子（6）。血浆滤液向下通过几毫米的长度将遇到至少6种细胞类型，每种细胞类型在形式和功能上高度特化。肾单位50内衬的细胞谱系来自2个胚胎来源。输尿管芽从中肾（Wolffian）管出现，并且51与后肾间充质细胞相互作用以形成帽间充质。由这种相互作用形成的肾泡52将最终发育成更近端的结构（肾小球和大部分成熟肾单位53），子宫芽形成集合管（2）。成熟哺乳动物肾单位的远曲小管54和集合管由主细胞和插入细胞（α和β）组成，决定终末细胞分化的发育因素仍在研究中（7）。这些细胞类型的区别在于其独特的功能作用，主要是主细胞的离子和水运输以及插入细胞的酸和碱分泌。为了研究这些特殊上皮细胞类型的功能和调节机制，研究人员长期以来一直对开发接近这些上皮细胞特征的强大细胞培养模型感兴趣。使用从取自一系列动物模型的肾组织中的体内和离体61研究获得的知识，在主要细胞模型系中寻找62特定特征。当在过滤器支持物上培养63时，稳健的细胞系将分化成上皮单层。细胞将具有转运离子的能力，主要是通过64个内源性上皮钠通道（ENaC）沿着由Na+-K+-65 ATP酶建立的产电梯度转运钠。模型细胞将能够通过顶端和基底钾66通道（最显著的是位于顶端的肾外髓钾通道，ROMK）进行钾转运。细胞67将对渗透梯度的变化敏感，并且能够通过68个水通道蛋白（Aqp 2）运输水。更重要的是，对于功能研究，细胞应该对生理浓度下的几种激素输入敏感，这与肾肾单位部分最相关，这包括胰岛素，血管加压素和对醛固酮信号传导的真正盐皮质激素受体反应。多年来开发的许多细胞系表现出这些特征中的一些或几个，但没有一个具有所有期望的特征（5）。只有当自发转化的细胞系73来源于从显微解剖的小鼠皮质集合管获得的单个克隆时，才开发出一种新的细胞74模型，命名为mCCDcl 1，似乎表现出所有这些特征（4）。因此，这条75 mCCDcl 1线为该领域的研究人员所接受。细胞具有11-β-羟基类固醇脱氢酶2型（HSD 11b 2）和盐皮质激素和糖皮质激素受体（MR和GR），确保盐皮质激素对生理浓度的醛固酮产生真正的反应（这是最好的时机）。该细胞系现在作为模型79小鼠主要细胞系在数十个实验室中常规使用。然而，在Assmus及其同事的论文中（1），作者深入探讨了该细胞系的特征。通过从81系列稀释成单细胞后的亲本细胞中衍生出几个亚系，他们报告说，不仅82主要细胞特异性离子转运的一些所需特征减少或丢失，...
The kidney nephron represents an exquisite example of epithelial cell differentiation and specialization 48 in one small tubule (6). Plasma filtrate passing down the length of a few millimeters will encounter at 49 least 6 cell types, each highly specialized in form and function. The lineage of the cells lining the nephron 50 are from 2 embryonic sources. The ureteric bud emerges from the mesonephric (Wolffian) duct and 51 interacts with metanephric mesenchymal cells to form a cap mesenchyme. The renal vesicle formed 52 from this interaction will ultimately develop into the more proximal structures (glomerulus and most of 53 the mature nephron) with the uteric bud forming the collecting duct (2). The distal convoluted tubule 54 and collecting duct of the mature mammalian nephron are composed of principal and intercalated 55 (alpha and beta) cells, and the developmental factors that determine terminal cell differentiation are 56 still being investigated (7). These cell types are distinguished by their unique functional roles of, 57 predominantly, ion and water transport for principal cells and acid and base secretions for intercalated 58 cells. To study the function and mechanisms of regulation in these specialized epithelial cell types, 59 researchers have long been interested in developing robust cell culture models that closely approximate 60 the characteristics of these epithelial cells. Using the knowledge gained from in vivo and ex vivo 61 investigations in renal tissue taken from a range of animal models, specific characteristics were sought 62 in a principal cell model line. A robust cell line would polarize into epithelial monolayers when cultured 63 on filter supports. The cells would have the ability to transport ions, predominantly sodium via 64 endogenous epithelial sodium channels (ENaC) down an electrogenic gradient established by the Na+-K+-65 ATPase. Model cells would be capable of potassium transport through apical and basal potassium 66 channels (most notably the apically located renal outer medullary potassium channel, ROMK). The cells 67 would be sensitive to changes in osmotic gradients and be capable of water transport through 68 aquaporins (Aqp2). And more importantly for functional studies, the cells should be sensitive to several 69 hormonal inputs at physiological concentrations, most relevant for this renal nephron segment, this 70 would include insulin, vasopressin and a true mineralocorticoid receptor response to aldosterone 71 signaling. Many cell lines developed over the years exhibited some or several of these characteristics, 72 but none had all of the desired traits (5). It was only when a spontaneously transformed cell line was 73 derived from a single clone obtained from microdissected mouse cortical collecting duct that a novel cell 74 model, named mCCDcl1, was developed that appeared to exhibit all these characteristics (4). This 75 mCCDcl1 line therefore stood-out for researchers in the field. The cells possessed 11-β-hydroxysteroid 76 dehydrogenase type 2 (HSD11b2) and both mineralocorticoid and glucocorticoid receptors (MR and GR), 77 ensuring a true mineralocorticoid response to physiological concentrations of aldosterone could be 78 achieved (it was the best of times). The cell line is now routinely used in dozens of labs as a model 79 murine principal cell line. However, in the paper by Assmus and colleagues (1), the authors probed 80 deeper into the characteristics of this cell line. By deriving several sub-lines from the parental cells after 81 serial dilution to single cells, they report that not only were some of the desired characteristics of 82 principal cell-specific ion transport diminished or lost, markers to …