Columbia University, Depts. of Urology, Genetics & Development and Pathology 1130 St. Nicholas Avenue, New York NY, USA.
Columbia University, Department of Pathology, 630 West 168th Street, New York, NY, USA.
Dev Cell. 2013 Sep 16;26(5):469-482. doi: 10.1016/j.devcel.2013.07.017. Epub 2013 Aug 29.
The urothelium is a multilayered epithelium that serves as a barrier between the urinary tract and blood, preventing the exchange of water and toxic substances. It consists of superficial cells specialized for synthesis and transport of uroplakins that assemble into a tough apical plaque, one or more layers of intermediate cells, and keratin 5-expressing basal cells (K5-BCs), which are considered to be progenitors in the urothelium and other specialized epithelia. Fate mapping, however, reveals that intermediate cells rather than K5-BCs are progenitors in the adult regenerating urothelium, that P cells, a transient population, are progenitors in the embryo, and that retinoids are critical in P cells and intermediate cells, respectively, for their specification during development and regeneration. These observations have important implications for tissue engineering and repair and, ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome.
尿路上皮是一种多层上皮组织，作为尿路和血液之间的屏障，防止水和有毒物质的交换。它由专门用于合成和运输尿路上皮蛋白的浅层细胞组成，这些蛋白组装成坚韧的顶端斑块，还有一层或多层中间细胞，以及表达角蛋白 5 的基底细胞（K5-BC），这些细胞被认为是尿路上皮和其他特化上皮的祖细胞。然而，通过命运图谱分析发现，在成年再生尿路上皮中，中间细胞而不是 K5-BC 是祖细胞，在胚胎中 P 细胞是短暂的祖细胞，视黄酸分别在 P 细胞和中间细胞中对于它们在发育和再生过程中的特化是至关重要的。这些观察结果对组织工程和修复具有重要意义，最终可能导致预防尿路上皮屏障丧失的治疗方法，这是排尿功能障碍和膀胱疼痛综合征的主要原因。
