Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia.
Curr Top Dev Biol. 2010;90:193-229. doi: 10.1016/S0070-2153(10)90005-7.
The mammalian kidney may well be one of the most complex organs of postnatal life. Each adult human kidney contains on average more than one million functional filtration units, the nephrons, residing within a specialized cellular interstitium. Each kidney also contains over 25 distinct cell types, each of which must be specifically aligned with respect to each other to ensure both normal development and ultimately, normal renal function. Despite this complexity, the development of the kidney can be simplistically described as the coordinate formation of two distinct sets of tubules. These tubules develop cooperatively with each other in time and space, yet represent two distinct but classical types of tubulogenesis. The first of these tubules, the ureteric bud, forms as an outgrowth of another epithelial tube, the nephric duct, and undergoes extensive branching morphogenesis to create the collecting system of the kidney. The second tubules are the nephrons themselves which arise via a mesenchyme-to-epithelial transition induced by the first set of tubules. These tubules never branch, but must elongate to become intricately patterned and functionally segmented tubules. The molecular drivers for these two tales of tubulogenesis include many gene families regulating tubulogenesis and branching morphogenesis in other organs; however, the individual players and codependent interrelationships between a branched and non-branched tubular network make organogenesis in the kidney unique. Here we review both what is known and remains to be understood in kidney tubulogenesis.
哺乳动物的肾脏很可能是出生后生命中最复杂的器官之一。每个成年人的肾脏平均包含超过一百万个具有过滤功能的单位，即肾单位，位于一个特殊的细胞间质中。每个肾脏还包含超过 25 种不同的细胞类型，每种细胞类型都必须彼此对齐，以确保正常发育，最终实现正常的肾功能。尽管如此复杂，肾脏的发育仍可以简单地描述为两个不同的肾小管的协调形成。这些肾小管彼此在时间和空间上协同发育，但代表了两种不同但经典的管状发生类型。第一个肾小管，输尿管芽，作为另一个上皮管，即肾导管的外生生长物形成，并通过广泛的分支形态发生来创建肾脏的集合系统。第二个肾小管是肾单位本身，通过第一组肾小管诱导的间充质到上皮的转变而产生。这些肾小管从不分支，但必须伸长以形成错综复杂的图案和功能分段的肾小管。这两种管状发生的分子驱动因素包括许多调节其他器官管状发生和分支形态发生的基因家族;然而，分支和非分支管状网络之间的个体参与者和相互依存关系使肾脏发生具有独特性。在这里，我们回顾了已知的和仍有待理解的肾脏管状发生的情况。
