Department of Obstetrics and Gynaecology, School of Medicine, Keio University, Shinjuku, Tokyo 160-8582, Japan.
Reproduction. 2010 Jul;140(1):11-22. doi: 10.1530/REP-09-0438. Epub 2010 May 10.
The human uterus mainly consists of the endometrium and the outer smooth muscle layer termed the myometrium. The uterus harbours the exceptional and remarkable regenerative ability responsible for cyclical regeneration and remodelling throughout the reproductive life. The uterus must swiftly and cooperatively enlarge to hold the growing foetus during pregnancy. Furthermore, the endometrium, in particular the functionalis layer, must also regenerate, differentiate and regress with each menstrual cycle under hormonal control. Endometrial regeneration from the basal layer is thought to contribute to replacement of the functionalis layer followed by its slough off during menses and parturition. These morphological and functional features of human endometrium can be reproduced in murine models in which severely immunodeficient mice are xenotransplanted with dispersed human endometrial cells under the kidney capsule. The uterine myometrium possesses the similar plasticity of the endometrium. This is demonstrated by multiple cycles of pregnancy-induced enlargement and regression after parturition. It is likely that regeneration and remodelling in the female reproductive tract are achieved presumably through endometrial and myometrial stem cell systems. Recent evidence now supports the existence of these stem cell systems in humans. Here, we will review our current understanding of uterine stem/progenitor cells. We also propose a novel hypothetical model in which stem cell activities explain the physiological remodelling and regeneration of the human uterus and the pathogenesis of gynaecological diseases such as endometriosis.
人体子宫主要由子宫内膜和外层平滑肌层（称为子宫肌层）组成。子宫具有非凡而显著的再生能力，负责在整个生殖生命中进行周期性的再生和重塑。子宫必须迅速而协同地扩大，以在怀孕期间容纳不断生长的胎儿。此外，子宫内膜，特别是功能层，也必须在激素控制下，随着每个月经周期的进行而再生、分化和退化。人们认为，基底层的子宫内膜再生有助于替代功能层，随后在月经和分娩期间脱落。这些人类子宫内膜的形态和功能特征可以在鼠类模型中重现，其中严重免疫缺陷的小鼠被异种移植到肾脏包膜下分散的人类子宫内膜细胞。子宫肌层具有与子宫内膜相似的可塑性。这一点在分娩后多次妊娠引起的子宫增大和退化的周期中得到了证明。女性生殖道的再生和重塑可能是通过子宫内膜和子宫肌层干细胞系统来实现的。目前的证据支持这些干细胞系统在人类中的存在。在这里，我们将回顾我们对子宫干细胞/祖细胞的现有认识。我们还提出了一个新的假设模型，其中干细胞活动解释了人类子宫的生理重塑和再生，以及子宫内膜异位症等妇科疾病的发病机制。
